PIK3CA and cancer: Although some caution is required when interpreting these data as they were non-randomised and the number of patients with mutated PIK3CA who regularly used aspirin was small (n = 66), the results are striking, with a multivariate HR for cancer death of 0.18 (95% CI 0.06–0.61) P < 0.001 and 0.54 (95% CI 0.31–0.94) P = 0.01 for death from any cause for those that regularly took aspirin after a diagnosis of colorectal cancer.