Long-term outcome of sporadic and FAP-associated desmoid tumors treated with high-dose selective estrogen receptor modulators and sulindac: a single-center long-term observational study in 134 patients.

Summary

Aim of this study is to evaluate the outcome of long-term conservative treatment with sulindac and high-dose selective estrogen receptor modulators (SERMs) for sporadic and FAP-associated desmoid tumors. This study included all desmoid patients that were treated and followed at our institution and had completed at least 1 year of treatment. Response was defined as stable size or regression of desmoid size between two CT or MRI scans. A total of 134 patients were included. 64 (47.8 %) patients had a confirmed diagnosis of FAP, 69 (51.5 %) patients were sporadic. Overall 114 (85.1 %) patients showed regressive or stable desmoid size. Patients with previous history of multiple desmoid-related surgeries showed less-favorable response. The mean time to reach at least stable size was 14.9 (±9.1) months. After regression or stabilization, medication was tapered in 69 (60.5 %) of the treated patients with only one long-term recurrence after >10 years. The results of this study fortify the role of sulindac and high-dose SERMs as an effective and safe treatment for both, sporadic and FAP-associated desmoid tumors. While invasive treatment frequently results in high recurrence rates, high morbidity and high mortality, this conservative treatment is successful in most patients.