Does interval between hysterectomy and start of radiation treatment influence survival in early stage endometrial carcinoma? a national cancer database analysis.
Ghanem AI, Modh A, Burmeister C, Buekers T, and Elshaikh MA. Does interval between hysterectomy and start of radiation treatment influence survival in early stage endometrial carcinoma? a national cancer database analysis. Int J Radiat Oncol Biol Phys 2017; 99(2):E292.
Int J Radiat Oncol Biol Phys
Purpose/Objective(s): Adjuvant radiation therapy (RT) has been shown to improve outcomes in patients with early stage endometrial carcinoma. We analyzed the influence of the time interval between hysterectomy and RT initiation on overall survival (OS) among patients with early stage endometrioid uterine carcinoma (EUC) using the National Cancer Database (NCDB). Purpose/Objective(s): The NCDB was queried for patients with EUC with AJCC/FIGO-2009 stages I and II who underwent surgical staging followed by adjuvant RT using external beam (EBRT) or intravaginal brachytherapy (BT) or combination within 6 months of surgery. Cases without full demographic, pathological details and survival data recorded were excluded as well as those who have received chemotherapy or hormonal treatment or preoperative RT. In regards to OS endpoint, we used %findcut SAS macro tool to detect the most predictive cutoff for time interval between TAH-BSO and RT. The different studied time intervals were presented in weeks after hysterectomy. Groups were then created using this timing cut-off point. Log-rank p-values and Kaplan-Meier curves were created for OS analysis. Predictors of OS were identified by univariate and multivariate analyses. Results: We were able to identify 16520 cases which met inclusion criteria. The median follow up time was 59.1 months for the entire study cohort. Median age was 63 years, 89% of cases were white and 82% were AJCC/FIGO-2009 stage I. EBRT was used in 9569 (58%); whereas BT was utilized by 4265 cases (26%) and the remainder received both (16%). 10040 cases (61%) received RT 8 weeks or less after surgery (median 6 weeks); whereas 6480 patients (39%) had RT > 8 weeks after TAH-BSO (median 10 weeks). Treatment earlier than or equal 8 weeks was associated with significantly better OS using log-rank test (p= 0.0269) as well as improved 10 year OS (p= 0.0144) when compared to treatment delay more than 8 weeks after hysterectomy. On multivariate analysis of OS; older age, black race, urban location and women with higher grade tumors were all significantly associated with worse OS (p