Apoptotic and mitotic index in squamous cell carcinomas and premalignant lesions of the uterine cervix

The aim of this study was to determine the frequency of apoptotic and mitot ic cells in different grades of premalignant lesions and in different stage s of squamous cell carcinoma (SCC) of the uterine cervix. The apoptotic and mitotic indices (AI and MI) of 55 H&E-stained sections of cervical intraep ithelial neoplasia (CIN) and 30 SCCs were evaluated in light microscopy by a morphometric method. Twenty, 16, and 19 of 55 CIN cases were classified i n CIN I, CIN II, and CIN III group, respectively. No apoptosis was observed in the normal epithelium next to the dysplastic mucosa. There was no stati stically significant difference between CIN I and CIN II as well as CIN II and CIN III groups in terms of apoptotic and mitotic cell counts. Mitotic c ell counts were found significantly higher in CIN III group when compared w ith CIN I and CIN II groups together. There was no statistically significan t difference in the apoptotic and mitotic cell counts between nonkeratinizi ng and keratinizing types of SCC. In the SCC group, apoptotic cell counts d id not show significant difference between tumor stages. But mitotic counts were significantly higher in advanced stage rumors. The SCC group showed s ignificantly higher mitotic and apoptotic cell counts when compared with pr eneoplastic lesions. This study suggests that apoptotic function is not alt ered during progressive stages of dysplastic change in cervical epithelium, while proliferation is triggered only in late stages of dysplasia. Both ap optosis and mitosis are markedly increased in progression to malignancy in cervix epithelium. Mitotic cell counts may be helpful in predicting the ext ent of the disease in SCC. Resistance of cell death by apoptosis after inva sion may accelerate the net growth of the tumor resulting in advanced disea se.