NSAR improves survival in KRAS wild-type CRC
It is already well known that the regular use of aspirin is associated with improved survival for patients with colorectal cancer (CRC). What is not yet clear is which subtype of CRC would benefit the most from using aspirin (and other nonsteroidal anti-inflammatory drugs, NSAIDS), and what the timing of the NSAID-intake should be. According to the current US-American study who investigated these two issues, it is patients with KRAS wild-type tumors that have improved survival under NSAID intake, and NSAIDs have to be taken regularly after CRC diagnosis.
The study included close to 2,500 patients with incident invasive CRC, who filled out epidemiologic questionnaires at study enrollment and at 5-year follow-up. The authors then completed survival outcomes by linking the data to national death registries. BRAF- and KRAS-mutation status, microsatellite instability and CpG island methylator phenotype were also evaluated. The median follow-up after diagnosis was 10.8 years.
During follow-up, 381 patients died, 100 of which died from CRC. Post-diagnostic aspirin-only users had a more favorable overall survival (OS) than non-users (HR, 0.75) and also a more favorable CRC-specific survival (HR, 0.44). However, only patients with KRAS wild-type tumors had an improved OS after use of any NSAID after diagnosis (HR 0.60 vs. 1.24 in patients with KRAS-mutant tumors).
In this cohort of long-term CRC patients, regular use of NSAIDs after CRC diagnosis was significantly associated with improved survival only in individuals with KRAS wild-type tumors.