A Machine Learning-Driven Comparison of Ion Images Obtained by MALDI and MALDI-2 Mass Spectrometry Imaging

Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) enables label-free imaging of biomolecules in biological tissues. However, many species remain undetected due to their poor ionization efficiencies. MALDI-2 (laser-induced post-ionization) is the most widely used post-ionization method for improving analyte ionization efficiencies. Mass spectra acquired using MALDI-2 constitute a combination of ions generated by both MALDI and MALDI-2 processes. Until now, no studies have focused on a detailed comparison between the ion images (as opposed to the generated m/z values) produced by MALDI and MALDI-2 for mass spectrometry imaging (MSI) experiments. Herein, we investigated the ion images produced by both MALDI and MALDI-2 on the same tissue section using correlation analysis (to explore similarities in ion images for ions common to both MALDI and MALDI-2) and a deep learning approach. For the latter, we used an analytical workflow based on the Xception convolutional neural network, which was originally trained for human-like natural image classification but which we adapted to elucidate similarities and differences in ion images obtained using the two MSI techniques. Correlation analysis demonstrated that common ions yielded similar spatial distributions with low-correlation species explained by either poor signal intensity in MALDI or the generation of additional unresolved signals using MALDI-2. Using the Xception-based method, we identified many regions in the t-SNE space of spatially similar ion images containing MALDI and MALDI-2-related signals. More notably, the method revealed distinct regions containing only MALDI-2 ion images with unique spatial distributions that were not observed using MALDI. These data explicitly demonstrate the ability of MALDI-2 to reveal molecular features and patterns as well as histological regions of interest that are not visible when using conventional MALDI.

Sex as a Predictor of Response to Immunotherapy in Advanced Cutaneous Squamous Cell Carcinoma

Approximately 3-5% of patients with cutaneous squamous cell carcinoma (CSCC) develop advanced disease, accounting for roughly 1% of all cancer deaths in Australia. Immunotherapy has demonstrated significant clinical benefit in advanced CSCC in several key phase II studies; however, there are limited data for patients treated outside of clinical trials. This is particularly relevant in advanced CSCC, which is most often seen in elderly patients with significant comorbidities. Thus, we aim to describe our experience with immunotherapy in a cohort of patients with advanced CSCC in Australia. We retrospectively reviewed all advanced CSCC patients treated with immunotherapy within the Illawarra and Shoalhaven Local Health District. Among the 51 patients treated with immunotherapy, there was an objective response rate (ORR) of 53% and disease control rate (DCR) of 67%. Our most significant predictor of response was sex, with male patients more likely to have better responses compared to female patients (DCR 85% vs. 41%, p < 0.0001), as well as improved progression-free survival (HR 4.6, 95%CI 1.9-10.8, p = 0.0007) and overall survival (HR 3.0, 95%CI 1.3-7.1, p = 0.006). Differential expression analysis of 770 immune-related genes demonstrated an impaired CD8 T-cell response in female patients. Our observed ORR of 53% is similar to that described in current literature with durable responses seen in the majority of patients.

Efficacy and safety of cosibelimab, an anti-PD-L1 antibody, in metastatic cutaneous squamous cell carcinoma

BACKGROUND

Programmed cell death receptor-1 (PD-1)-blocking antibodies are approved to treat metastatic or locally advanced cutaneous squamous cell carcinoma (CSCC) cases ineligible for curative surgery or radiation. Notwithstanding, some patients experience inadequate responses or severe immune-related adverse events (AEs), indicating the need for improved therapies. Cosibelimab is a high-affinity programmed cell death-ligand 1 (PD-L1)-blocking antibody that activates innate and adaptive immunity by blocking PD-L1 interaction with PD-1 and B7-1 receptors. It is an unmodified immunoglobulin G1 subtype with a functional Fc domain capable of inducing antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. Here, we present results of the pivotal study of patients with metastatic CSCC from an open-label, multicenter, multiregional, multicohort, phase 1 trial of cosibelimab.

METHODS

In this trial, participants with metastatic CSCC received cosibelimab 800 mg intravenously every 2 weeks. Primary endpoint was objective response rate (ORR) by independent central review using Response Evaluation Criteria in Solid Tumors, V.1.1. Secondary endpoints included duration of response (DOR) and safety.

RESULTS

Objective response was observed in 37 of 78 participants (47.4% (95% CI: 36.0% to 59.1%)), with median follow-up of 15.4 months (range: 0.4 to 40.5) as of data cut-off. Median DOR was not reached (range: 1.4+ to 34.1+ months), with response ongoing in 73.0% of participants. Common treatment-emergent AEs (≥15%) were fatigue (26.9%), rash (16.7%), and anemia (15.4%). Eighteen participants (23.1%) experienced immune-related AEs (grade 3: n=2 (2.6%); no grade 4/5). No treatment-related deaths were reported.

CONCLUSIONS

Cosibelimab demonstrated clinically meaningful ORR and DOR and was associated with a manageable safety profile.

TRIAL REGISTRATION NUMBER

NCT03212404.

Exceptional Response to Olaparib: A Case Report of Metastatic Esophageal Squamous Cell Carcinoma in a Patient With Fanconi Anemia, Germline FANCA Mutation, and Somatic BRCA2 Mutations

Exceptional response to olaparib in a case with Fanconi anemia and metastatic esophageal carcinoma

Low Pretreatment CD4+:CD8+ T Cell Ratios and CD39+CD73+CD19+ B Cell Proportions Are Associated with Improved Relapse-Free Survival in Head and Neck Squamous Cell Carcinoma

The ectonucleotidases CD39 and CD73 are present on immune cells and play important roles in cancer progression by suppressing antitumour immunity. As such, CD39 and CD73 on peripheral blood mononuclear cells (PBMCs) are emerging as potential biomarkers to predict disease outcomes and treatment responses in cancer patients. This study aimed to examine T and B cells, including CD39 and CD73 expressing subsets, by flow cytometry in PBMCs from 28 patients with head and neck squamous cell carcinoma (HNSCC) and to assess the correlation with the treatment modality, human papillomavirus (HPV) status, and relapse-free survival (RFS). The PBMCs were examined pre-, mid-, and post-radiotherapy with concurrent cisplatin chemotherapy or anti-epidermal growth factor receptor antibody (cetuximab) therapy. Combination radiotherapy caused changes to T and B cell populations, including CD39 and CD73 expressing subsets, but no such differences were observed between concurrent chemotherapy and cetuximab. Pretreatment PBMCs from HPV+ patients contained increased proportions of CD39-CD73-CD4+ T cells and reduced proportions of CD39-/+CD73+CD4+ T cells compared to the equivalent cells from HPV- patients. Notably, the pretreatment CD4+:CD8+ T cell ratios and CD39+CD73+CD19+ B cell proportions below the respective cohort medians corresponded with an improved RFS. Collectively, this study supports the notion that CD39 and CD73 may contribute to disease outcomes in HNSCC patients and may assist as biomarkers, either alone or as part of immune signatures, in HNSCC. Further studies of CD39 and CD73 on PBMCs from larger cohorts of HNSCC patients are warranted.

Testosterone suppression plus enzalutamide versus testosterone suppression plus standard antiandrogen therapy for metastatic hormone-sensitive prostate cancer (ENZAMET): an international, open-label, randomised, phase 3 trial

BACKGROUND

The interim analysis of the ENZAMET trial of testosterone suppression plus either enzalutamide or standard nonsteroidal antiandrogen therapy showed an early overall survival benefit with enzalutamide. Here, we report the planned primary overall survival analysis, with the aim of defining the benefit of enzalutamide treatment in different prognostic subgroups (synchronous and metachronous high-volume or low-volume disease) and in those who received concurrent docetaxel.

METHODS

ENZAMET is an international, open-label, randomised, phase 3 trial conducted at 83 sites (including clinics, hospitals, and university centres) in Australia, Canada, Ireland, New Zealand, the UK, and the USA. Eligible participants were males aged 18 years or older with metastatic, hormone-sensitive prostate adenocarcinoma evident on CT or bone scanning with ^99mTc and an Eastern Cooperative Oncology Group performance status score of 0-2. Participants were randomly assigned (1:1), using a centralised web-based system and stratified by volume of disease, planned use of concurrent docetaxel and bone antiresorptive therapy, comorbidities, and study site, to receive testosterone suppression plus oral enzalutamide (160 mg once per day) or a weaker standard oral non-steroidal antiandrogen (bicalutamide, nilutamide, or flutamide; control group) until clinical disease progression or prohibitive toxicity. Testosterone suppression was allowed up to 12 weeks before randomisation and for up to 24 months as adjuvant therapy. Concurrent docetaxel (75 mg/m² intravenously) was allowed for up to six cycles once every 3 weeks, at the discretion of participants and physicians. The primary endpoint was overall survival in the intention-to-treat population. This planned analysis was triggered by reaching 470 deaths. This study is registered with ClinicalTrials.gov, NCT02446405, ANZCTR, ACTRN12614000110684, and EudraCT, 2014-003190-42.

