Clinical Calculator for Early Mortality in Metastatic Colorectal Cancer: An Analysis of Patients From 28 Clinical Trials in the Aide et Recherche en Cancérologie Digestive Database

Purpose Factors contributing to early mortality after initiation of treatment of metastatic colorectal cancer are poorly understood. Materials and Methods Data from 22,654 patients enrolled in 28 randomized phase III trials contained in the ARCAD (Aide et Recherche en Cancérologie Digestive) database were pooled. Multivariable logistic regression models for 30-, 60-, and 90-day mortality were constructed, including clinically and statistically significant patient and disease factors and interaction terms. A calculator (nomogram) for 90-day mortality was developed and validated internally using bootstrapping methods and externally using a 10% random holdout sample from each trial. The impact of early progression on the likelihood of survival to 90 days was examined with time-dependent Cox proportional hazards models. Results Mortality rates were 1.4% at 30 days, 3.4% at 60 days, and 5.5% at 90 days. Among baseline factors, advanced age, lower body mass index, poorer performance status, increased number of metastatic sites, BRAF mutant status, and several laboratory parameters were associated with increased likelihood of early mortality. A multivariable model for 90-day mortality showed strong internal discrimination (C-index, 0.77) and good calibration across risk groups as well as accurate predictions in the external validation set, both overall and within patient subgroups. Conclusion A validated clinical nomogram has been developed to quantify the risk of early death for individual patients during initial treatment of metastatic colorectal cancer. This tool may be used for patient eligibility assessment or risk stratification in future clinical trials and to identify patients requiring more or less aggressive therapy and additional supportive measures during and after treatment.

A randomised phase II trial and feasibility study of palliative chemotherapy in frail or elderly patients with advanced gastroesophageal cancer (321GO)

BACKGROUND

Elderly patients are commonly under-represented in cancer clinical trials. The 321GO was undertaken in preparation for a definitive phase three trial assessing different chemotherapy regimens in a frail and/or elderly population with advanced gastroesophageal (GO) cancer.

METHODS

Patients with advanced GO cancer considered unfit for conventional dose chemotherapy were randomly assigned in a 1 : 1 : 1 ratio to: epirubicin, oxaliplatin and capecitabine (EOX); oxaliplatin and capecitabine (OX); and capecitabine alone (X) (all 80% of full dose and unblinded). The primary end point was patient recruitment over an 18-month period. A registration study recorded treatment choice for all patients with advanced GO cancer at trial centres.

RESULTS

A total of 313 patients were considered for palliative chemotherapy for GO cancer over the 18-month period: 115 received full dose treatment, 89 less than standard treatment or entered 321GO and 111 no treatment. Within 321GO, 55 patients were randomly assigned (19 to OX and X; 17 to EOX). Progression-free survival (PFS) for all patients was 4.4 months and by arm 5.4, 5.6 and 3.0 months for EOX, OX and X, respectively. The number of patients with a good overall treatment utility (OTU), a novel patient-centred endpoint, at 12 weeks was 3 (18%), 6 (32%) and 1 (6%) for EOX, OX and X, respectively. At 6 weeks, 22 patients (41%) had experienced a non-haematologic toxicity ⩾grade 3, most commonly lethargy or diarrhoea. The OTU was prognostic for overall survival in patients alive at week 12 (logrank test P=0.0001).

CONCLUSIONS

It is feasible to recruit elderly and/or frail patients with advanced GO cancer to a randomised clinical trial. The OX is the preferred regimen for further study. Overall treatment utility shows promise as a comparator between treatment regimens for feasibility and randomised trials in the elderly and/or frail GO cancer population.

