Surgical outcome of desmoid tumors: Adjuvant radiotherapy delayed the recurrence, but did not affect long‐term outcomes

We retrospectively reviewed the outcomes of desmoid tumor (DT) patients treated by surgical excision.Among 155 consecutive patients, 119 patients satisfied our inclusion criteria. The mean follow-up duration was 82 months. Age, gender, location, size, depth, resection margin, adjuvant radiotherapy, and excision history were analyzed for the outcomes.The recurrence-free survival (RFS) rates were 75% at 5 years and 72% at 10 years. Twenty-seven (93.1%) out of 29 recurrences were detected within 5 years. In multivariate analysis, positive resection margin and excision history were independently associated with the RFS. In the comparison between the propensity score matched groups, adjuvant radiotherapy was not significantly associated with the RFS. The mean time interval from surgery to recurrence was 30.0 ± 28.7 months (median, 20 months; range, 4-123 months). This interval was significantly longer for patients who received adjuvant radiotherapy than for those who received surgical resection only, both in all recurrences and in recurrences in matched cases.Surgical excision appears to be a reliable treatment option for DTs. However, positive outcomes require a clear resection margin. Adjuvant radiotherapy may delay the recurrence of the tumor, although it seems to have no effect on the ultimate relapse rate.