FINDINGS

Between March 31, 2014, and March 24, 2017, 1125 participants were randomly assigned to receive non-steroidal antiandrogen (n=562; control group) or enzalutamide (n=563). The median age was 69 years (IQR 63-74). This analysis was triggered on Jan 19, 2022, and an updated survival status identified a total of 476 (42%) deaths. After a median follow-up of 68 months (IQR 67-69), the median overall survival was not reached (hazard ratio 0·70 [95% CI 0·58-0·84]; p<0·0001), with 5-year overall survival of 57% (0·53-0·61) in the control group and 67% (0·63-0·70) in the enzalutamide group. Overall survival benefits with enzalutamide were consistent across predefined prognostic subgroups and planned use of concurrent docetaxel. The most common grade 3-4 adverse events were febrile neutropenia associated with docetaxel use (33 [6%] of 558 in the control group vs 37 [6%] of 563 in the enzalutamide group), fatigue (four [1%] vs 33 [6%]), and hypertension (31 [6%] vs 59 [10%]). The incidence of grade 1-3 memory impairment was 25 (4%) versus 75 (13%). No deaths were attributed to study treatment.

INTERPRETATION

The addition of enzalutamide to standard of care showed sustained improvement in overall survival for patients with metastatic hormone-sensitive prostate cancer and should be considered as a treatment option for eligible patients.

FUNDING

Astellas Pharma.

Metastatic Ductal Eccrine Adenocarcinoma with Excellent Response to Immunotherapy

Eccrine carcinoma, a subtype of which is ductal eccrine adenocarcinoma (DEA), is a rare cutaneous malignancy. For metastatic eccrine carcinoma, there are very limited data to guide treatment. Conventional chemotherapy is of limited benefit and there is only a small body of evidence for the use of immunotherapy in non-DEA eccrine carcinomas. We report the first case of metastatic DEA treated with a multimodality approach including surgery, radiotherapy, and immunotherapy, with an excellent prolonged response to pembrolizumab, and provide a review of the literature on pathological and management aspects for this rare tumour subtype. A 60-year-old male with a history of pT1N0M0 left scalp DEA, managed 2 years prior with excision and adjuvant radiotherapy, represented with a symptomatic right pontine metastasis. Imaging demonstrated intracranial, pulmonary, and hilar disease; biopsy of the cranial and lung lesions showed metastatic adenocarcinoma, morphologically similar to the previously resected scalp DEA. The patient was treated with stereotactic resections of his pontine metastases and adjuvant cranial radiotherapy, then commenced on immunotherapy with pembrolizumab. The patient has completed 21 months of pembrolizumab with a significant radiological response of the pulmonary and hilar disease and nil evidence of intracranial recurrence or further metastases. In this case report, we provide the first evidence of efficacy of immunotherapy in metastatic DEA, demonstrating an excellent and prolonged response of metastatic DEA to pembrolizumab. Further research is required to better establish the role of immunotherapy within the management protocol for this uncommon but aggressive tumour subtype.

HER2-Positive Gastroesophageal Cancers Are Associated with a Higher Risk of Brain Metastasis

Brain metastasis from gastroesophageal adenocarcinomas (GOCs) is a rare but a devastating diagnosis. Human epidermal growth factor receptor 2 (HER2) is a prognostic and predictive biomarker in GOCs. The association of HER2 with GOC brain metastasis is not known. We performed a retrospective analysis of patients with GOCs with known HER2 status between January 2015 and November 2021. HER2 was assessed on either the primary tumour or metastasis by immunohistochemistry or in situ hybridization. The diagnosis of brain metastasis was made on standard imaging techniques in patients with symptoms or signs. HER2 results were available for 201 patients, with 34 patients (16.9%) HER2 positive. A total of 12 patients developed symptomatic brain metastasis from GOCs, of which 7 (58.3%) were HER2 positive. The development of symptomatic brain metastasis was significantly higher in the HER2-positive GOCs (OR8.26, 95%CI 2.09-35.60; p = 0.0009). There was no significant association of HER2 status and overall survival in patients with brain metastasis. Although the rate of brain metastasis remains low in GOCs, the incidence of symptomatic brain metastasis was significantly higher in patients with HER2-positive tumours.

Efficacy and safety of cosibelimab, an anti–PD-L1 antibody, in patients with metastatic cutaneous squamous cell carcinoma

9537

Background: Programmed death receptor-1 (PD-1)–blocking antibodies are approved as monotherapy treatment for patients (pts) with metastatic or locally advanced cutaneous squamous cell carcinoma (CSCC) who are not candidates for curative surgery or radiation. Cosibelimab is a high-affinity, fully human programmed death ligand-1 (PD-L1)–blocking antibody with a functional Fc domain capable of inducing antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against tumor cells. Study CK-301-101 (NCT03212404) is a global, multicenter, multicohort, pivotal trial that enrolled pts with select advanced cancers for treatment with cosibelimab. Here we present the primary analysis of the registration-enabling expansion cohort in pts with metastatic CSCC. Methods: Adult pts with Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 who had metastatic (nodal and/or distant) CSCC not amenable to local therapy were eligible to participate. Cosibelimab was administered as a fixed dose of 800 mg every 2 weeks (Q2W) intravenously. The primary endpoint was confirmed objective response rate (ORR; complete response [CR] + partial response [PR]) assessed by independent central review according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 and the key secondary endpoint was duration of response. Results: Seventy-eight pts with metastatic CSCC were treated with cosibelimab and comprise the efficacy and safety populations (59M/19F; median age: 71 years). The confirmed ORR was 47.4% (95% CI: 36.0, 59.1; 6 CRs and 31 PRs) and the median duration of response was not reached at the time of data cutoff (median duration of follow-up: 15.2 months), with 76% of responses ongoing (range: 1.4-31.8+ months). The Kaplan–Meier estimated probability of maintaining a response at 6 and 24 months was 88.1% and 72.5%, respectively. Treatment-related adverse events (TRAEs) were reported in 54 pts (69.2%); 7 pts (9.0%) experienced at least 1 grade 3 TRAE (no grade 4 or grade 5 TRAEs were reported) with the most common being increased serum lipase in 2 pts. Conclusions: Treatment with cosibelimab monotherapy resulted in a robust ORR with durable responses and demonstrated a predictable and manageable safety profile in pts with metastatic CSCC, supporting its use in the treatment of this cancer. Clinical trial information: NCT03212404.

Antitumor activity of sunvozertinib in NSCLC patients with EGFR Exon20 insertion mutations after platinum and anti-PD(L)1 treatment failures

9015

Background: Platinum-based chemotherapy is the 1st line standard of care for NSCLC patients with EGFR exon 20 insertion mutations (Exon20ins), with anti-PD(L)1 frequently used as well. Here we present anti-tumor activity of sunvozertinib in these patients whose disease had progressed on these therapies from two ongoing phase 1/2 studies (WK-KONG1, NCT03974022 and WU-KONG2, CTR20192097). Based on these data, sunvozertinib was granted the Breakthrough Therapy Designation by both US FDA and China NMPA. Methods: The objective of this study is to characterize the safety and efficacy of sunvozertinib in platinum-pretreated advanced NSCLC patients harboring EGFR Exon20ins, with or without anti-PD(L1) treatment. In addition, the effect of prior treatment on sunvozertinib’s safety and efficacy were explored. Results: As of July 30, 2021, a total of 52 locally advanced or metastatic NSCLC patients harboring EGFR Exon20ins post platinum treatment were enrolled into WU-KONG1 and WU-KONG2 studies, and included in the efficacy analysis set (dose range: 50 mg to 400 mg, once daily). Male/Female: 21/31; Median age 59; Asian/White: 44/8; Prior therapies: median 2.5 (range 1-10); 31% received prior anti-PD(L)1 treatment (all in £ 300 mg cohorts); 40% of the subjects with baseline brain metastasis. Partial response was observed at ≥ 100 mg. At the dose level of 100 mg, 200 mg, 300 mg and 400 mg, confirmed ORR was 50% (1/2), 55.6 % (5/9), 44.8% (13/29) and 22.2% (2/9), respectively. With a median follow-up time of 10.5 months, median DoR was not reached for 200 mg cohort; with a median follow-up of 7 months, median DoR of 300 mg group was 5.6 months. Progression free survival (PFS) rate at 6 months for 100 mg, 200 mg, 300 mg and 400 mg cohorts was 50%, 53.3%, 44.6% and 44.4%, respectively. In patients with/without prior anti-PD(L)1 treatment, comparable efficacy and safety profiles were observed. Conclusions: The data suggest sunvozertinib is active in platinum-pretreated patients with EGFR Exon20ins, irrespective of prior or after anti-PD(L)1 treatment. The updated data will be presented at the meeting. Sunvozertinib is currently in phase 2 pivotal clinical development (NCT03974022 and China CTR20211009). Clinical trial information: NCT03974022.

