The stages of vulvar cancer are indicated by Roman numerals that range from I to IV, with the lowest stage indicating cancer that is limited to the vulva. By stage IV, the cancer is considered advanced and has spread to nearby structures, such as the bladder or rectum, or to distant areas of the body. Care at Mayo Clinic
https://www.mayoclinic.org/diseases-conditions/vulvar-cancer/diagnosis-treatment/drc-20368072

