Table of Contents Author Guidelines Submit a Manuscript
Sarcoma
Volume 2018, Article ID 7972389, 8 pages
https://doi.org/10.1155/2018/7972389
Research Article

Radiation Therapy for Retroperitoneal Sarcomas: Influences of Histology, Grade, and Size

1Department of Surgery, Mayo Clinic, Rochester, MN 55901, USA
2Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55901, USA
3Department of Pathology, Mayo Clinic, Rochester, MN 55901, USA
4Department of Medical Oncology, Mayo Clinic, Rochester, MN 55901, USA

Correspondence should be addressed to Travis E. Grotz; ude.oyam@sivart.ztorg

Received 27 June 2018; Revised 26 October 2018; Accepted 14 November 2018; Published 5 December 2018

Academic Editor: Antoine Italiano

Copyright © 2018 Jennifer L. Leiting et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Perioperative radiation therapy (RT) has been associated with reduced local recurrence in patients with retroperitoneal sarcomas (RPS); however, selection criteria remain unclear. We hypothesized that perioperative RT would improve survival in patients with RPS and would be associated with pathological factors. The National Cancer Database (NCDB) from 2004 to 2012 was reviewed for patients with nonmetastatic RPS undergoing curative intent resection. Tumor size was dichotomized at 15 cm based on 8th edition American Joint Committee on Cancer (AJCC) staging. Patients with the highest comorbidity score were excluded. Unadjusted Kaplan–Meier and adjusted Cox proportional hazards modeling analyzed overall survival (OS). Multivariable logistic regression modeled margin positivity. A total of 2,264 patients were included; 727 patients (32.1%) had perioperative radiation in whom 203 (9.0%) had radiation preoperatively. Median (IQR) RPS size was 17.5 [11.0–27.0] cm. Histopathology was high grade in 1048 patients (43.7%). Multivariable analysis revealed that perioperative radiation was independently associated with decreased mortality (HR 0.72, 95% confidence intervals (CIs) 0.62–0.84, ), and preoperative RT was associated with reduced margin positivity (HR 0.72, 95% CI 0.53–0.97, ). Stratified survival analysis showed that radiation was associated with prolonged median OS for RPS that were high-grade (64.3 vs. 43.6 months, ), less than 15 cm (104.1 vs. 84.2 months, ), and leiomyosarcomatous (104.8 vs. 61.8 months, ). Perioperative radiation is independently associated with decreased mortality in patients with high-grade, less than 15 cm, and leiomyosarcomatous tumors. Preoperative radiation is independently associated with margin-negative resection. These data support the selective use of perioperative radiation in the multidisciplinary management of RPS.