Early non-invasive diagnosis of cervical cancer: Beyond Pap smears and human papilloma virus (HPV) testing

Abstract

Cervical cancer is a major gynecologic malignancy around the world. However, current diagnostic methods such as Pap smear and human papilloma virus (HPV) testing are insufficient for an early diagnosis of cervical cancer, follow-up on therapy efficacy or to identify the women who might progress to cervical cancer (only about 1-5% of the HPV-positive women will develop cervical cancer). Patients with atypical squamous cells of undetermined significance (ASC-US) clearly need a better screening test. Developing a non-invasive method for early diagnosis of cervical cancer is essential. Our in vitro and translational research data support the hypothesis that: 1. Squamous cell cervical cancer is related to specific upregulation of tissue and serum Insulin-like Growth Factor-II levels (IGF-II; 100% sensitivity and 100% specificity). Serum IGF-I, but not IGF-II levels are elevated in other gynecological, breast, lung and prostate cancers. Serum IGF-II test helps in diagnosing cervical cancer as early as ASC-US or cervical intraepithelial neoplasia (CIN)-I and in monitoring therapy efficacy (p < 0.001 by Student's 't' test and Chi-square analysis). 2. Concomittant to increased serum IGF-II levels, IGF-Binding Protein 3 (IGF-BP3) levels are significantly decreased in persistent CIN and cervical cancer (p < 0.0001). As IGF-BP3 modulates IGF-II biological activity, significantly decreased serum IGF-BP3 levels (levels normalize after therapy; p < 0.001) may indicate a poor prognosis. Similar to serum IGF-II, serum IGF-BP3 levels help monitoring therapy efficacy in cervical cancer and advanced CIN. Measurement of serum IGF-II levels will help in early diagnosis of cervical cancer and monitoring of therapy outcome. Serum IGF-BP3 in conjunction with IGF-II levels may help in predicting prognosis as well as monitoring therapy efficacy.