Expression of p27, p21, and p16 protein in early squamous cervical cancer and its relation to prognosis.

Objective: To examine the prognostic significance of the protein expression of the cyclin-dependent kinase (cdk) inhibitors p27, p21, and p16 in early squamous cervical cancer (SCC).
Methods: From 221 [corrected] patients who underwent radical hysterectomy and bilateral lymphadenectomy at our institution for stage IB SCC between 1987 and 1993, tissue blocks were available for this study. Immunohistochemistry using monoclonal antibodies against p27, p21, and p16 was used to examine protein expression. Ten patients who underwent hysterectomy for uterine prolaps served as controls.
Results: p21 and p16 expression were increased in SCC and high expression was observed in 20% (44/221) and 43% (94/220) of tumors, respectively. p27 was decreased in SCC and low expression was found in 80% (177/221) of tumors. In univariate analysis all classical clinicopathological parameters were associated with prognosis. Low p16 expression was significantly related to decreased overall (P = 0.036) but not disease-free survival (P = 0.103). In multivariate analysis, deep stromal invasion but none of the cdk inhibitors was independently related to survival.
Conclusion: The cdk inhibitors p27, p21, and p16 are not independently associated with prognosis in stage IB SCC.