Overall survival differences between women and men with leiomyosarcomas.

Abstract

e17562 Background: Leiomyosarcomas (LMS) are one of the most frequently occurring subtypes of soft tissue sarcomas and are associated with poor prognosis and high risk of recurrence even in the early stages of the disease. Primary management involves surgical excision followed by chemotherapy for all stages. We sought to determine the prognostic factors on associated with leiomyosarcoma survival. Methods: The National Cancer Database from 2004-2016 was utilized to obtain demographics, tumor characteristics and treatment factors of LMS. LMS was divided into three groups for analysis- women with uterine LMS, women with ex-uterine LMS and men with LMS. Univariate and backward stepwise multivariate logistic regression models were used to determine prognostic factors associated with long-term survival in each group. Kaplan-Meier method with log rank test was used to compare overall survival (OS) rates among the three groups. Results: A total of 23194 patients were identified. Only 18.7% of men with LMS utilized chemotherapy as compared to 47.4% women with uterine and 25.0% with ex-uterine LMS. Both men and women had comparable palliative care use- 3.9% in women with uterine LMS, 3.5% in women with ex-uterine LMS and 3.0% in men with LMS. There were statistically significant differences (P=0.000) between overall survival among the three groups. Median OS was highest among men with LMS (72m) followed by women with ex-uterine LMS (57.2m) and women with uterine LMS (36.7 m). On multivariate analysis, in women with uterine LMS, increasing age (OR =0.95, P=0.018), presence of lymphovascular invasion (OR=0.25, P=0.000) were associated with decrease in the likelihood of survival. In women with ex-uterine LMS, increasing age (OR=0.97, P=0.000), increasing stage (I-IV) (OR=0.56, P=0.000), presence of tumor (OR=0.39, P=0.001), those with residual tumor and surgical margins (OR=0.87, P=0.009), and patients who received systemic therapy and surgery (OR= 0.85, P=.0016) had a reduced likelihood of survival. In men with LMS, factors such as increasing age (OR=0.96, P=0.000), increasing number of regional lymph nodes (OR=0.91, P=0.027), having had a surgical diagnostic or staging procedure (OR= 0.69, P=0.004), increasing stage (OR = 0.64, P=0.005), and residual tumor or margins (OR=-0.76, P=0.013) were associated with reduced likelihood of survival. Results also suggest that increasing year of diagnosis was associated with an increased likelihood of survival (OR=1.51; P=0.000). Conclusions: Women were found to comprise almost two third of the patient population with LMS. Men were found to have longer survival than women with LMS, despite low utilization of chemotherapy. It may be due to poor prognosis of LMS in the female reproductive organs while LMS in the extremities has better prognosis. Future prospective trials should stratify based on sex and in women location.