Anal Cancer, from the CureRays guide library.

Anal cancer is usually cured without surgery, using a proven combination of radiation and chemotherapy that preserves normal function.

What it is.

Anal cancer develops in the anal canal, the short passage at the end of the digestive tract. Most cases are squamous cell carcinomas and are strongly linked to the human papillomavirus (HPV). It's an uncommon cancer, and one of the great success stories of cancer care: a combination of radiation and chemotherapy cures most cases without removing the anus, so patients keep normal bowel function. Surgery is now reserved mainly for the rare cancers that don't respond.

How radiation treats it.

Radiation uses focused, high-energy x-rays to damage the DNA of cancer cells so they can no longer divide, while healthy tissue repairs and recovers. Given together with chemotherapy, radiation is especially effective against anal cancer — the chemo sensitizes the cancer cells so a moderate radiation dose can cure the disease. Modern intensity-modulated radiation shapes the dose tightly around the tumor and lymph nodes while protecting nearby skin and organs, which makes treatment far more tolerable than it once was. The main side effects — skin irritation and bowel changes in the treated area — are temporary and managed closely by your team.

The ways we can treat it.

Intensity-modulated radiation therapy (IMRT). The preferred technique: it delivers a high dose to the tumor and at-risk lymph nodes while sparing the skin, hips, bladder, and genitals — reducing the harsh side effects of older radiation methods.

Concurrent chemotherapy. Mitomycin and 5-fluorouracil given during radiation make the cancer cells far more sensitive to it, dramatically improving cure rates.

Image-guided delivery. Daily imaging keeps the beams precisely on target through a treatment course of about 5-6 weeks.

Questions we hear often.

Will I need a colostomy or surgery? Usually not. The whole point of modern chemoradiation is to cure anal cancer while preserving normal function. Surgery is reserved for the minority of cases that don't fully respond.

How long is treatment? Radiation is typically given daily over about 5-6 weeks, with chemotherapy during the first and last weeks. Your plan is tailored to the tumor's size and location.

What are the side effects? Skin soreness in the treated area, diarrhea, and fatigue are common during treatment and usually settle within weeks afterward. Your team will help you manage them.

This guide is informational only. It is not medical advice — please confirm anything here with your care team.