Chemotherapy plus radiotherapy vs. radiotherapy alone in high-risk endometrioid endometrial carcinoma

Adding chemotherapy to radiotherapy in patients with high-risk endometrioid endometrial cancer (EEC) remains controversial, particularly in stages I-II. We aimed to investigate the effect of treatment modalities on survival in high-risk EEC patients.

Patients with high-risk EEC were evaluated retrospectively between 2010 and 2019. Patients who did not receive adjuvant treatment were excluded. We included seventy patients and formed two groups: patients who received radiotherapy (RT) alone and those who received chemotherapy and radiotherapy (CT and RT).

The median follow-up time was 60.3 months (8.0-143.5). 38.5% of the patients had relapsed. Recurrence-free survival (RFS) rates were 97. 1%, 68.3% , and 60.8% at 12-, 36-, and 60-month, respectively. Overall survival rates were 97.1%, 80.6%, and 72.6% at 12-, 36-, and 60-month, respectively. Hematological adverse events and neuropathy were more common in the CT and RT group than in the RT group. Multivariate Cox regression analysis for RFS revealed that the FIGO stage and treatment modalities were statistically independent factors (p=0.031 and p=0.040, respectively). Stage stratified log-rank test revealed that adding chemotherapy improved RFS in patients with stage III (p=0.020) but not in stage I-II disease (p=0.725). The number of chemotherapy cycles administered (≤4 vs. >4) did not affect survival in all patients and stage III disease (p=0.497, and p=0.436, respectively).

Adding chemotherapy to radiotherapy may be considered in high-risk stage III EEC. Further studies are needed to determine the optimal duration of chemotherapy.