Impact of regular aspirin use on overall and cancer-specific survival in patients with colorectal cancer harboring a PIK3CA mutation

<div><p></p><p><b>Background.</b> Recent data have suggested that regular aspirin use improves overall and cancer-specific survival in the subset of colorectal cancer (CRC) patients harboring <i>PIK3CA</i> mutations. However, the number of <i>PIK3CA</i>-mutated CRC patients examined in these studies was modest. Our collaborative study aims to validate the association between regular aspirin use and survival in patients with <i>PIK3CA</i>-mutated CRC.</p><p><b>Patients and methods.</b> Patients with <i>PIK3CA</i>-mutated CRC were identified at Moffitt Cancer Center (MCC) in the United States and Royal Melbourne Hospital (RMH) in Australia. Prospective clinicopathological data and survival data were available. At MCC, <i>PIK3CA</i> mutations were identified by targeted exome sequencing using the Illumina GAIIx Next Generation Sequencing platform. At RMH, Sanger sequencing was utilized. Multivariate survival analyses were conducted using Cox logistic regression.</p><p><b>Results.</b> From a cohort of 1487 CRC patients, 185 patients harbored a <i>PIK3CA</i> mutation. Median age of patients with PIK3CA-mutated tumors was 72 years (range: 34–92) and median follow up was 54 months. Forty-nine (26%) patients used aspirin regularly. Regular aspirin use was not associated with improved overall survival (multivariate HR 0.96, p = 0.86). There was a trend towards improved cancer-specific survival (multivariate HR 0.60, p = 0.14), but this was not significant.</p><p><b>Conclusions.</b> Despite examining a large number of patients, we did not confirm that regular aspirin use was associated with statistically significant improvements in survival in PIK3CA-mutated CRC patients. Prospective evaluation of this relationship is warranted.</p></div>