Rectal versus left-sided colon cancers: Clinicopathological differences observed in a pooled analysis of 4,182 patients enrolled to 8 clinical trials from the ARCAD database

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Background: Recent retrospective analysis of CALGB/SWOG 80405 showed that left-sided colon cancers (LCC) respond differently to biological therapy compared with right-sided tumors. However, differences between rectal cancers (RC) and LCC remain undefined. Herein, we report our exploration of differences between these two groups. Methods: Individual patient data from 4182 patients (pts) with metastatic colorectal cancers, enrolled onto 8 first-line randomized trials, were pooled. Only pts with tumor locations that were clearly defined as LCC (splenic flexure to sigmoid) or RC were included in this analysis. Differences in pt characteristics and disease factors according to LCC vs. RC were identified. The prognostic effect of primary tumor location on OS and PFS was quantified via multivariable Cox proportional hazards modeling stratified by treatment arm within each study and adjusting for age, sex, performance status, and prior surgery. Results: In total, 2,479 (59%) pts with LCC and 1,703 (41%) pts with RC were identified. Pts with RC, compared with LCC, were more likely to be male (68% vs. 62%, p < 0.001), have lung metastases (mets) (56% vs. 37%, p < 0.001), and have 2 or more metastatic sites (64% vs. 60%, p < 0.02), whereas pts with LCC were more likely to have liver mets (84% vs. 76%, p < 0.001). RC had a greater frequency of KRAS mutations (41% vs. 37%, p = 0.04) than LCC but there were no differences in the frequency of BRAF mutations (5% vs. 4%, p = 0.2). In multivariable analysis, no differences in OS or PFS were observed between pts with LCC vs. RC. While risk of death did not differ by primary tumor location, across all pts with LCC or RC, those with liver mets had a 17% increased risk of death compared to those with lung mets (HR = 1.17, p = 0.03) after adjusting for effects of other variables. Forthcoming prognostic analysis of LCC vs. RC within grouped backbone treatments (e.g., FOLFOX and FOLFIRI) is underway. Conclusions: Tumors arising in the rectum may carry clinical and molecular features that are distinct from LCC. Further investigations are warranted to determine whether RC should be treated with the same chemo backbone and biological therapy as LCC.

Prognosis of patients with peritoneal metastatic colorectal cancer given systemic therapy: an analysis of individual patient data from prospective randomised trials from the Analysis and Research in Cancers of the Digestive System (ARCAD) database

BACKGROUND

Patients with peritoneal metastatic colorectal cancer have reduced overall survival compared with patients with metastatic colorectal cancer without peritoneal involvement. Here we further investigated the effect of the number and location of metastases in patients receiving first-line systemic chemotherapy.

METHODS

We analysed individual patient data for previously untreated patients enrolled in 14 phase 3 randomised trials done between 1997 and 2008. Trials were included if protocols explicitly pre-specified and solicited for patients with peritoneal involvement in the trial data collection process or had done a formal peritoneum-focused review of individual pre-treatment scans. We used stratified multivariable Cox models to assess the prognostic associations of peritoneal metastatic colorectal cancer with overall survival and progression-free survival, adjusting for other key clinical-pathological factors (age, sex, Eastern Cooperative Oncology Group (ECOG) performance score, primary tumour location [colon vs rectum], previous treatment, and baseline BMI). The primary endpoint was difference in overall survival between populations with and without peritoneal metastases.

FINDINGS

Individual patient data were available for 10 553 patients. 9178 (87%) of 10 553 patients had non-peritoneal metastatic colorectal cancer (4385 with one site of metastasis, 4793 with two or more sites of metastasis), 194 (2%) patients had isolated peritoneal metastatic colorectal cancer, and 1181 (11%) had peritoneal metastatic colorectal cancer and other organ involvement. These groups were similar in age, ethnic origin, and use of targeted treatment. Patients with peritoneal metastatic colorectal cancer were more likely than those with non-peritoneal metastatic colorectal cancer to be women (565 [41%] of 1371 vs 3312 [36%] of 9169 patients; p=0·0003), have colon primary tumours (1116 [84%] of 1334 patients vs 5603 [66%]; p<0·0001), and have performance status of 2 (136 [10%] vs 521 [6%]; p<0·0001). We recorded a higher proportion of patients with mutated BRAF in patients with peritoneal-only (eight [18%] of 44 patients with available data) and peritoneal metastatic colorectal cancer with other sites of metastasis (34 [12%] of 289), compared with patients with non-peritoneal metastatic colorectal cancer (194 [9%] of 2230; p=0·028 comparing the three groups). Overall survival (adjusted HR 0·75, 95% CI 0·63-0·91; p=0·003) was better in patients with isolated non-peritoneal sites than in those with isolated peritoneal metastatic colorectal cancer. Overall survival of patients with two of more non-peritoneal sites of metastasis (adjusted HR 1·04, 95% CI 0·86-1·25, p=0.69) and those with peritoneal metastatic colorectal cancer plus one other site of metastasis (adjusted HR 1·10, 95% CI 0·89-1·37, p=0·37) was similar to those with isolated peritoneal metastases. Compared with patients with isolated peritoneal metastases, those with peritoneal metastases and two or more additional sites of metastasis had the shortest survival (adjusted HR 1·40; CI 1·14-1·71; p=0·0011).

