Three adiponectin rs1501299G/T, rs822395A/C, and rs822396A/G polymorphisms and risk of cancer development: a meta-analysis.

Many epidemiological studies have studied the associations between adiponectin rs1501299G/T, rs822395A/C, and rs822396A/G polymorphisms and risk of cancer development, while conflicting results have been reported. Therefore, we conducted a meta-analysis to assess the associations. We retrieved the following databases: Medline, Embase, Web of Science, and Wanfang, and the latest update date was 15th of August 2012. Odds ratio (OR) and corresponding 95 % confidence interval (95 % CI) were calculated by using fixed- or random-effect model. Overall, there were 13 case-control studies consisting of 7,902 subjects for adiponectin rs1501299G/T, seven studies consisting of 6,209 subjects for rs822395A/C, and seven studies consisting of 5,791 subjects for rs822396A/G polymorphism in this study. Combined analyses indicated that neither adiponectin rs822395A/C nor rs822396A/G was associated with risk of cancer incidence (OR (95 % CI) 0.91 (0.77-1.77), P z test = 0.26 for CC vs. AA and 0.96 (0.87-1.05) for C carriers vs. A carriers, P z test = 0.33 for rs822395A/C; 0.88 (0.53-1.47) for GG vs. AA, P z test = 0.63 and 0.94 (0.84-1.04) for G carriers vs. A carriers, P z test = 0.24 for rs822396A/G polymorphism). Similarly, combined analysis also indicated that adiponectin rs1501299G/T polymorphism was not associated with risk of cancer development (OR (95 % CI) 0.86 (0.73-1.01) for TT vs. GG, P z test = 0.07 and 1.17 (0.98-1.39), P z test = 0.08). However, when stratified analyses were conducted, the result indicated that T allele was significantly associated with increased cancer risk for Caucasians (OR (95 % CI) 1.28 (1.06-1.64) and P z test = 0.01 for G carriers vs. T carriers) and associated with increased risk of colorectal cancer development while with decreased risk of prostate cancer incidence compared to G allele (OR (95 % CI) 1.34 (1.14-1.57), P z test < 0.01 for G carriers vs. T carriers for colorectal cancer; 0.80 (0.65-0.97), P z test = 0.03 for TG vs. GG for prostate cancer). In summary, this meta-analysis indicated that adiponectin rs1501299G/T, rather than rs822395A/C and rs822396A/G polymorphism, was associated with risk of cancer development, especially for colorectal and prostate cancer.