Feature | Agenda

Last year saw the first ever biomarker-based approval in cancer. Pembrolizumab, a PD-1 inhibitor, was approved for the treatment of any and all solid tumors with a microsatellite instability-high (MSI-H) genotype resulting from deficient mismatch repair during DNA replication. MSI-H is the result of a large number of mutations and an actionable target for multiple agents, depending on tumor location. To date, pembrolizumab is the only agent with a pan-tumor indication for MSI-H. This year’s International Congress on Oncology Pathology™ will feature clinical updates on the assessment and targeting of MSI-H in order to address these advancements.

Another class of emerging biomarkers in cancer treatment are NTRK gene fusions. NTRK fusions, which can be treated by tropomyosin receptor kinase (TRK) inhibitors, result in constitutively activated chimeric TRK proteins. The resultant overexpression of kinase function is ultimately oncogenic. Like MSI-H, treatments for NTRK gene fusions have taken a tumor agnostic approach. Understanding the role of TRK inhibition is an essential step in meeting the future of cancer treatment. NTRK and TRK inhibition is just one of the many topics covered at this year’s meeting!

Even with the wide-reaching applications described, tumor-specific biomarkers are still an essential aspect of treatment. Breast cancer treatment is dependent on HER2 status, estrogen-receptor status, and progesteronereceptor status. In treating lung cancer, it is essential pathologists and oncologists test for various mutations, including EGFR, ALK, BRAF, and ROS1. These and more are encountered across multiple cancer types, where other biomarkers include RAS, NRAS, PIK3CA, TP53, MET, and so many more. Understanding the role of these mutations in cancer pathogenesis, and integrating the latest clinical data into practice, is an essential skill for all oncologists and pathologists.