An analysis of factors related to recurrence of myxofibrosarcoma

Objective: Myxofibrosarcoma is clinically characterized by a high frequency of local recurrence after surgery. To improve the clinical outcome of patients with myxofibrosarcoma, it is imperative to control any postsurgical local recurrence. Methods: In this study, we performed a retrospective clinicopathologic analysis of 100 consecutive patients with myxofibrosarcoma to identify factors related to poor prognosis. All of the patients had been diagnosed, and had undergone surgery at the National Cancer Center Hospital between 1999 and 2008. Results: At the initial visit to our hospital, 64 patients had primary myxofibrosarcoma, whereas 36 had undergone primary unplanned resection at other facilities. Of the 36 patients, 11 consulted our hospital before recurrence and 25 did so after recurrence. A histologically positive margin after surgery was evident in 28% of the cases overall. The estimated 5-year recurrencefree survival rate was 74.8%. Univariate analysis showed that primary unplanned resection at another facility (P = 0.0001) and a histologically positive margin (P = 0.0224) were significant predictors of local recurrence. When these two factors were subjected to multivariate analysis, only primary unplanned resection at another facility was significantly correlated with the estimated recurrence-free survival rate (P = 0.0011). Primary unplanned resection was also significantly related to the 5-year disease-free survival rate (P = 0.0401). Conclusions: Our findings indicate that primary unplanned resection at a non-referral hospital is the most important risk factor related to poor prognosis of myxofibrosarcoma. Accurate diagnosis and adequate initial surgery are most important factors for improving the clinical outcomes of myxofibrosarcoma.