Pelvic inflammation and the pathogenesis of ovarian cancer: a cohort study.

OBJECTIVE

The aim of this study was to determine whether pelvic inflammation contributes to the pathogenesis of ovarian cancer or other malignancies.

DESIGN

This article is a cohort study.

SETTING

The study was conducted in a tertiary university and provincial cancer referral institutions.

POPULATION SAMPLE: The population sample was composed of women referred for fertility surgery and women diagnosed with ovarian cancer in British Columbia.

METHODS

We conducted a cohort study using prospectively collected data on fertility surgery patients. Eight hundred eighty-eight women with past pelvic inflammation, as diagnosed by characteristic findings at fertility surgery, and 552 women without were compared for the subsequent development of malignancy, during the period of 1981 to 2012. Logistic regression was used to estimate adjusted odds ratios and 95% confidence intervals. Standardized incidence ratios were also calculated using age-specific cancer incidence rates among all women in British Columbia.

RESULTS

The adjusted odds ratio for ovarian cancer, after past inflammation, was 5.56 (95% confidence interval, 0.52-59.40). Age-adjusted ovarian cancer incidence was significantly elevated among women with previous pelvic inflammation (standardized incidence ratio, 3.99; 95% confidence interval, 1.46-8.68). The rates of other malignancies were similar in both cohorts.

CONCLUSION

The rate of ovarian cancer was not significantly elevated in women with past pelvic inflammation compared with the controls. However, a significantly increased risk for ovarian cancer was apparent among women with pelvic inflammation when compared with the general population. Pelvic inflammation may be a contributory factor in the pathogenesis of ovarian cancer.