A randomized, controlled, open-label, phase 2 study of cemiplimab ± RP1 in patients with advanced cutaneous squamous cell carcinoma (CERPASS)

TPS9593

Background: RP1 is an oncolytic virus (HSV-1) that expresses a fusogenic glycoprotein (GALV-GP R-) and granulocyte macrophage colony stimulating factor (GM-CSF). In preclinical studies, RP1 induced immunogenic tumor cell death and provided potent systemic anti-tumor activity, which is further improved by combining anti-PD-1 therapy. The prognosis for advanced and metastatic cutaneous squamous cell carcinoma (CSCC) remains poor for many patients despite the adoption of cemiplimab and pembrolizumab as a standard treatment. Preliminary results from IGNYTE, a phase I/II clinical study of RP1 in combination with nivolumab showed a high rate of deep and durable responses in patients (pts) with CSCC. This study is evaluating the efficacy and safety of cemiplimab ± RP1 versus cemiplimab alone in advanced CSCC. Methods: This global, multicenter, randomized phase 2 study is enrolling pts with metastatic or unresectable, locally advanced CSCC who are not candidates for/refuse surgery and/or radiation therapy. Key eligibility criteria include no prior treatment with anti-PD1/PD-L1 antibodies or oncolytic viruses. The clinical trial is enrolling approximately 180 pts from centers in the EU, Australia, Canada, and USA. Pts are randomized in a 2:1 ratio to receive combination therapy or monotherapy respectively. Pts receive 350 mg of cemiplimab intravenously (IV) Q3W for up to 108 weeks. In the RP1 + cemiplimab arm, RP1 is injected intratumorally at a starting RP1 dose of 1 × 106 plaque-forming units (PFU)/mL alone, followed by up to 7 doses of RP1 at 1 × 107 PFU/mL Q3W together with the same dose of cemiplimab. Pts in the combination arm may receive up to 8 additional RP1 doses if protocol specific criteria are met. No crossover is allowed. Pts are stratified by disease status (nodal or distant metastatic or locally advanced CSCC) and prior systemic therapy. Tumor assessments are performed every 9 weeks. The dual independent primary endpoints are overall response rate and complete response rate, both by a blinded independent review. Secondary endpoints include safety, progression-free survival, duration of response, and overall survival. Exploratory endpoints include quality of life, and immune biomarker analyses. This trial is currently enrolling pts. Clinical trial information: NCT04050436.

C-POST protocol update: A phase 3, randomized, double-blind study of adjuvant cemiplimab versus placebo post-surgery and radiation therapy (RT) in patients (pts) with high-risk cutaneous squamous cell carcinoma (CSCC)

TPS9592

Background: CSCC is the second most common skin cancer with an estimated incidence of 1 million cases per year in the US. While the surgical cure rate for CSCC is > 95%, some pts have high risk of recurrence as assessed by immune status, primary disease stage, extent of nodal involvement, presence of extracapsular extension (ECE), and prior treatment. Postoperative RT is recommended for these pts but relapse with locoregional recurrence or distant metastases may still occur. C-POST is evaluating the efficacy of cemiplimab as adjuvant therapy for pts with high-risk CSCC. Here, we provide summary of the most recent study protocol amendment. Methods: C-POST is a randomized, placebo-controlled, double-blind, multicenter Phase 3 study to evaluate cemiplimab as adjuvant treatment for pts with high-risk CSCC, based on surgical and clinicopathologic findings, who completed surgery and postoperative RT (minimum total dose 50Gy, within 10 weeks before randomization) (NCT03969004). Pts with at least one of the following high-risk features are eligible: (1) nodal disease with (a) ECE and at least one node ≥20 mm or (b) at least three lymph nodes positive on surgical pathology report, regardless of ECE; (2) in-transit metastases; (3) T4 lesion; (4) perineural invasion; and (5) recurrent CSCC with at least one other risk factor. Pts with CSCC involvement in at least three lymph nodes (feature 1b) were added to the eligibility criteria, as this group was found to be at similar risk of CSCC recurrence as the initially planned study population. Protocol amendment now allows patients with chronic lymphocytic leukemia (CLL) who are not on active treatment to be enrolled. The study has two parts. In Part 1 (blinded), pts are randomly assigned 1:1 to receive cemiplimab 350 mg or placebo intravenously every 3 weeks for 12 weeks, followed by cemiplimab 700 mg or placebo every 6 weeks for 36 weeks. In optional Part 2 (unblinded), pts in the placebo arm who experience disease recurrence and pts in the cemiplimab arm who experience disease recurrence ≥3 months after completion of 48-week treatment in Part 1 are eligible to receive open-label cemiplimab for up to 96 weeks. The trial is expected to enrol 412 pts from about 100 sites in North and South America, Europe, and Asia-Pacific regions. Key primary objective is to compare disease-free survival; secondary objectives include evaluating overall survival, freedom from locoregional relapse, and distant relapse with adjuvant cemiplimab versus placebo in patients with high-risk CSCC. This study is once again open for enrolment following interruptions owing to the COVID-19 pandemic. Clinical trial information: NCT03969004.

Sunvozertinib, a selective EGFR inhibitor for previously treated non-small cell lung cancer with EGFR exon 20 insertion mutations

Epidermal growth factor receptor exon 20 insertion mutations (EGFR exon20ins) are detected in approximately 2% of patients with non-small cell lung cancer (NSCLC). Due to lack of effective therapy, the prognosis of these patients was poor. Sunvozertinib (DZD9008) was designed as an oral, potent, irreversible and selective EGFR tyrosine kinase inhibitor, showing activity against EGFR exon20ins and other mutations. In both cell lines and xenograft models, sunvozertinib shows potent antitumor activity. In the two ongoing phase 1 clinical studies, sunvozertinib was tolerated up to 400 mg once daily. The most common drug-related adverse events included diarrhea and skin rash. Antitumor efficacy was observed at the doses of 100 mg and above in patients with EGFR exon20ins NSCLC across different subtypes, with prior amivantamab treatment as well as with baseline brain metastasis. The median duration of response (DoR) has not been reached.

Clinical and molecular profile of young adults with early-onset colorectal cancer: Experience from four Australian tertiary centers

BACKGROUND

Patients with early-onset colorectal cancer (EO-CRC) have unique characteristics. Contemporary data on the pathological and molecular features, and survival of EO-CRC are limited in the Australian context.

AIM

To determine the demographic, histopathological and molecular characteristics of adults with EO-CRC, and their survival.

METHODS

We conducted a retrospective study of adults aged 18-49 years with EO-CRC who were referred to the Illawarra Shoalhaven Local Health District, South Eastern Sydney Local Health District and Royal North Shore Hospital in New South Wales, Australia, between 2014 and 2018.

RESULTS

Of 257 patients included, 94 (37%) patients presented with de novo metastatic CRC, 80% patients had near-average risk family history and 89% had a symptomatic presentation. In 159 patients with nonmetastatic disease at diagnosis, stage III disease (OR 3.88 [95% CI: 1.13-13.3]; p = .03) and the presence of perineural invasion (PNI) (OR 6.63 [95% CI: 2.21-19.84]; p = .001) were risk factors associated with the development of metastatic disease. Among 94 patients with de novo metastatic disease, 43 (43%) and 12 (14%) patients harbored a KRAS or BRAF V600E mutation, respectively. The median overall survival was 29.6 months (95% CI: 20.4-38.7). BRAF mutation was associated with inferior survival (HR 3.00 [95% CI: 1.30-6.94]; p = .01).

