TGFBR1*6A/9A polymorphism and cancer risk: a meta-analysis of 13,662 cases and 14,147 controls

Published data on the association between TGFBR1*6A/9A polymorphism and cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. A total of 32 studies including 13,662 cases and 14,147 controls were involved in this meta-analysis. Overall, significantly elevated cancer risks were associated with TGFBR1*6A in all genetic models (for allelic effect: OR = 1.11; 95% CI = 1.03-1.21; for 6A/6A vs. 9A/9A: OR = 1.30; 95% CI = 1.01-1.69; for 9A/6A vs. 9A/9A: OR = 1.08; 95% CI = 1.01-1.15; for dominant model: OR = 1.08; 95% CI = 1.02-1.15; for recessive model: OR = 1.29; 95% CI = 1.00-1.68). In the subgroup analysis by cancer types, significant associations were found in breast cancer (for allelic effect: OR = 1.16; 95% CI = 1.01-1.34) and ovarian cancer (for allelic effect: OR = 1.24; 95% CI = 1.00-1.54; for 6A/6A vs. 9A/9A: OR = 2.34; 95% CI = 1.03-5.33). However, no significant associations were found in colorectal cancer, bladder cancer, prostate cancer and lung cancer for all genetic models. In summary, this meta-analysis suggests that the TGFBR1*6A/9A polymorphism is associated with cancer susceptibility, increasing the risk of breast and ovarian cancer.