Multiplex analysis of intratumoural immune infiltrate and prognosis in patients with stage II-III colorectal cancer from the SCOT and QUASAR 2 trials: a retrospective analysis

BACKGROUND

Tumour-infiltrating CD8+ cytotoxic T cells confer favourable prognosis in colorectal cancer. The added prognostic value of other infiltrating immune cells is unclear and so we sought to investigate their prognostic value in two large clinical trial cohorts.

METHODS

We used multiplex immunofluorescent staining of tissue microarrays to assess the densities of CD8+, CD20+, FoxP3+, and CD68+ cells in the intraepithelial and intrastromal compartments from tumour samples of patients with stage II-III colorectal cancer from the SCOT trial (ISRCTN59757862), which examined 3 months versus 6 months of adjuvant oxaliplatin-based chemotherapy, and from the QUASAR 2 trial (ISRCTN45133151), which compared adjuvant capecitabine with or without bevacizumab. Both trials included patients aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0-1. Immune marker predictors were analysed by multiple regression, and the prognostic and predictive values of markers for colorectal cancer recurrence-free interval by Cox regression were assessed using the SCOT cohort for discovery and QUASAR 2 cohort for validation.

FINDINGS

After exclusion of cases without tissue microarrays and with technical failures, and following quality control, we included 2340 cases from the SCOT trial and 1069 from the QUASAR 2 trial in our analysis. Univariable analysis of associations with recurrence-free interval in cases from the SCOT trial showed a strong prognostic value of intraepithelial CD8 (CD8IE) as a continuous variable (hazard ratio [HR] for 75th vs 25th percentile [75vs25] 0·73 [95% CI 0·68-0·79], p=2·5 × 10-16), and of intrastromal FoxP3 (FoxP3IS; 0·71 [0·64-0·78], p=1·5 × 10-13) but not as strongly in the epithelium (FoxP3IE; 0·89 [0·84-0·96], p=1·5 × 10-4). Associations of other markers with recurrence-free interval were moderate. CD8IE and FoxP3IS retained independent prognostic value in bivariable and multivariable analysis, and, compared with either marker alone, a composite marker including both markers (CD8IE-FoxP3IS) was superior when assessed as a continuous variable (adjusted [a]HR75 vs 25 0·70 [95% CI 0·63-0·78], p=5·1 × 10-11) and when categorised into low, intermediate, and high density groups using previously published cutpoints (aHR for intermediate vs high 1·68 [95% CI 1·29-2·20], p=1·3 × 10-4; low vs high 2·58 [1·91-3·49], p=7·9 × 10-10), with performance similar to the gold-standard Immunoscore. The prognostic value of CD8IE-FoxP3IS was confirmed in cases from the QUASAR 2 trial, both as a continuous variable (aHR75 vs 25 0·84 [95% CI 0·73-0·96], p=0·012) and as a categorical variable for low versus high density (aHR 1·80 [95% CI 1·17-2·75], p=0·0071) but not for intermediate versus high (1·30 [0·89-1·88], p=0·17).

INTERPRETATION

Combined evaluation of CD8IE and FoxP3IS could help to refine risk stratification in colorectal cancer. Investigation of FoxP3IS cells as an immunotherapy target in colorectal cancer might be merited.

FUNDING

Medical Research Council, National Institute for Health Research, Cancer Research UK, Swedish Cancer Society, Roche, and Promedica Foundation.

Durable responses to ATR inhibition with ceralasertib in tumors with genomic defects and high inflammation

BACKGROUNDPhase 1 study of ATRinhibition alone or with radiation therapy (PATRIOT) was a first-in-human phase I study of the oral ATR (ataxia telangiectasia and Rad3-related) inhibitor ceralasertib (AZD6738) in advanced solid tumors.METHODSThe primary objective was safety. Secondary objectives included assessment of antitumor responses and pharmacokinetic (PK) and pharmacodynamic (PD) studies. Sixty-seven patients received 20-240 mg ceralasertib BD continuously or intermittently (14 of a 28-day cycle).RESULTSIntermittent dosing was better tolerated than continuous, which was associated with dose-limiting hematological toxicity. The recommended phase 2 dose of ceralasertib was 160 mg twice daily for 2 weeks in a 4-weekly cycle. Modulation of target and increased DNA damage were identified in tumor and surrogate PD. There were 5 (8%) confirmed partial responses (PRs) (40-240 mg BD), 34 (52%) stable disease (SD), including 1 unconfirmed PR, and 27 (41%) progressive disease. Durable responses were seen in tumors with loss of AT-rich interactive domain-containing protein 1A (ARID1A) and DNA damage-response defects. Treatment-modulated tumor and systemic immune markers and responding tumors were more immune inflamed than nonresponding.CONCLUSIONCeralasertib monotherapy was tolerated at 160 mg BD intermittently and associated with antitumor activity.TRIAL REGISTRATIONClinicaltrials.gov: NCT02223923, EudraCT: 2013-003994-84.FUNDINGCancer Research UK, AstraZeneca, UK Department of Health (National Institute for Health Research), Rosetrees Trust, Experimental Cancer Medicine Centre.

SCOT: Tumor Sidedness and the Influence of Adjuvant Chemotherapy Duration on Disease Free Survival (DFS)

AIM

Patients with loco-regional right-sided colorectal tumors have a worse overall survival (OS). Here we investigate the difference in disease free survival (DFS) between colorectal patients with right and left sided tumors in the SCOT study.

METHODS

The SCOT study showed 3-months of oxaliplatin-containing adjuvant chemotherapy (OxFp) is non-inferior to 6-months for patients with stage III and high-risk stage II colorectal cancer. We divided the cohort into patients with left and right sided tumors, and evaluated the effect on DFS and the principle 3 versus 6-months analysis.

RESULTS

6088 patients with Stage III/high risk Stage II colorectal cancers were randomized between 27th March 2008 and 29th November 2013 from 244 centers internationally. In February 2017 (3-years FU) information on sidedness was available for 3309 patients (1238 R-sided, 2071 L-sided). Patients with right-sided tumors had a significantly worse DFS (3-year DFS right: 73.3% (se = 1.3%), left: 80.2% (se = 0.9%) HR 1.423 (95% CI 1.237-1.637; P < .0001). Adjusting for T and N-stage reduced the HR to 1.230 (95% CI 1.066-1.420, P = .005). The data did not suggest that sidedness affected the impact of chemotherapy duration on 3-year DFS (R: HR 1.024 [0.831-1.261], L: HR 0.944 [0.783-1.139]). Test for heterogeneity, P = .571. Further sub-set analysis was limited due to cohort size.

CONCLUSIONS

This is the first study to show that unselected patients with right-sided tumors had a worse DFS compared to left-sided tumors. Tumor sidedness did not impact upon the 3-months versus 6-months comparison in SCOT.

Durvalumab (MEDI 4736) with extended neoadjuvant regimens in rectal cancer: A randomised phase II trial (PRIME-RT)

TPS282

Background: Advances in multi-modality treatment of locally advanced rectal cancer (LARC) have resulted in low local recurrence rates, but many patients still die from distant disease. There is increasing recognition that with neoadjuvant treatment some patients achieve a complete response and may avoid surgical resection. PRIME-RT tests the inclusion of neoadjuvant immunotherapy with the aim of enhancing complete response rates, improving stoma-free survival and reducing distant relapse. Methods: PRIME-RT is a multi-centre, open label, phase II, randomised trial for patients with newly diagnosed LARC. Eligible patients are randomised to Arm A: short course radiotherapy (25 Gray in 5 fractions) with concomitant durvalumab, followed by durvalumab and FOLFOX chemotherapy, or Arm B: long course chemoradiotherapy (50 Gray to primary tumour, 45 Gray to elective nodes, in 25 fractions with capecitabine) with concomitant durvalumab followed by FOLFOX and durvalumab. The primary endpoint is complete response rate in each arm. Bio-specimens including serial tumour biopsies and peripheral blood samples are collected prior to, during, and following treatment to explore the molecular and immunological factors underpinning treatment response. The main trial will recruit up to 42 patients and commence after a safety run-in which is recruiting patients with metastatic disease. After opening in January 2021, the four patients completed the safety run in and the main trial commenced in March 2022. The trial is currently open across 5 UK sites. Up to date recruitment details will be provided at the time of presentation but at the time of writing this is ahead of target. Early recruitment to PRIME-RT has shown that adding immunotherapy in the neoadjuvant setting for LARC is feasible. Furthermore, on treatment biospecimen collection is also feasible across multiple sites. The expectation is that the trial will provide efficacy and safety information which allows the optimal treatment approach to be tested within a larger phase clinical trial. Core funding (Glasgow CRUK CTU) and trial-specific funding (Astrazeneca). Clinical trial: NCT04621370; ISRCTN18138369. Clinical trial information: ISRCTN18138369 .

Trifluridine-tipiracil plus bevacizumab versus capecitabine plus bevacizumab as first-line treatment for patients with metastatic colorectal cancer ineligible for intensive therapy (SOLSTICE): a randomised, open-label phase 3 study

BACKGROUND

Trifluridine-tipiracil plus bevacizumab has shown efficacy in previous phase 2 studies including patients with unresectable metastatic colorectal cancer. We aimed to investigate first-line trifluridine-tipiracil plus bevacizumab versus capecitabine plus bevacizumab in patients with unresectable metastatic colorectal cancer ineligible for intensive treatment.

METHODS

In this open-label, randomised, phase 3 study, we enrolled patients aged 18 years and older with histologically confirmed metastatic colorectal cancer, ineligible for full-dose doublet or triplet chemotherapy and curative resection across 25 countries and regions. Participants were randomly allocated (1:1) to trifluridine-tipiracil plus bevacizumab or capecitabine plus bevacizumab until disease progression or unacceptable toxicity using an interactive web response system, stratified by Eastern Cooperative Oncology Group (ECOG) performance status (0 vs 1 vs 2), primary tumour location (right vs left colon), and the main reason for not being a candidate for intensive therapy (clinical condition vs non-clinical condition). The primary endpoint was investigator-assessed progression-free survival, defined as the time from randomisation to radiological progression or death from any cause, in the intention-to-treat population. Safety was assessed in all patients having taken at least one dose of the study drug. The trial is ongoing, findings presented here are those of the primary analysis of progression-free survival, conducted after 629 events had occurred. This study is registered with ClinicalTrials.gov, NCT03869892.

FINDINGS

Between March 21, 2019, and Sept 14, 2020, 856 patients (54% male, 46% female) were randomly assigned to trifluridine-tipiracil plus bevacizumab (n=426) or capecitabine plus bevacizumab (n=430). After a median follow-up of 16·6 months (95% CI 16·5-17·1), the hazard ratio for progression-free survival for trifluridine-tipiracil plus bevacizumab versus capecitabine plus bevacizumab was 0·87 (0·75-1·02; p=0·0464; protocol-defined significance level of p=0·021 not met). Investigator-assessed median progression-free survival was 9·4 months (95% CI 9·1-10·9) with trifluridine-tipiracil plus bevacizumab versus 9·3 months (8·9-9·8) with capecitabine plus bevacizumab. The most common grade 3 and higher treatment-emergent adverse events were neutropenia (220 [52%] of 423 patients in the trifluridine-tipiracil plus bevacizumab group vs six [1%] of 427 in the capecitabine plus bevacizumab group), decreased neutrophil count (78 [18%] vs four [<1%]), anaemia (60 [14%] vs 16 [4%]), and hand-foot syndrome (none vs 61 [15%]). Nine deaths (five in the trifluridine-tipiracil plus bevacizumab group and four in the capecitabine plus bevacizumab group) were treatment related.

INTERPRETATION

First-line trifluridine-tipiracil plus bevacizumab was not superior to capecitabine plus bevacizumab in this population. As expected, the safety profile differed between the two treatments, but there were no new safety concerns. Trifluridine-tipiracil plus bevacizumab represents a feasible alternative to capecitabine plus bevacizumab in this population.

FUNDING

Servier International Research Institute, Suresnes, France.

