Background Fluoropyrimidines are used in chemotherapy combinations for multiple cancers. Deficient dihydropyrimidine dehydrogenase activity can lead to severe life‐threatening toxicities. DPYD*2A polymorphism is one of the most studied variants. The study objective was to document the impact of implementing this test in routine clinical practice. Methods We retrospectively performed chart reviews of all patients who tested positive for a heterozygous or homozygous DPYD*2A mutation in samples obtained from patients throughout the province of Quebec, Canada. Results During a period of 17 months, 2,617 patients were tested: 25 patients tested positive. All were White. Twenty‐four of the 25 patients were heterozygous (0.92%), and one was homozygous (0.038%). Data were available for 20 patients: 15 were tested upfront, whereas five were identified after severe toxicities. Of the five patients confirmed after toxicities, all had grade 4 cytopenias, 80% grade ≥3 mucositis, 20% grade 3 rash, and 20% grade 3 diarrhea. Eight patients identified with DPYD*2A mutation prior to treatment received fluoropyrimidine‐based chemotherapy at reduced initial doses. The average fluoropyrimidine dose intensity during chemotherapy was 50%. No grade ≥3 toxicities were observed. DPYD*2A test results were available in an average of 6 days, causing no significant delays in treatment initiation. Conclusion Upfront genotyping before fluoropyrimidine‐based treatment is feasible in clinical practice and can prevent severe toxicities and hospitalizations without delaying treatment initiation. The administration of chemotherapy at reduced doses appears to be safe in patients heterozygous for DPYD*2A. Implications for Practice Fluoropyrimidines are part of chemotherapy combinations for multiple cancers. Deficient dihydropyrimidine dehydrogenase activity can lead to severe life‐threatening toxicities. This retrospective analysis demonstrates that upfront genotyping of DPYD before fluoropyrimidine‐based treatment is feasible in clinical practice and can prevent severe toxicities and hospitalizations without delaying treatment initiation. This approach was reported previously, but insufficient data concerning its application in real practice are available. This is likely the first reported experience of systematic DPYD genotyping all over Canada and North America as well.

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The annual Eastern Canadian Gastrointestinal Cancer Consensus Conference was held in Halifax, Nova Scotia, 20–22 September 2018. Experts in radiation oncology, medical oncology, surgical oncology, and pathology who are involved in the management of patients with gastrointestinal malignancies participated in presentations and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses multiple topics in the management of pancreatic cancer, pancreatic neuroendocrine tumours, hepatocellular cancer, and rectal and colon cancer, including■ surgical management of pancreatic adenocarcinoma,■ adjuvant and metastatic systemic therapy options in pancreatic adenocarcinoma,■ the role of radiotherapy in the management of pancreatic adenocarcinoma,■ systemic therapy in pancreatic neuroendocrine tumours,■ updates in systemic therapy for patients with advanced hepatocellular carcinoma,■ optimum duration of adjuvant systemic therapy for colorectal cancer, and■ sequence of therapy in oligometastatic colorectal cancer.

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Abiraterone acetate has established a major role in the treatment paradigm of metastatic castration-resistant prostate cancer ever since pivotal trials, COU-AA-301 and COU-AA-302, have shown benefit in both the second-line and first-line (post- and pre-chemotherapy) setting, respectively, with improvement in overall survival as well as secondary end points such as prostate-specific antigen (PSA) and radiographic response rates, time to PSA progression, and progression-free survival. There has been a lot of interest and emphasis in the evaluation of patient-related outcomes (PROs) as it relates to quality of life, pain, adverse events, fatigue, and among others, in the use of different agents that have been shown to improve survival. This review examines the companion PROs in conjunction with abiraterone acetate use. This is particularly relevant since PROs are increasingly viewed as a key metric for drug label claims in granting approval across regulatory agencies, including the US Food and Drug Administration and the European Medicines Agency.

