Concomitant endometriosis in malignant and borderline ovarian tumours.

The aim of the study was to reveal the prevalence of concomitant endometriosis in malignant and borderline ovarian tumours. A retrospective analysis was performed of 530 patients with malignant ovarian tumours and 131 with borderline ovarian tumours, who underwent surgery in our hospital between 1995 and 2011. Forty-eight (7.3%) of 661 patients with malignant and borderline ovarian tumours were associated with endometriosis. Of the 48 endometriosis cases, 73% of those were atypical. Infertility was noted in 38% of patients with endometriosis-associated ovarian tumours. The most frequently endometriosis-associated subtypes were endometrioid (33%) and clear cell (18%) histologies. Of endometriosis-associated endometrioid and clear cell ovarian tumours, 70% were early stage and 60% were premenopausal. The prevalence of concomitant endometriosis in borderline tumours (12%) was found to be significantly higher than that found in the malignant ones (6%; p = .02). Of 32 endometriosis-associated malignant ovarian tumours, 69% were FIGO stages I and II. In conclusion, ovarian endometriosis is seen with both malignant and borderline ovarian tumours, the association being significant with borderline tumours. Fortunately, the endometriosis-associated malignant ovarian tumours are mostly early stage. Impact statement What is already known on this subject? Epidemiologic data suggest that endometriosis has malignant potential. However, a subgroup of women with endometriosis at a high risk for ovarian cancer is yet to be clarified. Currently, endometriosis and ovarian cancer association does not seem to have a clinical implication. What do the results of this study add? The findings of this study revealed that nearly 75% of endometriosis-associated ovarian tumours were of atypical endometriosis. Half of endometriosis-associated ovarian tumour cases were of endometrioid/clear cell histology and 70% were early-stage. Endometriosis was significantly associated with borderline ovarian tumours and the endometriosis-associated malignant ovarian tumours were mostly early stage. What are the implications of these findings for clinical practice and/or further research? Additional studies need to be conducted to develop screening approaches for malignant transformation or an association in women with endometriosis. Till that time, a change of current clinical practices cannot be justified. However, counselling and treating women with endometriosis who are at high risk for cancer coexistence or conversion is encouraged.

Prevalence of endometriosis in malignant epithelial ovary tumours.

OBJECTIVE: To determine the prevalence of ovarian endometriosis in malignant epithelial ovarian tumours. STUDY DESIGN: A retrospective analysis of 160 malignant and 23 borderline ovarian tumours during the period 1995-2001. RESULTS: Fourteen (7.7%) of the tumours contained endometriosis. This affected 22% of the endometrioid and 10.8% of the mixed adenocarcinomas. The mean age of the ovarian endometriosis patients was 43+/-13 range 26-70 years. The incidence in borderline tumours 13% (3/23) was higher than that in ovarian cancer 6.9% (11/160) (P>0.05). Eight (57%) of cases were classified as atypical and six (43%) as typical endometriosis. Nine cases were FIGO (International Federation of Gynaecology and Obstetrics) stage I and 5 stage III. CONCLUSIONS: Both malignant and borderline ovarian tumours are associated with ovarian endometriosis. In addition, atypical endometriosis was found associated with endometrioid and mixed epithelial ovarian tumours.