Cervical Cancer - Prevention & Screening

Definition

Cervical cancer prevention and screening focus on reducing incidence and mortality by detecting precancerous lesions early and preventing human papillomavirus (HPV) infection through vaccination.

Epidemiology

• Fourth most common cancer among women worldwide
• Higher incidence in low- and middle-income countries due to limited screening and HPV vaccination
• Peak incidence between 35–55 years
• HPV types 16 and 18 cause approximately 70% of cervical cancers
• Effective screening and vaccination programs have significantly reduced incidence in high-income countries

Etiology

• Persistent infection with high-risk HPV types (16, 18, 31, 33, 45, etc.)
• Co-factors: early sexual debut, multiple sexual partners, immunosuppression (HIV), smoking, long-term oral contraceptive use
• Other contributing factors: chronic cervical inflammation and co-infection with other STIs
• Genetic susceptibility may play a role in host immune response to HPV

Pathophysiology

• HPV infects basal epithelial cells of the transformation zone of the cervix through microabrasions
• Viral oncoproteins E6 and E7 inactivate tumor suppressor genes p53 and Rb, leading to uncontrolled cell proliferation
• Persistent infection may progress to cervical intraepithelial neoplasia (CIN) grades 1–3
• Untreated high-grade lesions may progress to invasive cervical carcinoma over years
• Integration of viral DNA into host genome is key step in malignant transformation