INTERPRETATION

Patients with peritoneal metastatic colorectal cancer have significantly shorter overall survival than those with other isolated sites of metastases. In patients with several sites of metastasis, poor survival is a function of both increased number of metastatic sites and peritoneal involvement. The pattern of metastasis and in particular, peritoneal involvement, results in prognostic heterogeneity of metastatic colorectal cancer.

FUNDING

None.

Combined Epiregulin and Amphiregulin Expression Levels as a Predictive Biomarker for Panitumumab Therapy Benefit or Lack of Benefit in Patients With RAS Wild-Type Advanced Colorectal Cancer

IMPORTANCE

RAS wild-type (wt) status is necessary but not sufficient for response to anti-epidermal growth factor receptor (EGFR) agents in advanced colorectal cancer (aCRC). RNA expression of EGFR ligands epiregulin (EREG) and amphiregulin (AREG) may correlate with EGFR-targeted therapy efficacy in aCRC, so may represent a much-needed additional predictive marker for these drugs.

OBJECTIVE

To examine a novel ligand model in a randomized clinical trial of panitumumab, irinotecan, and ciclosporin in colorectal cancer (PICCOLO) with with the a priori hypothesis that high tumor expression of either AREG or EREG would predict panitumumab therapy benefit in RAS-wt patients; and low expression, lack of efficacy.

DESIGN, SETTING, AND PARTICIPANTS

Prospectively planned retrospective biomarker study from the PICCOLO trial, which tested the addition of panitumumab to irinotecan therapy in patients with KRAS wt aCRC who experienced failure with prior fluoropyrimidine treatment. The analysis was conducted between 2012 and 2014. A predefined dichotomous model classified tumors as "high expressor" (either EREG or AREG in top tertile for messenger RNA level) or "low expressor" (neither EREG nor AREG in top tertile). Ligand expression was assessed as a prognostic and predictive biomarker. Expression of AREG/EREG and RAS and BRAF mutations were assessed in archival tumor tissue.

MAIN OUTCOMES AND MEASURES

Primary end point was progression-free survival (PFS); secondary end points were response rate and overall survival (OS).

RESULTS

Of the 696 PICCOLO trial patients in the irinotecan-vs-irinotecan with panitumumab randomization, 331 had sufficient tumor tissue available and measurement of ligand expression was successful in 323. High ligand expression was not prognostic for OS (hazard ratio [HR], 0.79 [95% CI, 0.58-1.09]; P = .15) or PFS (HR, 0.93 [95% CI, 0.68-1.27]; P = .64). The primary population had RAS wt aCRC (n = 220); for RAS wt patients with high ligand expression, median (interquartile range [IQR]) PFS was 8.3 [4.0-11.0] months (irinotecan with panitumumab) vs 4.4 [2.8-6.7] months (irinotecan alone); HR, 0.38 [95% CI, 0.24-0.61]; P < .001). In RAS wt patients with low ligand expression, median (IQR) PFS was 3.2 [2.7-8.1] months (irinotecan with panitumumab) vs 4.0 [2.7-7.5] months (irinotecan); HR, 0.93 [95% CI, 0.64-1.37]; P = .73; interaction test results were significant [P = .01]). Less marked effects were seen for response rate (interaction P = .17) and OS (interaction P = .11).

CONCLUSIONS AND RELEVANCE

High ligand expression is a predictive marker for panitumumab therapy benefit on PFS in RAS wt patients; conversely, patients with low ligand expression gained no benefit. The current "opt-in" strategy for anti-EGFR therapy in all patients with RAS wt aCRC should be questioned. Expression of EREG/AREG is a useful biomarker for anti-EGFR therapy; optimization for clinical use is indicated.

