Prognostic role of Rb, p16, Cyclin D1 proteins in soft tissue sarcomas

The aim of this study was to determine the expressions of Rb, p16, and cyclin D1 in soft tissue sarcomas, and we also wanted to identify the prognostic factors according to the clinicalpathologic features.

We reviewed the charts and radiographic films of 66 sarcoma patients. Tissue samples were collected from these patients. Immunochemistry was performed using formalin-fixed, paraffin-embedded tissue samples to examine the expressions of p16, Rb, and cyclin D1 proteins.

The median duration of overall survival was 47.8 months (range, 20.0 to 70.7 months) and the 5 years survival rate was 39%. As for the correlation between the degree of immunohistochemical staining for Rb protein and the histological tumor grades, there was a significant difference with a p-value of 0.019. However, no significant correlation was shown for p16 and cyclin D1. The overall survival duration of the Rb negative group (staining cell <20%) and the heterogeneous group (cell staining 20 to 80%) was 53.5±6.6 months and the overall survival duration of the Rb homogeneous group was 18.3±6.4 months, and there was a significant difference with a p-value of 0.016. However, no significant difference was shown between the survival rate according to the p16 and cyclin D1 expressions. On the multivariate analysis that was done with Rb, p16, the tumor size, grade and site, and patient age, the Rb gene expression was the most significant independent prognostic factor with a risk ratio of 3.01 (p=0.04).

The expression of Rb protein was correlated with the histologic grade and overall survival of patients with soft tissue sarcomas.