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Anal Dysplasia/Anal Cancer

Anal Dysplasia is a pre-cancerous condition which occurs when the cells of the lining of the anal canal undergo abnormal changes. The anal canal is the last few inches of the intestine. Anal dysplasia can progress from low risk changes to high risk changes before it turns into cancer.

Anal Cancer Causes

Anal cancer may be caused by the human papillomavirus (HPV). Anal cancer may develop slowly over a period of years. Anal cancer occurs mainly in two places: in the anal canal where the anus meets the rectum and in the skin just outside of the anal canal opening. Anal HPV can occur in some individuals even in the absence of anal intercourse.

Symptoms of Anal Dysplasia and Anal Cancer

There may be anal pain, bleeding, and discomfort. However, these same symptoms may be caused by other conditions such as hemorrhoids or anal fissures so it is important to keep in mind there may be no specific symptoms of anal cancer until it is quite advanced.

Risk Factors

  • Anal sex
  • HIV infection
  • Cervical High grade dysplasia or cervical cancer
  • Other HPV related disease such as warts or changes in the skin of the genital area
  • Immunosuppression from disease or medications such as ones that transplant patients need

Anal Dysplasia and Anal Cancer Prevention at UPMC

  • Practicing safe sex reduces the risk of getting HPV (Condoms are partially protective)
  • Stopping cigarette smoking
  • Treating HIV with antiretroviral therapy may reduce the risk of getting anal dysplasia but anal cancer can still occur despite antiretroviral therapy and high CD4 counts.

Diagnosing Anal Dysplasia and Anal Cancer

Anal Pap smears are how Anal Dysplasia and Anal Cancer is diagnosed. An anal pap smear is done by collecting cells from a swab that was inserted into the anus. Those cells are then examined by a pathologist looking for pre-cancerous or dysplastic changes, patients with any of the risk factors listed above should have an anal pap smear. 

  1. Normal
    • For HIV positive patients: repeat pap in 1 year
    • For HIV negative patients with risk factors: repeat in 2 years
  2. Abnormal - with any of the following abnormal results, the patients should be referred for high resolution anoscopy:
    • Atypical cells of undetermined significance high risk (ASCUS)
    • Low risk squamous intraepithial lesion (LSIL)
    • High risk squamous intraepithial lesion (HSIL)

Treating Anal Dysplasia and Anal Cancer

Low-grade lesions are low risk and generally do not have to be treated. They can be watched for signs of progression. However, visible warts are generally treated.

High risk lesions should be treated. There are multiple treatment options. Some include:

  • Electrocautery Treatment or Treatment by Infrared Coagulator (IRC): This destroys the lesion with heat or an intense beam of light. It can be uncomfortable and can cause some mild pain and slight bleeding afterwards. It is done in a clinic or office setting and one treatment may be enough.
    • Trichloroacetic Acid (TCA): The lesion is treated by being touched with acid- soaked cotton. Four or more treatments may be needed over several weeks. There is minimal, if any discomfort.