Distribution of malignant neoplasms among patients with endometriosis: an epidemiological study

Hypothesis/aims of study. The current analysis was undertaken to assess the incidence of malignant diseases in patients with endometriosis. Study design, materials and methods. This is a cohort study of women with surgically verified endometriosis retrieved from the Saint Petersburg 122 Clinical Hospital Discharge Register 1996–2006 ( n = 1551). Data were linked to the Saint Petersburg Cancer Agency to identify cases of malignancy. Results. Malignant diseases were identified in 6.3% ( n = 98) of cases. The median follow-up was 12.2 (7.5) years. Breast cancer ( n = 29), ovarian cancer ( n = 7), endometrial cancer ( n = 7), thyroid cancer ( n = 7), colorectal cancer ( n = 6), melanoma ( n = 6), non-Hodgkin’s lymphoma ( n = 4), and glioblastoma ( n = 3) were prevalent. Conclusion. The incidence of cancer in patients with endometriosis is low. Women with endometriosis have an increased risk of some malignancies, particularly ovarian cancer.