Strengthening Biomarker Research in Canadian Cancer Clinical Trials: A Pathology-Focused White Paper

Pathology is foundational to biomarker-driven and translational oncology research, yet systemic barriers limit full pathology engagement in Canadian cancer clinical trials, compromising the tissue-based questions such trials are designed to answer. This commentary and white paper synthesizes the perspectives of a national pathology working group convened at the 2025 Canadian Cancer Trials Group (CCTG) Annual General Meeting with a descriptive internal audit of the CCTG Tumour Tissue Data Repository (TTDR), in which biospecimen attrition was tabulated at the patient level by disease site; no inferential testing was performed. The TTDR data revealed substantial attrition across disease sites, with no tissue submitted for 32-44% of patients and slides submitted in place of formalin-fixed paraffin-embedded blocks for up to 51% of cases, reflecting persistent misalignment between protocol expectations and laboratory capacity. From these observations, five interrelated gaps were identified-in trial design, funding and resourcing, digital pathology infrastructure, academic recognition, and knowledge translation around consent and ethics governance. Five corresponding strategies are proposed to align research demands with pathology capacity, reduce attrition, and strengthen biomarker-driven trials. As a consensus- and experience-driven analysis rather than a systematic review, these recommendations are intended to frame a national conversation and a starting point for prospective evaluation.