Epidemiology and survival of metastatic gastrointestional stromal tumor: A Surveillance, Epidemiology, and End Results (SEER) database review.

Abstract

86 Background: Metastatic gastrointestinal stromal tumor (MGIST) is a rare disease with limited data available on its epidemiology and survival. We aimed to study the epidemiology and survival pattern of M-GIST by reviewing the Survival, Epidemiology and End Result (SEER) database. Methods: SEER database was reviewed for patients (pts) with histologically confirmed GIST between 2002 and 2007. Variables included were age, race, gender, date of diagnosis (DOD), stage, location of primary tumor, and disease specific survival (DSS). The association between survival and race, gender, and site of disease for metastatic GIST patients was investigated. Primary outcome was 3-year DSS. Survival rate was estimated using the Kaplan–Meier method and the difference in 3-years survival was tested by log-rank test. Cox proportional hazard regression model was employed to test the association between survival and age. Results: A total of 653 patients with MGIST pts were identified and 602 were included for analyses. The distribution of MGIST according to primary site was as follows: gastric (42%), small intestine (26.2%), colorectal (4.6%), peritoneal (4.5%), NOS (17%) and other sites (5.9%). The mean age of diagnosis was 61 years. Caucasians to African-American (AA) ratio was 3.5:1 and male to female ratio was 1.3:1. Three-year DSS was 56.5% for Caucasians compared to 62.9% in AA (p = 0.25). Three-year DSS was 57.8% for males compared to 58.6% in females (p = 0.88). Small intestine MGIST had the best 3-Year DSS of 73.8% compared to gastric MGIST, which had a 3-year DSS of 50.7%(p < 0.0001). Peritoneal MGIST had the worst prognosis with 3-year DSS of 34.4%. Conclusions: MGIST had significant difference in survival based on the location of primary tumor. In contrary to the findings of previous studies, small intestine MGIST had superior 3-year DSS compared gastric primary M-GIST. There was no statistically significant difference in survival based on gender or race. [Table: see text]