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Hormonal and reproductive factors and risk of esophageal cancer in Chinese postmenopausal women: a case-control study.

AIM
Since any relationship between hormonal and reproductive factors and risk of esophageal cancer is unclear, we investigated this question in Shandong province of China.


METHODS
A hospital-based 1:1 matched case-control study was conducted from January 2008 to November 2010, with face to face interviews conducted for 132 cases and 132 controls. All cases recruited in this study were confirmed by endoscopy and histological examination. Controls were first-visit outpatients who visited the same hosptial during the same period and were confirmed to have no malignancy. Conditional logistic regression analysis was employed to calculate risk of potential factors.


RESULTS
Esophageal cancer positive women had a higher prevalence of reflux, smoking status, lower BMI and less education than health controls (p<0.05). Women whose age of periods ended above 50 years and breastfed for more than 12 months had lower risk of esophageal cancer, with ORs (95% CI) of 0.42 (0.20-0.89) and 0.46 (0.21-0.98). Sensitivity analysis for the histological types of esophageal cancer showed no great difference between adenocarcinoma and squamous cell carcinoma.


CONCLUSION
In summary, our findings suggest an inverse association between later age of menopause and duration of breastfeeding and risk of esophageal cancer. However, many reproductive and sex hormonal factors did not seem to be associated with esophageal cancer, supporting the need to further evaluate reproductive factors in prospective studies.