Anal Cancer: The Basics

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

When your body makes stool (bowel movement), it sits in the rectum. The anus helps you control the movement of stool from the rectum to the outside of the body. Anal cancer is caused by anal cells growing out of control. As the number of cells grows, they form a tumor.

Anal cancer that has spread from the anus to another part of the body is called metastatic cancer.


Risks are:

Signs of Anal Cancer

Signs of anal cancer:

  • Bleeding when passing stool.
  • Pain or feeling of fullness in the anus.
  • Some people may be itchy, have discharge, have a change in normal bathroom habits, and may have pain when touched.

Diagnosis of Anal Cancer

When your healthcare providers think you may have anal cancer, they will do a full exam of your body and ask you questions about your health history. Your provider will do a digital rectal exam and also look at the anus with a scope. These tests are important, but a biopsy is the only way to know for sure if you have cancer. A biopsy:

  • Looks at a piece of the anus for cancer cells.
  • Is used to find out the cancer type, how normal it is [grade], and if it has spread.
  • The biopsy may be done using a needle, small pair of scissors, or clamps to remove a small piece of tissue.

A pathology report sums up these results and is sent to your healthcare provider, often 5-10 days after the biopsy. This report is an important part of planning your treatment. You can ask for a copy of your report for your records.

Staging Anal Cancer

To guide treatment, anal cancer is "staged." This stage is based on:

  • Size of the tumor and where the tumor is.
  • Whether cancer cells are in the lymph nodes.
  • Whether cancer cells are in other parts of the body.

Stages range from stage I (smallest, most confined tumors) to stage IV (tumors that have spread to other parts of the body, also called metastatic cancer). The stage and type of anal cancer will guide your treatment plan.


Often, these treatments are used:

  • Radiation therapy uses high-energy x-rays to kill cancer cells.
  • Chemotherapy is the use of medication to kill cancer cells.
  • Chemoradiation is the use of radiation and chemotherapy at the same time.
  • Surgery can be used in some cases to remove the tumor.

This article is a basic guide to anal cancer. You can learn more about your type of anal cancer and treatment by using the links below.

Anal Cancer: Staging and Treatment

Surgical Procedures: Surgery and Staging for Anal Cancer


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.

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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 Bartlet


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