Prognostic factors of myxofibrosarcomas: implications of margin status, tumor necrosis, and mitotic rate on survival.
BACKGROUND
Myxofibrosarcomas (MFS) are characterized by tumor progression with increased metastases after local recurrences (LR). Few series had appropriately addressed what parameters independently affect prognosis.


METHODS
Seventy primary localized MFS were analyzed for local recurrence-free survival (LRFS), metastasis-free survival (MeFS), and disease-specific survival (DSS). Follow-up was obtained in 61 cases.


RESULTS
Thirty-eight males and 32 females had primary tumors ranging from 1.5 to 24 cm. Thirty and 40 tumors were superficial and deep, respectively, with 26 cases (38%) having positive margins. The 5-year LRFS-, MeFS-, and DSS-rates were 30%, 60%, and 73%. Positive margins (P = 0.0003) were the only inferior LRFS predictor. High grade (FNCLCC 2 and 3) was a negative factor of both MeFS (P = 0.0078) and DSS (P = 0.0174), and high stage (AJCC stage 3) was predictive of MeFS (P = 0.0470). However, both grading and staging were not prognostically independent. In multivariate analyses, mitoses >or=20/10 HPF (P = 0.0009, RR = 9.71) and positive margins (P = 0.0203, RR = 4.27) were independent adverse DSS predictor. However, tumor necrosis >or=10% (P = 0.0092, RR = 3.91) independently correlated with worse MeFS, together with mitoses >or=20/10 HPF (P = 0.0176, RR = 3.80) and positive margins (P = 0.0121, RR = 3.41).


CONCLUSIONS
Margin status and histologic property both affect the prognosis of MFS. The former correlates with improved LRFS and translates into final survival benefits.
Department of Pathology, Chi-Mei Foundation Medical Center, Tainan, Taiwan.
Ching-Nan
CN
Lin
Shin-Cheng
SC
Chou
Chien-Feng
CF
Li
Kun-Bow
KB
Tsai
Wen-Chung
WC
Chen
Ching-Yeh
CY
Hsiung
Cheng-Fang
CF
Yen
Hsuan-Ying
HY
Huang
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D005354:Fibrosarcoma / Q000401:mortality / Q000473:pathology*; D006801:Humans; D018208:Liposarcoma, Myxoid / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D008940:Mitotic Index; D015999:Multivariate Analysis; D009236:Myxosarcoma / Q000401:mortality / Q000473:pathology*; D009336:Necrosis / Q000473:pathology; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D012983:Soft Tissue Neoplasms / Q000401:mortality / Q000473:pathology*; D016019:Survival Analysis