A Canadian single-centre experience with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for abdominal malignancies.

BACKGROUND: Cytoreductive surgery in combination with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) has recently shown promise for the treatment of patients with various types of peritoneal carcinomatosis (PC). However, it is an extensive procedure that is associated with a variety of morbidities. We evaluated the safety and clinical outcomes of CRS-HIPEC performed at our centre. METHODS: Patients with abdominal malignancies who underwent CRS-HIPEC between February 2005 and December 2018 at the Centre hospitalier de l'Université de Montréal (CHUM) were retrospectively reviewed. RESULTS: A total of 141 patients were identified (66 with appendiceal cancer, 62 with colorectal cancer, 10 with mesothelioma and 3 with small intestinal tumours). The median age was 55 years. Median overall survival (OS) was not reached for patients with appendiceal tumours; it was 38.3 months for colorectal cancers. Among patients with colorectal cancer, survival was significantly better for those who received intraperitoneal HIPEC with oxaliplatin (74.9 mo) compared with mitomycin C (29.1 mo) (p = 0.006). Complete cytoreductive surgery and low peritoneal carcinomatosis index were associated with the highest overall survival in patients with appendiceal tumours and those with colorectal tumours. CONCLUSION: CRS-HIPEC can be performed with acceptable morbidity in patients with PC. These results validate the outcomes of previously reported trials, but further prospective trials are warranted to determine which patients will most benefit from the addition of HIPEC to CRS.

Implementing DPYD*2A Genotyping in Clinical Practice: The Quebec, Canada, Experience.

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.

The prognostic impact of KRAS, TP53, STK11 and KEAP1 mutations and their influence on the NLR in NSCLC patients treated with immunotherapy.

BACKGROUND: PD-L1 expression is used to predict NSCLC response to ICIs, but its performance is suboptimal. The impact of KRAS mutations in these patients is unclear. Studies evaluating co-mutations in TP53, STK11 and KEAP1 as well as the NLR showed that they may predict the benefit of ICIs. PATIENTS & METHODS: This is a retrospective study of patients with NSCLC treated with ICIs at the CHUM between July 2015 and June 2020. OS and PFS were compared using Kaplan-Meier and logrank methods. Co-mutations in TP53, STK11 and KEAP1 as well as the NLR were accounted for. ORR and safety were compared using Wald method. RESULTS: From 100 patients with known KRAS status, 50 were mutated (KRASMut). Mutation in TP53, STK11 and KEAP1 were present, and their status known in, respectively, 19/40 (47.5 %), 8/39 (20.5 %) and 4/38 (10.5 %) patients. STK11Mut and KEAP1Mut were associated with shorter overall survival when compared with wild type tumors (respectively median OS of 3.3 vs 20.4, p = 0.0001 and 10.1 vs 17.7, p = 0.24). When KRAS status was compounded with STK11/KEAP1, KRASMut trended to a better prognosis in STK11+KEAP1WT tumors (median OS 21.1 vs 15.8 for KRASWT, p = 0.15), but not for STK11+/-KEAP1Mut tumors. The NLR was strongly impacted by STK11 (6.0Mutvs 3.6WT, p = 0.014) and TP53 (3.2Mutvs 4.8WT, p = 0.048), but not by KEAP1 or KRAS mutations. CONCLUSION: STK11Mut and KEAP1Mut are adverse predictors of ICI therapy benefit. The NLR is strongly impacted by STK11Mut but not by KEAP1Mut, suggesting differences in their resistance mechanism. In STK11-KEAP1WT tumors, KRASMut seem associated with improved survival in NSCLC patients treated with ICIs. MICROABSTRACT: Response of NSCLC to immunotherapy is not easily predictable. We conducted a retrospective study in 100 patients with NSCLC and a known KRAS status. By accounting for different co-mutations, KRAS mutation was found to be associated with a better median overall survival in STK11 and KEAP1 wild-type tumors (21.1 vs 15.8, p = 0.15). NLR was impacted by STK11, but not KEAP1 mutation, suggesting a difference in their resistance mechanism.

COVID-19 Impact on Diagnosis and Staging of Colorectal Cancer: A Single Tertiary Canadian Oncology Center Experience.

BACKGROUND: Public health measures have imposed drastic reductions in cancer screening programs at the beginning of the COVID-19 pandemic, with an unknown impact on the diagnosis and staging of colorectal cancer (CRC). METHODS: Newly diagnosed CRC cases at the Centre Hospitalier de l'Université de Montréal (CHUM) were divided into two groups according to the timeline: pre-pandemic (1 January 2018-12 March 2020), and pandemic (13 March 2020-30 June 2021) periods. Colonoscopy, surgery, and staging at diagnosis during the pandemic period were compared to the pre-pandemic period. RESULTS: 254 CRC diagnoses were made during the pre-pandemic period in comparison to 125 during the pandemic period. Mean diagnosis rates were lower in the pandemic period (7.8 vs. 9.8 diagnoses/month, p = 0.048). Colonoscopy deadlines were less respected in the pandemic period (51.7% vs. 38.3%, p = 0.049). The rate of elective surgery did not differ (2.9 vs. 3.5 surgeries/month, p = 0.39) and mean delays were similar (58.6 vs. 60.4 days, p = 0.77). Stages at diagnosis did not differ (p = 0.17). Most of the delayed colonoscopies led to a stage 0 or I CRC (p = 0.2). CONCLUSION: In our center, the COVID-19 pandemic resulted in a decreased rate of CRC diagnosis and increased endoscopic delays without affecting the rate of advanced stage disease. Delays to surgery were quite similar once the CRC diagnosis was established.

Outcomes of Older Patients with Resectable Colorectal Liver Metastases Cancer (CRLM): Single Center Experience.

Surgery is the only potential curative option of CRLM if resectable. The curative approach in patients over 70 years old is challenging mainly because of comorbidities and other geriatric syndromes. Herein, we report outcomes of older patients with resectable CRLM in our center. We retrospectively analyzed characteristics and outcomes of older patients with CRLM operated at "Centre Hospitalier de l'Université de Montréal" (CHUM) between 2010 and 2019. We identified 210 patients aged ≥70 years with a median age of 76 (range: 70-85). CRLM were synchronous in 56% of patients. Median disease-free survival (DFS) was 41.3 months. Median overall survival (OS) was 62.2 months and estimated 5-year survival rate was 51.5% similar to those of younger counterparts. Patients with metachronous CRLM had a trend to a higher OS compared to those with synchronous disease (67.2 vs. 58.7 months; p = 0.42). Factors associated with lower survival in the multivariate analysis were right-sided tumors and increased Charlson Comorbidity index (CCI). Survival outcomes of patients aged ≥70 years were comparable to those of younger patients and those reported in the literature. Age should not be a limiting factor in the curative management of older patients with resectable CRLM.

A Pan-Canadian Validation Study for the Detection of EGFR T790M Mutation Using Circulating Tumor DNA From Peripheral Blood.

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.

Eastern Canadian Gastrointestinal Cancer Consensus Conference 2019.

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.

Impact of abiraterone on patient-related outcomes in metastatic castration-resistant prostate cancer: current perspectives.

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.