Additionally, lower CYP2A6 and CYP2C8 are associated with advanced clinicopathological features including tumor staging, vascular invasion, intrahepatic metastasis, and high alpha fetoprotein (all <i>P</i> < 0.05).
Immunohistochemical analyses of 118 primary bladder tumors revealed that CYP2A6 protein expression was also higher in invasive tumors, especially in those of the scattered type.
Increased gastrointestinal toxicities were associated with the presence of UGT1A6*2 or UGT1A7*3 and an improved tumour response was noted in those without variant alleles of CYP2A6 or UGT1A1*60.
However, to date only a few and inconclusive studies have addressed the risk that a given CYP2A6 polymorphism presents for the development of tobacco-related tumors.
Subdividing gastric adenocarcinoma according to tumor differentiation, patients with the well-differentiated type were 4.9-fold more likely to have the CYP2A6 homozygote deletion genotype (OR = 4.91, 95% CI 1.17-20.52).