CONCLUSION

The prevalence of KRAS and BRAF mutations in our cohort is similar to the overseas experience. Stage III disease at diagnosis, presence of PNI and BRAF mutation are adverse prognostic indicators. A better understanding of the molecular landscape is needed for this patient cohort, so as to better tailor prevention strategies, screening and treatment pathways.

547 CERPASS: A randomized, controlled, open-label, phase 2 study of cemiplimab ± RP1 in patients with advanced cutaneous squamous cell carcinoma

Background

The prognosis for advanced and metastatic cutaneous squamous cell carcinoma (CSCC) remains poor for many patients with the disease despite approval of the anti-PD1 antibodies cemiplimab and pembrolizumab.1 2 RP1 is an oncolytic virus (HSV-1) that expresses a fusogenic glycoprotein (GALV-GP R-) and granulocyte macrophage colony stimulating factor (GM-CSF). In preclinical studies, RP1 induced immunogenic tumor cell death and provided potent systemic anti-tumor activity, which is further improved by combining anti-PD-1 therapy.3 Preliminary results from IGNYTE, a phase I/II clinical study of RP1 in combination with nivolumab showed a high rate of deep and durable responses in patients (pts) with CSCC.4 The objective of this trial is to evaluate the safety and efficacy of cemiplimab + RP1 versus cemiplimab alone in advanced CSCC.

Methods

This global, multicenter, randomized phase 2 study is enrolling pts with metastatic or unresectable, locally advanced CSCC who are not candidates for/refuse surgery and/or radiotherapy. Key eligibility criteria include no prior treatment with anti-PD1/PD-L1 antibodies or oncolytic viruses. The clinical trial will enroll approximately 180 pts from centers in the EU, Australia, Canada and USA. Pts will be randomized in a 2:1 ratio favoring the RP1 + cemiplimab arm. Pts will receive 350 mg of cemiplimab intravenously (IV) Q3W for up to 108 weeks. In the RP1 + cemiplimab arm, RP1 will be injected intratumorally at a starting RP1 dose of 1 × 10^6 plaque forming units (PFU)/mL alone, followed by up to 7 doses of RP1 at 1 × 10^7 PFU/mL Q3W together with cemiplimab. Pts in the combination arm may receive up to 8 additional RP1 doses. No crossover will be allowed. Pts will be stratified by disease status and prior systemic therapy. Tumor assessments will be performed every 9 weeks. Primary endpoints are overall response rate and complete response rate by blinded independent review. Secondary endpoints include safety, progression free survival, duration of response and overall survival. Exploratory endpoints include viral shedding and biodistribution, and immune biomarker analyses. This trial is currently enrolling pts.

Trial Registration

NCT04050436

References

Migden MR, Rischin D, Schmults CD, Guminski A, Hauschild A, Lewis KD, Chung CH, Hernandez-Aya L, Lim AM, Chang ALS, Rabinowits G, Thai AA, Dunn LA, Hughes BGM, Khushalani NI, Modi B, Schadendorf D, Gao B, Seebach F, Li S, Li J, Mathias M, Booth J, Mohan K, Stankevich E, Babiker HM, Brana I, Gil-Martin M, Homsi J, Johnson ML, Moreno V, Niu J, Owonikoko TK, Papadopoulos KP, Yancopoulos GD, Lowy I, Fury MG. PD-1 blockade with cemiplimab in advanced cutaneous squamous-cell carcinoma. N Engl J Med 2018;379(4):341–351.

Grob JJ, Gonzalez R, Basset-Seguin N, Vornicova O, Schachter J, Joshi A, Meyer N, Grange F, Piulats JM, Bauman JR, Zhang P, Gumuscu B, Swaby RF, Hughes BGM. Pembrolizumab monotherapy for recurrent or metastatic cutaneous squamous cell carcinoma: a single-arm phase II trial (KEYNOTE-629). J Clin Oncol 2020;38(25):2916–2925.

Thomas S, Kuncheria L, Roulstone V, Kyula JN, Mansfield D, Bommareddy PK, Smith H, Kaufman HL, Harrington KJ, Coffin RS. Development of a new fusion-enhanced oncolytic immunotherapy platform based on herpes simplex virus type 1. J Immunother Cancer 2019;7(1):214.

Middleton M, Aroldi F, Sacco J, Milhem M, Curti B, VanderWalde A, Baum S, Samson A, Pavlick A, Chesney J, Niu J, Rhodes T, Bowles T, Conry R, Olsson-Brown A, Earl Laux D, Kaufman H, Bommareddy P, Deterding A, Samakoglu S, Coffin R, Harrington K. 422 An open-label, multicenter, phase 1/2 clinical trial of RP1, an enhanced potency oncolytic HSV, combined with nivolumab: updated results from the skin cancer cohorts. J Immunother Cancer 2020; 8 (3).

Ethics Approval

The study was approved by institutional review board or the local ethics committee at each site. Informed consent was obtained from patients before participating into the trial.

Rectal cancer treatment and outcomes in elderly patients treated with curative intent

The elderly population comprises a significant proportion of patients diagnosed with rectal cancer. However, there is a lack of evidence to guide treatment decisions in this group. Thus, this multicentre study compares the histopathology, treatment patterns and outcomes between the elderly and young populations with non-metastatic rectal cancer. The present study reported on the clinicopathological variables, treatment modalities and survival outcomes in 736 patients diagnosed with non-metastatic rectal cancer between 2006 and 2015. Patients were divided into the following two groups, <70 and ≥70 years of age, which were compared using Chi-square and survival outcome analysis using Kaplan-Meier. Elderly patients made up nearly half of the cohort and were less likely to undergo trimodality therapy or be discussed in a multidisciplinary meeting. Surgery in the elderly patients was associated with increased mortality. Elderly patients had worse cancer-specific survival (75 vs. 85%), which was particularly evident in stage III disease (hazard ratio, 2.1). Elderly patients in this subgroup treated with trimodality therapy had similar survival outcomes to younger patients. Elderly patients with locally advanced rectal cancer comprise a large proportion of the patient cohort. Consideration should be given for trimodality therapy in this group, taking into account biological age, especially in the context of increasing life expectancy and improvement in the management of age-related comorbidities.

Combination chemotherapy with NAB® -paclitaxel and capecitabine for patients with advanced biliary tract cancer (NAP-CAPABIL Pilot Study)

BACKGROUND

 Advanced biliary tract cancer (ABTC) is a highly aggressive malignancy, with a 5-year overall survival of < 10%. Although preliminary evidence suggests a role of targeted treatments or immunotherapy in a subset of patients, chemotherapy remains the standard second-line treatment in the majority. We conducted a pilot study of second-line chemotherapy with capecitabine and nab-paclitaxel after failure of gemcitabine and platinum.

METHODS

Eligible patients had histologically proven, unresectable biliary tract cancer, which had progressed on a gemcitabine/platinum doublet. In this single-arm, multicenter trial, all patients received capecitabine (825 mg/m² bd PO D1-14 q21d) and nab-paclitaxel (125 mg/m² IV D1,8 q21d) until progression or unacceptable toxicity. The primary objective was feasibility of delivering the proposed regimen, with secondary objectives of disease control measures and QOL outcomes.

RESULTS

Ten patients were enrolled between 2015 and 2016 from four cancer centers in NSW. Treatment was generally well tolerated with grade III toxicities in five patients (including infection, cholangitis, obstruction, and intestinal perforation) and no grade IV toxicity. Median treatment duration was 4.3 months, with a disease control rate of 80% (8/10), and median progression-free and overall survival of 5.7 and 12.1 months, respectively. Quality of life data and specimens for translational research have been collected.

CONCLUSIONS

Our pilot study demonstrates that combination of capecitabine and nab-paclitaxel is feasible as a second-line treatment in ABTC. Adequate safety and promising early efficacy signals make further assessment of the combination in a formal phase II or III trial reasonable.

CLINICAL TRIAL INFORMATION

ACTRN12615000504516.

