p27(kip1) protein expression correlates with survival in myxoid and round-cell liposarcoma.
OBJECTIVE
The p27(kip1) protein (p27) is a cyclin-dependent kinase inhibitor that has been shown to be an independent prognostic factor in a variety of human neoplasms. Low expression of p27 tends to occur in more aggressive neoplasms. The role of p27 as an independent prognostic factor in the spectrum of myxoid and round-cell liposarcomas has not been examined.


METHODS
Forty-seven cases of myxoid and round-cell liposarcomas were examined. Clinicopathologic features and immunohistochemical expression of p27 and Ki-67 antigen were studied in all cases. Survival analysis was performed using the log-rank test and the Cox multivariate regression model.


RESULTS
The male:female ratio was 1. 4:1, and the mean age at diagnosis was 45 years. The tumors were located in the lower extremities (94%) and retroperitoneum (6%). The median tumor size was 13.5 cm. The median follow-up was 6.3 years, and the overall 5- and 10-year survival rates were 76% and 67%, respectively. Low expression of p27 was identified in 34 cases (72%) and correlated with decreased metastasis-free (P =.026) and overall survival (P =.008). In a multivariate analysis, only round-cell differentiation and low expression of p27 independently predicted decreased metastasis-free and overall survival.


CONCLUSIONS
p27 expression predicts the clinical behavior of myxoid and round-cell liposarcomas, even in neoplasms with few or no round-cell differentiation.
Department of Laboratory Medicine and Pathology and Department of Oncology, Mayo Clinic, Rochester, MN, USA.
A M
AM
Oliveira
A G
AG
Nascimento
S H
SH
Okuno
R V
RV
Lloyd
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D018797:Cell Cycle Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D004791:Enzyme Inhibitors / Q000032:analysis*; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D007866:Leg / Q000473:pathology; D008080:Liposarcoma / Q000235:genetics* / Q000473:pathology; D018208:Liposarcoma, Myxoid / Q000235:genetics* / Q000473:pathology; D008297:Male; D008869:Microtubule-Associated Proteins / Q000032:analysis / Q000096:biosynthesis*; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D012044:Regression Analysis; D012186:Retroperitoneal Neoplasms / Q000235:genetics* / Q000473:pathology; D012983:Soft Tissue Neoplasms / Q000235:genetics* / Q000473:pathology; D016019:Survival Analysis; D025521:Tumor Suppressor Proteins
D014408:Biomarkers, Tumor; D018797:Cell Cycle Proteins; D004791:Enzyme Inhibitors; D019394:Ki-67 Antigen; D008869:Microtubule-Associated Proteins; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27