Cancer, Clinical Trials, and Canada: Our Contribution to Worldwide Randomized Controlled Trials.

Canada has a long tradition of leading practice-changing clinical trials in oncology. Here, we describe methodology, results, and interpretation of oncology RCTs with Canadian involvement compared to RCTs from other high-income countries (HICs). A literature search identified all RCTs evaluating anti-cancer therapies published 2014-2017. RCTs were classified based on the country affiliation of first authors. The study cohort included 636 HIC-led RCTs; 155 (24%) had Canadian authors. Three-quarters (112/155, 72%) of Canadian RCTs were conducted in the palliative setting, compared to two thirds (299/481, 62%) of RCTs from other HICs (p = 0.022). Canadian RCTs were more likely than those from other HICs to be supported by industry (85% vs. 69%, p < 0.001). The proportion of positive Canadian trials that met the ESMO-MCBS threshold for substantial clinical benefit was comparable to RCTs without Canadian authors (29% vs. 32%, p = 0.137). Thirteen percent (20/155) of all Canadian trials were affiliated with the Canadian Cancer Trials Group (CCTG). Canada plays a meaningful role in the global cancer research ecosystem but is overly reliant on industry support. The very low proportion of trials that identify a new treatment with substantial clinical benefit is worrisome. A renewed investment in cancer clinical trials is needed in Canada.