PANTHER: AZD8931, inhibitor of EGFR, ERBB2 and ERBB3 signalling, combined with FOLFIRI: a Phase I/II study to determine the importance of schedule and activity in colorectal cancer

BACKGROUND

Epidermal growth factor receptor (EGFR) is a therapeutic target to which HER2/HER3 activation may contribute resistance. This Phase I/II study examined the toxicity and efficacy of high-dose pulsed AZD8931, an EGFR/HER2/HER3 inhibitor, combined with chemotherapy, in metastatic colorectal cancer (CRC).

METHODS

Treatment-naive patients received 4-day pulses of AZD8931 with irinotecan/5-FU (FOLFIRI) in a Phase I/II single-arm trial. Primary endpoint for Phase I was dose limiting toxicity (DLT); for Phase II best overall response. Samples were analysed for pharmacokinetics, EGFR dimers in circulating exosomes and Comet assay quantitating DNA damage.

RESULTS

Eighteen patients received FOLFIRI and AZD8931. At 160 mg bd, 1 patient experienced G3 DLT; 160 mg bd was used for cohort expansion. No grade 5 adverse events (AE) reported. Seven (39%) and 1 (6%) patients experienced grade 3 and grade 4 AEs, respectively. Of 12 patients receiving 160 mg bd, best overall response rate was 25%, median PFS and OS were 8.7 and 21.2 months, respectively. A reduction in circulating HER2/3 dimer in the two responding patients after 12 weeks treatment was observed.

CONCLUSIONS

The combination of pulsed high-dose AZD8931 with FOLFIRI has acceptable toxicity. Further studies of TKI sequencing may establish a role for pulsed use of such agents rather than continuous exposure.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov number: NCT01862003.

RAS Mutation Status Should Not Be Used to Predict Outcome from Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Colorectal Peritoneal Metastases

BACKGROUND

Genetic biomarkers guide systemic anti-cancer treatment (SACT) in metastatic colorectal cancer. It has been suggested they have a role in selecting patients with colorectal peritoneal metastases (CRPM) for cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). This study aims to quantify the effect of mutation status on overall survival (OS), adjusting for confounders such as pre-operative systemic anticancer treatment (SACT).

PATIENTS AND METHODS

Retrospective analysis of patients undergoing CRS/HIPEC for CRPM at a national peritoneal tumour centre (2004-2017) was performed. Demographics, treatment history and operative data were extracted. Known biomarker gene mutation status was noted including: KRAS, NRAS, BRAF, PIK3CA and MMR. Cox regression analysis and Kaplan-Meier curves were used to determine overall survival.

RESULTS

One hundred ninety-five patients were included. Median follow-up time was 34.7 months (range 5.4-184.9 months) and median OS was 38.7 months (95% CI 32.4-44.9 months). Biomarker status was as follows: KRAS (n = 114), NRAS (n = 85), BRAF (n = 44), PIK3CA (n = 15) and MMR (n = 21). Mutation rates were 45.6%, 3.5%, 13.6%, 13.3% and 14.3%, respectively. Seventy-four per cent underwent complete cytoreduction (CC = 0), 81% received SACT pre-CRS/HIPEC and 65% post-CRS/HIPEC. RAS (p = 0.21) or BRAF (p = 0.109) mutation status did not predict OS. Nodal involvement, extramural vascular invasion, Peritoneal Cancer Index (PCI) score, CC score, SACT post-HIPEC and NRAS mutation were significant negative predictors of OS in univariate analysis (p < 0.05). Multivariate Cox regression confirmed CC-score > 1 (HR: 7.599, 95% CI 3.402-16.974, p < 0.0001) as a negative predictor of OS. RAS mutation status did not affect outcome (HR: 1.682, 95% CI 0.995-2.843, p = 0.052).

CONCLUSIONS

RAS mutation status should not in isolation be used to select patients for CRS/HIPEC.

CXD101 and nivolumab in patients with metastatic microsatellite-stable colorectal cancer (CAROSELL): a multicentre, open-label, single-arm, phase II trial

BACKGROUND

Patients with microsatellite stable (MSS) colorectal carcinoma (CRC) do not respond to immune checkpoint inhibitors. Preclinical models suggested synergistic anti-tumour activity combining CXD101 and anti-programmed cell death protein 1 treatment; therefore, we assessed the clinical combination of CXD101 and nivolumab in heavily pre-treated patients with MSS metastatic CRC (mCRC).

PATIENTS AND METHODS

This single-arm, open-label study enrolled patients aged 18 years or older with biopsy-confirmed MSS CRC; at least two lines of systemic anticancer therapies (including oxaliplatin and irinotecan); at least one measurable lesion; Eastern Cooperative Oncology Group performance status of 0, 1 or 2; predicted life expectancy above 3 months; and adequate organ and bone marrow function. Nine patients were enrolled in a safety run-in study to define a tolerable combination schedule of CXD101 and nivolumab, followed by 46 patients in the efficacy assessment phase. Patients in the efficacy assessment cohort were treated orally with 20 mg CXD101 twice daily for 5 consecutive days every 3 weeks, and intravenously with 240 mg nivolumab every 2 weeks. The primary endpoint was immune disease control rate (iDCR).

RESULTS

Between 2018 and 2020, 55 patients were treated with CXD101 and nivolumab. The combination therapy was well tolerated with the most frequent grade 3 or 4 adverse events being neutropenia (18%) and anaemia (7%). Immune-related adverse reactions commonly ascribed to checkpoint inhibitors were surprisingly rare although we did see single cases of pneumonitis, hypothyroidism and hypopituitarism. There were no treatment-related deaths. Of 46 patients assessable for efficacy, 4 (9%) achieved partial response and 18 (39%) achieved stable disease, translating to an immune disease control rate of 48%. The median overall survival (OS) was 7.0 months (95% confidence interval 5.13-10.22 months).

CONCLUSIONS

The primary endpoint was met in this phase II study, which showed that the combination of CXD101 and nivolumab, at full individual doses in the treatment of advanced or metastatic MSS CRC, was both well tolerated and efficacious.

A phase II study of retifanlimab (INCMGA00012) in patients with squamous carcinoma of the anal canal who have progressed following platinum-based chemotherapy (POD1UM-202)

Background

Locally advanced or metastatic squamous carcinoma of the anal canal (SCAC) has poor prognosis following platinum-based chemotherapy. Retifanlimab (INCMGA00012), a humanized monoclonal antibody targeting programmed death protein-1 (PD-1), demonstrated clinical activity across a range of solid tumors in clinical trials. We present results from POD1UM-202 (NCT03597295), an open-label, single-arm, multicenter, phase II study evaluating retifanlimab in patients with previously treated advanced or metastatic SCAC.

Patients and methods

Patients ≥18 years of age had measurable disease and had progressed following, or were ineligible for, platinum-based therapy. Retifanlimab 500 mg was administered intravenously every 4 weeks. The primary endpoint was overall response rate (ORR) by independent central review. Secondary endpoints were duration of response (DOR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety.

Results

Overall, 94 patients were enrolled. At a median follow-up of 7.1 months (range, 0.9-19.4 months), ORR was 13.8% [95% confidence interval (CI) 7.6% to 22.5%], with one complete response (1.1%) and 12 partial responses (12.8%). Responses were observed regardless of human immunodeficiency virus or human papillomavirus status, programmed death ligand 1 (PD-L1) expression, or liver metastases. Stable disease was observed in 33 patients (35.1%) for a DCR of 48.9% (95% CI 38.5% to 59.5%). Median DOR was 9.5 months (range, 5.6 months-not estimable). Median (95% CI) PFS and OS were 2.3 (1.9-3.6) and 10.1 (7.9-not estimable) months, respectively. Retifanlimab safety in this population was consistent with previous experience for the PD-(L)1 inhibitor class.

Conclusions

Retifanlimab demonstrated clinically meaningful and durable antitumor activity, and an acceptable safety profile in patients with previously treated locally advanced or metastatic SCAC who have progressed on or are intolerant to platinum-based chemotherapy.

•

Retifanlimab (PD-1 inhibitor) monotherapy demonstrated encouraging results in patients with platinum-refractory SCAC.

•

Clinically meaningful antitumor activity was reported with ORR of 13.8% and stable disease in 35.1%, for a DCR of 48.9%.

•

Observed responses in advanced SCAC were durable (median 9.5 months).

•

Acceptable safety profile consistent with that reported for the PD-(L)1 inhibitor class.

•

Promising results warrant further investigation of retifanlimab in advanced SCAC as well as earlier stages of disease.

A multi-arm, phase 2, open-label study to assess the efficacy of RXC004 as monotherapy and in combination with nivolumab in patients with ring finger protein 43 (RNF43) or R-spondin (RSPO) aberrated, metastatic, microsatellite stable colorectal cancer following standard treatments

TPS3637

Background: The Wnt pathway is a critical driver of cancer. RXC004 is a potent, selective, orally active inhibitor of the key Wnt pathway regulator, Porcupine. Inhibition of Porcupine blocks the release of all Wnt ligands from cells, preventing both tumour growth and tumour immune evasion. Wnt pathway alterations, including loss-of-function (LoF) RNF43 mutations and RSPO gene fusions, increase expression of the Wnt receptor Frizzled (Fzd) on the tumour cell surface, driving Wnt-ligand signalling. These alterations are present in ̃8% (Gao, 2013; Cerami, 2012; Shesagiri, 2012; Shinmura, 2014; Kleeman, 2019) of colorectal cancers (CRC). LoF RNF43 mutations are associated with poor prognosis in MSS CRC (Yaeger, 2018 ). Preclinical genetically selected CRC models showed disease stabilisation, differentiation towards a normal colonic phenotype with increased mucin secretion, and reduced metabolic activity on FDG-PET. In a Phase 1 study in patients with advanced solid tumours (NCT03447470), RXC004 was safe and tolerated at doses up to 2mg QD, the recommended phase 2 dose (RP2D), and showed a differentiated efficacy signal in Wnt-ligand dependent tumours (Cook, 2021 ). Methods: The PORCUPINE (NCT04907539) trial is a 2-arm Phase 2 trial of RXC004 monotherapy (Arm A) and RXC004 in combination with nivolumab (Arm B). 20 evaluable patients will be enrolled into each Arm. The study initially opened with Arm A; Arm B will be opened once the RP2D for RXC004 in combination with nivolumab is established in a separate phase 1 study. Once Arm B is opened, patients in Arm A may be treated with RXC004 + nivolumab if they have progressive disease on the first RECIST assessment scan. To be eligible for this study, patients must have metastatic microsatellite stable (MSS) CRC that has progressed following standard therapies. Tumours must have a LoF RNF43 mutation, or an RSPO2/3 fusion. As Wnt inhibition can affect bone metabolism, patients undergo a screening DEXA scan and receive prophylactic denosumab throughout the treatment period. The primary endpoint for Arm A is the disease control rate (DCR= CR+PR+SD at 16 wks), and for Arm B is objective response rate (ORR). Secondary endpoints are Safety and PK. Exploratory endpoints include FDG-PET changes and on-treatment changes in protein and gene expression in tumour biopsies. For Arm A, a target value (TV) of 60% DCR is considered a clinically significant improvement over standard of care against a lower reference value (LRV) of 40% DCR (Grothey, 2013; Mayer, 2015 ). For Arm B, a TV of 30% ORR is considered clinically significant against a LRV of 10% ORR (Eng, 201 9). RXC004 is also being investigated in a second Phase 2 trial, PORCUPINE 2 (NCT04907851), in Biliary Tract Cancers and RNF-43 mutated Pancreatic Cancers. Clinical trial information: NCT04907539.

