Retroperitoneal sarcoma: a 10-year follow-up analysis using hospital-based cancer registry data in Japan.

Abstract

We sought clinical characteristics, survival outcomes, and prognostic factors for overall survival of retroperitoneal sarcoma in Japan. A Japanese hospital-based cancer registry database with a pivotal 10-year follow-up was used to identify and enroll patients, registered from 106 institutions, diagnosed with retroperitoneal sarcoma in 2008-2009. Treating hospitals were divided by hospital care volume; high-volume hospitals and low-volume hospitals were defined as ≥4 and<4 cases/year, respectively. A total of 91 men and 97 women were included, with a median age of 64years. The most common histological type was liposarcoma in 101 patients, followed by leiomyosarcoma in 38 patients. The 5-year and 10-year overall survival rates were 44.1 and 28.3%. The majority of patients (n=152, 80.9%) were treated at low-volume hospitals. High-volume hospital patients had higher 10-year overall survival rates than low-volume hospital patients (51.2% vs 23.2%, P=0.026). Multivariate analysis revealed age over 60years, treatment in low-volume hospitals and chemotherapy were independent predictors of unfavorable survival while treatment with surgery was an independent predictor of favorable survival. The possibility of surgical removal was suggested to be the most important prognostic factor for retroperitoneal sarcoma. Better survival was shown in patients treated at high-volume hospitals in our series.