Anal Cancer, Screening, and Prevention

The most common risk factor for anal cancer is being infected with the human papillomavirus (HPV). HPV is a sexually transmitted virus that may also cause warts in and around the anus or genitals in both men and women. Other risk factors include

  • Age (55 and older)
  • Anal sex
  • Multiple sex partners
  • History of HPV-related cancers, especially cervical
  • History of abnormal cervical pap smears
  • Weakened immune system due to HIV, chemotherapy, or organ transplant medications.
  • Prior pelvic radiation therapy for rectal, prostate, bladder, or cervical cancer


Although few cancers are totally preventable, avoiding risk factors and getting regular checkups are vitally important. Using condoms may reduce, but not eliminate, the risk of HPV infection. All people ages 9 to 45 can get the HPV vaccine to protect against genital warts and HPV-related cancer. It is recommended that children get the vaccine at age 11 or 12 so they are fully protected years before becoming sexually active.


People at increased risk for anal cancer should have a yearly anorectal exam and anal pap smear. An anal pap smear uses a swab to take anal cell samples that are then sent to a lab and examined under a microscope. This screening looks for precancerous cells called dysplasia. If dysplasia is detected, you may need further treatment to eradicate these areas to reduce your risk of getting anal cancer, such as proceeding with High-Resolution Anoscopy (HRA). HRA allows the physician to evaluate the anal canal with a special microscope and stains to identify the precancerous areas. A biopsy is done, and the area is fulgurated or removed with heat. The procedure is performed with mild sedation and local anesthesia, and close follow-up is necessary due to the elevated risk of recurrence.


While as many as 20% of patients with anal cancer may not have symptoms, the following symptoms could be indicators of anal cancer or other less serious conditions. If you are experiencing any of these symptoms, a healthcare provider should evaluate you.

  • Bleeding
  • Pain in the anal region
  • A mass or growth in the anal opening
  • Anal itching
  • Change in bowel habits, e.g., having more or fewer bowel movements or more straining during defecation.
  • Narrowing of the stools
  • Discharge mucous or purulent material from the anus.

Diagnostic procedures

  • Digital rectal exam
  • Exam of the anal canal with an anoscope
  • Biopsy of the mass
  • Pelvic MRI and CT scan are used to determine the extent of cancer after a confirmed diagnosis is obtained.


Most cases of anal cancer have high cure rates when treated early. Combination therapy with radiation and chemotherapy is considered the gold standard treatment for most anal cancers.