Clinical and Pathologic Characteristics of Serous Carcinoma Confined to the Endometrium: A Multi-institutional Study

The objective of this study was to analyze the clinical and pathologic factors in patients with uterine serous carcinoma confined to the endometrium. A total of 236 uterine serous carcinoma patients from the pathology databases of 4 large academic institutions were included in the study. Clinical and pathologic variables were analyzed, including patient demographics, tumor size (<= 2 vs. >2cm), myometrial invasion, lymphovascular invasion, lymph node status, tumor location (endometrium vs. polyp), cervical involvement, lower uterine segment involvement, FIGO stage, pelvic washings, recurrence, overall survival, and progression-free survival. Of 236 patients, 55 (23%) had tumors limited to the endometrium. Forty-four patients (80%) had Stage IA tumors. The tumor was confined to a polyp in 17 (30.9%) patients. Twenty patients (36.4%) had tumor sizes >2cm and 12 (21.8%) exhibited lymphovascular invasion. Only 3 patients (5.4 %) had cervical stromal involvement. Thirty-three (66%) patients underwent pelvic and para-aortic lymphadenectomy with 2 positive para-aortic lymph nodes identified. Seven (12.7%) patients had positive washings, whereas 8 patients (14.5 %) had disease recurrence. At a median follow-up of 46 months, there was no difference in overall survival (P = 0.216) or progression-free survival (P = 0.063) between patients with tumors confined to a polyp, patients with tumors confined to the endometrium, and patients with tumors present in both polyp and the endometrium. Uterine serous carcinoma with only endometrial involvement, even when confined to a polyp, can be associated with poor prognosis, further stressing the importance of complete surgical staging and adjuvant treatment in this setting.