Mortality of intra-abdominal desmoid tumors in patients with familial adenomatous polyposis: a single center review of 154 patients.

INTRODUCTION: Intra-abdominal desmoid tumors are one of the leading causes of death in patients with familial adenomatous polyposis. Their behavior is unpredictable and their biology is poorly understood, accounting for the lack of a standardized medical and surgical approach. The aim of this study was to evaluate the mortality rate of patients with intra-abdominal desmoid tumors and to identify prognostic factors for the evolution of the disease.

MATERIALS AND METHODS: A total of 154 patients with intra-abdominal desmoid tumors were included in the study. Each tumor was staged and each patient was categorized according to the stage of their most advanced tumor. Mortality was analyzed and the univariate risk factors associated with survival were included in a multivariable Cox regression model. A scoring system was derived from the multivariate analysis to refine outcomes within stages.

RESULTS: Five-year survival of patients with stage I, II, III, and IV intra-abdominal desmoid tumor were 95%, 100%, 89%, and 76% respectively (P < 0.001). Severe pain/narcotic dependency, tumor size larger than 10 cm, and need for total parenteral nutrition were shown to further define survival within stages. Five-year survival rate of stage IV patient with all of the above-mentioned risk factors was only 53%.

CONCLUSIONS: Our study confirmed the validity of the staging system to predict mortality in patients with intra-abdominal desmoid tumors and identified additional risk factors able to better define the risk of death within each stage. Risk stratification is crucial in directing patients with advanced disease and poor prognosis to the most appropriate medical and surgical options.