Non-endometrioid endometrial cancer: Analysis of different adjuvant treatment modalities

Adjuvant treatment for endometrial carcinoma (EC) is decided based on risk assessment. Tumors of non-endometrioid (NE) histology are classified as high-risk and adjuvant treatment is recommended.

We analyzed retrospectively all NEEC patients treated in two Portuguese oncology centers, between 2009 and 2018. Comparison of adjuvant modalities were performed by overall survival (OS) and disease-free survival (DFS) analysis.

A total of 66 patients were included, with mean age 69 years. Serous histology was found in 34 patients (51.5%), clear-cell in 13 (19.7%) and carcinosarcoma in 18 (27.3%). Based on FIGO staging-system, 34 (51.5%) patients were diagnosed at stages III-IV. Following surgery, no further treatment was performed in 16 patients (24.4%), 11 (16.7%) received isolated chemotherapy (CT), 11 (16.7%) isolated radiotherapy (RT) and 28 (42.4%) combination therapy (CT+RT). Kaplan-Meier analysis showed higher median (m)DFS in the CT+RT group: 30.7 months (m) compared to RT alone: 14.1 m. The mDFS of the isolated CT group was 10.8 m and for patients with no further treatment it was 5.7 m, p = 0.03. Median OS was also increased in the combination group CT+RT (78.3 m) compared to isolated RT (64.3 m), isolated CT (37.3 m) and no further treatment (46.7 m), p=0.005. Multivariate Cox-regression using CT+RT as reference, showed hazard-ratio of 3.5 (p = 0.05) and 4.5 (p = 0.01) for the CT and for no-treatment group respectively.

In NEEC patients, DFS and OS analysis showed better prognosis in combination of CT+RT. Patients that underwent only RT had better survival outcomes when compared to those treated with CT only.