Multivariate analysis of reproductive risk factors for ovarian cancer in Alexandria, Egypt

Ovarian cancer is the eighth leading cancer in women, as it accounts for 4% of all malignant tumors in females. The incidence of ovarian cancer is up to 10 times higher in western countries than in rural Asian and Africa ones. Different reproductive characteristics, life styles and specific medical conditions are responsible for different pattern and incidence of ovarian cancer worldwide.

A case control study was conducted during the time period from 2000 to 2003 including 172 cases of epithelial ovarian cancer, recently diagnosed and confirmed by histopathology. The patients were accessed at the hospitals currently covered by Alexandria Cancer Registry. In addition, 441 control subjects, comparable by age and address, were randomly selected from patients admitted to the same hospitals for nongynecological, non-endocrinal acute diseases. Both cases and controls were subjected to a specific predesigned questionnaire to cover menstrual, reproductive and lifestyle indicators. Univariate and multivariate analysis were conducted and 5% level of significance was adopted.

Significantly increased risks were reported with increased number of abortions and increased number of ovarian cycles (OR=1.8, 95% CI (1.7-2.8), and 2.8, 95% CI 2.8 (1.5-5.2), respectively. Similarly, high risks were also reported for increased number of pregnancies, OR=1.6, 95% CI 1.1-2.4) for 1 to three pregnancies and 4.2, 95% CI 1.2-15.9) for more than four pregnancies On the other hand, decreased risks were reported for those with increased parity compared to nulliparous.

Although ovarian cancer is less frequent in our community, yet the significant positive and negative associations between risk factors and ovarian cancer were similar to the results of other studies, apart from the primary prevention program that should be outlined according to prevalence of significant risk factors in the studied local community.