Prognostic Factors and Outcomes for Patients With Myxofibrosarcoma: A 13-Year Retrospective Evaluation.

BACKGROUND: Soft-tissue sarcomas are rare entities that are divided into approximately 50 histological subtypes. Myxofibrosarcoma (MFS) represents approximately 20% of all soft-tissue sarcomas, especially in elderly patients in their sixth to eighth decades of life. The treatment for soft-tissue sarcomas varies from primary surgical resection to neoadjuvant or adjuvant radiotherapy or cytotoxic chemotherapy. The aim of this study was to evaluate the prognostic factors affecting survival of patients with MFS, taking into account gender, tumour grade, state of the resection margin, local recurrence, use of radiotherapy, presence of metastases and blood levels of haemoglobin and C-reactive protein in a retrospective, single-centre analysis with a minimum follow-up period of 60 months (range=60-156 months). PATIENTS AND METHODS: The study included 34 patients (male/female=20/14). Tumour localization, tumour grade, tumour margins, local recurrence, the use of radiotherapy, the presence of metastasis, and the blood levels of haemoglobin and C-reactive protein preoperatively and during follow-up were evaluated. RESULTS: MFS constituted the most common high-grade sarcoma (G2/G3, 79.4%) in our cohort and was generally located in a lower limb (73.6%). Negative margins (R0) were detected in 67.6% of patients after surgical resection, and local recurrence occurred in 23.5% of all patients after a mean disease-free period of 19.4 months. Both parameters exerted no significant influence on survival. Radiotherapy was performed in a neoadjuvant or an adjuvant setting in 50% of patients (eight neoadjuvant, nine adjuvant). Metastasis occurred after a mean of 20.4 months in 38.2% of the patients. Higher C-reactive protein levels showed a trend towards being associated with worse survival, but the association was not significant (p=0.084); haemoglobin level had no influence on the survival rate (p=0.426). Tumour grade and metastasis were significant prognostic factors of survival (log-rank test p=0.041 and p=0.00007). Ten patients (29.4%) died due to MFS during our follow-up period. CONCLUSION: The tumour grade and metastasis of MFS are independently associated with disease-specific survival, whereas negative surgical margins, local recurrence and blood levels of C-reactive protein and haemoglobin were not significant prognostic factors. The understanding of the molecular biological patterns that result in the metastasis of these tumours will help develop better treatment plans in the future.