NEOPRISM-CRC: Neoadjuvant pembrolizumab stratified to tumor mutation burden for high-risk stage 2 or stage 3 deficient-MMR/MSI-high colorectal cancer

TPS3645

Background: The prognostic advantage of early stage deficient-MMR/MSI-High CRC is lost after relapse, so there is a pressing clinical need to maximize the chance of cure in the early stages where prevalence of dMMR is higher comprising approximately 12% of Stage 3 and 20% of Stage 2 CRC. The efficacy of adjuvant checkpoint inhibition in this patient group has yet to be demonstrated in the context of micrometastatic disease without a supporting immune-competent microenvironment. Longitudinal studies especially in the neoadjuvant setting would optimally interrogate post-immunotherapy changes both in time and space. The NEOPRISM-CRC (NEOadjuvant PembRolizumab In Stratified Medicine – ColoReCtal) study is a Phase II Trial to determine whether neoadjuvant Pembrolizumab stratified to tumour mutation burden (TMB) is efficacious and safe. It will also be a platform to explore the relationships between possible predictive novel biomarkers and response to Pembrolizumab in blood, tumour tissue and microbiome. Methods: The study population consists of subjects with newly diagnosed operable dMMR/MSI-H CRC. Patients must be fit and eligible for planned curative surgery based on a) radiological node positive T1-4 CRC or b) high risk T3 defined as EITHER ≥ 5mm of extramural depth of invasion or unequivocal EMVI on imaging (regardless of depth), or T4 disease. They will receive one of two pre-operative regimens depending upon their TMB based on the FoundationOne®CDx test (FM1CDx). All patients will have one 21 day cycle of Pembrolizumab 200 mg IV. Prior to cycle 2 and with the result of the FM1CDx test, patients will continue their treatment as follows: A) TMB-high (defined as ≥20 mutations per Mb) or TMB-medium (defined as 6-19 mutations per Mb), or MSI-H on PCR if FM1CDx test is not evaluable: A further 2 cycles of Pembrolizumab 200 mg IV every 21 days. B) TMB-low (defined as ≤5 mutations per Mb), or if FM1CDx and PCR tests are not evaluable: No further Pembrolizumab given. Surgery to remove the CRC will be performed 4-6 weeks after the last dose of Pembrolizumab in both arms. Following resection patients may receive adjuvant chemotherapy in accordance with local institutional guidelines. The primary end point is pathological complete response rate (pCR). Secondary endpoints include 3 year RFS, OS, safety and health-related quality of life. Up to 32 patients will be registered over a 18-24 month period assuming that the pCR with 3 cycles of Pembrolizumab will be ≥ 33% for patients with high or medium TMB based on the FM1CDx profile, and intend to rule out a percentage ≤10%. To reach 80% power with 5% statistical significance, 19 patients are required in the high/medium TMB arm. The trial will be considered a success if at least 5/19 patients have a pCR after 3 cycles of Pembrolizumab. Enrolment will commence in March 2022. Clinical trial information: NCT05197322.

Clinico-pathological predictors of clinical complete response in rectal cancer

PURPOSE

Prediction of clinical complete response in rectal cancer before neoadjuvant chemo-radiotherapy treatment enables treatment selection. Patients predicted to have complete response could have chemo-radiotherapy, and others could have additional doublet chemotherapy at this stage of their treatment to improve their overall outcome. This work investigates the role of clinical variables in predicting clinical complete response.

METHOD

Using the UK-based OnCoRe database (2008 to 2019), we performed a propensity-score matched study of 322 patients who received neoadjuvant chemoradiotherapy. We collected pre-treatment clinic-pathological, inflammatory and radiotherapy-related characteristics. We determined the odds for the occurrence of cCR using conditional logistic regression models. We derived the post-model Area under the Curve (AUC) as an indicator of discrimination performance and stated a priori that an AUC of 0.75 or greater was required for potential clinical utility.

RESULTS

Pre-treatment tumour diameter, mrT-stage, haemoglobin, alkaline phosphate and total radiotherapy depths were associated with cCR on univariable and multivariable analysis. Additionally, neutrophil to lymphocyte ratio (NLR), neutrophil-monocyte to lymphocyte ratio (NMLR), lymphocyte count and albumin were all significantly associated with cCR on multivariable analysis. A nomogram using the above parameters was developed with a resulting ROC AUC of 0.75.

CONCLUSION

We identified routine clinic-pathological, inflammatory and radiotherapy-related variables which are independently associated with cCR. A nomogram was developed to predict cCR. The performance characteristics from this model were on the prior clinical utility threshold. Additional research is required to develop more associated variables to better select patients with rectal cancer undergoing chemoradiotherapy who may benefit from pursuing a W&W strategy.

Durvalumab (MEDI 4736) with extended neoadjuvant regimens in rectal cancer: A randomized phase II trial (PRIME-RT)

TPS231

Background: Advances in multi-modality treatment of locally advanced rectal cancer (LARC) have resulted in low local recurrence rates, but many patients still die from distant disease. There is increasing recognition that with neoadjuvant treatment some patients achieve a complete response and may avoid surgical resection. The PRIME-RT trial tests the inclusion of neoadjuvant immunotherapy with the aim of enhancing complete response rates, improving stoma-free survival and reducing distant relapse. Methods: PRIME-RT is a multi-centre, open label, phase II, randomised trial for patients with newly diagnosed LARC. Eligible patients are randomised to Arm A: short course radiotherapy (25 Gray in 5 fractions) with concomitant durvalumab, followed by durvalumab and FOLFOX chemotherapy, or Arm B: long course chemoradiotherapy (50 Gray to primary tumour, 45 Gray to elective nodes, in 25 fractions with capecitabine) with concomitant durvalumab followed by FOLFOX and durvalumab. The primary endpoint is complete response rate in each arm. Bio-specimens including serial tumour biopsies and peripheral blood samples are collected prior to, during, and following treatment to explore the molecular and immunological factors underpinning treatment response. The main trial will recruit up to 42 patients and commence after a safety run-in (n≥6) which is recruiting patients with metastatic disease. After opening in January 2021, three patients have been treated within the safety run-in; 2 in Arm A and 1 in Arm B. Early recruitment to PRIME-RT has shown that adding immunotherapy in the neoadjuvant setting for LARC is feasible. The expectation is that the trial will provide efficacy and safety information which allows the optimal treatment approach to be tested within a larger phase clinical trial. Funding information Core funding (Glasgow CRUK CTU) and trial specific funding (Astrazeneca). Trial registration Clinicaltrials.gov NCT04621370 (Registered 9 Nov 2020) ISRCTN18138369 (Registered 27 October 2020) Clinical trial information: NCT04621370.

Clinical performance of Immunoscore in stage III colorectal cancer patients in the SCOT and IDEA-HORG cohorts

196

Background: The ESMO clinical practice guidelines recommend consideration of Immunoscore (IS) for risk assessment of early colon cancer patients. IS clinical performance was assessed in the SCOT and IDEA-HORG trials evaluating 3 vs. 6 months (3m vs. 6m) of mFOLFOX6 adjuvant chemotherapy in stage III colorectal cancer (CRC). Methods: 1,002 formalin-fixed paraffin-embedded (FFPE) tumor samples (762 from SCOT;240 from HORG) were collected, of which 851 were eligible for biomarker analysis. Eligible samples were classified into 2 groups using pre-defined cut-offs (IS-Low, IS- High) and the performance of IS to predict 3 year disease-free survival (3y-DFS) was evaluated. Results: IS was successfully assessed in 846 cases (99%). 615 (72.7%) samples were classified as IS-High (311 and 304 in 3m and 6m arm, respectively). No significant association between IS and patients’ gender, age, PS, BMI or primary tumour location was observed. However, a significant difference between IS-High (43.7%) and IS Low (57.1%) was observed in the proportion of high risk (T4 and/or N2) tumours (p=0.001). Patients with IS-High tumors had significantly longer 3y-DFS (79.4%, 95%CI: 75.9%-82.4%) compared to those with IS-Low tumors (65.0%, 95%CI: 58.3%-70.9%); adjusted hazard ratio (HR) 1.9 (95%CI: 1.46-2.46; p<0.0001). Similarly, IS-High was significantly correlated with longer 3y-DFS in both treatment arms: 78.5% (95% CI 73.4%-82.7%) for IS-High and 65.8% (95% CI 56.1%-73.9%) for IS-Low in 3m arm; 80.3% (95% CI 75.3%-84.5%) for IS-High and 64.4% (95% CI 54.8%-72.6%) for IS-Low in 6m arm. The estimated HRs according to treatment duration and IS classification were 1.80 (95% CI 1.25-2.60) in 3m arm, 2.00 (95% CI 1.38-2.92) in 6m arm and 1.89 (95% CI 1.46-2.47) in the total study population; interaction p = 0.687. Conclusions: The results of this study confirm the prognostic value of IS observed in the IDEA-France trial (Pagès F et al 2020). However, this analysis was not powered to determine the predictive value of IS for treatment duration. Similar analysis of patients treated with CAPOX is warranted.

Trifluridine/tipiracil in combination with oxaliplatin and either bevacizumab or nivolumab in metastatic colorectal cancer: a dose-expansion, phase I study

Background

In preclinical studies trifluridine/tipiracil (FTD/TPI) plus oxaliplatin (Industriestrasse, Holzkirchen, Germany) sensitised microsatellite stable (MSS) metastatic colorectal cancer (mCRC) to anti-programmed cell death protein-1; the addition of oxaliplatin or bevacizumab (F Hoffmann- la ROCHE AG, Kaiseraugst, Switzerland) enhanced the antitumour effects of FTD/TPI. This study aimed to investigate the safety and efficacy of FTD/TPI plus oxaliplatin and either bevacizumab or nivolumab (Uxbridge business Park, Uxbridge, United Kingdom) in patients with mCRC who had progressed after at least one prior line of treatment.

Patients and methods

In 14-day cycles, patients received FTD/TPI 35 mg/m² (twice daily, days 1-5) plus oxaliplatin 85 mg/m² (day 1), and, on day 1, either bevacizumab 5 mg/kg (cohort A) or nivolumab 3 mg/kg (cohort B). Patients in Cohort B had confirmed MSS status.

Results

In total, 54 patients were enrolled: 37 in cohort A and 17 in cohort B. Recruitment in cohort B was stopped early due to the low response rate (RR) observed at interim analyses of efficacy. The most common adverse events (AEs) in cohort A were neutropenia/decreased neutrophils (75.7%), nausea (59.5%), vomiting (40.5%), diarrhoea (37.8%), peripheral sensory neuropathy (37.8%), fatigue (35.1%) and decreased appetite (35.1%). In cohort B, the most common AEs were neutropenia/decreased neutrophils (70.6%), diarrhoea (58.8%), nausea (47.1%), vomiting (47.1%), fatigue (47.1%), asthenia (41.2%), paraesthesia (41.2%), thrombocytopenia/decreased platelets (35.3%) and decreased appetite (35.3%). Confirmed objective RR was 17.1% in cohort A and 7.1% in cohort B; the corresponding values for median progression-free survival in the two cohorts were 6.3 and 6.0 months.

Conclusion

FTD/TPI plus oxaliplatin and bevacizumab or nivolumab had an acceptable safety profile and demonstrated antitumour activity in previously treated patients with mCRC.

•

This study evaluated the safety and efficacy of FTD/TPI plus oxaliplatin and either bevacizumab or nivolumab in mCRC patients.

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FTD/TPI plus oxaliplatin in combination with bevacizumab or nivolumab had an acceptable and manageable safety profile.

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Antitumour activity was observed following treatment with FTD/TPI plus oxaliplatin and bevacizumab.

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Despite a modest RR with the addition of nivolumab, survival data were promising in these poor-prognosis patients.

Duration of Adjuvant Doublet Chemotherapy (3 or 6 months) in Patients With High-Risk Stage II Colorectal Cancer

PURPOSE

As oxaliplatin results in cumulative neurotoxicity, reducing treatment duration without loss of efficacy would benefit patients and healthcare providers.

PATIENTS AND METHODS

Four of the six studies in the International Duration of Adjuvant Chemotherapy (IDEA) collaboration included patients with high-risk stage II colon and rectal cancers. Patients were treated (clinician and/or patient choice) with either fluorouracil, leucovorin, and oxaliplatin (FOLFOX) or capecitabine and oxaliplatin (CAPOX) and randomly assigned to receive 3- or 6-month treatment. The primary end point is disease-free survival (DFS), and noninferiority of 3-month treatment was defined as a hazard ratio (HR) of < 1.2- v 6-month arm. To detect this with 80% power at a one-sided type one error rate of 0.10, a total of 542 DFS events were required.

RESULTS

3,273 eligible patients were randomly assigned to either 3- or 6-month treatment with 62% receiving CAPOX and 38% FOLFOX. There were 553 DFS events. Five-year DFS was 80.7% and 83.9% for 3-month and 6-month treatment, respectively (HR, 1.17; 80% CI, 1.05 to 1.31; P [for noninferiority] .39). This crossed the noninferiority limit of 1.2. As in the IDEA stage III analysis, the duration effect appeared dependent on the chemotherapy regimen although a test of interaction was negative. HR for CAPOX was 1.02 (80% CI, 0.88 to 1.17), and HR for FOLFOX was 1.41 (80% CI, 1.18 to 1.68).

