Cautious optimism—the current role of immunotherapy in gastrointestinal cancers

  • S. Mendis BC Cancer
  • S. Gill BC Cancer
Keywords: Gastrointestinal Neoplasm, Esophageal Neoplasms, Stomach Neoplasm, Hepatocellular Cancer, Colorectal Neoplasms, Monoclonal antibodies, Immunological antineoplastic agents, Microsatellite Instability


Immunotherapy has been described as the “fourth pillar” of oncology treatment, in conjunction with surgery, chemotherapy, and radiotherapy. However, the role of immunotherapy in gastrointestinal tumours is still evolving. Data for checkpoint inhibition in esophagogastric, hepatocellular, colorectal, and anal squamous cell carcinomas are expanding. In phase iii trials in the second-line setting, PD-1 inhibitors have demonstrated positive results for the subset of esophageal cancers that are positive for PD-L1 at a combined positive score of 10 or more. Based on results of phase ii trials, PD-1 inhibitors were approved in North America for use in PD-L1–positive chemorefractory gastric cancers, in hepatocellular carcinoma after sorafenib exposure, and in treatment refractory deficient mismatch repair (dmmr) or high microsatellite instability (msi-h) tumours, regardless of tissue site. Combination use of PD-1 and ctla-4 inhibitors has been approved by the U.S. Food and Drug Administration for chemorefractory dmmr or msi-h colorectal cancer. Responses to checkpoint inhibition are durable, particularly in the dmmr or msi-h colorectal cancer cohort. As trials of combination immunotherapy, immunotherapy in combination with other systemic therapies, and immunotherapy in combination with other treatment modalities move forward in multiple tumour sites, cautious optimism is called for. The treatment landscape is continually changing, and expanded indications are likely to be just around the corner.

Author Biographies

S. Mendis, BC Cancer

Dr Shehara Mendis is medical oncology fellow at BC Cancer. She completed a Bachelor of Medicine, Bachelor of Surgery and Bachelor of Medical Science (MBBS, BMedSci) through the University of Melbourne (Melbourne, Australia) in 2008. She completed medical oncology training and attained Fellowship of the Royal Australasian College of Physicians (FRACP) in 2016. After completing a clinical research fellowship in 2017 she moved to Vancouver to undertake a gastrointestinal translational and clinical research fellowship at BC Cancer and is concurrently completing a Masters of Cancer Sciences through the University of Melbourne.

S. Gill, BC Cancer

Dr. Sharlene Gill is a medical oncologist specializing in gastrointestinal (GI) malignancies. She received a Bachelor’s of Science in Pharmacy (Honors) and an MD (Doctor of Medicine) from the University of British Columbia in 1996 followed by residencies in Internal Medicine and Medical Oncology. Dr. Gill subsequently completed a fellowship in Gl Oncology at the Mayo Clinic (Rochester, MN) and a Master’s of Public Health from the Harvard School of Public Health (Boston, MA) before returning to Vancouver, Canada where she is presently a Professor of Medicine at the University of British Columbia and staff oncologist at the BC Cancer Agency.

Dr. Gill’s areas of expertise are colorectal, pancreatic and hepatobiliary cancers. In addition to her clinical work, she is actively engaged in education and research, with over 80 peer-reviewed publications and book chapters to her credit. 

How to Cite
Mendis, S., & Gill, S. (2019). Cautious optimism—the current role of immunotherapy in gastrointestinal cancers. Current Oncology, 27(S2).