Human TERT promoter mutations as a prognostic biomarker in glioma

The TERT promoter (pTERT) mutations, C228T and C250T, play a significant role in malignant transformation by telomerase activation, oncogenesis and immortalisation of cells. C228T and C250T are emerging as important biomarkers in many cancers including glioblastoma multiforme (GBM), where the prevalence of these mutations is as high as 80%. Additionally, the rs2853669 single nucleotide polymorphism (SNP) may cooperate with these pTERT mutations in modulating progression and overall survival in GBM. Using liquid biopsies, pTERT mutations, C228T and C250T, and other clinically relevant biomarkers can be easily detected with high precision and sensitivity, facilitating longitudinal analysis throughout therapy and aid in cancer patient management.

In this review, we explore the potential for pTERT mutation analysis, via liquid biopsy, for its potential use in personalised cancer therapy. We evaluate the relationship between pTERT mutations and other biomarkers as well as their potential clinical utility in early detection, prognostication, monitoring of cancer progress, with the main focus being on brain cancer.

Retrospective Evaluation of the Use of Pembrolizumab in Malignant Mesothelioma in a Real-World Australian Population

INTRODUCTION

We investigated the efficacy and toxicity of pembrolizumab in patients with mesothelioma from a real-world Australian population. We aimed to determine clinical factors and predictive biomarkers that could help select patients who are likely to benefit from pembrolizumab.

METHOD

Patients with mesothelioma who were treated with pembrolizumab as part of the Insurance and Care New South Wales compensation scheme were included. Clinical information was collected retrospectively. Tumor biomarkers such as programmed death-ligand 1 (PD-L1), BAP1, and CD3-positive (CD3+) tumor-infiltrating lymphocytes (TILs) were examined using archival formalin-fixed paraffin-embedded tumor samples.

RESULTS

A total of 98 patients were included with a median age of 70 years (range, 46-91 y); 92% were men; 76% had epithelioid subtype; 21% had an Eastern Cooperative Oncology Group (ECOG) performance status of 0. Pembrolizumab was used as second-line or subsequent-line treatment in 94 patients and as first-line treatment in four patients. The overall response rate was 18%, and the disease control rate was 56%. The median progression-free survival (PFS) was 4.8 months (95% confidence interval: 3.6-6.2), and the median overall survival (OS) was 9.5 months (95% confidence interval: 6.6-13.7). Immune-related adverse events occurred in 27% of patients, of which nine (9%) were of grade 3 or higher. In the multivariable analysis, factors independently associated with longer PFS included baseline ECOG status of 0 (median PFS: 12 mo versus 4 mo, p < 0.01) and PD-L1 tumor proportion score of greater than or equal to 1% (median PFS: 6 mo versus 4 mo, p < 0.01). Baseline platelet count of less than or equal to 400 × 109/liter was independently associated with longer PFS and OS (median PFS: 6 mo versus 2 mo, p = 0.05; median OS: 10 mo versus 4 mo, p = 0.01), whereas lack of pretreatment dexamethasone was independently associated with OS but not PFS (median OS: 10 mo versus 3 mo, p = 0.01). The odds of response were higher for patients with baseline ECOG status of 0 (p = 0.02) and with greater than or equal to 5% CD3+ TILs in the tumor (p < 0.01). PD-L1 expression, BAP1 loss, and CD3+ TILs in the stroma were not significantly associated with the overall response rate.

CONCLUSIONS

Immunotherapy is a reasonable treatment option for patients with mesothelioma. Our results are comparable to other clinical trials investigating pembrolizumab in mesothelioma in terms of response. Good performance status assessment remains the most robust predictor for patient outcomes. CD3+ TILs in the tumor may help select patients that are likely to respond to pembrolizumab, whereas factors such as PD-L1 expression, baseline platelet count, and lack of pretreatment dexamethasone may help predict survival outcomes from pembrolizumab treatment.

High body mass index is associated with an increased overall survival in rectal cancer

Background

The impact of increased body mass index (BMI) on clinical outcomes in locoregional rectal cancer is unknown.

Methods

This is a retrospective cohort study which included 453 consecutive rectal cancer patients undergoing definitive treatment, with confirmed stage I, II or III rectal adenocarcinoma. The association of BMI at diagnosis with overall survival (OS), cancer specific survival (CSS) and disease-free survival (DFS) was explored, controlling for key covariates using multivariable analyses. BMI as defined by the World Health Organization (WHO) is as follows: BMI <18.5-underweight; 18.5-24.9-normal; 25.0-29.9-pre-obesity; >30-obese.

Results

Overweight and obese patients had significantly better OS than underweight/normal weight patients (5-year OS 80% for overweight, 77% for obese, and 65% for underweight/normal weight patients, P=0.02). High BMI (>25) was significantly associated with improved OS in univariate [0.62 (0.4-0.8) P=0.007] and multivariable [0.65 (0.4-0.9) P=0.023] analyses. When stratified by stage, high BMI was associated with improved OS in stage III patients (P=0.0009), but not stage II (P=0.21) or stage I (0.54). High BMI was also significantly associated with improved CSS in univariate (HR 0.62, P=0.048) and multivariable analyses (HR 0.58, P=0.03).

Conclusions

In our study a BMI greater than 25 is significantly associated with a longer OS and CSS in patients with locoregional rectal cancer. These findings may be due to the reduced metabolic capacity for non-obese patients to deal with rectal cancer treatment as well as the burden of disease, however further research is needed to evaluate this.

Central Venous Catheter Thrombosis in Cancer: A Multi-Centre Retrospective Study Investigating Risk Factors and Contemporary Trends in Management

Objectives:

Central venous access is needed to facilitate chemotherapy for many cancer patients. Central venous catheter-related thrombosis (CVCT) is a major complication that can cause significant morbidity and mortality. We sought to explore the rate of CVCT in a general cancer population in Australia and to identify factors associated with increased risk of thrombosis.

Design:

This is a multi-centre retrospective cohort study.

Setting and participants:

We analysed key patient, treatment, and cancer-related factors for 317 patients with cancer and central venous catheters inserted for systemic therapy.

Main outcome measures:

Symptomatic CVCT confirmed with imaging and management of patients with CVCT.

Results:

A total of 402 cases of central line insertion were analysed. Central venous catheter-related thrombosis occurred in 24 patients (6.0%). Having a peripherally inserted central catheter (PICC; HR = 3.78, 95% CI = 1.28-11.19, P = .02) compared with an implantable port and a body mass index of ⩾25.0 kg/m² (HR = 3.60, 95% CI = 1.31-9.85, P = .01) were independently associated with increased risk of thrombosis. Central venous catheter-related thrombosis was managed mostly with removal of the catheter (19 of 24 cases) and anticoagulation, including direct-acting oral anticoagulants in 5 patients.

Conclusions:

This work explored rates of CVCT in a general cancer population, observing increased rates in those with PICCs or increased body mass index.

Pancreatitis and Biliary Obstruction Secondary to Duodenal Metastasis from Rapidly Progressing Lung Adenocarcinoma Treated with Common Bile Duct Stenting

Non-small cell lung cancer (NSCLC) is characterised by diffuse metastases, with common sites being the brain, liver, bones, and adrenal glands. Small bowel metastasis from NSCLC is a rare phenomenon, particularly in patients with an adenocarcinoma histology. We report the case of a 56-year-old lung adenocarcinoma patient with a duodenal metastasis diagnosed on FDG/PET-CT and confirmed on duodenal biopsy. Although initially asymptomatic, he subsequently presented with obstructive jaundice secondary to rapid local disease progression at the duodenal metastasis, requiring endoscopic intervention for biliary drainage. He was commenced on single agent pembrolizumab, with disease response on subsequent follow-up. This case highlights a rare case of gastrointestinal metastasis from NSCLC requiring endoscopic intervention due to rapid progression of the disease at the site of metastasis.

Comparison of peripheral blood mononuclear cell isolation techniques and the impact of cryopreservation on human lymphocytes expressing CD39 and CD73

CD39 and CD73 are ecto-nucleotidases present on human peripheral blood mononuclear cells (PBMCs) and are emerging biomarkers on these cells in various disorders including cancer. Many factors influence PBMC quality, so it is essential to validate sample processing methods prior to incorporation in clinical studies. This study examined the impact of both PBMC cryopreservation and PBMC isolation using SepMate density gradient centrifugation on CD39 and CD73 expressing subsets. First, PBMCs were isolated from the peripheral blood of 11 healthy donors by routine Ficoll-Paque density gradient centrifugation, cryopreserved and compared with freshly isolated PBMCs by flow cytometry. The proportions of T and B cells expressing combinations of CD39 and CD73 were relatively stable over 6-month cryopreservation, although some T cell combinations revealed small but significant changes. Second, peripheral blood was collected from six healthy donors to compare PBMCs isolated by SepMate or Ficoll-Paque density gradient centrifugation. Compared with Ficoll-Paque, the more rapid SepMate method yielded 9.1% less PBMCs but did not alter cell viability or proportions of T and B cells expressing combinations of CD39 and CD73. The present study reveals that cryopreservation is suitable for studying T and B cells expressing combinations of CD39 and CD73. However, caution should be exercised when observing small differences in these cryopreserved subsets between different cohorts. Further, SepMate and Ficoll-Paque methods of PBMC isolation show similar results for T and B cell subset analysis; however, SepMate is a faster and easier approach.