CONCLUSION

Although noninferiority has not been demonstrated in the overall population, the convenience, reduced toxicity, and cost of 3-month adjuvant CAPOX suggest it as a potential option for high-risk stage II colon cancer if oxaliplatin-based chemotherapy is suitable. The relative contribution of the factors used to define high-risk stage II disease needs better understanding.

Early Adaptation of Colorectal Cancer Cells to the Peritoneal Cavity Is Associated with Activation of "Stemness" Programs and Local Inflammation

PURPOSE

At diagnosis, colorectal cancer presents with synchronous peritoneal metastasis in up to 10% of patients. The peritoneum is poorly characterized with respect to its superspecialized microenvironment. Our aim was to describe the differences between peritoneal metastases and their matched primary tumors excised simultaneously at the time of surgery. Also, we tested the hypothesis of these differences being present in primary colorectal tumors and having prognostic capacity.

EXPERIMENTAL DESIGN

We report a comprehensive analysis of 30 samples from peritoneal metastasis with their matched colorectal cancer primaries obtained during cytoreductive surgery. We tested and validated the prognostic value of our findings in a pooled series of 660 colorectal cancer primary samples with overall survival (OS) information and 743 samples with disease-free survival (DFS) information from publicly available databases.

RESULTS

We identified 20 genes dysregulated in peritoneal metastasis that promote an early increasing role of "stemness" in conjunction with tumor-favorable inflammatory changes. When adjusted for age, gender, and stage, the 20-gene peritoneal signature proved to have prognostic value for both OS [adjusted HR for the high-risk group (vs. low-risk) 2.32 (95% confidence interval, CI, 1.69-3.19; P < 0.0001)] and for DFS [adjusted HR 2.08 (95% CI, 1.50-2.91; P < 0.0001)].

CONCLUSIONS

Our findings indicated that the activation of "stemness" pathways and adaptation to the peritoneal-specific environment are key to early stages of peritoneal carcinomatosis. The in silico analysis suggested that this 20-gene peritoneal signature may hold prognostic information with potential for development of new precision medicine strategies in this setting.

The impact of changes in service delivery in patients with colorectal cancer during the first peak of the COVID-19 pandemic

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Background: Increased levels of anxiety and distress in both patients and physicians have been reported in response to the significant impact COVID-19 has on cancer service delivery globally. We aimed to investigate how these changes have been perceived by patients diagnosed with colorectal cancer and identify determinants of increased anxiety. Methods: Survey (32-item) of consecutive patients diagnosed with colorectal cancer attending a large tertiary comprehensive cancer centre in the United Kingdom (18 May to 1 July 2020). Self-reported GAD-7 (both paper/electronic forms) was used as a screening tool for anxiety. Statistical analyses of associations:Chi-square, Fisher’s exact, and uni- and multi-variable analyses were performed using SPSS v19 and R. Results: A total of 143 patients (response rate 67%), 82% male, and median age of 61-70 years were included. Majority of patients had telephone consultation (78%), including 40% who had scan results discussed over the phone; with favourable feedback received with both respectively. Twenty-three patients (18%) were considered to have anxiety, with 7 (6%) scoring for moderate or severe anxiety. Three items asked patients if they had concerns about getting COVID-19, were worried that COVID-19 would have effect on mental health, and affect their experience of cancer care. Patients answering positively to any of these items were most likely to have anxiety; multivariate analysis – OR 2.361 (95% CI 1.187-4.694, p=0.014), 3.219 (95% CI 1.401-7.395, p=0.006) and 3.206 (95% CI 1.036-9.920, p=0.043), respectively. Majority of the patients did not feel that they needed support during the pandemic period and hence the available well-being services were not used. Patients felt that friends and family had been very supportive but less so the primary care services (p<0.05). However, they felt they were supported by the clinical team. Conclusions: At our centre, during the first-peak of COVID-19 pandemic in the UK, patients with colorectal cancer did not display increased rates of significant anxiety. The findings of this survey suggests that some service changes implemented, including increased telephone follow-up, may have already improved the overall experience of cancer care. Importantly, patients were much more concerned about their cancer treatment than COVID-19, emphasising the need to continue to provide comprehensive cancer care even if we get a “2nd wave” of COVID-19.

Phase II study evaluating trifluridine/tipiracil + bevacizumab and capecitabine + bevacizumab in first-line unresectable metastatic colorectal cancer (mCRC) patients who are noneligible for intensive therapy (TASCO1): Results of the final analysis on the overall survival

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Background: Our phase II randomized study was conducted in patients with previously untreated unresectable mCRC not eligible to receive standard oxaliplatin- or irinotecan- based chemotherapy regimens. The results of the primary study analysis were reported earlier and demonstrated a promising efficacy in terms of progression-free survival (PFS) and an acceptable safety profile for the combination of trifluridine/tipiracil + bevacizumab (E. Van Cutsem et al. Ann. Oncol. 2020). Here we present the final end-of-study analysis on the overall survival (OS). Methods: Eligible patients were randomized in 1:1 ratio to receive either trifluridine/tipiracil administered orally at 35 mg/m²/dose bid from days 1-5 and days 8-12, and bevacizumab at 5 mg/kg on days 1 and 15 of a 28-day treatment cycle (TT-B), or capecitabine administered orally at 1250 or 1000 mg/m²/dose bid (according to the patient’s status) from days 1-14 and bevacizumab at 7.5 mg/kg on day 1 of a 21-day treatment cycle (C-B). Cycles were repeated until documented disease progression, unacceptable toxicity, or investigator’s/patient’s decision. Following the treatment discontinuation, all patients were followed for OS until the end-of-study, which was defined as the date of the withdrawal visit for the last patient. In the absence of death confirmation or for patients alive as of the end-of-study date, survival time was censored at the date of their last study follow-up. For the OS analysis the HR and the corresponding 2-sided 80% and 2-sided 95% CIs for TT-B versus C-B were estimated using a Cox proportional hazard model adjusting for the stratification factors based on IWRS data. OS was summarized using Kaplan-Meier curves and further characterized in terms of the median and survival probabilities at 6, 12, 18, and 24 months along with the corresponding 2-sided 80% and 2-sided 95% CI (Brookmeyer and Crowley CI for median and Kalbfleisch and Prentice CI for survival probabilities). Results: From April 2016 to March 2017, 153 patients were randomized and followed until end-of-study on September 1, 2020. Twenty-one patients, 11 from TT-B and 10 from C-B, were alive and censored for the analysis. Median OS was 22.31 months in TT-B and 17.67 months in C-B with HR 0.78 (95% CI, 0.55, 1.10). Survival probability at 18 months in TT-B was 0.62 (95% CI, 0.50, 0.72), and 0.47 (95% CI, 0.35, 0.57) in C-B. Conclusions: Our study demonstrated earlier a median PFS of 9.2 months for TT-B and 7.8 months for C-B when administered to patients with previously untreated unresectable mCRC ineligible for standard combination chemotherapy. The final study analysis performed on OS, the main secondary endpoint, provided further evidence for TT-B as a noteworthy valuable regimen in this population settings. Clinical trial information: NCT02743221.

Three-dimensional (3D) magnetic resonance volume assessment and loco-regional failure in anal cancer: early evaluation case-control study

Background

The primary aim was to test the hypothesis that deriving pre-treatment 3D magnetic resonance tumour volume (mrTV) quantification improves performance characteristics for the prediction of loco-regional failure compared with standard maximal tumour diameter (1D) assessment in patients with squamous cell carcinoma of the anus undergoing chemoradiotherapy.

Methods

We performed an early evaluation case-control study at two UK centres (2007–2014) in 39 patients with loco-regional failure (cases), and 41 patients disease-free at 3 years (controls). mrTV was determined using the summation of areas method (Vol_sum). Reproducibility was assessed using intraclass concordance correlation (ICC) and Bland-Altman limits of agreements. We derived receiver operating curves using logistic regression models and expressed accuracy as area under the curve (ROC_AUC).

Results

The median time per patient for Vol_sum quantification was 7.00 (inter-quartile range, IQR: 0.57–12.48) minutes. Intra and inter-observer reproducibilities were generally good (ICCs from 0.79 to 0.89) but with wide limits of agreement (intra-observer: − 28 to 31%; inter-observer: − 28 to 46%). Median mrTVs were greater for cases (32.6 IQR: 21.5–53.1 cm³) than controls (9.9 IQR: 5.7–18.1 cm³, p < 0.0001). The ROC_AUC for mrT-size predicting loco-regional failure was 0.74 (95% CI: 0.63–0.85) improving to 0.82 (95% CI: 0.72–0.92) when replaced with mrTV (test for ROC differences, p = 0.024).

Conclusion

Preliminary results suggest that the replacement of mrTV for mrT-size improves prediction of loco-regional failure after chemoradiotherapy for squamous cell carcinoma of the anus. However, mrTV calculation is time consuming and variation in its reproducibility are drawbacks with the current technology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07613-7.

Blood-based RAS mutation testing: concordance with tissue-based RAS testing and mutational changes on progression

Aim: To determine the concordance between plasma and tissue RAS mutation status in metastatic colorectal cancer patients to gauge whether blood-based testing is a viable alternative. We also evaluated the change in mutation status on progression. Materials/methods: RAS testing was performed on plasma from patients commencing first-line therapy (OncoBEAM™ RAS CEIVD kit). Results were then compared with formalin-fixed paraffin embedded tumor samples. Results: The overall percentage agreement (concordance) was 86.0% (86/100), which demonstrates that blood-based testing is an alternative to tissue-based testing. Reproducibility was 100% between three laboratories and 20% showed changes in their RAS mutational status on progression. Conclusion: These results show good concordance between tissue and plasma samples and suggest the need for longitudinal plasma testing during treatment to guide management decisions.

International Rare Cancers Initiative Multicenter Randomized Phase II Trial of Cisplatin and Fluorouracil Versus Carboplatin and Paclitaxel in Advanced Anal Cancer: InterAAct

PURPOSE

To compare cisplatin plus fluorouracil (FU) versus carboplatin plus paclitaxel in chemotherapy-naïve advanced anal cancer to establish the optimal regimen.

PATIENTS AND METHODS

Patients who had not received systemic therapy for advanced anal cancer were randomly assigned 1:1 to intravenous cisplatin 60 mg/m2 (day 1) plus FU 1,000 mg/m2 (days 1-4) every 21 days or carboplatin (area under the curve, 5; day 1) plus paclitaxel 80 mg/m2 (days 1, 8, and 15) every 28 days for 24 weeks, until disease progression, intolerable toxicity, or withdrawal of consent. Primary end point was objective response rate (ORR). Primary and secondary end points were assessed in a hierarchic model to compare the regimens and pick the winner.

RESULTS

We conducted an international multicenter randomized phase II study in 60 centers between December 2013 and November 2017. Median follow-up was 28.6 months. A total of 91 patients were randomly assigned: 46 to cisplatin plus FU and 45 to carboplatin plus paclitaxel. ORR was 57% (95% CI, 39.4% to 73.7%) for cisplatin plus FU versus 59% (95% CI, 42.1% to 74.4%) for carboplatin plus paclitaxel. More serious adverse events were noted in the cisplatin plus FU arm (62%) compared with the carboplatin plus paclitaxel arm (36%; P = .016). Median progression-free survival was 5.7 months (95% CI, 3.3 to 9.0 months) for cisplatin plus FU compared with 8.1 months (95% CI, 6.6 to 8.8 months) for carboplatin plus paclitaxel. Median overall survival was 12.3 months for cisplatin plus FU (95% CI, 9.2 to 17.7 months) compared with 20 months (95% CI, 12.7 months to not reached) for carboplatin plus paclitaxel (hazard ratio, 2.00; 95% CI, 1.15 to 3.47; P = .014).

CONCLUSION

This is the first international randomized trial to our knowledge conducted in chemotherapy-naïve advanced anal cancer. Although there was no difference in ORR, the association with clinically relevant reduced toxicity and a trend toward longer survival suggest that carboplatin plus paclitaxel should be considered as a new standard of care.

