Background: CYP2C9 enzymes are involved in non-steroidal anti-inflammatory drug (NSAID) metabolism. Therefore, we investigated whether CYP2C9*2 and *3 variant alleles, encoding for enzymes with lower activity, increased the protective effect of NSAIDs on colorectal cancer. Methods: Individual and combined associations of NSAIDs and CYP2C9*2 and 3 variant alleles with colorectal cancer were studied in 7757 Caucasian individuals of The Rotterdam Study, a population-based prospective cohort since 1990. Additive and multiplicative effect modification models were used to examine drug-gene interactions. Results: There were 212 incident cases of colorectal cancer during follow-up. A reduced risk of colorectal cancer was observed in individuals who used NSAIDs for more than a year (HR 0.45; 95% CI 0.28 to 0.71), and in carriers of an CYP2C9 variant allele associated with lower enzymatic activity (HR 0.67; 95% CI 0.47 to 0.96). The combination of both determinants was associated with a further risk reduction but without synergy. Conclusion: Both NSAID use and CYP2C9*2 and/or *3 carriage are associated with a reduced risk of colorectal cancer. However, no interaction between the determinants was found, which might indicate independent pathophysiological mechanisms.

, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,
hdl.handle.net/1765/16442
The Netherlands Journal of Medicine
Erasmus MC: University Medical Center Rotterdam

Siemes, C, Eijgelsheim, M, Dieleman, J.P, van Schaik, R.H.N, Uitterlinden, A.G, van Duijn, C.M, … Visser, L.E. (2009). No modification of the beneficial effect of NSAIDs on colorectal cancer by CYP2C9 genotype. The Netherlands Journal of Medicine, 2009(4), 134–141. Retrieved from http://hdl.handle.net/1765/16442