The Prognosis of Stage IA Mixed Endometrial Carcinomady

A Retrospective Cohort Study

Wenhui Li, MD; Lei Li, MD; Ming Wu, MD; Jinghe Lang, MD; Yalan Bi, MD


Am J Clin Pathol. 2019;152(5):616-624. 

In This Article

Abstract and Introduction


Objectives: To explore the survival and definition of stage IA mixed endometrial carcinoma.

Methods: From June 1, 2010, to June 1, 2017, cases with stage IA endometrial cancer were included in this study. The survival outcomes were compared among patients with endometrioid (group A), nonendometrioid (group B), and mixed subtypes (group C) and among patients with different proportions of nonendometrioid components (<5%, >50%, and others).

Results: In total, 890 cases were included, comprising 808 (90.8%), 33 (3.7%), and 47 (5.3%) cases in groups A, B, and C, respectively. After a median follow-up of 55.9 months, groups B and C had significantly more inferior disease-free survival, overall survival, and cancer-specific overall survival. Patients with a nonendometrioid proportion of more than 50% and serous subtype also had a significantly more inferior prognosis. Adjuvant therapy could improve the prognosis in mixed endometrial carcinomas.

Conclusions: Patients with endometrial cancer of mixed subtypes had inferior survival outcomes.


Endometrial cancer is ranked fourth in estimated new cases and sixth in estimated deaths in the United States,[1] and it is ranked ninth and 10th, respectively, in China, corresponding to 63,400 new cases and 21,800 deaths.[2] Currently, there is insufficient evidence to recommend screening for endometrial cancer in women at average risk or at increased risk.[3] As the disease is frequently symptomatic at an early stage, endometrial cancer is often diagnosed at stage I.[4] Although most carcinomas of the endometrioid subtype have a favorable prognosis, the definition and prognosis of mixed endometrial carcinomas as a rare subtype remain debated. Mixed endometrial cancer, including cases with less than 5% serous or clear carcinoma, can exhibit aggressive features similar to pure serous or clear carcinoma. The presence of different components suggests that the pathogenic and metastatic processes of these tumors are different from those of "pure" carcinoma.[5] The World Health Organization (WHO) recommends the use of a 5% threshold for the minor component in defining mixed endometrial cancer,[6] but few studies have examined tumors that fall under that threshold, and the relevance of this threshold to survival outcomes remains unclear. Until such studies are available, it is recommended not to use a specific quantitative threshold to exclude cases that clearly exhibit prototypical features of serous carcinoma or clear cell carcinoma.[7]

To explore the prognosis of mixed endometrial cancer and the effect of various proportions of nonendometrioid components on survival, we performed a retrospective cohort study to compare survival outcomes among patients with endometrioid, nonendometrioid, and mixed subtypes, as well as among patients with different proportions of nonendometrioid components using a newly developed protocol.