Trifluridine/tipiracil plus bevacizumab in patients with untreated metastatic colorectal cancer ineligible for intensive therapy: the randomized TASCO1 study

BACKGROUND

We designed an open-label, noncomparative phase II study to assess the safety and efficacy of first-line treatment with trifluridine/tipiracil plus bevacizumab (TT-B) and capecitabine plus bevacizumab (C-B) in untreated patients with unresectable metastatic colorectal cancer (mCRC) who were not candidates for combination with cytotoxic chemotherapies.

PATIENTS AND METHODS

From 29 April 2016 to 29 March 2017, 153 patients were randomly assigned (1:1) to either TT-B (N = 77) or C-B (N = 76). The primary end point was progression-free survival (PFS). The primary PFS analysis was performed after 100 events (radiological progression or death) were observed. Secondary end points included overall survival (OS), quality of life (QoL; QLQ-C30 and QLQ-CR29 questionnaires), and safety.

RESULTS

Median (range) duration of treatment was 7.8 (6.0-9.7) months and 6.2 (4.1-9.1) months in the TT-B and C-B groups, respectively. Median (range) PFS was 9.2 (7.6-11.6) and 7.8 (5.5-10.1) months, respectively. Median (range) OS was 18 (15.2 to NA) and 16.2 (12.5 to NA) months, respectively. QoL questionnaires showed no relevant changes over time for either treatment. Therapies were well tolerated. Patients receiving TT-B had more grade ≥3 neutropenia (47% versus 5% with C-B). Patients receiving C-B had more grade ≥3 hand-foot syndrome (12% versus 0% with TT-B) and grade ≥3 diarrhea (8% versus 1% with TT-B), consistent with the known safety profiles of these agents.

CONCLUSION

TT-B treatment showed promising clinical activity in untreated patients with unresectable mCRC ineligible for intensive therapy, with an acceptable safety profile and no clinically relevant changes in QoL.

CLINICAL TRIAL INFORMATION

NCT02743221 (ClinicalTrials.gov).

Overall survival (OS) and long-term disease-free survival (DFS) of three versus six months of adjuvant (adj) oxaliplatin and fluoropyrimidine-based therapy for patients (pts) with stage III colon cancer (CC): Final results from the IDEA (International Duration Evaluation of Adj chemotherapy) collaboration

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Background: In overall population, IDEA pooled analysis did not demonstrate non-inferiority (NI) regarding 3y DFS in pts with stage III CC receiving 3m vs. 6m of adj FOLFOX/CAPOX. However, in pts treated with CAPOX (especially in low-risk pts), 3m of therapy was as effective as 6m. Results of OS and 5y DFS are reported. Methods: OS was defined as time from enrollment to death due to all causes. OS NI margin was conservatively set to be Hazard Ratio (HR) = 1.11, which is equivalent to: the maximum acceptable loss of OS efficacy, by shortening treatment to 3m, was half of the OS efficacy gained in MOSAIC trial (i.e., 2.26% absolute reduction in 5y OS rate). Pre-planned sub-group analyses included by regimen and risk group for both OS and 5y DFS. NI was to be declared if the one-sided false discovery rate adjusted (FDRa) NI p-value < 0.025. Results: With an overall median survival follow-up of 72 m (range per study, 62 to 84 m), 2584 deaths and 3777 DFS events among 12,835 pts from six trials were observed. Across 6 studies, 39.5% of pts received CAPOX (rate by study, 0% to 75.1%). Overall, the 5y OS rate was 82.4% (3m) and 82.8% (6m), with estimated OS HR of 1.02 (95% confidence interval [CI], 0.95-1.11; FDRa NI p, 0.058) and absolute 5-y OS rate difference of -0.4% (95% CI, -2.1 to 1.3%). Overall, the 5y DFS rate was 69.1% (3m) and 70.8% (6m), with estimated DFS HR of 1.08 (95%CI, 1.01-1.15, FDRa NI p, 0.22). HRs (95% CI) within subgroups see table. Conclusions: 5y OS rate reported in IDEA trials was higher than historical rates, regardless of duration of therapy. While overall survival in IDEA did not meet prior statistical assumptions for NI in overall population, the 0.4% difference in 5y OS should be placed in clinical context. OS and 5y DFS results continue to support the use of 3m adjuvant CAPOX for the vast majority of stage III colon cancer pts. This conclusion is strengthened by the substantial reduction of toxicities, inconveniencies and cost associated with shorter treatment duration. Clinical trial information: NCT01150045; 2009-010384-16; NCT00749450; ISRCTN59757862; 2007-003957-10; UMIN000008543; 2007-000354 . [Table: see text]

Trifluridine/tipiracil in combination with oxaliplatin and either bevacizumab or nivolumab: Results of the expansion part of a phase I study in patients with metastatic colorectal cancer

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Background: Trifluridine/tipiracil (FTD/TPI) is approved for use in patients (pts) with pretreated mCRC. In vivo studies have shown an increase in anti-tumor activity when combining FTD/TPI, oxaliplatin or bevacizumab, and an increase in tumor immunogenicity after treatment with FTD/TPI and oxaliplatin (Ghiringhelli, 2018). The recommended dose for expansion had been defined as FTD/TPI 35 mg/m² bid, days 1–5 q14, together with oxaliplatin 85 mg/m² (day 1). Methods: In addition to FTD/TPI and oxaliplatin, eligible pts received bevacizumab 5 mg/kg (Cohort A) or nivolumab 3 mg/kg (Cohort B) on day 1. Eligibility criteria included measurable disease, performance status (PS) 0-1, normal organ function, progression after > 1 prior anti-tumor therapy (excluding oxaliplatin), and confirmed MSS status (Cohort B). A Bayesian design was used for futility and efficacy assessments. Efficacy endpoints of objective response rate (ORR), disease control rate (DCR), progression free survival (PFS) and adverse events (AEs) were assessed for each cohort; biomarkers of immune function including PD-L1 expression for Cohort B. Results: A total of 37 and 17 pts were enrolled in Cohorts A and B respectively; with a median age of 64 years (range 33 to 83 years), 61% and 39% had an PS of 0 and 1. At baseline, no pt showed PD-L1 expression on tumor cells, and only 1 pt on immune cells (5% threshold). At data cutoff, 32 and 12 pts were evaluable for response in Cohorts A and B. In Cohort A, ORR was 13% (1 CR; 3 PR), and DCR was 91%. The mPFS was 6.9 months (95% IC, 4.3-9.3). In Cohort B, ORR was 8% (1 PR), DCR was 67%. The mPFS was 6.5 months (95% IC, 1.8-8.6). Overall, the most common treatment-related AEs (≥20% of pts) included neutropenia, nausea, diarrhoea, and fatigue; only 1 pt reported grade 3 febrile neutropenia; 5 pts discontinued due to AEs and no treatment-related death were reported. Conclusions: In this study, bevacizumab in addition to FTD/TPI and oxaliplatin showed antitumor activity. The cohort of nivolumab was prematurely discontinued due to lack of efficacy. Both cohorts showed an acceptable safety profile in pretreated mCRC pts. Clinical trial information: NCT02848443.

Temporal improvements in loco-regional failure and survival in patients with anal cancer treated with chemo-radiotherapy: treatment cohort study (1990-2014)

Background

We evaluated oncological changes in patients with squamous cell carcinoma of the anus (SCCA) treated by chemoradiotherapy (CRT) from a large UK institute, to derive estimates of contemporary outcomes.

Methods

We performed a treatment-cohort analysis in 560 patients with non-metastatic SCCA treated with CRT over 25 years. The primary outcomes were 3-year loco-regional failure (LRF), 5-year overall survival (OS), and 5-year cancer-specific survival (CSS). We developed prediction models; and overlaid estimates on published results from historic trials.

Results

Age distributions, proportions by gender and cT stage remained stable over time. The median follow-up was 61 (IQR: 36–79) months. Comparing the first period (1990–1994) with the last period (2010–2014), 3-year LRF declined from 33 to 16% (P_trends < 0.001); 5-year OS increased from 60% to 76% (P_trends = 0.001); and 5-year CCS increased from 62% in to 80% (P_trends = 0.001). For 2020, the models predicted a 3-year LRF of 14.7% (95% CIs: 0–31.3); 5-year OS of 74.7% (95% CIs: 54.6–94.9); and 5-year CSS of 85.7% (95% CIs: 75.3–96.0). Reported oncological outcomes from historic trials generally underestimated contemporary outcomes.

Conclusions

Current and predicted rates for 3-year LRF and 5-year survivals are considerably improved compared with those in historic trials.

3-month versus 6-month adjuvant chemotherapy for patients with high-risk stage II and III colorectal cancer: 3-year follow-up of the SCOT non-inferiority RCT

BACKGROUND

Oxaliplatin and fluoropyrimidine chemotherapy administered over 6 months is the standard adjuvant regimen for patients with high-risk stage II or III colorectal cancer. However, the regimen is associated with cumulative toxicity, characterised by chronic and often irreversible neuropathy.

OBJECTIVES

To assess the efficacy of 3-month versus 6-month adjuvant chemotherapy for colorectal cancer and to compare the toxicity, health-related quality of life and cost-effectiveness of the durations.

DESIGN

An international, randomised, open-label, non-inferiority, Phase III, parallel-group trial.

SETTING

A total of 244 oncology clinics from six countries: UK (England, Scotland, Wales and Northern Ireland), Denmark, Spain, Sweden, Australia and New Zealand.

PARTICIPANTS

Adults aged ≥ 18 years who had undergone curative resection for high-risk stage II or III adenocarcinoma of the colon or rectum.

INTERVENTIONS

The adjuvant treatment regimen was either oxaliplatin and 5-fluorouracil or oxaliplatin and capecitabine, randomised to be administered over 3 or 6 months.

MAIN OUTCOME MEASURES

The primary outcome was disease-free survival. Overall survival, adverse events, neuropathy and health-related quality of life were also assessed. The main cost categories were chemotherapy treatment and hospitalisation. Cost-effectiveness was assessed through incremental cost comparisons and quality-adjusted life-year gains between the options and was reported as net monetary benefit using a willingness-to-pay threshold of £30,000 per quality-adjusted life-year per patient.

RESULTS

Recruitment is closed. In total, 6088 patients were randomised (3044 per group) between 27 March 2008 and 29 November 2013, with 6065 included in the intention-to-treat analyses (3-month analysis, n = 3035; 6-month analysis, n = 3030). Follow-up for the primary analysis is complete. The 3-year disease-free survival rate in the 3-month treatment group was 76.7% (standard error 0.8%) and in the 6-month treatment group was 77.1% (standard error 0.8%), equating to a hazard ratio of 1.006 (95% confidence interval 0.909 to 1.114; p-value for non-inferiority = 0.012), confirming non-inferiority for 3-month adjuvant chemotherapy. Frequent adverse events (alopecia, anaemia, anorexia, diarrhoea, fatigue, hand-foot syndrome, mucositis, sensory neuropathy, neutropenia, pain, rash, altered taste, thrombocytopenia and watery eye) showed a significant increase in grade with 6-month duration; the greatest difference was for sensory neuropathy (grade ≥ 3 was 4% for 3-month vs.16% for 6-month duration), for which a higher rate of neuropathy was seen for the 6-month treatment group from month 4 to ≥ 5 years (p < 0.001). Quality-of-life scores were better in the 3-month treatment group over months 4-6. A cost-effectiveness analysis showed 3-month treatment to cost £4881 less over the 8-year analysis period, with an incremental net monetary benefit of £7246 per patient.

CONCLUSIONS

The study achieved its primary end point, showing that 3-month oxaliplatin-containing adjuvant chemotherapy is non-inferior to 6 months of the same regimen; 3-month treatment showed a better safety profile and cost less. For future work, further follow-up will refine long-term estimates of the duration effect on disease-free survival and overall survival. The health economic analysis will be updated to include long-term extrapolation for subgroups. We expect these analyses to be available in 2019-20. The Short Course Oncology Therapy (SCOT) study translational samples may allow the identification of patients who would benefit from longer treatment based on the molecular characteristics of their disease.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN59757862 and EudraCT 2007-003957-10.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 64. See the NIHR Journals Library website for further project information. This research was supported by the Medical Research Council (transferred to NIHR Evaluation, Trials and Studies Coordinating Centre - Efficacy and Mechanism Evaluation; grant reference G0601705), the Swedish Cancer Society and Cancer Research UK Core Clinical Trials Unit Funding (funding reference C6716/A9894).