e21010 Background: ICIs changed the way NSCLC is treated, but not all patients benefit from it. PD-L1 level is used to predict response to therapy, but its performance is sub-optimal. KRAS is important in NSCLC tumorigenesis, but the impact of its mutations in patients treated with ICIs is unclear. Similarly, studies evaluating co-mutations in TP53, STK11 and KEAP1 as well as the NLR showed that they may predict the benefit of ICIs. Methods: We conducted a retrospective study including all consenting patients with NSCLC treated with ICIs at the CHUM between July 2015 and June 2020. OS and PFS were compared in co-mutation subgroups using Kaplan-Meier and logrank methods. Co-mutations in TP53, STK11 and KEAP1 as well as the NLR were accounted for. Overall response rate (ORR) and safety data was also compared in subgroups and will be detailed at the meeting. Results: We included 100 patients with known KRAS status. From these, 50 were wild-type ( KRASWT) and 50 were mutated ( KRASMut). The most frequent mutation was G12C (54%). Co-mutation status for TP53, STK11 and KEAP1 were known for, respectively, 40, 39 and 38 patients. Co-mutations for these genes were present in respectively 19 (47.5%), 8 (20.5%) and 4 (10.5%). Data comparing KRASMut and KRASWT showed non-significant differences in survival (median OS of respectively 21.1 vs. 17.7 months, p = 0.27). The presence of STK11 and/or KEAP1 mutations was associated with a negative impact on survival when compared with wild-type (median OS 7.4 vs 20.4 months, p = 0.001). When the presence of a KRAS mutation was compounded with STK11 and KEAP1, KRASMut (vs KRASWT) trended to a better prognosis in STK11+KEAP1WT tumors (median OS of 21.1 for KRASMut vs 15.8 for KRASWT, p = 0.15), but not in STK11+/-KEAP1Mut tumors (7.4 for KRASMut vs 7.0 for KRASWT). No influence on survival was seen in relationship to the TP53 co-mutation. Interestingly, the NLR was significantly higher with STK11 mutations (6.66Mut vs 3.59WT, p = 00012), slightly lower with TP53 mutations (3.23Mut vs 4.82WT, p = 0.047) but not impacted by KEAP1 (3.72Mut vs 4.20WT, p = 0.72) or KRAS mutations (4.32Mut vs 5.21WT, p = 0.34). Conclusions: The STK11 and KEAP1 mutations are significant adverse predictors of ICI therapy benefit. The NLR is strongly impacted by STK11 mutations but not by KEAP1 mutations suggesting marked differences in the resistance mechanism for both mutations. In STK11-KEAP1WT tumors, KRAS mutations seems to be associated with improved survival in NSCLC patient treated with ICIs.

Introduction Genotyping circulating tumor DNA (ctDNA) is a promising noninvasive clinical tool to identify the EGFR T790M resistance mutation in patients with advanced NSCLC with resistance to EGFR inhibitors. To facilitate standardization and clinical adoption of ctDNA testing across Canada, we developed a 2-phase multicenter study to standardize T790M mutation detection using plasma ctDNA testing. Methods In phase 1, commercial reference standards were distributed to participating clinical laboratories, to use their existing platforms for mutation detection. Baseline performance characteristics were established using known and blinded engineered plasma samples spiked with predetermined concentrations of T790M, L858R, and exon 19 deletion variants. In phase II, peripheral blood collected from local patients with known EGFR activating mutations and progressing on treatment were assayed for the presence of EGFR variants and concordance with a clinically validated test at the reference laboratory. Results All laboratories in phase 1 detected the variants at 0.5 % and 5.0 % allele frequencies, with no false positives. In phase 2, the concordance with the reference laboratory for detection of both the primary and resistance mutation was high, with next-generation sequencing and droplet digital polymerase chain reaction exhibiting the best overall concordance. Data also suggested that the ability to detect mutations at clinically relevant limits of detection is generally not platform-specific, but rather impacted by laboratory-specific practices. Conclusions Discrepancies among sending laboratories using the same assay suggest that laboratory-specific practices may impact performance. In addition, a negative or inconclusive ctDNA test should be followed by tumor testing when possible.

The annual Eastern Canadian Gastrointestinal Cancer Consensus Conference 2019 was held in Morell, Prince Edward Island, 19–21 September 2019. Experts in medical oncology, radiation oncology, and surgical oncology who are involved in the management of patients with gastrointestinal malignancies participated in presentations and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses multiple topics in the management of anal, colorectal, biliary tract, and gastric cancers, including: radiotherapy and systemic therapy for localized and advanced anal cancer; watch and wait strategy for the management of rectal cancer; role of testing for dihydropyrimidine dehydrogenase (DPD) deficiency prior to commencement of fluoropyrimidine therapy; radiotherapy and systemic therapy in the adjuvant and unresectable settings for biliary tract cancer; and radiotherapy and systemic therapy in the perioperative setting for early-stage gastric cancer.