Dysplastic changes,referred to as cervical intraepithelial neoplasia(CIN) begin in the deepest layer of the cervical epithelium,usually at the junction of the stratified squamous epithelium of the lower third of the cervical canal with the secretory epithelium of the upper two-thirds. Dysplasia may progress to involve the full thickness of epithelium. Not all dysplasia develop into malignant disease,but it is not possible to predict how far development will go,and whether it will remain static or regress. Early detention with a screening programme can allow abnormal tissue to be removed before it becomes malignant. Established malignancy is staged according to how extensive the tumour is.
Stage I refers to disease confined to the cervix.
Stage II through IV reflect increasing spread,including involvement of the rectum,bladder and structures out with the pelvis. Early spread is via the lymph nodes and local spread is commonly to the uterus,vagina,bladder and rectum. In late stages spread via the blood to the liver,lungs and bones may occur.
Risk factors include frequent sexual intercourse with multiple partners from an early age,all of which increase the likelihood of being exposed to a carcinogenic agent. Barrier contraceptives protect against the disease. The human papillomavirus(HPV),which causes genital warts,is strongly associated with this cancer.