TRIAL REGISTRATION

isrctn Identifier: ISRCTN93248876.

Body Mass Index Is Prognostic in Metastatic Colorectal Cancer: Pooled Analysis of Patients From First-Line Clinical Trials in the ARCAD Database

PURPOSE

In recent retrospective analyses of early-stage colorectal cancer (CRC), low and high body mass index (BMI) scores were associated with worsened outcomes. Whether BMI is a prognostic or predictive factor in metastatic CRC (mCRC) is unclear.

PATIENTS AND METHODS

Individual data from 21,149 patients enrolled onto 25 first-line mCRC trials during 1997 to 2012 were pooled. We assessed both prognostic and predictive effects of BMI on overall survival and progression-free survival, and we accounted for patient and tumor characteristics and therapy type (targeted v nontargeted).

RESULTS

BMI was prognostic for overall survival (P < .001) and progression-free survival (P < .001), with an L-shaped pattern. That is, risk of progression and/or death was greatest for low BMI; risk decreased as BMI increased to approximately 28 kg/m(2), and then it plateaued. Relative to obese patients, patients with a BMI of 18.5 kg/m(2) had a 27% increased risk of having a PFS event (95% CI, 20% to 34%) and a 50% increased risk of death (95% CI, 43% to 56%). Low BMI was associated with poorer survival for men than women (interaction P < .001). BMI was not predictive of treatment effect.

CONCLUSION

Low BMI is associated with an increased risk of progression and death among the patients enrolled on the mCRC trials, with no increased risk for elevated BMI, in contrast to the adjuvant setting. Possible explanations include negative effects related to cancer cachexia in patients with low BMI, increased drug delivery or selection bias in patients with high BMI, and potential for an interaction between BMI and molecular signaling pathways.

The prevalence and outcomes of frailty in older cancer patients: a systematic review

BACKGROUND

Frailty is a state of vulnerability to poor resolution of homeostasis following a stressor event, such as chemotherapy or cancer surgery. Better knowledge of the epidemiology of frailty could help drive a global cancer care strategy for older people. The aim of this review was to establish the prevalence and outcomes of frailty and pre-frailty in older cancer patients.

METHODS

Observational studies that reported data on the prevalence and/or outcomes of frailty in older cancer patients with any stage of solid or haematological malignancy were considered. We searched Medline, CINAHL, Cochrane Library, EMBASE, Web of Science, Allied and Complementary medicine, Psychinfo and ProQuest (1 January 1996 to 30 June 2013). The primary outcomes were prevalence of frailty, treatment-related side-effects, unplanned hospitalization and mortality. Risk of bias was assessed using the Newcastle-Ottawa checklist.

RESULTS

Data from 20 studies evaluating 2916 participants are included. The median reported prevalence of frailty and pre-frailty was 42% (range 6%-86%) and 43% (range 13%-79%), respectively. A median of 32% (range 11%-78%) of patients were classified as fit. Frailty was independently associated with increased all-cause mortality [adjusted 5-year hazard ratio (HR) 1.87, 95% confidence interval (CI) 1.36-2.57]. There was evidence of increased risk of postoperative mortality for both frailty (adjusted 30-day HR 2.67, 95% CI 1.08-6.62) and pre-frailty (adjusted HR 2.33, 95% CI 1.20-4.52). Treatment complications were more frequent in those with frailty, including intolerance to cancer treatment (adjusted odds ratio 4.86, 95% CI 2.19-10.78) and postoperative complications (adjusted 30-day HR 3.19, 95% CI 1.68-6.04).

CONCLUSIONS

More than half of older cancer patients have pre-frailty or frailty and these patients are at increased risk of chemotherapy intolerance, postoperative complications and mortality. The findings of this review support routine assessment of frailty in older cancer patients to guide treatment decisions, and the development of multidisciplinary geriatric oncology services.

Association of age with survival in patients with metastatic colorectal cancer: analysis from the ARCAD Clinical Trials Program

PURPOSE

This study addressed whether age is prognostic for overall survival (OS) or progression-free survival (PFS) in patients with metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

A total of 20,023 patients from 24 first-line clinical trials in the ARCAD (Aide et Recherche en Cancérologie Digestive) database were analyzed. Primary age effects and interactions with age,sex, performance status (PS), and metastatic site were modeled using Cox proportional hazards stratified by treatment arm within study.