Novel phase I trial design to evaluate the addition of cediranib or selumetinib to preoperative chemoradiotherapy for locally advanced rectal cancer: the DREAMtherapy trial

BACKGROUND

The DREAMtherapy (Dual REctal Angiogenesis MEK inhibition radiotherapy) trial is a novel intertwined design whereby two tyrosine kinase inhibitors (cediranib and selumetinib) were independently evaluated with rectal chemoradiotherapy (CRT) in an efficient manner to limit the extended follow-up period often required for radiotherapy studies.

PATIENTS AND METHODS

Cediranib or selumetinib was commenced 10 days before and then continued with RT (45 Gy/25#/5 wks) and capecitabine (825 mg/m2 twice a day (BID)). When three patients in the cediranib 15-mg once daily (OD) cohort were in the surveillance period, recruitment to the selumetinib cohort commenced. This alternating schedule was followed throughout. Three cediranib (15, 20 and 30 mg OD) and two selumetinib cohorts (50 and 75 mg BID) were planned. Circulating and imaging biomarkers of inflammation/angiogenesis were evaluated.

RESULTS

In case of cediranib, dose-limiting diarrhoea, fatigue and skin reactions were seen in the 30-mg OD cohort, and therefore, 20 mg OD was defined as the maximum tolerated dose. Forty-one percent patients achieved a clinical or pathological complete response (7/17), and 53% (9/17) had an excellent clinical or pathological response (ECPR). Significantly lower level of pre-treatment plasma tumour necrosis factor alpha (TNFα) was found in patients who had an ECPR. In case of selumetinib, the 50-mg BID cohort was poorly tolerated (fatigue and diarrhoea); a reduced dose cohort of 75-mg OD was opened which was also poorly tolerated, and further recruitment was abandoned. Of the 12 patients treated, two attained an ECPR (17%).

CONCLUSIONS

This novel intertwined trial design is an effective way to independently investigate multiple agents with radiotherapy. The combination of cediranib with CRT was well tolerated with encouraging efficacy. TNFα emerged as a potential predictive biomarker of response and warrants further evaluation.

Pattern Recognition Receptor Polymorphisms as Predictors of Oxaliplatin Benefit in Colorectal Cancer

BACKGROUND

Constitutional loss of function (LOF) single nucleotide polymorphisms (SNPs) in pattern recognition receptors FPR1, TLR3, and TLR4 have previously been reported to predict oxaliplatin benefit in colorectal cancer. Confirmation of this association could substantially improve patient stratification.

METHODS

We performed a retrospective biomarker analysis of the Short Course in Oncology Therapy (SCOT) and COIN/COIN-B trials. Participant status for LOF variants in FPR1 (rs867228), TLR3 (rs3775291), and TLR4 (rs4986790/rs4986791) was determined by genotyping array or genotype imputation. Associations between LOF variants and disease-free survival (DFS) and overall survival (OS) were analyzed by Cox regression, adjusted for confounders, using additive, dominant, and recessive genetic models. All statistical tests were two-sided.

RESULTS

Our validation study populations included 2929 and 1948 patients in the SCOT and COIN/COIN-B cohorts, respectively, of whom 2728 and 1672 patients had functional status of all three SNPs determined. We found no evidence of an association between any SNP and DFS in the SCOT cohort, or with OS in either cohort, irrespective of the type of model used. This included models for which an association was previously reported for rs867228 (recessive model, multivariable-adjusted hazard ratio [HR] for DFS in SCOT = 1.19, 95% confidence interval [CI] = 0.99 to 1.45, P = .07; HR for OS in COIN/COIN-B = 0.92, 95% CI = 0.63 to 1.34, P = .66), and rs4986790 (dominant model, multivariable-adjusted HR for DFS in SCOT = 0.86, 95% CI = 0.65 to 1.13, P = .27; HR for OS in COIN/COIN-B = 1.08, 95% CI = 0.90 to 1.31, P = .40).

CONCLUSION

In this prespecified analysis of two large clinical trials, we found no evidence that constitutional LOF SNPs in FPR1, TLR3, or TLR4 are associated with differential benefit from oxaliplatin. Our results suggest these SNPs are unlikely to be clinically useful biomarkers.

Prospective pooled analysis of four randomized trials investigating duration of adjuvant (adj) oxaliplatin-based therapy (3 vs 6 months {m}) for patients (pts) with high-risk stage II colorectal cancer (CC)

3501

Background: 6m of oxaliplatin-based treatment is an option as adj chemotherapy for patients with high risk stage II CC (T4, inadequate nodal harvest, poorly differentiated, obstruction, perforation or vascular/perineural invasion). The IDEA collaboration showed shorter treatment duration to be appropriate for most pts with stage III colon cancer. The results of the 4 IDEA studies with stage II pts are presented here. Methods: A prospective, pre-planned pooled analysis of high-risk stage II patients from 4 concurrently conducted randomized phase III trials (SCOT, TOSCA, ACHIEVE-2, HORG) was performed to evaluate non-inferiority (NI) of 3m compared with 6m (ref) of adj FOLFOX/CAPOX (regimen preselected, not randomized). The primary endpoint was disease-free survival (DFS), NI was to be declared if the 2-sided 80% confidence interval (CI) for DFS hazard ratio (HR 3m v 6m) estimated by a stratified Cox model was below 1.2. 542 DFS events were required to provide 80% power to declare NI. NI was also examined within regimen, T4 (Yes v No) and inadequate nodal harvest (Yes v No) as pre-planned subgroups. Results: The primary analysis included 3273 randomised pts of which 1254 had FOLFOX and 2019 had CAPOX. There were 552 events and the median follow-up was 60.2 m. There was significantly less grade 3-5 toxicity with 3m treatment (p < .0001). The 5-year DFS rate was 80.7% and 84.0% for 3m and 6m treatment with an estimated DFS HR of 1.18 (80% CI:1.05-1.31, p for NI = 0.404). For CAPOX the estimated HR was 1.02 (80% CI: 0.88-1.17, p for NI = 0.087) and for FOLFOX the estimated HR was 1.42 (80% CI: 1.19-1.70, p for NI = 0.894). The test for interaction between duration and regimen was not statistically significant (p = .174 adjusted for multiple testing) but was stronger than that for the other subgroups examined. Conclusions: In the overall population non-inferiority for 3m adj treatment in pts with high-risk stage II CC was not shown. As with the stage III population the choice of adj regimen appears important (although this did not reach statistical significance) with a small difference in DFS between 3 and 6 m treatment if CAPOX is used. Clinical trial information: ISRCTN59757862.

Biomarker concordance between primary colorectal cancer and its metastases

Background

The use of biomarkers to target anti-EGFR treatments for metastatic colorectal cancer (CRC) is well-established, requiring molecular analysis of primary or metastatic biopsies. We aim to review concordance between primary CRC and its metastatic sites.

Methods

A systematic review and meta-analysis of all published studies (1991–2018) reporting on biomarker concordance between primary CRC and its metastatic site(s) was undertaken according to PRISMA guidelines using several medical databases. Studies without matched samples or using peripheral blood for biomarker analysis were excluded.

Findings

61 studies including 3565 patient samples were included. Median biomarker concordance for KRAS (n = 50) was 93.7% [[67], [68], [69], [70], [71], [72], [73], [74], [75], [76], [77], [78], [79], [80], [81], [82], [83], [84], [85], [86], [87], [88], [89], [90], [91], [92], [93], [94], [95], [96], [97], [98], [99], [100]], NRAS (n = 11) was 100% [[90], [91], [92], [93], [94], [95], [96], [97], [98], [99], [100]], BRAF (n = 22) was 99.4% [[80], [81], [82], [83], [84], [85], [86], [87], [88], [89], [90], [91], [92], [93], [94], [95], [96], [97], [98], [99], [100]], and PIK3CA (n = 17) was 93% [[42], [43], [44], [45], [46], [47], [48], [49], [50], [51], [52], [53], [54], [55], [56], [57], [58], [59], [60], [61], [62], [63], [64], [65], [66], [67], [68], [69], [70], [71], [72], [73], [74], [75], [76], [77], [78], [79], [80], [81], [82], [83], [84], [85], [86], [87], [88], [89], [90], [91], [92], [93], [94], [95], [96], [97], [98], [99], [100]]. Meta-analytic pooled discordance was 8% for KRAS (95% CI = 5–10%), 8% for BRAF (95% CI = 5–10%), 7% for PIK3CA (95% CI = 2–13%), and 28% overall (95% CI = 14–44%). The liver was the most commonly biopsied metastatic site (n = 2276), followed by lung (n = 438), lymph nodes (n = 1123), and peritoneum (n = 132). Median absolute concordance in multiple biomarkers was 81% (5–95%).

Interpretation

Metastatic CRC demonstrates high concordance across multiple biomarkers, suggesting that molecular testing of either the primary or liver and lung metastasis is adequate. More research on colorectal peritoneal metastases is required.

QoL from TASCO1: Health-related quality of life of trifluridine/tipiracil-bevacizumab and capecitabine-bevacizumab as first-line treatments in metastatic colorectal cancer patients not eligible for intensive chemotherapy—Results from the TASCO1 phase II study

676

Background: TASCO1 is a phase II study which evaluated the safety and efficacy of trifluridine/tipiracil + bevacizumab (TT-B) and capecitabine + bevacizumab (C-B) in first-line unresectable mCRC patients non-eligible for intensive therapy. Promising activity was shown on progression-free survival with TT-B (9.2 months) and C-B (7.8 months). Here we present the Quality of Life (QoL) analysis of the two treatment arms. Methods: In TASCO1, patients were randomized 1:1 to receive TT-B (n = 76) on a four-week cycle or C-B (n = 77) on a three-week cycle. QoL was assessed in TASCO1 at baseline and at each 12 weeks thereafter, until discontinuation of study treatment, using the QLQ-C30 and QLQ-CR29 questionnaires. Responses were described separately in each arm using descriptive statistics. Results: For QLQ-C30, 121 patients completed baseline questionnaire. No clinically relevant difference was observed on treatment in mean change of score from baseline for the global health status, functioning scales, and for most of the symptom scales, except for nausea/vomiting and diarrhoea (worsening in the TT-B group and stable in the C-B group for both symptoms), fatigue (stable in the TT-B group and worsening in the C-B), loss appetite (worsening in the two groups) and insomnia (improvement in the two groups). For QLQ-CR29, 117 patients completed baseline questionnaire. No clinically relevant difference on treatment was observed in mean change of score from baseline for most of items except for the following: hair loss, trouble with taste (worsening for both symptoms in the TT-B group while stable for hair loss and improvement for trouble with taste in the C-B group), sore skin, dry mouth (stable in the TT-B group and worsening in the C-B group for both symptoms), and anxiety (stable in the TT-B group and improvement in the C-B group). Conclusions: The Global Health Scale was maintained in Trifluridine/tipiracil+bevacizumab arm as well as in the capecitabine+bevacizumab arm. No clinically relevant difference from baseline was observed over time in both groups except for few sub-scales. Clinical trial information: NCT02743221.

A core outcome set for clinical trials of chemoradiotherapy interventions for anal cancer (CORMAC): a patient and health-care professional consensus

Chemoradiotherapy is the primary treatment for patients with squamous cell carcinoma of the anus, but variations in the reported outcomes have restricted between-study comparisons. Treatment-related morbidity is considerable; however, no trial has comprehensively quantified long-term side-effects or quality of life. Therefore, we established the first international health-care professional and patient consensus to develop a core outcome set, using the Core Outcome Measures in Effectiveness Trials method. We used the results from our previous systematic review and combined them in this Review with patient interviews to derive a comprehensive list of outcomes, followed by a two-round Delphi survey completed by 149 participants (55 patients and 94 health-care professionals) from 11 countries. The Delphi results were discussed at a consensus meeting of health-care professionals and patients. Agreement was reached on 19 outcomes across four domains: disease activity, survival, toxicity, and life impact. Implementation of the Core Outcome Research Measures in Anal Cancer (CORMAC) set in future trials will serve as a framework to achieve standardisation, facilitate selection of health-area-specific evaluation tools, reduce redundancy of outcome lists, allow between-study comparisons, and ultimately enhance the relevance of trial findings to health-care professionals, trialists, and patients.

