Survival after minimally invasive hysterectomy for type 2 uterine cancer

Abstract

Objectives: Minimally invasive surgical (MIS) staging has become the standard of care for low-grade clinical stage I endometrioid uterine cancer based on randomized studies demonstrating survival outcomes comparable to laparotomy. However, there is limited data on the use of MIS for high-grade uterine cancers at much higher risk for local disease extension and metastasis. The LACC trial showed inferior survival among early-stage cervical cancer patients undergoing MIS compared to laparotomy. The aim of this study was to test the hypothesis that MIS staging of type 2 uterine cancers would be associated with inferior survival. Methods: The National Cancer Database was used to identify women with type 2 uterine cancer (serous, carcinosarcoma, high-grade endometrioid, clear cell) diagnosed from 2010-2015 who underwent primary surgical management. Patients with low grade endometrioid uterine cancer were excluded. MIS included both laparoscopic and robotic approaches. Inverse probability of treatment weighting (IPTW) was used to balance confounders between the MIS and laparotomy groups. Variables in the propensity score model included age, race, median neighborhood education and income, insurance status, year of diagnosis, tumor stage, size, and grade, medical co-morbidities, facility type, and location. Kaplan-Meier curves and Cox regression were used to compare survival. Results: A total of 54,027 women (mean age 65.0±10.1 years) were included in the analysis. 33,763 (62.5%) underwent MIS approach. Compared to those in the laparotomy group, patients treated with MIS were noted to have tumors that were smaller, had earlier stage disease, and were less likely to be graded as poorly differentiated. Following weighting, the 5 year survival rates were 63.4% for laparotomy and 66.5% for MIS. (Figure 1). Patients treated with an MIS approach demonstrated significantly improved survival compared to an open approach (HR=0.87; 95% CI [0.84, 0.91], p Download : Download high-res image (103KB) Download : Download full-size image Conclusions: MIS staging was performed in two-thirds of patients with type 2 uterine cancer yet with significant baseline differences compared to the laparotomy group. Propensity score weighted matching was used in an attempt to create equivalent cohorts from this large retrospective sample. Our findings support the null hypothesis that MIS staging is not inferior to laparotomy, which are consistent with prior literature on type 1 uterine cancer and reinforce that MIS is the preferred approach for surgical staging of all types of uterine cancer.