Words to know: Anal cancer
- Anus
- The opening at the end of the bowel where stool leaves the body.
- Anal canal
- The short tube that connects the rectum to the anus.
- HPV (human papillomavirus)
- A common virus spread by skin contact during sex. Long-lasting infection causes most anal cancers.
- Squamous cell carcinoma
- Cancer that starts in flat cells lining the anal canal. The most common type of anal cancer.
- HSIL
- High-grade squamous intraepithelial lesion. Precancer cells that could turn into cancer over time.
- Anoscopy
- A look inside the anus with a short lighted tube.
- High-resolution anoscopy
- A closer look at the anal lining with a magnifying scope, used to find precancer.
- Biopsy
- Taking a small piece of tissue to look at under a microscope.
- Lymph nodes
- Small bean-shaped glands that help fight infection. Anal cancer can spread to those in the groin and pelvis.
- Stage
- A measure of how big the cancer is and how far it has spread.
- Chemoradiation
- Chemotherapy and radiation given during the same weeks.
- Mitomycin
- A chemotherapy drug given with fluorouracil and radiation for anal cancer.
- Fluorouracil (5-FU)
- A chemotherapy drug often given through a small portable pump over several days.
- Capecitabine
- A chemotherapy pill that turns into fluorouracil in the body.
- IMRT
- Intensity-modulated radiation therapy. Radiation shaped closely to the tumor to protect healthy tissue.
- Complete clinical response
- When exams and scans no longer show any cancer after treatment.
- Abdominoperineal resection (APR)
- Surgery that removes the anus and rectum, leaving a permanent colostomy.
- Colostomy
- An opening in the belly where stool leaves the body into a bag.
- Sitz bath
- Sitting in a few inches of warm water to soothe and clean the anal area.
- Immunotherapy
- Medicine that helps your immune system find and attack cancer.
- Retifanlimab
- An immunotherapy drug approved for advanced anal cancer.
- Metastatic
- Cancer that has spread to distant parts of the body.
- Vaginal dilator
- A smooth tube used after pelvic radiation to keep the vagina from narrowing.
- CD4 count
- A blood test that measures immune cells in people living with HIV.
Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.