Detection of aberrations of chromosome 17 and p53 gene expression and their correlation to histologic grading and prognosis in primary invasive squamous cell carcinoma of the cervix.

We analyzed tumor tissues from 14 patients with invasive squamous cell carcinoma of the cervix for aberrations of chromosome 17 and p53 expression. All but 3 patients were negative for p53 protein expression, the protein being detected in 2 International Federation of Obstetrics and Gynecology stage IIa cancers and 1 stage Ib G3 carcinoma. Significant cytogenetic aberrations in the form of losses and gains of chromosome 17 were diagnosed in 9 and 7 patients, respectively. There was no correlation with tumor prognosis, clinical stage or histologic grade. According to most reports, almost all cervical carcinomas contain integrated human papilloma virus (HPV) and express E6 oncoproteins. Increasing evidence suggests that E6 protein interaction leads to p53 mutation in HPV-infected cervical epithelium. Since most cervical tumors are infected with HPV, and the tumors originate through p53 gene mutation caused by the said interaction, which leads subsequently to the overexpression of p53 oncoprotein, lack of the latter in the remaining 11 cervical tumors may either be the result of technical shortcomings, or the tumor may arise in such circumstances through a p53-independent pathway. On the other hand, 2 of 3 stage IIa cancers and 1 Ib G3 carcinoma were found to be p53 positive, thus supporting the notion that p53 inactivation is a relatively late event in the progression of cervical cancer.