Anal Cancer: Staging and Treatment

Author: Christina Bach, MBE, LCSW, OSW-C
Last Reviewed: December 28, 2022

What is staging for cancer?

Staging is the process of learning how much cancer is in your body and where it is. Tests like digital rectal exams, biopsies using an anoscope, CTs and MRIs are done to help stage your cancer. Your providers need to know about your cancer and your health so that they can plan the best treatment for you.

Staging looks at the size of the tumor and where it is, and if it has spread to other organs. The staging system for anal cancer is called the “TNM system,” as described by the American Joint Committee on Cancer. It has three parts:

  • T-describes the size/location/extent of the "primary" tumor in the anus.
  • N-describes if the cancer has spread to the lymph nodes.
  • M-describes if the cancer has spread to other organs (metastases).

Your healthcare provider will use the results of the tests you had to determine your TNM result and combine these to get a stage from 0 to IV.

How is anal cancer staged?

Staging of anal cancer is based on:

  • The size of your tumor.
  • If the cancer has spread to the lymph nodes, and if it has, how many lymph nodes are affected.
  • If the cancer has spread to other organs. This is called metastasis.

Staging is important because it helps to guide your treatment plan. The staging system is very complex. Below is a summary staging system. Be sure to talk to your provider about the stage of your cancer.

  • Stage 0: The tumor is only in the surface area of the anus. The tumor has not spread to the lymph nodes or to other organs.
  • Stage I: The tumor is located in the anus and is 2 cm or less in size. It has not spread to the lymph nodes or to other organs.
  • Stage II: The tumor is located in the anus and is 2-5 cm in size. It has not spread to the lymph nodes or to other organs.
  • Stage III: The tumor is located in the anus and is more than 5 cm in size is at least 2 cm in size and could be larger than 5 cm in size. It may also have spread to the lymph nodes and to nearby organs like the vagina, urethra, or bladder.
  • Stage IV: The tumor can be any size and has spread to other organs and to the lymph nodes.

How is anal cancer treated?

Treatment for anal cancer is based on your health, your goals, the size of the tumor, and if it has spread to the lymph nodes or other organs. There can be more than one type of treatment used to treat anal cancer. Some of the treatments used include:

  • Radiation.
  • Chemotherapy.
  • Surgery.
  • Clinical Trials.

Often, chemotherapy and radiation are used together to treat anal cancer. This is called chemoradiation.


Radiation is the use of high-energy x-rays to kill cancer cells. Radiation can be the only treatment for earlier-stage anal cancers or used in combination with chemotherapy. (chemoradiotherapy).

  • You will need to go to a radiation treatment center 5 days a week for up to six weeks for your treatment.
  • The treatments are painless and take just a few minutes.
  • Radiation can irritate your skin causing it to become red, painful, or to break down. You may also experience have fatigue, diarrhea, and lower blood counts.
  • Radiation to the pelvic area can impact sexual health and fertility. Before starting this treatment, be sure to talk with your provider about your sexual health and fertility concerns.


Chemotherapy is the use of anti-cancer medicines that go through your whole body. These medicines may be given through a vein (IV, intravenously) or by mouth. Chemotherapy in anal cancer can be used with radiation therapy or as the only treatment, depending on the stage of your cancer.

The chemotherapy medications used to treat anal cancer include 5-FU, mitomycin, capecitabine, cisplatin, paclitaxel, oxaliplatin, leucovorin, and docetaxel. These may be used in combination you may be given more than one medication, which is called a regimen.

Two newer medications, nivolumab and pembrolizumab, are also being used to treat anal cancer. These medications are called monoclonal antibodies. They work to stimulate the immune system to destroy cancer cells. These may be used in patients with metastatic disease or those whose cancer has progressed after their first treatments.


Surgery is not often used to treat anal cancer. It may be used in an early stage, superficial cancer. This may be called perianal cancer. The surgery to remove the tumor is called a local excision.

If you have advanced anal cancer or cancer that has returned after treatment or has not responded to treatment, your provider may recommend an abdominal perineal resection (APR). In this surgery, the anus is cut, including the anal muscles, and a permanent colostomy to collect stool is placed.