Factors influencing recurrence of stage I-III rectal cancer in regional Australia

BACKGROUND

As treatments for rectal cancer improve with developments in surgical techniques, radiotherapy and chemotherapy, the nature of recurrences are evolving. We used a comprehensive database of a large Australian population with stage I-III rectal adenocarcinoma to identify timing and prognostic significance of recurrences, and factors associated with risk of developing recurrent disease.

METHODS

All patients with locoregional rectal cancer treated with curative intent in our health district from 2006 to 2017 were included. Multivariate analysis using Cox regression models were used to identify factors associated with recurrence.

RESULTS

A total of 483 patients were included. Recurrence occurred in 117 (24.2%) of 483 patients, being locoregional in 15 (3.1%) patients, distant in 85 patients (17.6%) and both locoregional and distant in 17 (3.5%) patients. Compared to those with locoregional recurrence, those with both locoregional and distant recurrence had worse cancer-specific survival. On univariate analysis, factors associated with recurrence included stage, grade, radiotherapy, chemotherapy, surgery type and distal tumour location. Factors which remained significant on multivariate analysis included higher grade and stage.

CONCLUSION

In the era of multimodality therapy for rectal cancer, recurrences are predominantly distant. Traditional predictors including higher stage, grade and distal tumour location remain independently associated with recurrence, despite current treatment paradigms.

Expression of cancer stem cell markers is prognostic in metastatic gastroesophageal adenocarcinoma

Gastroesophageal adenocarcinoma is a common and highly lethal malignancy. Cancer stem cells (CSCs) have a key role in the development and progression of metastatic disease. While expression of CSC markers CD44, CD133 and aldehyde dehydrogenase 1 (ALDH1) in locoregional gastroesophageal cancer is known to be associated with poorer clinical outcomes, the significance of CSC marker expression in distal metastatic disease is unknown. We investigated the clinicopathological and prognostic associations of the CSC markers, CD44, CD133, and ALDH1, on metastatic deposits from gastroesophageal adenocarcinomas, and evaluated the association of CSC expression with urokinase-type plasminogen activator receptor (uPAR) expression. Of the 36 patients included in the study, 16 (44%) were positive for CD44, 13 (36%) were positive for CD133, and 26 (72%) were positive for ALDH1. CD44 expression was significantly associated with poorer overall survival (OS) in univariate [hazard ratio (HR) 2.9, 95% confidence interval (CI) 1.3-6.9, p=0.008] and multivariate analyses (HR 2.5, 95%CI 1.1-6.2, p=0.04). ALDH1 expression was significantly associated with poorer OS in univariate (HR 2.4, 95% CI 1.01-5.7, p=0.04) analysis but was not significant in multivariate analysis. Both CD44 and ALDH1 expression were significantly associated with uPAR expression. We found no association between CD133 expression and OS. CD44 expression on metastatic disease from gastroesophageal adenocarcinomas is an independent prognostic marker associated with poorer OS. These results expand current evidence to support the role of CSCs as biomarkers in metastatic gastroesophageal cancer.

Immunomagnetic isolation of circulating melanoma cells and detection of PD-L1 status

Personalised medicine targeted to specific biomarkers such as BRAF and c-Kit has radically improved the success of melanoma therapy. More recently, further advances have been made using therapies targeting the immune response. In particular, therapies targeting the PD-1/PD-L1 or CTLA-4 axes alone or in combination have shown more sustained responses in 30–60% of patients. However, these therapies are associated with considerable toxicities and useful biomarkers to predict responders and non-responders are slow to emerge. Here we developed a reliable melanoma circulating tumor cell (CTC) detection method with PD-L1 evaluation on CTCs. A set of melanoma cell surface markers was tested as candidates for targeted melanoma CTC isolation and a melanoma specific immunostaining-based CTC identification protocol combined with PD-L1 detection was established. In vitro testing of the effect of exposure to blood cells on melanoma cell PD-L1 expression was undertaken. Immunomagnetic targeting isolated melanoma CTCs in up to 87.5% of stage IV melanoma patient blood samples and 3 8.6% of these had some PD-L1 expressing CTCs. Our in vitro data demonstrate PD-L1 induction on melanoma cells in the blood.This study established a robust, reliable method to isolate melanoma CTCs and detect expression of PD-L1 on these cells.

Patterns of adjuvant therapy use and survival outcomes in patients with rectal cancer not receiving neoadjuvant therapy in an Australian cohort

675

Background: Consensus international guidelines recommend the use of neoadjuvant chemo-radiotherapy in patients with stage II-III rectal cancer. Despite this, due to factors including inaccurate/under-staging, patient co-morbidities and acute presentations, a proportion will undergo up-front surgical resection. The survival benefit of adjuvant therapy is unclear in this real world, non-trial population. Methods: A retrospective analysis of patients presenting with stage II-III rectal adenocarcinoma in South Western Sydney and Illawarra Shoalhaven Health Districts, Australia, between 2006 to 2015 was performed. Data was extracted from electronic health records, with institutional ethics approval. Treatment modalities, clinicopathological, recurrence and survival data were analyzed. The primary endpoint was overall survival (OS) by treatment modality. Results: 549 patients were identified, of which 295 (54%) underwent up-front surgical resection without neoadjuvant therapy. Of this cohort, 137 (46%) had no adjuvant therapy (Group A), 103 (35%) had adjuvant chemotherapy alone (Group B), and 55 (19%) had adjuvant radiotherapy +/- chemotherapy (Group C). Receipt of any adjuvant treatment was significantly associated with improved OS (5 year OS 56 vs. 79%, HR 0.44, 95% CI 0.3 – 0.6, p < 0.0001) and recurrence free survival (5 yr RFS 25% vs. 47%, HR 0.66, 95% CI 0.5 – 0.9, p=0.01), but not cancer specific survival (5yr CSS 75 vs. 80%, HR 0.78, 95% CI 0.5 – 1.3, p = 0.30). Group B had improved OS compared to Group A (5 yr OS 56% vs. 80%, HR 0.35, 95% CI 0.22 – 0.55, p < 0.0001). There was a trend to improved OS in Group C vs. Group A (5yr OS 56.0% vs. 69.2%, HR 0.79 95% CI 0.6 – 1.01, p = 0.052). The improved OS in Group B versus Group A remained significant in multivariate analysis (HR 0.41, 95% CI 0.22 – 0.77, p = 0.005). Conclusions: Adjuvant chemotherapy improved OS in this real world cohort, and there was a trend to a benefit with adjuvant chemo-radiotherapy. However, the lack of difference in cancer specific survival suggests that this benefit may be partly driven by patient selection bias. Further exploratory analyses to identify sub-groups deriving a cancer specific survival benefit are required.

Rectal cancer treatment and outcomes in elderly patients treated with curative intent

678

Background: There is limited information on outcomes in elderly patients with rectal cancer as they are often excluded from clinical trials. This study aimed to assess treatment patterns and outcomes in these patients. Methods: We utilised data from electronic records to identify patients aged ≥ 70 years with a histological diagnosis of rectal cancer from 2006-2015, treated in the South Western Sydney and Illawarra Shoalhaven Local Health Districts, Australia. Treatment modalities, recurrence and survival data were analysed. Results: We identified 942 patients with rectal cancer, with median follow-up of 3.4 years. 393 patients (42%) were aged ≥ 70 years. Median age of this cohort was 77 years (range 70–96 years). Elderly patients were more likely to present with locoregional disease (stage I-III, 83% vs. 75%) and more likely to receive palliative treatment only (21% vs. 16%, p = 0.0005). Of 704 patients who received treatment with curative intent, 300 (43%) were ≥ 70 years. Although clinicopathological features were similar between elderly and young patients, patients ≥ 70 years were more likely to be treated with surgery alone (56% vs. 28%, p < 0.0001), less likely to receive neoadjuvant (25% vs. 44%, p < 0.0001) or adjuvant treatments (29% vs. 55%, p < 0.0001), or be discussed in a multidisciplinary meeting (51% vs. 61%, p = 0.001). Compared to younger patients, elderly patients had a significantly poorer overall survival (HR 2.9, 95% CI 2.2 – 3.7, p < 0.0001). There were no significant differences in cancer specific survival (HR 1.4, 95% CI 0.98 – 2.0, p = 0.06) or relapse free survival (HR 0.92, 95% CI 0.7 – 1.2, p = 0.60). Conclusions: Although more elderly patients were treated with palliative intent compared to younger patients, the majority of elderly rectal cancer patients were still treated with curative intent. Most had surgery alone. Uptake of neoadjuvant and adjuvant therapy, as well as multidisciplinary involvement, was lower. Elderly patients had similar cancer-specific outcomes compared to younger patients, supporting curative intent treatment in these patients. Further analyses are underway to identify subgroups in the elderly population who benefit from trimodality therapy, and potential differences in their disease biology.