RESULTS

Of total patients, 3,051 (15%) were age < or =50 years. Age was prognostic for both OS (P < .001)and PFS (P < .001), with U-shaped risk (i.e., highest risk was evident in youngest and oldest patients). Relative to patients of middle age, the youngest patients experienced 19% (95% CI, 7% to 33%) increased risk of death and 22% (95% CI, 10% to 35%) increased risk of progression. The oldest patients experienced 42% (95% CI, 31% to 54%) increased risk of death and 15% (95% CI, 7% to 24%) increased risk of progression or death. This relationship was more pronounced in the first year of follow-up. Age remained marginally significant for OS (P = .08) when adjusted forPS, sex, and presence of liver, lung, or peritoneal metastases, and age was significant in an adjusted model for PFS (P = .005). The age effect did not differ by site of metastatic disease, year of enrollment, type of therapy received, or biomarker mutational status.

CONCLUSION

Younger and older age are associated with poorer OS and PFS among treated patients with mCRC. Younger and older patients may represent higher-risk populations, and additional studies are warranted.

Nomograms for overall survival (OS) and progression-free survival (PFS) in metastatic colorectal cancer (mCRC): Construction from 19,678 ARCAD patients

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Background: Prospective survival prediction of patients with metastatic colorectal cancer is difficult. Prognosis estimation based on readily available clinicopathologic factors has the potential to inform clinical practice and improve risk stratification for clinical trials. We constructed prognostic nomograms for OS and PFS in mCRC using the multi-trial ARCAD database. Methods: Data from 19,678 mCRC pts accrued to 24 first line randomized phase III clinical trials since 1997 were used to construct and validate Cox models for PFS and OS, stratified by treatment arm within each study. Candidate variables included age, gender, BMI, performance status, colon vs. rectal cancer, prior chemotherapy, number of metastatic sites, sites of metastases (liver, lung, lymph nodes), and baseline bilirubin, albumin, white blood cell count, hemoglobin, platelets, absolute neutrophil count, and derived neutrophil:lymphocyte ratio (dNLR). Missing data (<11%) were imputed, continuous variables modeled with splines, and clinically relevant pairwise interactions considered if p<0.001. Final models were internally validated via bootstrapping to obtain optimism-corrected calibration and discrimination C-indices, and externally validated using a 10% holdout sample from each trial. Results: Nomograms for OS and PFS including remaining variables were well calibrated with C-indices of 0.66 and 0.60, respectively. Evaluation of external validity revealed good concordance; 71% and 67% respectively between predicted (> vs. <50% probability) and actual (yes/no) 1-year OS and 6-month PFS, and median 1-year OS and 6-month PFS predictions fell within the actual 95% Kaplan-Meier intervals. Gender, liver and lung metastases, and dNLR were not prognostic for OS; prior chemo, colon vs. rectum, dNLR, liver and lymph node metastases, and gender did not predict for PFS. No clinically relevant pairwise interactions were identified. Conclusions: The proposed nomograms are well calibrated and internally and externally valid. These tools have the potential to aid prognostication and patient/physician communication, and balance risk in randomized trials in mCRC.

InterAACT: An international multicenter open label randomized phase II advanced anal cancer trial comparing cisplatin (CDDP) plus 5-fluorouracil (5-FU) versus carboplatin (CBDCA) plus weekly paclitaxel (PTX) in patients with inoperable locally recurrent (ILR) or metastatic disease

