OBJECTIVE: To study the association of polymorphisms in the X-ray repair cross-complementing gene 1 (XRCC1) and papillary thyroid carcinoma (PTC). METHODS: A hospital based, matched case-control study was carried out. The polymorphisms in XRCC1 for 105 pairs of cases with PTC and controls were identified by PCR-RFLP. RESULTS: The frequencies of Arg/Arg, Arg/Trp and Trp/Trp genotypes at XRCC1 Arg194Trp site were 47.6%, 49.5% and 2.9% among cases compared to 45.7%, 48.6% and 5.7% among controls. There was no statistically significant difference between the two groups (chi(2) = 1.07, P = 0.59). The frequencies of Arg/Arg, Arg/Gln and Gln/Gln genotypes at XRCC1 Arg399Gln site were 46.7%, 41.9% and 11.4% among cases, while 54.2%, 42.9% and 2.9% among controls respectively. There was statistically significant difference between the two groups (chi(2) = 6.40, P = 0.04). Individuals with Gln/Gln genotype had a 3.65-fold increased risk of developing PTC compared to Arg/Arg genotype (OR = 4.65, 95% CI: 1.24 - 17.45). The multivariate conditional logistic regression analysis showed that the XRCC1 Arg399Gln polymorphism, negative life events and X-irradiation history were associated with PTC, with odds ratios of 2.71 (95% CI: 1.22 - 6.05), 5.34 (95% CI: 1.40 - 20.38) and 0.38 (95% CI: 0.12 - 0.72) respectively. However, XRCC1 Arg194Trp polymorphism, drinking tea, fruit and economic levels did not show statistically significant associations with PTC. CONCLUSION: The Gln/Gln genotype at XRCC1 Arg399Gln site and negative life events significantly increased while X-irradiation history decreased the risk of developing PTC.
OBJECTIVE: To study the association of polymorphisms in the X-ray repair cross-complementing gene 1 (XRCC1) and papillary thyroid carcinoma (PTC). METHODS: A hospital based, matched case-control study was carried out. The polymorphisms in XRCC1 for 105 pairs of cases with PTC and controls were identified by PCR-RFLP. RESULTS: The frequencies of Arg/Arg, Arg/Trp and Trp/Trp genotypes at XRCC1Arg194Trp site were 47.6%, 49.5% and 2.9% among cases compared to 45.7%, 48.6% and 5.7% among controls. There was no statistically significant difference between the two groups (chi(2) = 1.07, P = 0.59). The frequencies of Arg/Arg, Arg/Gln and Gln/Gln genotypes at XRCC1Arg399Gln site were 46.7%, 41.9% and 11.4% among cases, while 54.2%, 42.9% and 2.9% among controls respectively. There was statistically significant difference between the two groups (chi(2) = 6.40, P = 0.04). Individuals with Gln/Gln genotype had a 3.65-fold increased risk of developing PTC compared to Arg/Arg genotype (OR = 4.65, 95% CI: 1.24 - 17.45). The multivariate conditional logistic regression analysis showed that the XRCC1Arg399Gln polymorphism, negative life events and X-irradiation history were associated with PTC, with odds ratios of 2.71 (95% CI: 1.22 - 6.05), 5.34 (95% CI: 1.40 - 20.38) and 0.38 (95% CI: 0.12 - 0.72) respectively. However, XRCC1Arg194Trp polymorphism, drinking tea, fruit and economic levels did not show statistically significant associations with PTC. CONCLUSION: The Gln/Gln genotype at XRCC1Arg399Gln site and negative life events significantly increased while X-irradiation history decreased the risk of developing PTC.