Association of ancestry with frequency of actionable genomic alterations in colorectal cancer patients

A study at Memorial Sloan Kettering Cancer Center (New York, NY) compared molecular profiles and clinical outcomes in a large cohort (n=4,441) of colorectal cancer patients with different ancestries. Patients with African ancestry (AFR) had shorter overall survival from time of diagnosis (median 45.7 months versus 67.1 months; p<0.001). The fraction of patients who qualify for immunotherapy based on FDA guidelines was lower in AFR versus European (EUR) ethnic patients (13.5% versus 20.4%; p=0.008). AFR patients had lower rates of clinically actionable alterations than EUR patients (5.6% versus 11.2%; p=0.01); this difference was driven by a depletion of actionable BRAF mutations in the AFR group (1,8% versus 5,0%; p=0.04). Somatic APC alterations were associated with longer OS in EUR patients, East Asian patients, and South Asian patients, but not in AFR patients. The authors conclude that AFR patients had fewer clinically actionably alterations than patients from other ancestries. The prognostic value of somatic APC alterations was also lower in AFR patients.