Objective: To investigate clinicopathological features of endometriosis-associated epithelial ovarian carcinoma.
Methods: Retrospective follow-up study, clinicopathological data from patients with ovarian epithelial carcinoma were retrieved, analyzed and compared. Among the 727 cases, 34 were found to originate from endometriosis (group A), 33 were found to have co-existing ovarian endometriosis (group B), and the remaining 660 had no ovarian endometriosis at all (group C).
Result: Seven hundred and twenty-seven epithelial ovarian carcinoma patients were identified and their clinicopathological data retrieved. Sixty-seven (9.2%) of these cases were found to have coexisting endometriosis. The frequency of malignant tumors arising from ovarian endometriosis in this case series was estimated to be 0.87% (34/3890). The mean (standard deviation) age in groups A, B, and C were (47.2 +/- 1.3), (47.8 +/- 1.2), (51.2 +/- 0.4) years, respectively, with patients in group C being significantly older (P = 0.013). Patients with coexisting ovarian endometriosis were mostly diagnosed at stage I (P = 0.000) and having subtype of clear-cell (P = 0.000), while other patients were mostly diagnosed at stage III (P = 0.001), and having subtype of serous carcinoma (P = 0.000). The estrogen receptor (ER) positivity was significantly lower in groups A and B than that in group C (22.2%, 31.6% vs 43.9%; P = 0.018), but the difference in positivity of progestogen receptor among the three groups did not reach statistical significance (22.2%, 15.8% vs 35.5%; P = 0.082). While the five-year overall survival rate for all patients was 55.6%, significant difference in overall survival among the three groups was found 78.9%, 92.8%, 51.9%, respectively, for groups A, B and C (P = 0.000).
Conclusion: Patients of endometriosis-associated epithelial ovarian carcinoma, especially patients with tumors arising from endometriosis, were found to be younger, having a significant lower stage and a better survival, and were mostly diagnosed with the subtype of clear-cell.