Plasma Tie2 is a tumor vascular response biomarker for VEGF inhibitors in metastatic colorectal cancer

Oncological use of anti-angiogenic VEGF inhibitors has been limited by the lack of informative biomarkers. Previously we reported circulating Tie2 as a vascular response biomarker for bevacizumab-treated ovarian cancer patients. Using advanced MRI and circulating biomarkers we have extended these findings in metastatic colorectal cancer (n = 70). Bevacizumab (10 mg/kg) was administered to elicit a biomarker response, followed by FOLFOX6-bevacizumab until disease progression. Bevacizumab induced a correlation between Tie2 and the tumor vascular imaging biomarker, Ktrans (R:-0.21 to 0.47) implying that Tie2 originated from the tumor vasculature. Tie2 trajectories were independently associated with pre-treatment tumor vascular characteristics, tumor response, progression free survival (HR for progression = 3.01, p = 0.00014; median PFS 248 vs. 348 days p = 0.0008) and the modeling of progressive disease (p < 0.0001), suggesting that Tie2 should be monitored clinically to optimize VEGF inhibitor use. A vascular response is defined as a 30% reduction in Tie2; vascular progression as a 40% increase in Tie2 above the nadir. Tie2 is the first, validated, tumor vascular response biomarker for VEGFi.

Factors affecting local regrowth after watch and wait for patients with a clinical complete response following chemoradiotherapy in rectal cancer (InterCoRe consortium): an individual participant data meta-analysis

BACKGROUND

In patients with rectal cancer who achieve clinical complete response after neoadjuvant chemoradiotherapy, watch and wait is a novel management strategy with potential to avoid major surgery. Study-level meta-analyses have reported wide variation in the proportion of patients with local regrowth. We did an individual participant data meta-analysis to investigate factors affecting occurrence of local regrowth.

METHODS

We updated search results of a recent systematic review by searching MEDLINE and Embase from Jan 1, 2016, to May 5, 2017, and used expert knowledge to identify published studies reporting on local regrowth in patients with rectal cancer managed by watch and wait after clinical complete response to neoadjuvant chemoradiotherapy. We restricted studies to those that defined clinical complete response using criteria equivalent to São Paulo benchmarks (ie, absence of residual ulceration, stenosis, or mass within the rectum on clinical and endoscopic examination). The primary outcome was 2-year cumulative incidence of local regrowth, estimated with a two-stage random-effects individual participant data meta-analysis. We assessed the effects of clinical and treatment factors using Cox frailty models, expressed as hazard ratios (HRs). From these models, we derived percentage differences in mean θ as an approximation of the effect of measured covariates on between-centre heterogeneity. This study is registered with PROSPERO, number CRD42017070934.

FINDINGS

We obtained individual participant data from 11 studies, including 602 patients enrolled between March 11, 1990, and Feb 13, 2017, with a median follow-up of 37·6 months (IQR 25·0-58·7). Ten of the 11 datasets were judged to be at low risk of bias. 2-year cumulative incidence of local regrowth was 21·4% (random-effects 95% CI 15·3-27·6), with high levels of between-study heterogeneity (I²=61%). We noted wide between-centre variation in patient, tumour, and treatment characteristics. We found some evidence that increasing cT stage was associated with increased risk of local regrowth (random-effects HR per cT stage 1·40, 95% CI 1·00-1·94; p_trend=0·048). In a subgroup of 459 patients managed after 2008 (when pretreatment staging by MRI became standard), 2-year cumulative incidence of local regrowth was 19% (95% CI 13-28) for stage cT1 and cT2 tumours, 31% (26-37) for cT3, and 37% (21-60) for cT4 (random-effects HR per cT stage 1·50, random-effects 95% CI 1·03-2·17; p_trend=0·0330). We estimated that measured factors contributed 4·8-45·3% of observed between-centre heterogeneity.

INTERPRETATION

In patients with rectal cancer and clinical complete response after chemoradiotherapy managed by watch and wait, we found some evidence that increasing cT stage predicts for local regrowth. These data will inform clinician-patient decision making in this setting. Research is needed to determine other predictors of a sustained clinical complete response.

FUNDING

None.

Chemotherapy dose reductions in obese patients undergoing adjuvant chemotherapy for colorectal cancer: secondary analyses of trial data and the Greater Manchester and Cheshire Cancer Network Audit

763

Background: In patients with stage II/III colorectal cancer receiving adjuvant chemotherapy, doses are calculated using body surface area (BSA) but often capped at BSA > 2.0. Dose capping might be a mechanism of reported poorer survival in obese patients. We aimed to investigate the different dosing schedules across BMI categories, using trial and ‘real world’ audit datasets, and determine its impact upon overall survival. Methods: Data was accessed for 1122 patients from the control arm of the MOSAIC trial (accessed via the Data Project Sphere) and 327 patients from the Greater Manchester and Cheshire Cancer Network (GMCCN) audit. Pearson’s χ2 and correlation coefficient were used to assess the relationship between BMI (expressed as normal, overweight and obese: and as continuous, respectively) and dose reductions. A multiple logistic regression model was constructed to compare the odds of receiving dose reductions in each BMI category. 4-year overall survival was calculated for each BMI category and dose status. Results: In MOSAIC, there were increasing dose reductions by BMI category: normal, 3%; overweight, 5%; and obese, 11%, with similar patterns in the GMCCN OxMdG group. Obese patients in MOSAIC and the GMCCN OxMdG group had 3- and 12-fold higher odds (OR = 3.4 and 12.5, CI = 1.6-7.0 and 2.0-78.1), respectively, of receiving dose reductions. However, these differences did not translate to differences in overall survival by BMI category or dose status. Conclusions: In our investigated datasets, there appears to be a relationship between increasing BMI and dose reductions, though it is modest and does not manifest as a detrimental influence on overall survival. Our findings agreed with other studies performed using stage IV cancer patients, although the relationship between increasing BMI and dose reductions is more prominent in patients with metastatic disease. Investigating other outcome measures such as cancer-specific survival and chemotherapy related toxicity is required for clarity.

SCOT: Tumor sidedness and the influence of chemotherapy duration on DFS

558

Background: Patients with R-sided tumours who develop metastatic disease have a worse prognosis compared to patients with L-sided tumours. The latter may also have a greater benefit from treatment with EGFR inhibitors. In general, registry studies and meta-analyses have shown that patients with loco-regional R-sided tumours have a worse overall survival (OS). This has recently been confirmed by the PETACC8 study but only after they had relapsed. There was not a significant difference in disease free survival (DFS). Methods: The SCOT study showed that 3-months of oxaliplatin-containing adjuvant chemotherapy (OxFp) was non-inferior to 6-months for patients with stage III and high-risk stage II colorectal cancer. Here we divide the population into left and right-sided tumours to see whether sidedness had an impact on DFS. We also evaluated whether sidedness impacted on the 3 vs. 6-months comparison in SCOT. Results: 6088 patients with Stage III/high risk Stage II cancers or the colon or rectum were randomised between March 27, 2008 and November 29, 2013 from 244 centres (164 UK, 32 Australia, 19 Spain, 14 Sweden, 10 Denmark and 5 New Zealand). In February 2017 (3-years FU) information on sidedness was available for 3219 patients (1207 R-sided, 2012 L-sided). Characteristics: Right: median age: 65, Male: 53%, T4 41%, Stage II: 17%; Left: median age: 65, Male: 66%, T4 24%, Stage II: 21%). Patients with R-sided tumours had a significantly worse DFS (3-year DFS right: 73% (se=1%), left: 80% (se=1%). HR 1.401 (95% CI 1.216-1.615; p=0.000004). Adjusting for T and N-stage reduced the HR to 1.215 (95% ci 1.051-1.404, p=0.009). The data did not suggest that sidedness affected the impact of chemotherapy duration on 3-year DFS (R: HR (3 month/6 month) 1.049 (0.849 -1.296) L: 0.910 (0.753-1.099). Test for homogeneity, p=0.327). Further sub-set analysis was limited due to cohort size. Conclusions: This is the first study to show that unselected patients with R-sided tumours had a worse DFS compared to L-sided tumours. This implies that prognosis is influenced primarily by greater recurrence rather than the contributing factors that influence OS. Tumour sidedness did not impact on the 3-months vs. 6-months comparison in SCOT. Clinical trial information: ISRCTN59757862.

Waiting Times for Treatment of Rectal Cancer in North West England

An interim goal of the NHS National Cancer Plan is that, by 2005, patients with cancer should be treated within one month of diagnosis and within two months from urgent general practitioner referral. Preoperative radiotherapy for rectal cancer reduces the risk of local recurrence and may translate into improved patient survival. We conducted a prospective audit of existing waiting times for preoperative radiotherapy experienced by 65 patients with rectal cancer referred to the Christie Cancer Centre, Manchester, UK, between May and November 2002. The median time between referral from the surgeon to the start of radiotherapy was 40 days (range 11-85). Only 4 patients (6%) received radiotherapy within 28 days of referral by the surgeon. 62 patients (95%) underwent surgery within 14 days of completing radiotherapy. Delays in the provision of preoperative radiotherapy were primarily due to shortages of radiography staff and equipment. Lack of such infrastructure will prove a major stumbling block to achieving the targets of the NHS Cancer Plan.

Nodal stage migration and prognosis in anal cancer: a systematic review, meta-regression, and simulation study

BACKGROUND

In patients with squamous cell carcinoma of the anus (SCCA), lymph node positivity (LNP) indicates poor prognosis for survival and is central to radiotherapy planning. Over the past three decades, LNP proportion has increased, mainly reflecting enhanced detection with newer imaging modalities; a process known as nodal stage migration. If accompanied by constant T stage distributions, prognosis for both lymph node-positive and lymph node-negative groups may improve without any increase in overall survival for individual patients; a paradox termed the Will Rogers phenomenon. Here, we aim to systematically evaluate the impact of nodal stage migration on survival in SCCA and address a novel hypothesis that this phenomenon results in reduced prognostic discrimination.

METHODS

We did a systematic review and meta-regression to quantify changes in LNP over time and the impact of this change on survival and prognostic discrimination. We searched MEDLINE, Embase, and the Cochrane Library to identify randomised trials and observational studies in patients with SCCA published between Jan 1, 1970, and Oct 11, 2016. Studies were eligible if patients received chemoradiotherapy or radiotherapy as the main treatment, reported LNP proportions (all studies), and reported overall survival (not necessarily present in all studies). We excluded studies with fewer than 50 patients. We extracted study-level data with a standardised, piloted form. The primary outcome measure was 5-year overall survival. To investigate scenarios in which reduced prognostic discrimination might occur, we simulated varying true LNP proportions and true overall survival, and compared these with expected observed outcomes for varying levels of misclassification of true nodal state.

FINDINGS

We identified 62 studies reporting LNP proportions, which included 10 569 patients. From these, we included 45 studies (6302 patients) with whole cohort 5-year overall survival, 11 studies with 5-year survival stratified by nodal status, and 20 studies with hazard ratios in our analyses of temporal changes. In 62 studies, the LNP proportions increased from a mean estimate of 15·3% (95% CI 10·5-20·1) in 1980 to 37·1% (34·0-41·3) in 2012 (p<0·0001). In 11 studies with prognostic data, increasing LNP was associated with improved overall survival in both lymph node-positive and lymph node-negative categories, whereas the proportions with combined tumour stage T3 and T4 remained constant. In 20 studies, across a range of LNP proportions from 15% to 40%, the hazard ratios for overall survival of lymph node-positive versus lymph node-negative patients decreased significantly from 2·5 (95% CI 1·8-3·3) at 15% LNP to 1·3 (1·2-1·9; p=0·014) at 40% LNP. The simulated scenarios reproduced this effect if the true LNP proportions were 20% or 25%, but not if the true LNP proportions were 30% or greater.

INTERPRETATION

We describe a consequence of staging misclassification in anal cancer that we have termed reduced prognostic discrimination. We used this new observation to infer that the LNP proportions of more than 30% seen in modern clinical series (11 out of 15 studies with a median year since 2007) are higher than the true LNP proportion. The introduction of new staging technologies in oncology might misclassify true disease stage, spuriously informing disease management and ultimately increasing the risk of overtreatment.

