PROGRESSION OF HUMAN PAPILLOMA VIRUS (HPV) INFECTION TO CERVICAL CANCER

Stage 0: Initial HPV infection

16

Human papilloma virus infects the basal cells of the cervical epithelium (typically at the transformation zone of the cervix).

Stage 1: Persistent infection & Early cellular changes

17

HPV evades immune clearance and establishes persistent infection.
Viral DNA integrates into host DNA → expression of viral oncogenes E6 and E7, which:
• Inhibit p53 and Rb tumor suppressor proteins.
• Cause genomic instability and uncontrolled cell proliferation.
This is the earliest point where changes can begin leading to precancerous lesions.

Stage 2: Cervical intraepithelial neoplasia (CIN) or SIL (Squamous Intraepithelial Lesion)

18

These are precancerous stages and are classified based on the severity of abnormal cell changes.
CIN 1. Low grade SIL—Mild dysplasia, abnormal cells in lower 1/3 of epithelium often clear spontaneously
CIN 2. High-grade SIL—Moderate dysplasia, abnormal cells in lower 2/3 may regress or progress
CIN 3. High-grade SIL—Severe dysplasia / carcinoma in situ (full-thickness abnormal cells, but no invasion)High risk of progression

Stage 3: Invasive Cervical Cancer

19

Once abnormal cells break through the basement membrane, it becomes invasive cancer.
DESCRIPTION
Stage I— Cancer confined to the cervix
Stage II— Cancer spreads beyond cervix, but not to pelvic wall or lower vagina.

Stage 4: Metastatic Cervical Cancer

20

Cancer spreads to distant organs involving pelvic wall and/or lower vagina, possibly causes kidney issues.
Cancer has spread to bladder, rectum, or distant organs (e.g., lungs, liver)