Immunohistochemistry for p21(Waf1/Cip1), p53, proliferating cell nuclear antigen (PCNA), Ki-67, and Bcl-2 revealed that there was no significant difference in the cell proliferation activity between HPV-positive and HPV-negative lesions, suggesting that HPV infection alone does not induce cell proliferation in those lesions.
Furthermore, the 10 apoptosis-negative (< or =10%) cases of HPV-positive SCC were almost exclusively p21/WAF-1-negative (chi2 = 12.1406; P = 0.0005), indicating the significance of the relationship between HPV infection and the phenotype that is expected from HPV-induced inhibition of p53.
Positive immunostaining of cyclin D1 and p21WAF1/CIP1 was not related to high-risk factors (pelvic lymph node metastasis, deep cervical stromal invasion, parametrial invasion, large tumor size, and unusual histologic type) and human papilloma virus infection.