TPS792

Background: Metastatic squamous cell carcinoma of the anus (SCCA) is a rare condition with 5-year overall survival (OS) rate of 32%. CDDP/5-FU is commonly used in the first-line treatment of patients with ILR or metastatic disease. This practice is based on retrospective series and data from randomised trials are lacking. Recent retrospective studies showed promising activity of CBDCA/PTX in this setting. Methods: InterAACT is an international, multicentre, open label, randomised phase II trial comparing two chemotherapy regimens in patients with ILR or metastatic SCCA. Eligible patients are randomised in a 1:1 ratio to CDDP (60 mg/mq, D1q21) plus 5-FU (1000 mg/mq/24h, D1-4q21) or CBDCA (AUC 5, D1q28) plus PTX (80 mg/mq, D1,8,15q28). Stratification factors are: performance status, extent of disease, HIV status and country. The primary endpoint is response rate (RR). Secondary endpoints include progression-free survival, OS, toxicity and quality of life. Based on a RR estimate of 40% in the CDDP/5-FU arm 80 patients are to be recruited to detect 10% difference in RR between the two arms with 80% power (phase II selection trial design). Correlative biomarker analyses are planned in tumour tissue and blood samples. The trial is sponsored by The Royal Marsden NHS Foundation Trust and endorsed by the International Rare Cancer Initiative (IRCI) group. Approximately 50 centres in the UK, Europe (EORTC), Scandinavia, US (ECOG-ACRIN) and Australia (AGITG) are estimated to participate and recruitment is anticipated to be completed within 3 years. Recruitment started in December 2013. As of September 16, 2014, 6 sites in the UK are open to recruitment and 6 patients have been randomised (3 to CDDP/5-FU and 3 to CBDCA/PTX). InterAACT aims to provide the first randomised evidence for the treatment of ILR and metastatic SCCA, to identify the optimal chemotherapy backbone to combine with targeted agents in future studies and to confirm the feasibility of conducting an international multicentre trial for this rare tumour. Clinical trial information: NCT02051868.

Individual patient data analysis of progression-free survival versus overall survival as a first-line end point for metastatic colorectal cancer in modern randomized trials: findings from the analysis and research in cancers of the digestive system database

PURPOSE

Progression-free survival (PFS) has previously been established as a surrogate for overall survival (OS) for first-line metastatic colorectal cancer (mCRC). Because mCRC treatment has advanced in the last decade with extended OS, this surrogacy requires re-examination.

METHODS

Individual patient data from 16,762 patients were available from 22 first-line mCRC studies conducted from 1997 to 2006; 12 of those studies tested antiangiogenic and/or anti-epidermal growth factor receptor agents. The relationship between PFS (first event of progression or death) and OS was evaluated by using R(2) statistics (the closer the value is to 1, the stronger the correlation) from weighted least squares regression of trial-specific hazard ratios estimated by using Cox and Copula models.

RESULTS

Forty-four percent of patients received a regimen that included biologic agents. Median first-line PFS was 8.3 months, and median OS was 18.2 months. The correlation between PFS and OS was modest (R(2), 0.45 to 0.69). Analyses limited to trials that tested treatments with biologic agents, nonstrategy trials, or superiority trials did not improve surrogacy.

CONCLUSION

In modern mCRC trials, in which survival after the first progression exceeds time to first progression, a positive but modest correlation was observed between OS and PFS at both the patient and trial levels. This finding demonstrates the substantial variability in OS introduced by the number of lines of therapy and types of effective subsequent treatments and the associated challenge to the use of OS as an end point to assess the benefit attributable to a single line of therapy. PFS remains an appropriate primary end point for first-line mCRC trials to detect the direct treatment effect of new agents.

Mismatch repair status and BRAF mutation status in metastatic colorectal cancer patients: a pooled analysis of the CAIRO, CAIRO2, COIN, and FOCUS studies

PURPOSE

To determine the prevalence and prognostic value of mismatch repair (MMR) status and its relation to BRAF mutation (BRAF(MT)) status in metastatic colorectal cancer (mCRC).

EXPERIMENTAL DESIGN

A pooled analysis of four phase III studies in first-line treatment of mCRC (CAIRO, CAIRO2, COIN, and FOCUS) was performed. Primary outcome parameter was the hazard ratio (HR) for median progression-free survival (PFS) and overall survival (OS) in relation to MMR and BRAF. For the pooled analysis, Cox regression analysis was performed on individual patient data.

