NMA: Nonprescription Medicines Academy

Aspirin Offers Survival Benefit for Patients With PIK3CA-Mutated Colorectal Cancer

December 14th, 2012

For the 15% to 20% of patients with colorectal cancer who have mutations in PIK3CA (the gene encoding phosphatidylinositol-4,5-bisphosphonate 3-kinase, catalytic subunit alpha polypeptide), regular use of aspirin after diagnosis appears to offer a significant survival benefit, based on data from participants in the Nurses’ Health Study and the Health Professionals Follow-up Study. It is speculated that aspirin down-regulates phosphatidylinositol 3-kinase (PI3K) signaling activity by inhibiting prostaglandin-endoperoxide synthase 2 (PTGS2, also known as cyclooxygenase-2).

The current analysis included information for 964 study participants with rectal or colon cancer, including data on aspirin use after diagnosis and the presence or absence of PIK3CA mutation. Among patients with mutated-PIK3CA cancers, regular use of aspirin after diagnosis was associated with an 82% reduction in colorectal cancer–specific mortality (HR, 0.18; 95% CI, 0.06–0.61; P <0.001) and a 46% reduction in overall mortality (HR, 0.54; 95% CI, 0.31–0.94; P = 0.01). No survival benefit was seen among patients with wild-type PIK3CA for either colorectal cancer–specific survival (HR, 0.96; 95% CI, 0.69–1.32; P = 0.76) or overall survival (HR, 0.94; 95% CI, 0.75–1.17; P = 0.96).

The authors concluded that the PIK3CA mutation may serve as a predictive molecular biomarker for adjuvant aspirin therapy in patients with newly diagnosed colorectal cancer.

N Engl J Med. 2012;367:1596-606.