[1212] Endometriosis-Associated Carcinomas Exhibit Significant Site-Specific Differences: Analysis of 396 Cases

Frank N Moore, Lorraine Pan, Teri A Longacre. Stanford, Palo Alto, CA

Background: Recent studies document a shared increased rate of ARID1A mutations in endometriosis and endometriosis associated carcinomas and a common endometriosis-carcinoma pathway has been proposed. However, the relative proportions, association with other histologic types, and site of origin (ovarian vs extra-ovarian) have not been well examined.
Design: We performed a retrospective, consecutive review of pathology reports to identify all malignancies associated with concurrent endometriosis in the past 10 years using the following parameters in our search criteria: “endometriosis”, “endometriotic”, “endometrioma” in association with the following: “carcinoma”, “adenocarcinoma”, “borderline”, “low malignant potential”, “sarcoma”, “adenosarcoma”, and “carcinosarcoma”. In each case, the primary site and type of tumor was recorded in addition to the site(s) of endometriosis.
Results: 396 cases of simultaneous endometriosis and gynecologic malignancy were identified. The most common site of malignancy was the ovary (67%), followed by uterus, fallopian tube, pelvis/peritoneum, and cervix. The 3 most common types of malignancies were endometrioid (45%), clear cell (23%) and serous carcinomas (13%). Analysis of the entire 10 year data set suggested the majority of endometriosis-associated ovarian carcinomas were endometrioid (53%), followed by clear cell (17.5%), and serous (15.6%). However, subanalysis of the ovarian cancers diagnosed in the last five years (almost all of which were diagnosed by gynecologic pathologists using standard diagnostic criteria, often in conjunction with immunohistochemistry), showed a preponderance of clear cell carcinomas (37%) with fewer serous (16%) and endometrioid (33%) carcinomas. In contrast, extra-ovarian endometriosis-associated cancers were more commonly endometrioid (64% and 68%, 10-year and 5-year analyses). Extra-ovarian endometriosis-associated clear cell carcinoma was extremely rare (4% and 6%, 10-year and 5-year analyses).
Conclusions: Clear cell carcinoma is the most common ovarian cancer associated with endometriosis when tumor classification is based on uniform diagnostic criteria informed by immunohistochemistry and subspecialty-trained gynecologic pathologists. However, this subtype is extremely rare in extra-ovarian endometriosis associated cancer. These data suggest that the endometriosis-carcinoma pathway is non-uniform and differs depending on site of disease.
Category: Gynecologic & Obstetrics

Tuesday, March 20, 2012 9:15 AM

Platform Session: Section E, Tuesday Morning

 

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