How many stages does cervical cancer have?

Patient's question:

No

Doctor's answer:

Phase 0: The cancer cells are still confined within the cervical epithelial area.
Phase 1: The cancer cells are limited only to the cervix. From this phase onwards, the cancer has already begun to invade.
Phase 2: The cancer cells have invaded the upper third of the vagina or the connective tissue adjacent to the uterus.
Phase 3: The cancer cells have invaded the lower third of the vagina or have already spread to the pelvic cavity.
Phase 4: The cancer cells have the reproductive organs or have exceeded the pelvic cavity's boundaries, directly invading the rectum or bladder, or even distant metastasis has occurred.
There are five stages in total, and active treatment is required.