Altered DNA repair can be associated with aggressive tumor biology and impact on survival of cancer patients. We investigated whether genetic variation of human apurinic/apyrimidinic (AP) endonuclease, a key multifunctional gene involved in the base excision repair pathway, would play a role in gastric cancer survival outcomes. We genotyped APE1 rs1760944 by the TaqMan method in 925 gastric cancer patients. Analyses of association between the polymorphism and survival outcomes were carried out using the Kaplan-Meier method, Cox proportional hazards models, and the log-rank test. Survival analyses for all patients showed that the differences in median survival time between gastric cancer carriers with APE1 rs1760944 TT (55 months) and those with GT/GG (78 months), were statistically significant (P = 0.025, log-rank test). Kaplan-Meier survival estimates revealed that gastric cancer patients carrying the GT/GG genotypes had a higher survival than TT, and this protective effect was also more pronounced among subgroups with tumor size >5 cm (hazard ratio = 0.66, 95% confidence interval = 0.49-0.88), diffuse-type gastric cancer (0.76, 0.60-0.97), T3 depth of invasion (0.73, 0.57-0.93), lymph node metastasis (0.73, 0.58-0.92), no distant metastasis (0.81, 0.66-0.99), and TNM stage III and IV (0.75, 0.58-0.99 for stage III; 0.50, 0.29-0.88 for stage IV). Our results showed that the genetic variant rs1760944 in APE1 was associated with gastric cancer survival in a Chinese population. Larger studies are needed to verify our findings in different populations.
© 2011 Japanese Cancer Association.