p53, cyclin-D1, PCNA, AgNOR expression in squamous cell cancer of the lip: a multicenter study

The development of squamous cell carcinoma of the lower lip is an interesting model of photocarcinogenesis because of the structural and topographic characteristics of the lips. The purpose of this study was to evaluate the expression of immunohistochemical markers on the lips of patients with lower lip squamous cell carcinoma (LLSCC), compared with a control population.

Of the 98 subjects involved in the study, 58 were suffering from squamous cell carcinoma of the lower lip. The remaining 40 acted as a control. The case studies were taken from six university and hospital dermatology and plastic surgery departments. Questionnaires were administered to assess the risk factors for LLSCC. The cases involving squamous cell carcinoma underwent surgical excision and punch biopsy specimens were obtained from 20 control patients. Tissues were prepared in 5-microm-thick sections to carry out the following immunohistochemical study: PCNA, p53, AgNOR, cyclin-D1, bcl-2.

The lower lip was the predominant location of squamous cell carcinoma, with the following factors playing important roles: chronic sun exposure, history of smoking, alcohol use and familial risk of cutaneous tumors. The male/female ratio in our survey was 5:1. The p53 protein was positive in approximately 50% of SCC cases and in 20% of controls. This protein is mostly associated with chronically photoexposed skin areas. AgNOR positivity increased with the loss of cellular differentiation; a progressive increase in size and a poorly defined shape were evident in poorly differentiated carcinomas.

The results of this multicenter study showed that there is a noticeable difference in the expression of PCNA, p53, cyclin-D1, and AgNOR in tissues from patients with LLSCC and controls.