CHIP and mCAs increase breast cancer risk and colorectal cancer mortality. CHIP linked to higher breast cancer risk (HR, 1.30; 95% CI, 1.03-1.64; P =.02) and colorectal cancer death (HR, 2.50; 95% CI, 1.32-4.72; P = .004). mCAs with cell fraction >5% raise breast cancer risk (HR, 1.39; 95% CI, 1.06-1.83; P =.01) and colon cancer death (HR, 2.19; 95% CI, 1.11-4.3; P =.02).