ABSTRACT
Medical diagnostic X-ray workers are one occupational group that expose to the long-term low-dose external radiation over their working lifetime, and they may under risk of different cancers. This study aims to determine the relationship between the occupational X-ray radiation exposure and cancer risk among these workers in Jiangsu, China. We conducted Nested case-control study to investigate the occupational X-ray radiation exposure and cancer risk. Data were collected through self-administered questionnaire, which includes but not limits to demographic data, personal behaviors and family history of cancer. Retrospective dose reconstruction was conducted to estimate the cumulative doses of the x-ray workers. Inferential statistics, t-test and 2 tests were used to compare the differences between each group. We used the logistic regression model to calculate the odds ratio (OR) and 95% confidence interval (CI) of cancer by adjusting the age, gender. All 34 breast cancer cases and 45 esophageal cancer cases that detected in a cohort conducted among health workers between 1950~2011 were included in this presented study, and 158 cancer-free controls were selected by frequency-matched (1:2). Our study found that the occupational radiation exposure was associated with a significantly increased cancer risk compared with the control, especially in breast cancer and esophageal cancer (adjusted OR=2.90, 95% CI: 1.19-7.04 for breast cancer; OR=4.19, 95% CI: 1.87-9.38 for esophageal cancer, and OR=3.43, 95% CI: 1.92-6.12 for total cancer, respectively). The occupational X-ray radiation exposure was associated with increasing cancer risk, which indicates that proper intervention and prevention strategies may be needed in order to bring down the occupational cancer risk.
Subject(s)
Breast Neoplasms/etiology , Esophageal Neoplasms/etiology , Neoplasms, Radiation-Induced/etiology , Occupational Diseases/etiology , Occupational Exposure/adverse effects , Radiation Exposure/adverse effects , X-Rays/adverse effects , Adult , Aged , Breast Neoplasms/epidemiology , Case-Control Studies , China/epidemiology , Esophageal Neoplasms/epidemiology , Female , Follow-Up Studies , Humans , Middle Aged , Neoplasm Staging , Neoplasms, Radiation-Induced/epidemiology , Occupational Diseases/epidemiology , Prognosis , Retrospective Studies , Risk Assessment , Young AdultABSTRACT
OBJECTIVE: To study the relationship between two polymorphisms, Arg194Trp and Arg399Glu, of DNA repair gene X-ray repair cross-complementing group 1 (XRCC1) and the susceptibility of breast cancer in Chinese women. METHODS: A case-control study with 698 histologically-confirmed female breast cancer cases and 813 cancer-free controls frequency-matched by age and residential area was conducted, and the genotypes were determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assays. Logistic regression analysis was used to evaluate the odds ratios (ORs) and 95% confidence intervals (CIs) of XRCC1 Arg194Trp and Arg399Glu with susceptibility of breast cancer. A Meta-analysis was used to evaluate the association of Arg399Glu with breast cancer in Chinese women. RESULTS: The genotype frequencies of Arg/Arg, Arg/Trp, Trp/Trp, Arg/Trp + Trp/Trp of XRCC1 gene 194 locus were 48.81% (327/670), 39.85% (267/670), 11.34% (76/670), 51.19% (343/670) in cases and 48.80% (387/793), 41.99% (333/793), 9.21% (73/793), 51.20% (406/793) in controls. Compared to Arg/Arg, the adjusted ORs (95%CIs) were 0.98 (0.75 - 1.28), 1.17 (0.76 - 1.80), 1.09 (0.86 - 1.40). The frequencies of Arg/Arg, Arg/Trp, Trp/Trp, Arg/Gln + Gln/Gln of XRCC1 399 locus were 52.40% (349/666), 38.29% (255/666), 9.31%(62/666), 47.60% (317/666) in cases and 52.22% (412/789), 38.53% (304/789), 9.25% (73/789), 47.78%(377/789) in controls. Compared to Arg/Arg, the adjusted ORs (95%CIs) were 0.93(0.63 - 1.08), 0.96 (0.42 - 1.09), 0.91 (0.62 - 1.05). No significant associations were found between these two polymorphisms and breast cancer risk, also in subgroups stratified by menopause status, history of breast-feed, reproduction and taking oral contraceptives. The overall ORs (95%CIs) of 399 Arg/Trp + Trp/Trp vs Arg/Arg from Meta analysis was 0.97 (0.85 - 1.10). CONCLUSION: The XRCC1 Arg194Trp and Arg399Gln may not play an important role in the susceptibility of breast cancer in Chinese women.