Clinical Trials

You may be offered a clinical trial as part of your treatment plan. To find out more about current clinical trials, visit the OncoLink Clinical Trials Matching Service.

Making Treatment Decisions

Your care team will make sure you are included in choosing your treatment plan. This can be overwhelming as you may be given a few options to choose from. It feels like an emergency, but you can take a few weeks to meet with different providers and think about your options and what is best for you. This is a personal decision. Friends and family can help you talk through the options and the pros and cons of each, but they cannot make the decision for you. You need to be comfortable with your decision – this will help you move on to the next steps. If you ever have any questions or concerns, be sure to call your team.

You can learn more about anal cancer at

Resources for More Information

The Anal Cancer Foundation

SEER Statistics,, retrieved 7 January 2019.

American Cancer Society, Anal Cancer,, retrieved 7 January 2019

NCCN Clinical Practice Guidelines: Anal Carcinoma (V.2.2018). (requires log-in)

Bryant, A. K., Mudgway, R., Huynh-Le, M. P., Simpson, D. R., Mell, L. K., Gupta, S., ... & Murphy, J. D. (2018). Effect of CD4 Count on Treatment Toxicity and Tumor Recurrence in Human Immunodeficiency Virus–Positive Patients With Anal Cancer. International Journal of Radiation Oncology* Biology* Physics, 100(2), 478-485.

Colón-López, V., Shiels, M. S., Machin, M., Ortiz, A. P., Strickler, H., Castle, P. E., ... & Engels, E. A. (2018). Anal cancer risk among people with HIV infection in the United States. Journal of Clinical Oncology, 36(1), 68.

Edge SB, Byrd DR, Compton CC, et al., eds. (2017). AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer, retrieved from

James, R. D., Glynne-Jones, R., Meadows, H. M., Cunningham, D., Myint, A. S., Saunders, M. P., ... & Falk, S. (2013). Mitomycin or cisplatin chemoradiation with or without maintenance chemotherapy for treatment of squamous-cell carcinoma of the anus (ACT II): a randomised, phase 3, open-label, 2× 2 factorial trial. The Lancet Oncology, 14(6), 516-524.

McCloskey, J., Kast, W. M., Flexman, J. P., McCallum, D., French, M. A., & Phillips, M. (2018). A new explanation for rising rates of anal cancer. Papillomavirus Research, 5, S10.

Mitchell, M. P., Abboud, M., Eng, C., Beddar, A. S., Krishnan, S., Delclos, M. E., ... & Das, P. (2014). Intensity-modulated radiation therapy with concurrent chemotherapy for anal cancer: outcomes and toxicity. American Journal of Clinical Oncology, 37(5), 461-466.

Morris, V. K., Salem, M. E., Nimeiri, H., Iqbal, S., Singh, P., Ciombor, K., ... & Xiao, L. (2017). Nivolumab for previously treated unresectable metastatic anal cancer (NCI9673): a multicentre, single-arm, phase 2 study. The Lancet Oncology, 18(4), 446-453.

Moscicki, A. B., Darragh, T. M., Berry-Lawhorn, J. M., Roberts, J. M., Khan, M. J., Boardman, L. A., ... & Likes, W. M. (2015). Screening for anal cancer in women. Journal of lower genital tract disease, 19(3 0 1), S26.

Palefsky, J., & Berry, M. (2015). Prevention of Anal Cancer—Can We Do Better?. Diseases of the Colon & Rectum, 58(5), e76.

Shiels, M. S., Kreimer, A. R., Coghill, A. E., Darragh, T. M., & Devesa, S. S. (2015). Anal cancer incidence in the United States, 1977-2011: distinct patterns by histology and behavior. Cancer Epidemiology and Prevention Biomarkers, cebp-0044.

Wilkes, G. (2011). Anal Cancer. In Yarbro C.H, Wujcik, D. & Gobel, B.H. (2011). Cancer Nursing (pp. 1246- 1257). Sudbury, MA: Jones and Bartlett.

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