Hormonal therapy or chemotherapy for early-stage, low-grade endometrial cancer with malignant peritoneal cytology: A comparative effectiveness study.

ABSTRACT

OBJECTIVE: To examine trends, characteristics, and outcomes related to hormonal therapy (HT) or chemotherapy (CT) use for early-stage, low-grade endometrial cancer with malignant peritoneal cytology (MPC). METHODS: This is a comparative effectiveness study querying the National Cancer Database from 2010 to 2017. Study population was 2730 women with stage I grade 1-2 endometrioid endometrial cancer who had MPC at primary hysterectomy. Patients were stratified based on postoperative therapy as CT (n = 348, 12.7%), HT (n = 112, 4.1%), and neither two (n = 2270, 83.2%). Outcome measures included (i) trends and characteristics related to adjuvant therapy, assessed with a multivariable logistic regression model, and (ii) overall survival (OS) assessed with a multivariable Cox proportional hazards regression model. RESULTS: The number of women who received HT (2.7% to 4.5%) or no adjuvant systemic therapy (81.8% to 84.4%) increased while CT use decreased (15.5% to 11.1%)(P = 0.04). In a multivariable analysis, HT use was associated with older age, more recent year of diagnosis, grade 1 lesions, treatment at academic/research facilities, performance of minimally invasive surgery, no lympho-vascular space invasion, and absence of radiotherapy compared to CT use (P < 0.05). Neither HT (adjusted-hazard ratio [aHR] 0.61, 95% confidence interval [CI] 0.27-1.40) nor CT (aHR 1.33, 95% CI 0.92-1.93) were associated with OS compared to no adjuvant systemic therapy. In the low-risk group (stage IA, grade 1-2 tumors, and no lympho-vascular space invasion; n = 1453), 69 (4.7%) women received HT and 117 (8.1%) received CT. OS was similar across the three groups (P = 0.89). CONCLUSION: There was an increasing utilization of HT and decreasing utilization of CT as adjuvant therapy for early-stage, low-grade endometrial cancer with MPC. These two adjuvant therapies were not associated with short-term OS compared to neither two.