Safety and Efficacy of Oxaliplatin Doublet Adjuvant Chemotherapy in Elderly Patients With Stage III Colon Cancer

BACKGROUND

Colon cancer is common in the elderly, but owing to under representation in clinical trials, the benefit of standard therapies is uncertain in this age group. We aimed to clarify the efficacy and complications of adjuvant oxaliplatin and fluoropyrimidine chemotherapy for patients 70 years and older with stage III colon cancer.

PATIENTS AND METHODS

All patients with stage III colon adenocarcinoma were identified from an Australian cancer registry (2006-2013). Multivariable Cox hazard regression was used to determine prognostic factors for all-cause mortality. Chemotherapy complications were quantified using discontinuation rates, hospital admissions, and mortality for 12 months after starting chemotherapy.

RESULTS

A total of 2164 patients fulfilled our inclusion criteria, including 1080 (49.9%) patients ≥ 70 years. Patients ≥ 70 years were less likely to receive adjuvant chemotherapy (60.7% vs. 89.6%) or oxaliplatin doublet chemotherapy (18.8% vs. 71.2%). Older patients receiving oxaliplatin were more likely to cease treatment early (18.7% vs. 7.6%) and require hospital admission (67.0% vs. 53.5%). The addition of oxaliplatin provided an overall survival benefit for patients < 70 years (hazard ratio, 0.44; 95% confidence interval, 0.3-0.6; P < .0001) and for patients ≥ 70 years (hazard ratio, 0.64; 95% confidence interval, 0.5-0.9; P = .005).

CONCLUSIONS

Despite a modestly increased rate of hospital admission and early chemotherapy cessation, we demonstrate a persistent survival benefit for the addition of oxaliplatin to a fluoropyrimidine as adjuvant treatment for stage III colon cancer in elderly patients.

Cryopreservation for delayed circulating tumor cell isolation is a valid strategy for prognostic association of circulating tumor cells in gastroesophageal cancer

AIM

To demonstrate the feasibility of cryopreservation of peripheral blood mononuclear cells (PBMCs) for prognostic circulating tumor cell (CTC) detection in gastroesophageal cancer.

METHODS

Using 7.5 mL blood samples collected in EDTA tubes from patients with gastroesopheagal adenocarcinoma, CTCs were isolated by epithelial cell adhesion molecule based immunomagnetic capture using the IsoFlux platform. Paired specimens taken during the same blood draw (n = 15) were used to compare number of CTCs isolated from fresh and cryopreserved PBMCs. Blood samples were processed within 24 h to recover the PBMC fraction, with PBMCs used for fresh analysis immediately processed for CTC isolation. Cryopreservation of PBMCs lasted from 2 wk to 25.2 mo (median 14.6 mo). CTCs isolated from pre-treatment cryopreserved PBMCs (n = 43) were examined for associations with clinicopathological variables and survival outcomes.

RESULTS

While there was a significant trend to a decrease in CTC numbers associated with cryopreserved specimens (mean number of CTCs 34.4 vs 51.5, P = 0.04), this was predominately in samples with a total CTC count of > 50, with low CTC count samples less affected (P = 0.06). There was no significant association between the duration of cryopreservation and number of CTCs. In cryopreserved PBMCs from patient samples prior to treatment, a high CTC count (> 17) was associated with poorer overall survival (OS) (n = 43, HR = 4.4, 95%CI: 1.7-11.7, P = 0.0013). In multivariate analysis, after controlling for sex, age, stage, ECOG performance status, and primary tumor location, a high CTC count remained significantly associated with a poorer OS (HR = 3.7, 95%CI: 1.2-12.4, P = 0.03).

CONCLUSION

PBMC cryopreservation for delayed CTC isolation is a valid strategy to assist with sample collection, transporting and processing.

The urokinase plasminogen activation system in gastroesophageal cancer: A systematic review and meta-analysis

Background

The urokinase plasminogen activation (uPA) system is a crucial pathway for tumour invasion and establishment of metastasis. Although there is good evidence that uPA system expression is a clinically relevant biomarker in some solid tumours, its role in gastroesophageal cancer is uncertain.

Results

We identified 22 studies encompassing 1966 patients which fulfilled the inclusion criteria. uPA, uPAR, or PAI-1 expression is significantly associated with high risk clinicopathological features. High uPA expression is associated with a shorter RFS (HR 1.90 95% 1.16–3.11, p = 0.01) and OS (HR 2.21 95% CI 1.74–2.80, p < 0.0001). High uPAR expression is associated with poorer OS (HR 2.21 95%CI 1.82–2.69, p < 0.0001). High PAI-1 expression is associated with shorter RFS (HR 1.96 96% CI 1.07–3.58, p = 0.03) and OS (HR 1.84 95%CI 1.28–2.64, p < 0.0001). There was no significant association between PAI-2 expression and OS (HR 0.97 95%CI 0.48–1.94, p < 0.92) although data was limited.

Materials and Methods

We undertook a systematic review evaluating expression of uPA, urokinase plasminogen activator receptor (uPAR), plasminogen activator inhibitor-1 (PAI-1/SerpinE1) and plasminogen activator inhibitor-2 (PAI-2/SerpinB2) on primary oesophageal, gastro-oesophageal junction, and gastric adenocarcinomas. We performed a meta-analysis of clinicopathological associations, overall survival (OS) and recurrence free survival (RFS).

Conclusions

We conclude that the uPA system is a clinically relevant biomarker in primary gastroesophageal cancer, with higher expression of uPA, uPAR and PAI-1 associated with higher risk disease and poorer prognosis. This also highlights the potential utility of the uPA system as a therapeutic target for improved treatment strategies.

Deflexifol (a novel formulation of 5FU): Phase 1 dose escalation study of infusional and bolus schedules after failure of standard treatment

2529

Background: 5-Fluorouracil (5FU) is administered in combination with leucovorin (LV) to enhance clinical activity. However, simultaneous administration is not feasible as 5FU and LV are chemically incompatible, so the maximum possible interaction for benefit is not achieved Deflexifol, an all in one formulation of 5FU/LV with cyclodextrin (HP-β-CD 100mg/ml, 5-FU 15mg/ml & LV 1mg/ml) at physiological pH, was developed to improve efficacy and tolerance. Methods: A phase I dose-escalation trial to assess the safety, tolerability, MTD and DLT of Deflexifol given in two schedules has been completed. Secondary objectives included the pharmacokinetic (PK) profile and efficacy outcomes. Cohorts of patients with advanced malignancy after failure of standard treatment received Deflexifol as 46-h infusion Q2W or bolus weekly x6 in a standard 3+3 phase I design with no intra-patient dose escalation from dose level 1: 375mg/m² bolus or 1200mg/m² infusional up to dose level 5: 575mg/m² bolus or 3600mg/m² infusional. PK sampling of 5FU and dihydroFU was conducted on all patients to assess PK variability and adequacy of dosing. Results: 40 patients (21 infusional, 19 bolus) with breast (7), colorectal (24), other GI (6) & NSCLC (3) received a total 293 courses of treatment. No > grade 1 toxicity was noted at 375-475 mg/m2 bolus, or at 1200-2400 mg/m2 infusion. The DLT in bolus schedule was grade 3 diarrhea and myelosuppression at 575 mg/m2, with no DLT in the infusion schedule at the maximum dose 3600 mg/m2. The MTD have been established for both treatment arms: bolus 525mg/m²; 46-h infusion 3,600mg/m², with no grade IV toxicity observed. Other grade 3 toxicities were nausea, vomiting, and raised liver function tests. 5FU PK in this mixture is similar to 5FU alone. Encouraging efficacy results were seen with partial response in 1 patient and stable disease in 23 patients. Median PFS was (12.3 wks) and OS was (24.8 wks). Conclusions: Deflexifol has little toxicity and is effective in bolus and infusion schedules at doses equal to or greater than those feasible with 5FU and LV infused separately. A first-line phase II study in combination with oxaliplatin is planned. Clinical trial information: 044867.

