Anal cancer is a rare cancer that develops in the anal canal. The anal canal is a short tube at the end of the rectum through which stool exits the body.

Signs of anal cancer include bleeding from the rectum and anal pain.

Anal cancer is mainly treated with a combination of chemotherapy and radiation. The combination of the treatments increases the potential of curing the disease but it also increases the risk of side effects.


Symptoms of anal cancer include:

  • Anal or rectal bleeding
  • Pain around the anus
  • A mass/growth in the anal canal
  • Anal itching


Anal cancer forms due to a genetic mutation turning healthy and normal cells into abnormal cells. Unlike the healthy cells, the abnormal cells multiply more rapidly and don’t die. The accumulation of abnormal cells forms a mass or tumor. Moreover, the cancerous cells can separate from the initial mass and spread in other areas of the body (metastasize).

Anal cancer is often associated with a sexually transmitted disease called human papillomavirus (HPV). Traces of HPV are found in most anal cancer cases; therefore, it is considered as the most common cause of anal cancer.

Risk factors

Factors that increase the risk of anal cancer include:

  • Age: People aged 50 and over have a high risk of developing anal cancer
  • Multiple sex partners: People with many sexual partners in their lifetime have a higher risk of anal cance
  • Anal sex: Engaging in anal sex increases the risk of anal cancer
  • Smoking
  • Human papillomavirus: HPV infection can lead to anal cancer as well as cervical cancer.
  • Drugs or conditions that suppress the immune system: People who take immunosuppressive drugs, including people who received organ transplants have a risk of anal cancer. HIV (virus that causes AIDS) suppresses the immune system thus increasing the risk of anal cancer.


The general complications in cancers involve metastasis. However, anal cancer rarely metastasizes to distant parts of the body. A small percentage of tumors may spread to the liver and lungs making it extremely difficult to treat.


There is no guaranteed way to prevent anal cancer; however, the risk can be reduced in the following ways:

  • Practicing safe sex: Safe sex or abstaining from sex can prevent HPV and HIV thus reduce the risk of anal cancer
  • Vaccination against HPV: Gardasil and Cervarix are the vaccines given against HPV. Both sexes can be vaccinated against HPV.
  • Quitting smoking: It is recommended that smokers should stop smoking to reduce the risk of anal cancer.