STING: STING and DNA damage repair markers as predictors of response to chemotherapy and immunotherapy in gastric and oesophageal cancer

Stomach and oesophagus cancers account for 5.2% of cancer-related death in Australia. This is partly due to the large proportion of disease diagnosed at an incurable stage. Even those amenable to curative intent treatment experience high rates of recurrence and those with advanced disease respond poorly to treatment relative to other cancers. Personalising treatment offers the chance to avoid unnecessary toxicities, improve patient outcomes and reduce the potential financial and resource burden on healthcare systems.

DNA damage repair pathways stand at the crossroads between both traditional cytotoxic agents, radiotherapy and immune checkpoint inhibitors. Chemotherapy and radiotherapy rely on inducing excessive DNA damage to cancer cells whilst generating neoantigens which enable intrinsic immune-mediated defences to recognise and attack cancer cells. These is increasing interest in targeting DNA damage repair mechanisms to synergistically enhance responses to existing therapies in cancer.

This study aims to determine if STING expression level and haplotype analysis can improve on PD-L1 combined positive score and Immunoscore ability to predict patient survival in patients with gastric and oesophageal cancer.