Characterizing the efficacy and trends of adjuvant therapy versus observation in women with early stage (uterine confined) leiomyosarcoma: a National Cancer Database study.

Objective: The utility of adjuvant therapy for women with uterine confined leiomyosarcoma remains uncertain. We sought to identify trends, analyze efficacy, and assess survival impact of adjuvant therapy in this patients.

Methods: We performed an observational cohort study of 1030 women with early stage leiomyosarcoma from the 2008-2014 National Cancer Database. Multi-nominal logistic regression was used to identify trends in receipt of adjuvant treatment. Demographic and clinical characteristics were compared. Kaplan-Meier curves were used to estimate survival.

Results: There were 547 who (53.1%) received observation, 79 (7.7%) received radiation alone, 340 (33.0%) received chemotherapy alone, and 64 (6.2%) received chemoradiation. Patients were more likely to be observed if tumor size was <5 cm (hazard ratio [HR]=0.97; 95% confidence interval [CI]=0.95-0.99; p=0.017) and less likely to be observed if lymphovascular space invasion (LVSI) was present (HR=0.60; 95% CI=0.41-0.89; p=0.010). Patients were more likely to receive chemotherapy if they were younger (HR=0.78; 95% CI=0.65-0.94; p=0.010) and if they had LVSI (HR=1.47; 95% CI=1.01-2.16; p=0.040). There was an independent association between older age, tumor size >5 cm, and LVSI with worsened survival, with the strongest predictor of mortality being the presence of LVSI. With a median survival of 61.9 months, there was no difference in estimated overall survival at 1 and 3 years based on receipt of adjuvant treatment as compared to observation (p=0.500).

Conclusion: Although women with uterine confined leiomyosarcoma experience high recurrence rates and poor survival outcomes, adjuvant treatment does not appear to confer a survival benefit.