Does screening for cervical intra-epithelial neoplasm in developing countries prevent invasive cervical cancer?

In a bid to evaluate the practical relevance of screening for cervical intraepithelial neoplasia (CIN) in reducing the incidence of invasive cancer in Nigeria, we performed a comparative study of CIN and invasive carcinoma in Ibadan, Nigeria over a period of 8 and 16 years respectively. 4.5% of patients with invasive cervical cancer were under the age of 30 years. It peaked at 28% in the age group 41-50 years. In comparison, <3% of patients with CIN were below 20 years of age while it had the highest incidence of 37%, 34% and 36% respectively in age 40 years and below. The mean age for CIN was 39.6 +/- 9.6 (SD) years compared to 51.3 +/- 11.1 (SD) years for invasive cervical cancer (p < 0.01). There was a 10 year interval between the onset and peak age incidence of invasive cancer and CIN respectively, even though there was an overlap of cases from the third decade. We therefore suggest a combined approach of public education to encourage early presentation and provision of health service outlets for cervical cancer screening in Nigeria to reduce the burden of cervical cancer.