Deflexifol (a novel formulation of 5FU): Pharmacokinetics in a phase 1 trial in comparison to 5FU

2530

Background: Simultaneous administration of 5-fluorouracil (5FU) and leucovorin (LV) is generally not feasible as 5FU and LV are chemically incompatible (CaPO4 crystals), so the maximum possible interaction for benefit is not achieved. Deflexifol, an all in one formulation of 5FU/LV with cyclodextrin (HP-β-CD 100mg/ml, 5-FU 15mg/ml & LV 1mg/ml) at pH 7, was developed to overcome this problem. Methods: Limited sampling PK was done with dose 1 and 6 in a standard 3+3 phase I trial of Deflexifol given in two schedules (46-h infusion Q2W or bolus weekly x6) with no intrapatient dose escalation, at doses shown in Table. Sample times were infusion: 0, 2, 46h; bolus: 0, 0.2, 0.4, 1, 24h. 5FU and dihydroFU were measured as per Ackland et al, Anal Biochem 1997. 5FU AUC, clearance (CLR) and t1/2 were estimated for each patient to assess PK variability and adequacy of dosing compared to previous reports. Results: 40 patients were treated (21 infusion, 19 bolus, median age 67, 19 M, 21 F). The MTD(bolus) was 575 mg/m2, with no DLT in infusion schedule to 3600 mg/m2. PK showed substantial inter-patient variability – CLR(bolus) 21-900 L/h, t1/2 0.11-0.52 h, with intra-patient dose 6 CLR = 54-117% of dose 1, and a trend to increased AUC (mg/L.h) with dose (Table). Infusion CLR and AUC estimates were highly variable (CLR range 2-1200), with many cases with insufficient data. Compared to historical data with 5FU alone, AUC was likely subtherapeutic until 475mg/m2 bolus and for many patients with infusion <3000mg/m2. Conclusions: 5FU PK with Deflexifol is similar to 5FU alone. No evidence of saturation of kinetics over this dose range was seen, or induction of metabolism with repeated dosing. In each schedule AUC data supports the clinical impression of reduced toxicity at the same dose of 5FU. Accurate estimation of infusion PK requires more than 2 timepoints. PK in a phase II study is planned. Clinical trial information: 044867. [Table: see text]

Sidedness is prognostic in locoregional colon cancer: an analysis of 9509 Australian patients

BACKGROUND/AIM

Right sided colon cancer (RsCC) is proposed to be a distinct disease entity to left sided colon cancer (LsCC). We seek to confirm primary tumour location as an independent prognostic factor in locoregional colorectal cancer.

METHODS

All patients with stage I - III primary adenocarcinoma of colon were identified from the New South Wales (NSW) clinical cancer registry (2006-2013). Primary tumour location (RsCC vs LsCC) survival analyses were conducted using the Kaplan-Meier method, and adjusted hazard ratios for 5-year all-cause mortality (OS) and 5-year cancer specific mortality (CSS) were obtained using Cox proportional hazards regression.

RESULTS

We identified 9509 patients including 5051 patients with RsCC and 4458 with LsCC. Patients with RsCC were more likely to be older, female, have a higher Charlson comorbidity index, and have worse tumour prognostic factors. In univariate analysis of all stages combined, those patients with RsCC had a worse overall survival (OS, HR 1.20 95% CI 1.11-1.29, p < 0.0001), although this was not significant in the multivariate analysis (HR 0.96 95% CI 0.89-1.04, p = 0.35). Stage I patients with RsCC had a trend to improved OS (multivariate HR 0.84 95% CI 0.69-1.01, p = 0.07) and a significantly improved CSS (multivariate HR 0.51 95% CI 0.35-0.75, p = 0.0006). In stage II patients with RsCC there was a significantly improved OS (multivariate HR 0.85 95% CI 0.75-0.98, p = 0.02) and CSS (multivariate HR 0.59 95% CI 0.45-0.78, p = 0.0002) compared to LsCC. In stage III patients, those with RsCC had a worse OS (multivariate HR 1.13 95% CI 1.01-1.26, p = 0.032) and a trend to worse CSS (multivariate HR 1.12 95% CI 0.94-1.33, p = 0.22).

CONCLUSIONS

Primary tumour location is an important prognostic factor in locoregional colon cancer with an effect that varies by stage. RsCC is associated with lower all-cause mortality in stage II, and higher all-cause mortality in stage III.

Phase 1 study of infusional or bolus deflexifol (a novel formulation of 5FU, folinic acid, and cyclodextrin) after failure of standard treatment

TPS812

Background: 5FU is a commonly used anti-cancer agent first synthesized in 1957, and is now most commonly used in combination with FA, which enhances its clinical activity. Physical incompatibilities between 5FU and LV necessitate the infusion of each component separately, often through a central line due to high pH; resulting in adverse events, which leads to poor outcomes due to treatment interruption and discontinuation. A novel all in one reformulation of 5FU/LV at physiological pH has been developed as an alternative to serial administration of 5FU and LV in a high Ph solution [Locke JM, Anticancer Drugs 2009]. Preclinical testing demonstrated that the reformulation is stable bioequivalent to 5FU with reduced side effects [Stutchbury TK, Anticancer drugs 2011]. Methods: An open label phase 1 dose escalation study is underway in 2 schedules (bolus and infusion) to assess the safety and tolerability in patients with advanced malignancy after failure of standard treatment (including fluoropyrimidine regimens). To determine the maximum tolerated dose defined as: 2 out of 6 patients experience DLTs dose escalation is halted and declared DLT Dose. The previous dose level will be considered for expansion to x6 patients to confirm Maximum Tolerated Dose (MTD). Also to determine pharmacokinetic profile. Patients enrolled in Cohorts 1 to 4, have been completed without DLT. Dose-limiting toxicity (DLT) is defined as: Any Grade 3 or 4 non-haematologic toxicity (CTACE criteria). Patients developing Grade 3 or 4 diarrhoea, failing maximal anti-diarrheal medications. Febrile neutropenia, Grade 4 neutropenia > 7 days, Grade 4 thrombocytopenia > 7 days Any grade of thrombocytopenia associated with bleeding. Currently proceeding with (bolus 575mg/m2 weekly x 6, infusion 3600mg/m2/46h q2W). Limited sampling PK of 5-FU and dihydoFU is being conducted (3 at each of the 5 dose levels, doses 1 and 6). In both schedules to assess PK variability, adequacy of dosing in comparison to previous reports. The incidence of AEs and SAEs (CTACE 4.03) will be summarized by severity and relationship to study treatment. Clinical trial information: 044867.

Anticancer activity of combination targeted therapy using cetuximab plus vemurafenib for refractory BRAF (V600E)-mutant metastatic colorectal carcinoma

Mismatch-repair-deficient colorectal cancers often contain kinase-activating V600E BRAF mutations, but no clinical utility has yet been demonstrated in this setting for monotherapy using oral braf kinase inhibitors such as vemurafenib or dabrafenib. Recent studies have indicated that tumour resistance to braf inhibition is mediated by upregulated epidermal growth factor receptor (egfr) signalling, disruption of which is a routine treatment strategy in KRAS wild-type colorectal cancer. In this report, we describe the clinical course of a heavily pretreated patient who elected to receive off-label dual-targeted braf- and egfr-inhibitory therapy with good tolerance and apparent clinical benefit.

Complete Radiologic Response of Bulky Cerebral Metastases From Newly Diagnosed HER2-Positive Breast Cancer to Upfront Trastuzumab-Based Chemotherapy

The blood-brain barrier is traditionally regarded as an insurmountable obstacle to the effective drug therapy of brain metastases from solid tumors. Here we describe a striking case of complete radiologic response to chemotherapy, and propose that the critical success factors include the large tumor size, HER2-positivity, and concomitant use of trastuzumab.