RESULTS

The primary tumors of 3,063 patients were analyzed, of which 153 (5.0%) exhibited deficient MMR (dMMR) and 250 (8.2%) a BRAF(MT). BRAF(MT) was observed in 53 (34.6%) of patients with dMMR tumors compared with 197 (6.8%) of patients with proficient MMR (pMMR) tumors (P < 0.001). In the pooled dataset, median PFS and OS were significantly worse for patients with dMMR compared with pMMR tumors [HR, 1.33; 95% confidence interval (CI), 1.12-1.57 and HR, 1.35; 95% CI, 1.13-1.61, respectively), and for patients with BRAF(MT) compared with BRAF wild-type (BRAF(WT)) tumors (HR, 1.34; 95% CI, 1.17-1.54 and HR, 1.91; 95% CI, 1.66-2.19, respectively). PFS and OS were significantly decreased for patients with BRAF(MT) within the group of patients with pMMR, but not for BRAF status within dMMR, or MMR status within BRAF(WT) or BRAF(MT).

CONCLUSIONS

Prevalence of dMMR and BRAF(MT) in patients with mCRC is low and both biomarkers confer an inferior prognosis. Our data suggest that the poor prognosis of dMMR is driven by the BRAF(MT) status.

Mismatch repair status and BRAF mutation status in metastatic colorectal cancer patients: a pooled analysis of the CAIRO, CAIRO2, COIN, and FOCUS studies

PURPOSE

To determine the prevalence and prognostic value of mismatch repair (MMR) status and its relation to BRAF mutation (BRAF(MT)) status in metastatic colorectal cancer (mCRC).

EXPERIMENTAL DESIGN

A pooled analysis of four phase III studies in first-line treatment of mCRC (CAIRO, CAIRO2, COIN, and FOCUS) was performed. Primary outcome parameter was the hazard ratio (HR) for median progression-free survival (PFS) and overall survival (OS) in relation to MMR and BRAF. For the pooled analysis, Cox regression analysis was performed on individual patient data.

RESULTS

The primary tumors of 3,063 patients were analyzed, of which 153 (5.0%) exhibited deficient MMR (dMMR) and 250 (8.2%) a BRAF(MT). BRAF(MT) was observed in 53 (34.6%) of patients with dMMR tumors compared with 197 (6.8%) of patients with proficient MMR (pMMR) tumors (P < 0.001). In the pooled dataset, median PFS and OS were significantly worse for patients with dMMR compared with pMMR tumors [HR, 1.33; 95% confidence interval (CI), 1.12-1.57 and HR, 1.35; 95% CI, 1.13-1.61, respectively), and for patients with BRAF(MT) compared with BRAF wild-type (BRAF(WT)) tumors (HR, 1.34; 95% CI, 1.17-1.54 and HR, 1.91; 95% CI, 1.66-2.19, respectively). PFS and OS were significantly decreased for patients with BRAF(MT) within the group of patients with pMMR, but not for BRAF status within dMMR, or MMR status within BRAF(WT) or BRAF(MT).

CONCLUSIONS

Prevalence of dMMR and BRAF(MT) in patients with mCRC is low and both biomarkers confer an inferior prognosis. Our data suggest that the poor prognosis of dMMR is driven by the BRAF(MT) status.

A feasibility study testing four hypotheses with phase II outcomes in advanced colorectal cancer (MRC FOCUS3): a model for randomised controlled trials in the era of personalised medicine?

BACKGROUND

Molecular characteristics of cancer vary between individuals. In future, most trials will require assessment of biomarkers to allocate patients into enriched populations in which targeted therapies are more likely to be effective. The MRC FOCUS3 trial is a feasibility study to assess key elements in the planning of such studies.

PATIENTS AND METHODS

Patients with advanced colorectal cancer were registered from 24 centres between February 2010 and April 2011. With their consent, patients' tumour samples were analysed for KRAS/BRAF oncogene mutation status and topoisomerase 1 (topo-1) immunohistochemistry. Patients were then classified into one of four molecular strata; within each strata patients were randomised to one of two hypothesis-driven experimental therapies or a common control arm (FOLFIRI chemotherapy). A 4-stage suite of patient information sheets (PISs) was developed to avoid patient overload.

RESULTS

A total of 332 patients were registered, 244 randomised. Among randomised patients, biomarker results were provided within 10 working days (w.d.) in 71%, 15 w.d. in 91% and 20 w.d. in 99%. DNA mutation analysis was 100% concordant between two laboratories. Over 90% of participants reported excellent understanding of all aspects of the trial. In this randomised phase II setting, omission of irinotecan in the low topo-1 group was associated with increased response rate and addition of cetuximab in the KRAS, BRAF wild-type cohort was associated with longer progression-free survival.

