The Predictive Impact of HPV Genotypes, Tumor Suppressors and Local Immune Response in the Regression of Cervical Intraepithelial Neoplasia 2-3: A Prospective Population-Based Cohort Study

Cervical intraepithelial neoplasia (CIN) is caused by human papillomavirus (HPV); however, factors such as HPV genotype and individual immune response may also contribute to its development. The loop electrosurgical excision procedure (LEEP) is a treatment for high-grade cervical intraepithelial neoplasia (CIN), as approximately 30% of these cases may progress to cancer. However, 20-40% of cases will regress spontaneously. HPV16 infection constitutes the highest risk for progression to cervical cancer and a lower probability of regression. Knowledge regarding the regression of lesions caused by other high-risk genotypes alone or in association with biomarker expression and lesion length has been limited. In the present study, the regression rates of high-grade squamous intraepithelial lesions were calculated. Twenty-one percent of the 161 women diagnosed with CIN2-3 on colposcopy-directed biopsies exhibited regression (defined as CIN1 or less) in the subsequent cone excisions. The mean interval between biopsy and treatment was 113 days (range of 71-171). High-grade lesions of the squamous epithelium caused by HPV16, together with lesions caused by HPV31, 52 and 58, showed significantly lower regression rates (HR 0.54, 0.22-0.75; low-regression group) than lesions caused by HPV18, 33, 35, 39, and 45 (HR 2.85, 1.54-5.28; high-regression group). A multivariate analysis of HPV genotypes, epithelial expressions of pRb and p53, immune cell proportions in the stroma (CD4/CD25 and CD4/CD8), and lesion lengths correctly predicted regression in 78% (Harrell's C). A Harrell's C value of 82% for the low-regression group indicates that different HPV genotypes or groups, together with divergent patterns of tumor suppressors, immune cells, and lesion size, can give prognostic information regarding the outcome of CIN2-3.