The effect of complete surgical staging and adjuvant chemotherapy on survival in stage I, grade 1 and 2 endometrioid ovarian carcinoma.

OBJECTIVES: To assess the effect of complete surgical staging and adjuvant chemotherapy on survival in stage I, low grade endometrioid ovarian cancer. METHODS: This retrospective study was conducted at two cancer centers from July 2001 to December 2019. Inclusion criteria were all stage I, grade 1 and 2 endometrioid ovarian cancer patients. Patients with mixed histology, concurrent endometrial cancer, neoadjuvant chemotherapy, and patients who did not undergo follow-up at our centers were excluded. Clinical, pathologic, recurrence, and follow-up data were collected. Cox proportional hazard model evaluated predictive factors. Recurrence-free survival and overall survival were calculated using the Kaplan-Meier method. RESULTS: There were 131 eligible stage I patients: 83 patients (63.4%) were stage IA, 5 (3.8%) were stage IB, and 43 (32.8%) were stage IC, with 80 patients (61.1%) having grade 1 and 51 (38.9%) patients having grade 2 disease. Complete lymphadenectomy was performed in 34 patients (26.0%), whereas 97 patients (74.0%) had either partial (n=22, 16.8%) or no (n=75, 57.2%) lymphadenectomy. Thirty patients (22.9%) received adjuvant chemotherapy. Median follow-up was 51.5 (95% CI 44.3 to 57.2) months. Five-year recurrence-free survival was 88.0% (95% CI 81.6% to 94.9%) and 5 year overall survival was 95.1% (95% CI 90.5% to 99.9%). In a multivariable analysis, only grade 2 histology had a significantly higher recurrence rate (HR 3.42, 95% CI 1.03 to 11.38; p=0.04). There was no difference in recurrence-free survival (p=0.57) and overall survival (p=0.30) in patients with complete lymphadenectomy. In stage IA/IB, grade 2 there was no benefit of adjuvant chemotherapy (p=0.19), and in stage IA/IB, low grade without complete surgical staging there was no benefit of adjuvant chemotherapy (p=0.16). Twelve patients (9.2%) had recurrence; 3 (25%) were salvageable at recurrence and are alive with no disease. CONCLUSIONS: Patients with stage I, low grade endometrioid ovarian cancer have a favorable prognosis, and adjuvant chemotherapy and staging lymphadenectomy did not improve survival.