The goal of treatment is to eliminate cancer while preserving function. Most cases of anal cancer can be managed without surgery, but in advanced cases or when other treatments are ineffective, surgery may be required.

The full effects of chemoradiation may take several months to become clear. Because of this, regular follow-up appointments are essential to track progress. Your doctors will use digital rectal exams and anoscopy to monitor any remaining cancer, as it can continue shrinking for up to six months. In some cases, the cancer may resolve on its own without additional treatment.

Stages I-II

At these stages, the tumors are in the anal canal, but have not spread to lymph nodes nor organs. 

• Chemoradiation: The standard treatment combines external beam radiation therapy (EBRT) with chemotherapy, typically 5-fluorouracil (5-FU) and mitomycin-C. For patients who are HIV-positive, cisplatin may be used instead of mitomycin-C to balance effectiveness with immune system considerations. 

Stage IIIA, IIIB, IIIC

At these stages, the cancer has spread to adjacent organs and/or nearby lymph nodes, but it has not yet spread to distant areas of the body.

• Chemoradiation: The main treatment remains chemotherapy combined with radiation to shrink and destroy the tumor. 

Stage IV

When anal cancer is Stage IV, it means the cancer has spread beyond the pelvis to distant organs such as the liver, lungs, bones, or far-away lymph nodes. While treatment may not eliminate the cancer entirely, it can help slow its growth, manage symptoms, and improve quality of life.

Doctors will tailor a treatment plan based on where the cancer has spread, how your body responds, and your personal goals. The most common options include:

• Chemotherapy: The first-line treatment for metastatic anal cancer, chemotherapy drugs like 5-FU, mitomycin, and cisplatin help slow cancer growth and relieve symptoms.

• Radiation Therapy: Palliative radiation can help shrink tumors and relieve pain or other symptoms, especially if cancer has spread to the bones, brain, or lymph nodes.

• Immunotherapy: For certain patients, immune checkpoint inhibitors may help the body recognize and fight cancer cells, particularly if chemotherapy is no longer effective.

• Clinical Trials: Emerging therapies are being tested for advanced anal cancer. If traditional treatments aren’t working, participating in a clinical trial may provide access to new and promising therapies.

Persistent Disease 

If cancer is still present after six months, additional treatment may be considered.

Immunotherapy

Immunotherapy helps the immune system recognize and fight cancer cells more effectively. Immune checkpoint inhibitors, like nivolumab (OPDIVO®), may be used for certain advanced cases, especially in patients with specific genetic markers or when other treatments haven’t worked. 

Clinical Trials

Clinical trials test new or combined treatments to evaluate their safety and effectiveness. Patients with anal cancer may have access to trials for emerging therapies, like targeted therapies or new immunotherapies. Participation in a trial may offer access to treatments not widely available. You can talk to your provider about available trials or visit ClinicalTrials.gov for current listings.

Abdominoperineal Resection (APR)

For cases where chemoradiation and immunotherapy do not work, an abdominoperineal resection (APR) may be necessary. This procedure involves:

• Removing the anus, rectum, and part of the colon.

• Creating a permanent colostomy (an opening in the abdomen where waste exits into an ostomy bag).

Most anal cancer cases do not require surgery, but when necessary, procedures like APR can be life-saving. If you are facing a possible colostomy, talk to your medical team and ostomy specialists to understand what to expect and how to manage your new lifestyle.

Living with an Ostomy

If an APR is performed, a colostomy will divert waste from the intestines to an opening in the abdominal wall (a stoma). 

• Colostomy bags attach to the stoma to collect waste.

• Modern colostomy care allows people to maintain an active lifestyle.

• Ostomy nurses and support groups help with adjusting to life after surgery.

Though an ostomy can be a major life change, many people adapt well and continue their daily activities with proper support and education.