Anal cancer is an uncommon type of cancer that occurs in the anal canal. The anal canal is a short tube at the end of your rectum through which stool leaves your body.

Anal cancer can cause signs and symptoms such as rectal bleeding and anal pain.

Most people with anal cancer are treated with a combination of chemotherapy and radiation. Though combining anal cancer treatments increases the chance of a cure, the combined treatments also increase the risk of side effects.

Types of Anal Cancer

There are various forms of anal cancer, each defined by the type of tumor that develops. A tumor is an abnormal growth in the body. Tumors can either be benign or malignant. Malignant tumors may spread to other parts of the body over time, if left untreated. Examples of tumors include:

• Benign tumors. Tumors that are benign are noncancerous tumors. In the anus, this can include polyps, skin tags, granular cell tumors, and genital warts (condylomas).
• Precancerous conditions. This refers to benign tumors that may become malignant over time, which is common in anal intraepithelial neoplasia (AIN) and anal squamous intraepithelial neoplasia (ASIL).
• Squamous cell carcinoma. Squamous cell cancer is the most common type of anal cancer in the United States. According to the American Cancer Society, it accounts for 9 out of 10 cases. These malignant tumors in the anus are caused by abnormal squamous cells (cells that line most of the anal canal).
• Bowen’s disease. This condition, also known as squamous cell carcinoma in situ, is characterized by abnormal cells on anal surface tissue that haven’t invaded deeper layers.
• Basal cell carcinoma. Basal cell carcinoma is a type of skin cancer that generally affects skin exposed to the sun. Because of this, it’s a very rare form of anal cancer.
• Adenocarcinoma. This is a rare form of cancer that arises from the glands surrounding the anus.
• Anal cancer symptoms can be similar to those of hemorrhoids, irritable bowel syndrome (IBS), and many gastrointestinal diseases. These include:
• changes in bowel habits
• thin stools
• bleeding from the rectum
• pain, pressure, or the formation of a lump near the anus
• discharge from the anus or itching

How is anal cancer diagnosed

Anal cancer often presents with rectal bleeding. People who experience bleeding, itching, or pain in the anus often go to the doctor before anal cancer progresses past stage one. In other cases, anal cancer is diagnosed during routine exams or procedures.

Digital rectal exams can detect some cases of anal carcinoma. These are usually part of a prostate exam for men. Manual rectal exams, where the doctor inserts a finger into the anus to feel for lumps or growths, are common in pelvic exams for both genders.

Anal Pap smears can also be used to test for anal cancer. This procedure is similar to a traditional Pap smear: A doctor will use a large cotton swab to collect cells from the anal lining. These cells are then studied for abnormalities.

A doctor may also biopsy a set of cells or tissues to test for anal cancer if an abnormality is detected.

Regards
Amalia Azzarti
Managing Editor
Journal of clinical Oncology and Cancer Research.