Toward Observation as First-line Management in Abdominal Desmoid Tumors.

BACKGROUND: Desmoid tumors (DT) occur sporadically, in familial adenomatous polyposis, or in association with pregnancy. Initial observation has been proposed in the management of DT. An advantage of this approach is to select patients who have indolent disease versus those who require intervention. Here we report our multidisciplinary experience of abdominal DT as it relates to nonoperative management. METHODS: Patients seeking care from 1980 to 2012 with pathologically confirmed DT were identified from clinical research databases. Clinicopathologic data and management strategies were collected, and statistical analyses were performed by Chi square and t tests. RESULTS: A total of 213 patients were identified; DT occurred in abdominal wall (n = 103, 48 %), intra-abdominally (n = 92, 43 %), or at both sites (n = 18, 9 %). Patients were predominantly female (72 %); disease was sporadic (48 %), associated with familial adenomatous polyposis (38 %), or associated with pregnancy (14 %). Patient presentation was stratified into 3 groups: untreated (group A; n = 176), DT resected elsewhere (group B; n = 19), or recurrent DT (group C; n = 18). In group A, 109 patients were initially observed, with 51 patients requiring intervention as a result of progression or symptoms. Of the 58 patients who underwent only observation, 93 % experienced spontaneous regression or stable disease (median follow-up 38 months). Of the 67 patients in group A who underwent resection, 28 % experienced recurrence (median 22 months). Abdominal wall DT >7 cm and intra-abdominal DT were more likely to recur (P < 0.01). CONCLUSIONS: Initial observation has been implemented for abdominal DT at our institution. Over half of patients observed required no intervention with prolonged follow-up. Tumor size and site may predict progression during observation, therefore representing higher-risk groups.