Myxofibrosarcoma: Prognostic factors and survival in a series of patients treated at a single institution

Background. First described in 1977, myxofibrosarcoma is one of the most common sarcoma subtypes of the elderly. Until some years ago, myxofibrosarcoma was diagnosed as "myxoid malignant fibrous histiocytoma." The aim of this retrospective case series analysis was to investigate prognostic factors and the clinical outcome of a cohort of patients with myxofibrosarcoma treated at a single institution. Methods. We reviewed 158 patients with localized myxofibrosarcoma who underwent surgery at the Istituto Nazionale Tumori of Milan, Italy, over 15 years. Local recurrence, distant metastases, and survival were analyzed. Results. One hundred twenty patients had primary tumors, while 38 patients had locally recurrent tumors. Five-year overall survival was 77%. Tumor size, grade, and margins were statistically significant predictors of survival. Fiveyear local recurrence and distant metastases rate were 18% and 15%, respectively. Surgical margins were the only statistically significant prognosticator of local relapses. Patients treated with radiotherapy had the same prognosis as nontreated patients, but likely they had worse local presentations. The histological grade correlated with distant recurrences but not with local relapses. The value of adjuvant chemotherapy could not be determined. Conclusions. Patients with myxofibrosarcoma have a better disease-specific survival than other sarcoma subtypes, but also a higher local relapse rate. This is likely related to the peculiar local growth pattern of these tumors. Adequate surgery should be pursued, while the role of adjuvant therapies need to be investigated.