Clinical comparison between neuroendocrine and endometrioid type carcinoma of the uterine corpus

Objective: To compare the clinicopathologic features and survival outcomes of neuroendocrine tumor of the uterine corpus (NET-U) to endometrioid type endometrial carcinoma (EC). Methods: From 1993 to 2012, the Surveillance, Epidemiology and End Results cancer registry was queried for women diagnosed with EC or NET-U. Data regarding stage, grade, presence of extra-uterine disease, lymph node metastasis, receipt of adjuvant radiation, surgical intervention and overall survival (OS) was extracted. Chi-square tests, t-tests and Kaplan Meir curves were used for statistical analysis. Results: A total of 98,363 patients were identified: 98,245 with EC and 118 with NET-U. The mean age at diagnosis for EC was 61.7 years and 64.8 years for NET-U (p=0.01). NET-U cases were more likely to be poorly differentiated (97.0% vs. 15.6%; p <= 0.01) and have nodal metastasis (56.4% vs. 11.1%; p <= 0.01) when compared to EC. Presence of extrapelvic disease at the time of diagnosis was observed more frequently in NET-U compared to EC, 49.1% vs. 4.8%, respectively (odds ratio=18; 95% confidence interval=13.1-27.2; p <= 0.01). Significant improvement in OS was observed in NET-U patient who received radiation (OS: 7.7 vs. 3.3 years; p <= 0.01) or underwent surgical management (5.6 vs. 0.9 years; p <= 0.01). The OS for EC was 14.4 vs. 4.6 years for NET-U (p <= 0.01). Conclusion: NET-U represents an aggressive form of uterine malignancy. When compared to EC, patients with NET-U present at more advanced stage, have more frequent extra-uterine disease and lower OS.