Current Role of Immunotherapy in Gastric, Esophageal and Gastro-Esophageal Junction Cancers-A Report from the Western Canadian Gastrointestinal Cancer Consensus Conference.

Gastric, esophageal and gastro-esophageal junction cancers are associated with inferior outcomes. For early-stage disease, perioperative chemotherapy or chemoradiation followed by surgery is the standard treatment. For most patients with advanced upper gastrointestinal tract cancers, platinum-based chemotherapy remains a standard treatment. Recently, several randomized clinical trials have demonstrated the benefit of immunotherapy involving checkpoint inhibitors alone or in combination with chemotherapy in patients with gastro-esophageal cancer and have changed the treatment landscape. The Western Canadian Gastrointestinal Cancer Consensus Conference (WCGCCC), involving experts from four Western Canadian provinces, convened virtually on 16 June 2021 and developed the recommendations on the role of immunotherapy in patients with gastro-esophageal cancer.

Systemic Therapy and Its Surgical Implications in Patients with Resectable Liver Colorectal Cancer Metastases. A Report from the Western Canadian Gastrointestinal Cancer Consensus Conference.

The Western Canadian Gastrointestinal Cancer Consensus Conference (WCGCCC) convened virtually on 4 November 2021. The WCGCCC is an interactive multi-disciplinary conference attended by health care professionals, including surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals from across four Western Canadian provinces, British Columbia, Alberta, Saskatchewan, and Manitoba, who are involved in the care of patients with gastrointestinal cancer. They participated in presentation and discussion sessions for the purpose of developing recommendations on the role of systemic therapy and its optimal sequence in patients with resectable metastatic colorectal cancer.

BRAF V600E mutation and MET amplification as resistance pathways of the second-generation anaplastic lymphoma kinase (ALK) inhibitor alectinib in lung cancer.

BACKGROUND: Anaplastic lymphoma kinase (ALK) targeted therapies have demonstrated remarkable efficacy in ALK-positive lung adenocarcinomas. However, patients inevitably develop resistance to such therapies. To investigate novel mechanisms of resistance to second generation ALK inhibitors, we characterized and modeled ALK inhibitor resistance of ALK-positive patient-derived xenograft (PDX) models established from advanced-stage lung adenocarcinoma patients who have progressed on one or more ALK inhibitors. METHODS: Whole exome sequencing was performed to identify resistance mechanisms to ALK inhibitors in PDXs generated from biopsies at the time of relapse. ALK fusion status was confirmed using fluorescent in situ hybridization, immunohistochemistry, RNA-sequencing, RT-qPCR and western blot. Targeted therapies to overcome acquired resistance were then tested on the PDX models. RESULTS: Three PDX models were successfully established from biopsies of two patients who had progressed on crizotinib and/or alectinib. The PDX models recapitulated the histology and ALK status of their patient tumors, as well as their matched patients' clinical treatment outcome to ALK inhibitors. Whole exome sequencing identified MET amplification and previously unreported BRAF V600E mutation as independent mechanisms of resistance to alectinib. Importantly, PDX treatment of inhibitors specific for these targets combined with ALK inhibitor overcame resistance. CONCLUSIONS: Bypass signaling pathway through c-MET and BRAF are independent mechanisms of resistance to alectinib. Individualized intervention against these resistance pathways could be viable therapeutic options in alectinib-refractory lung adenocarcinoma.