CONCLUSIONS

Patient samples can be collected and analysed within workable time frames and with reproducible mutation results. Complex multi-arm designs are acceptable to patients with good PIS. Randomisation within each cohort provides outcome data that can inform clinical practice.

Molecular markers of chemotherapeutic response and toxicity in colorectal cancer

Outcomes in colorectal cancer have improved over the last 15 years; this is in part due to the optimization of 5-fluorouracil schedules and the introduction of new and effective chemotherapeutic agents, such as irinotecan and oxaliplatin. However, not all patients respond to these agents and a proportion may suffer severe side effects from particular chemotherapy drugs. These observations have resulted in a concerted research effort to identify markers of chemotherapy efficacy and toxicity. Here we review the evidence for using molecular markers to individualize chemotherapy treatment in colorectal cancer.

Panitumumab and irinotecan versus irinotecan alone for patients with KRAS wild-type, fluorouracil-resistant advanced colorectal cancer (PICCOLO): a prospectively stratified randomised trial

Background

Therapeutic antibodies targeting EGFR have activity in advanced colorectal cancer, but results from clinical trials are inconsistent and the population in which most benefit is derived is uncertain. Our aim was to assess the addition of panitumumab to irinotecan in pretreated advanced colorectal cancer.

Methods

In this open-label, randomised trial, we enrolled patients who had advanced colorectal cancer progressing after fluoropyrimidine treatment with or without oxaliplatin from 60 centres in the UK. From December, 2006 until June, 2008, molecularly unselected patients were recruited to a three-arm design including irinotecan (control), irinotecan plus ciclosporin, and irinotecan plus panitumumab (IrPan) groups. From June 10, 2008, in response to new data, the trial was amended to a prospectively stratified design, restricting panitumumab randomisation to patients with KRAS wild-type tumours; the results of the comparison between the irinotcan and IrPan groups are reported here. We used a computer-generated randomisation sequence (stratified by previous EGFR targeted therapy and then minimised by centre, WHO performance status, previous oxaliplatin, previous bevacizumab, previous dose modifications, and best previous response) to randomly allocate patients to either irinotecan or IrPan. Patients in both groups received 350 mg/m² intravenous irinotecan every 3 weeks (300 mg/m² if aged ≥70 years or a performance status of 2); patients in the IrPan group also received intravenous panitumumab 9 mg/kg every 3 weeks. The primary endpoint was overall survival in KRAS wild-type patients who had not received previous EGFR targeted therapy, analysed by intention to treat. Tumour DNA was pyrosequenced for KRAS_c.146, BRAF, NRAS, and PIK3CA mutations, and predefined molecular subgroups were analysed for interaction with the effect of panitumumab. This study is registered, number ISRCTN93248876.

Results

Between Dec 4, 2006, and Aug 31, 2010, 1198 patients were enrolled, of whom 460 were included in the primary population of patients with KRAS_c.12–13,61 wild-type tumours and no previous EGFR targeted therapy. 230 patients were randomly allocated to irinotecan and 230 to IrPan. There was no difference in overall survival between groups (HR 1·01, 95% CI 0·83–1·23; p=0·91), but individuals in the IrPan group had longer progression-free survival (0·78, 0·64–0·95; p=0·015) and a greater number of responses (79 [34%] patients vs 27 [12%]; p<0·0001) than did individuals in the irinotecan group. Grade 3 or worse diarrhoea (64 [29%] of 219 patients vs 39 [18%] of 218 patients), skin toxicity (41 [19%] vs none), lethargy (45 [21]% vs 24 [11%]), infection (42 [19%] vs 22 [10%]) and haematological toxicity (48 [22%] vs 27 [12%]) were reported more commonly in the IrPan group than in the irinotecan group. We recorded five treatment-related deaths, two in the IrPan group and three in the irinotecan group.

Interpretation

Adding panitumumab to irinotecan did not improve the overall survival of patients with wild-type KRAS tumours. Further refinement of molecular selection is needed for substantial benefits to be derived from EGFR targeting agents.

Funding

Cancer Research UK, Amgen Inc.