Cancer is always named for the part of the body where it starts, even if it spreads to other body parts later. When cancer starts in the vagina, it is called vaginal cancer. The vagina, also called the birth canal, is the hollow, tube-like channel between the bottom of the uterus and the outside of the body. When cancer starts in the vulva, it is called vulvar cancer. The vulva is the outer part of the female genital organs.