Sporadic extra abdominal wall desmoid-type fibromatosis: surgical resection can be safely limited to a minority of patients

Background: To analyse the natural history of extra-abdominal wall desmoid-type fibromatosis (DF) and compare outcome in patients who underwent initial surgery with those who did not.

Patients and methods: All consecutive patients affected by primary sporadic extra-abdominal wall DF observed between January 1992 and December 2012 were included. Patients were divided into surgical (SG) or non-surgical groups (NSG) according to initial treatment. Relapse free survival was calculated for SG, and crude cumulative incidence (CCI) of switching to surgery or other treatments for NSG.

Results: 216 patients were identified, 94 in SG (43%), 122 in NSG (57%). A shift towards a more systematic use of a conservative approach (78% of all comers) was observed in the latter years (2006-2012), although a small proportion of patients (28%) had been offered the conservative strategy even in the early period (1992-2005). Median follow-up (FU) was 49 mo. (interquartile (IQ), 20-89 mo.), 76 months for SG and 39 months for NSG. 5-year relapse-free survival (RFS) for SG was 80% (95% confidence interval (CI), 72-89%). For the NSG, 5-year CCI of switching to surgery was 5% (95% CI: 1.7%, 14%), and 51% to other treatments (95% CI: 41%, 65%). 27 (20%) NSG patients underwent spontaneous regression.

Conclusion: A non-surgical approach to extra-abdominal wall DF allowed surgery to be avoided in the majority of patients. This approach can be safely proposed and surgery offered as an option in selected cases.