FUNDING

Bowel Disease Research Foundation.

Final DFS results of the SCOT study: An international phase III randomised (1:1) non-inferiority trial comparing 3 versus 6 months of oxaliplatin based adjuvant chemotherapy for colorectal cancer

3502

Background: Six months of oxaliplatin-based treatment has been the mainstay of adjuvant chemotherapy for colorectal cancer for the last 13 years. Neurotoxicity from oxaliplatin is cumulative, dose limiting, and potentially irreversible. A shorter duration of treatment would save patients significant toxicity/time and substantially reduce the costs of the drug, its administration, and treatment of adverse effects. Methods: SCOT is a non-inferiority randomised study designed to determine whether 3 months of adjuvant chemotherapy with OxMdG or Xelox (physician/patient choice) in Stage III/high risk Stage II colorectal cancer is as effective as 6 months treatment. Non-inferiority was determined to be a maximum 2.5% fall in 3-year disease-free survival (DFS) on the 3 month arm (from 78% on the 6 month arm) corresponding to a hazard ratio upper limit of 1.13. The study was designed with 90% power at the 2.5% 1-sided level of statistical significance and aimed to recruit 9500 patients to observe 2,750 DFS events (relapses/deaths/new colorectal cancers). Analysis used a Cox model adjusted for study minimisation factors. Results: 6088 patients (60% male, median age 65) with Stage III/high risk Stage II cancers of the colon or rectum were randomised between 27th March 2008 and 29th November 2013. The arms were balanced for clinical and pathological factors. Intended treatment was OxMdG for 1981 and Xelox for 4107 patients. There were 1469 DFS events (734 in 3 month arm and 735 in 6 month arm) giving the study 66% power. 3 year DFS was 76.8% (se = .8%) for the 3 month arm and 77.4% (se = .8%) for the 6 month arm (HR 1.008, 95% CI 0.910-1.117, test for non-inferiority p = 0.014). Non-inferiority appeared stronger for Xelox than OxMdG (test for heterogeneity, p = .059). Results will be shown broken down by stage, site, age, gender and achieved duration of treatment. Conclusions: The SCOT study has shown that 3 months adjuvant treatment is not inferior to 6 months treatment. However the SCOT study is part of the IDEA consortium and the results from the 6 studies in the IDEA consortium addressing the same duration question will also be presented at ASCO 2017. Clinical trial information: ISRCTN59757862.

Inter-tumor validation, through advanced MRI and circulating biomarkers, of plasma Tie2 as the vascular response biomarker for bevacizumab

11521

Background: VEGF inhibitor (VEGFi) use is compromised by lack of predictive/ response biomarkers. Previously, we identified plasma Tie2 (pTie2) as a vascular response biomarker (VRB) for bevacizumab (bev) in ovarian cancer (OC). Here, we applied dynamic contrast-enhanced MRI (DCE-MRI) and circulating biomarkers in colorectal cancer (CRC), to validate pTie2 as the first tumor VRB. Methods: Seventy patients were recruited, with untreated, mCRC and ≥1 lesion of 3-10cm diameter for DCE-MRI. Patients received bev 10mg/kg for 2 weeks to elicit a biomarker response and then FOLFOX6/bev until progressive disease (PD) Thirteen circulating and 6 imaging biomarkers were measured before and during treatment and at PD. Unsupervised correlation analysis identified bev-induced biomarker correlations. Biomarkers were evaluated by clustered parameter-time course studies to determine their epithelial or vascular origin. Clinical significance was determined by relating the biomarker data to tumor 3D volumetric change assessed by MRI and PFS. The emergent vascular biomarker signal was modelled with epithelial biomarkers to assess the independent contribution of the vascular compartment to PD. Results: Bev induced significant correlations between pTie2, Ang2 and Ktrans. Cluster analysis of Tie2 concentration-time course curves showed that pTie2 reflected tumor Ktransbut not CK18, an epithelial antigen, i.e. changes in pTie2 reflected tumor vascular biology Patients who had the greatest area under the pTie2-time curve had tumors with high Ktransand/or low pVEGFR2, pre-treatment. They also had the greatest reduction in tumor volume and longest PFS. Fusion of pTie2 and CK18 data significantly improved modelling of PD. Conclusions: Bev impacts tumor vasculature causing proportional changes in pTie2. Information from pTie2 adds clinical value to that derived from the epithelial compartment. Thus (i) pTie2 is the first vascular response biomarker for bev and probably all VEGFi and (ii) demonstration of separate vascular and epithelial compartments in ovarian and CRC validates the vascular compartment as a target. This work identifies the first assay that could optimise use of VEGFi. Clinical trial information: 2009-011377-33.

MABp1 to improve clinical outcomes of patients with symptomatic refractory metastatic colorectal cancer patients: Per-protocol population analysis of phase III study (PT026)

3530

Background: Refractory metastatic colorectal cancer (mCRC) patients derive minimal benefit from further exposure to toxic agents. MABp1 is an anti-interleukin 1 alpha antibody that is shown to prolong survival (NCT01767857) and improves outcomes when assessed with a primary endpoint based on a constellation of objective and patient self-reported measures (NCT02138422) (Hickish T. et al Lancet Oncology 2017). In the latter study, clinically advanced patients were enrolled (symptomatic, ECOG 1,2), and 18% of patients progressed prior to reaching the endpoint assessments. Here we present the outcomes in per-protocol population (PP), those patients completing week 8 assessments. Methods: 309 patients randomized 2:1 to receive MABp1 versus placebo. Patients were ECOG 1-2, with mCRC refractory to chemotherapy, any degree of weight loss, and cancer-associated symptoms. The composite primary endpoint assessed the rate of patients achieving stabilization or improvement in lean body mass (LBM) and two of three symptom measures (pain, fatigue, appetite loss) from screening to the week 8 assessment. The study was designed for placebo cross-over, thus OS analysis for MABp1 vs placebo was not possible. Results: 57 patients (38 MABp1 [18%] and 19 placebo [19%]) discontinued study prior to the week 8 assessment due to disease progression, including 17 (8%) and 11 (11%) deaths in MABp1 and placebo respectively. 62% of placebo patients received MABp1 after 8 weeks. 252 patients, 40% in MABp1 (68/169) vs 23% in placebo (19/83) met the primary endpoint (p = 0.003). 139 patients were available for PP survival analysis (90 MABp1 vs 49 Placebo). Median OS of those achieving the primary endpoint was 11.7 months vs 5.7 months for those that did not (HR 0.39; p < 0.0001). Radiographic stable disease was improved (42% vs 12%; p < 0.001) and incidence of SAEs (6% vs 15%; p = 0.11) reduced in those achieving the primary endpoint. Conclusions: Achieving the primary endpoint was associated with improvement in outcomes, RECIST stabilization, SAEs and survival. Further study should confirm the effect of MABp1 on survival in this population. Clinical trial information: NCT02138422.

Nintedanib (N) plus best supportive care (BSC) versus placebo plus BSC for the treatment of patients (pts) with metastatic colorectal cancer (mCRC) refractory to standard therapies: Health-related quality of life (HRQoL) results of the Phase III LUME-Colon 1 study

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Background: N is a multiple angiokinase inhibitor (including VEGFR, PDGFR and FGFR). A randomised Phase III study, LUME-Colon 1 (NCT02149108), evaluated the efficacy and safety of N in pts with refractory mCRC after failure of standard therapies. LUME-Colon 1 showed a statistically significant improvement in PFS (HR [95% CI] 0.58 [0.49–0.69]; p < 0.0001) but no difference in OS (HR [95% CI]: 1.01 [0.86–1.19]; p = 0.8659). Here, we report the HRQoL outcomes. Methods: 768 pts with mCRC adenocarcinoma refractory to standard chemotherapy were randomised 1:1 to receive either N (200 mg bid) + BSC or P (bid) + BSC in 21-day courses until disease progression or undue toxicity. HRQoL was assessed every 21 days using the EORTC QLQ-C30 instrument; the main endpoints of interest were the differences in mean scores up to median follow-up time (treatment difference, TD) for physical functioning (PF) and global health status/QoL (QL) scales using a longitudinal model, with 95% CIs and associated p-values adjusted for baseline stratification factors. Time to deterioration (TTD) of scores and status change ( ≥ 10 point change from baseline) were also assessed. Results: Compliance with questionnaire completion was high ( > 85% in first 12 cycles). Mean baseline (N vs P) PF (80 vs 80) and QL (65 vs 65) scale scores were balanced between treatment arms. The mean TD favoured N vs P for PF scale scores (TD 2.66 [95% CI: 0.97–4.34]; p = 0.0020) and QL scale scores (TD 1.61 [95% CI: −0.04–3.27]; p = 0.0555). TTD of PF (HR 0.84; 95% CI: 0.69–1.03; p = 0.0904) and QL (HR 0.90; 95% CI: 0.75–1.08; p = 0.2674) scores were not significantly different between treatment groups, although the percentage of patients with improved PF (17.2% vs 11.8%; p = 0.0462) and QL scores (30.3% vs 21.6%: p = 0.0102) were both significantly higher for N vs P. Conclusions: In LUME-Colon 1, patient reported outcomes confirmed that overall HRQoL was not impaired by treatment with N. There was evidence for improvement of PF and QL with N vs P, corresponding to the significant increase in PFS observed. Clinical trial information: NCT02149108.

Clinical development of new drug-radiotherapy combinations

In countries with the best cancer outcomes, approximately 60% of patients receive radiotherapy as part of their treatment, which is one of the most cost-effective cancer treatments. Notably, around 40% of cancer cures include the use of radiotherapy, either as a single modality or combined with other treatments. Radiotherapy can provide enormous benefit to patients with cancer. In the past decade, significant technical advances, such as image-guided radiotherapy, intensity-modulated radiotherapy, stereotactic radiotherapy, and proton therapy enable higher doses of radiotherapy to be delivered to the tumour with significantly lower doses to normal surrounding tissues. However, apart from the combination of traditional cytotoxic chemotherapy with radiotherapy, little progress has been made in identifying and defining optimal targeted therapy and radiotherapy combinations to improve the efficacy of cancer treatment. The National Cancer Research Institute Clinical and Translational Radiotherapy Research Working Group (CTRad) formed a Joint Working Group with representatives from academia, industry, patient groups and regulatory bodies to address this lack of progress and to publish recommendations for future clinical research. Herein, we highlight the Working Group's consensus recommendations to increase the number of novel drugs being successfully registered in combination with radiotherapy to improve clinical outcomes for patients with cancer.

Is monitoring of plasma 5-fluorouracil levels in metastatic / advanced colorectal cancer clinically effective? A systematic review

Background

Pharmacokinetic guided dosing of 5-fluorouracil chemotherapies to bring plasma 5-fluorouracil into a desired therapeutic range may lead to fewer side effects and better patient outcomes. High performance liquid chromatography and a high throughput nanoparticle immunoassay (My5-FU) have been used in conjunction with treatment algorithms to guide dosing. The objective of this study was to assess accuracy, clinical effectiveness and safety of plasma 5-fluorouracil guided dose regimen(s) versus standard regimens based on body surface area in colorectal cancer.

Methods

We undertook a systematic review. MEDLINE; MEDLINE In-Process & Other Non-Indexed Citations; EMBASE; Cochrane Library; Science Citation Index and Conference Proceedings (Web of Science); and NIHR Health Technology Assessment Programme were searched from inception to January 2014. We reviewed evidence on accuracy of My5-FU for estimating plasma 5-fluorouracil and on the clinical effectiveness of pharmacokinetic dosing compared to body surface area dosing. Estimates of individual patient data for overall survival and progression-free survival were reconstructed from published studies. Survival and adverse events data were synthesised and examined for consistency across studies.

Results

My5-FU assays were found to be consistent with reference liquid chromatography tandem mass spectrometry. Comparative studies pointed to gains in overall survival and in progression-free survival with pharmacokinetic dosing, and were consistent across multiple studies.

Conclusions

Although our analyses are encouraging, uncertainties remain because evidence is mainly from outmoded 5-fluorouracil regimens; a randomised controlled trial is urgently needed to investigate new dose adjustment methods in modern treatment regimens.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2581-x) contains supplementary material, which is available to authorized users.