The 2R2R genotype (rs34743033) was not significantly associated with developing MTX-induced oral mucositis compared with the 2R3R/3R3R genotypes, which was confirmed in a meta-analysis [odds ratio (OR): 1.17 (0.62-2.19)].
MTX AUC0-48h was a significant predictor of overall toxic adverse events during MTX courses (R(2) = 0.043; P < .001), whereas the thymidylate synthase rs34743033 tandem repeat polymorphism was predictive of stomatitis (R(2) = 0.018; P = .009), a frequent side effect of high-dose MTX.