The association of SIPA1 gene polymorphisms with breast cancer risk: evidence from published studies.

Previous studies have focused on the association of signal-induced proliferation associated 1 gene (SIPA1) with carcinogenesis of many cancers, including breast cancer. It has been suggested that SIPA1 polymorphisms are associated with susceptibility to breast cancer. In the present study, we performed a meta-analysis to systematically summarize the possible association between SIPA1 and the risk for breast cancer. We conducted a search of case-control studies on the associations of SPIA1 with susceptibility to breast cancer in PubMed, Embase, International Statistical Institute Web of Science, Wanfang Database in China, and Chinese National Knowledge Infrastructure databases. Data from eligible studies were extracted for meta-analysis. Breast cancer risk associated with SIPA1 was estimated by pooled odds ratios and 95% confidence intervals. Four studies on SIPA1 and breast cancer were included in our meta-analysis. Our results showed that rs746429 was associated with the risk of breast cancer. However, rs931127 and rs3741378 were not found to be associated with breast cancer in our analysis. This meta-analysis suggests that rs746429 is associated with the risk of breast cancer. Well-designed studies with larger sample size and more ethnic groups are required to further validate the results.

Null genotype of GSTT1 contributes to esophageal cancer risk in Asian populations: evidence from a meta-analysis.

BACKGROUND/AIMS: Glutathione S-transferase T1 (GSTT1), a phase-II enzyme, plays an important role in detoxification of carcinogen electrophiles. Many studies have investigated the association between GSTT1 polymorphism and esophageal cancer risk in Asian populations, but its actual impact is not clear owing to apparent inconsistencies among those studies. Thus, a meta-analysis was performed to explore the effect of GSTT1 polymorphism on the risk of developing esophageal cancer. METHODS: A literature search of PubMed, Embase, and Wanfang databases up to August 2012 was conducted and 15 eligible papers were finally selected, involving a total of 1,626 esophageal cancer cases and 2,216 controls. We used the pooled odds ratio (OR) with its corresponding 95% confidence interval (95%CI) to estimate the association of GSTT1 polymorphism with esophageal cancer risk. Subgroup analyses and sensitivity analyses were performed to further identify the association. RESULTS: Meta-analysis of total studies showed the null genotype of GSTT1 was significantly associated with an increased risk of esophageal cancer in Asians (OR=1.26, 95%CI=1.05-1.52, POR=0.015, I2=42.7%). Subgroup analyses by sample size and countries also identified a significant association. Sensitivity analysis further demonstrated a relationship of GSTT1 polymorphism to esophageal cancer risk in Asians. CONCLUSIONS: The present meta-analysis of available data showed a significant association between the null genotype of GSTT1 and an increased risk of esophageal cancer in Asians, particularly in China.