Any type of abnormal cellular changes is called dysplasia. Anal dysplasia is a term used to describe conditions that precede anal squamous cell carcinoma. Infection with human papillomavirus (HPV) is associated with these changes.
What is anal dysplasia?
Dysplasia refers to any kind of abnormal changes in body cells. Anal dysplasia, anal intraepithelial neoplasia (AIN), and squamous intraepithelial lesions (SIL) are terms used to describe conditions that occur before the development of anal squamous cell carcinoma (SCC). The anus is located at the end of the digestive tract and is the part of the rectum that allows stool to pass out of the body.
How is anal dysplasia related to anal cancer?
HPV infects the lowest cellular layer of the skin, the basal membrane. As shown in diagrams, precancerous cells extend toward the surface. The diagram also provides alternative names for this process and shows the degrees of dysplasia. For example, condyloma (warts) are considered a form of mild dysplasia. These warts are not cancer but indicate an HPV infection.
Diagram
LSIL represents low-grade squamous intraepithelial lesion, while HSIL represents high-grade squamous intraepithelial lesion. The diagram shows where HPV infects the lowest level of skin cells (basal membrane). It also demonstrates how infected cells move up to the skin’s surface. Infected cells also grow below the basal membrane, which is where cancer begins.
Besides anal cancer, HPV infection is linked to other cancers, including cancers of the urinary system, genital organs of both sexes, head, and neck. HPV infection is common, with most sexually active American adults becoming infected with HPV at some point in their lives.
What are the risk factors for developing anal dysplasia or anal cancer?
Several risk factors are associated with anal dysplasia and anal cancer, including:
- Infection with human papillomavirus (HPV)
- Having a higher number of sexual partners
- Anal intercourse
- Smoking
- Having untreated anal sores
- Genital dysplasia
- Immunosuppression due to:
- Human immunodeficiency virus (HIV)
- Hematologic malignancy (blood cancer)
- Medications
- Inflammatory bowel disease (IBD)
- Solid organ transplantation
How common is anal cancer?
According to the American Cancer Society, approximately 8,300 new cases of anal cancer are diagnosed in the United States each year, with around 1,280 people dying from the disease. The incidence of anal cancer is increasing.
What are the symptoms of anal dysplasia?
Anal dysplasia often does not cause symptoms. When symptoms do occur, they may include:
- Anal itching (also known as pruritus)
- Pressure – a sensation of having a lump or mass in the anus
- Pain
What are the symptoms of anal cancer?
- A lump near or on the anus
- Bleeding from the rectum or anus
- Leakage of stool from the anus
It’s important to note that most of these symptoms and signs can be caused by less serious conditions. This is why it is essential to see a doctor for an examination so the correct diagnosis can be made.
How is anal dysplasia diagnosed?
Your doctor will examine you visually and by palpation for any anal abnormalities or symptoms. There are two main methods for diagnosing anal dysplasia, in addition to a physical exam:
- Anal Pap test, which involves collecting cells from the anus to be examined under a microscope.
- Biopsy, which involves removing a tissue sample that is then examined microscopically by a pathologist.
How is anal cancer diagnosed?
Anal cancer is diagnosed through a biopsy, where a tissue sample is taken and examined microscopically.
How is anal dysplasia treated?
There is a new method for detecting and treating anal squamous intraepithelial lesions (SIL). This technique, called narrow band imaging chromoendoscopy with acetic acid (NBIA), combines the use of an endoscope (a thin, flexible tube that allows the doctor to view inside the gastrointestinal tract) with special dyes or stains to highlight abnormal tissue. During the procedure, any abnormal tissue identified can be destroyed, reducing the risk of the dysplasia progressing to anal cancer.
If there are anal warts (caused by HPV), they can be treated in various ways, such as:
- Topical medications
- Cryotherapy (freezing)
- Surgical removal or burning
What happens after treatment for anal dysplasia?
Following treatment for anal dysplasia, your doctor will likely continue to monitor you through regular follow-up visits.
How is anal cancer treated?
Current treatment for anal cancer typically involves a combination of chemotherapy and radiation therapy.
How can anal dysplasia and anal cancer be prevented?
There is no definitive way to prevent anal dysplasia and cancer, but certain steps can reduce your risk, including:
Get the HPV vaccine.
The U.S. Centers for Disease Control and Prevention (CDC) recommend that all boys and girls aged 11 or 12 receive two doses of the HPV vaccine, spaced six to twelve months apart. A third dose is needed if the two doses are given less than five months apart. For children older than 14, three doses over six months are required. If you didn’t get vaccinated when you were younger, it’s recommended to get the vaccine now. Women up to age 26 and men up to age 21 should receive the vaccine, along with men up to age 26 who have sex with men, transgender adults up to age 26, and adults up to age 26 with weakened immune systems, including those with HIV.
Use condoms.
It’s crucial to use condoms during all types of sexual activity and with sex toys. HPV can spread through skin-to-skin contact, so while condoms are highly effective, they do not offer complete protection.
Continue your treatment if you’re HIV-positive.
Quit smoking.
Get regular Pap smears and anal exams.
This is especially important for people engaging in receptive anal intercourse.
Cancer treatment can be very effective, and many people with anal cancer are cured. The prognosis depends on several factors, such as your overall health and how early the cancer is detected.
When to contact your doctor if you suspect anal dysplasia or have been diagnosed with it:
Reach out to your doctor if you experience symptoms of anal dysplasia, anal warts, or anal cancer. These symptoms include rectal bleeding, a lump in the area, or swelling of the anus. After your initial visit, make sure to attend any follow-up appointments as scheduled.