Outcomes of Primary Colorectal Sarcoma: A National Cancer Data Base (NCDB) Review.

INTRODUCTION: Primary colorectal sarcomas are a rare entity with anecdotally poor outcomes. We sought to inform surgeons, oncologists, and researchers of the characteristics and outcomes of these understudied and difficult-to-manage tumors.

METHODS: The National Cancer Data Base (NCDB) was queried for patients with pathologically confirmed primary sarcoma of the colon or rectum (1998-2012). Gastrointestinal stromal tumors were excluded. Unadjusted overall survival was reported using the Kaplan-Meier method. Patients with colorectal adenocarcinoma were used as a comparison cohort.

RESULTS: Four hundred thirty-three patients with primary colorectal sarcoma were identified (57.5% leiomyosarcoma subtype). Median age was 63 [inter-quartile range 52, 75] years with 23.1% between the ages of 18 and 50 and 48.7% female. Majority of sarcomas were located in the colon (70.7%). When compared to 696,902 patients with adenocarcinoma, sarcoma patients were younger, had larger tumors, were more likely node negative and rectal in location, and higher grade (all p < 0.001), while sex, race, and comorbidity score were similar (all p > 0.05). Overall survival was lower at 5 years in patients with sarcoma (43.8%) than adenocarcinoma (52.3%, p < 0.001).

CONCLUSION: Primary colorectal sarcomas are rare and present at a younger age and higher grade than adenocarcinoma of the colon and rectum. Survival is significantly worse compared to adenocarcinoma patients.