Anal Cancer

Definition
Anal cancer occurs when abnormal cells grow within the anus or anal canal and form a benign or malignant tumor. Squamous cell carcinoma, which includes basaloid, epidermoid, cloacogenic, or mucoepidermoid, is a common form of anal cancer. Rare types of anal cancer often include gastrointestinal stromal tumors (GIST) and melanoma. Depending on the cancer’s severity level or progression, a combination of treatment options may be considered to successfully manage or treat anal cancer.

Causes
According to the American Society of Colon and Rectal Surgeons, the human papilloma virus (HPV) is often linked to anal cancer as a potential cause. Although HPV has been associated with anal cancer, most patients with HPV do not get anal cancer. Cancer of the cervix, vagina, or vulva may also lead to anal cancer.

Risk Factors
In the United States, anal cancer is relatively uncommon and affects approximately one in 600 people each year. Nevertheless, there are certain risk factors that may increase the likelihood of this cancer. People over the age of 55 are generally at risk of developing anal cancer. Additionally, those who smoke, have a weakened immune system, long-standing anal fistula, HPV, or have had previous pelvic radiation therapy are at risk.

Symptoms
Roughly 20% of patients will not experience symptoms of anal cancer, especially if it’s found early. Regardless, symptoms of anal cancer may include:

  • Bleeding from the rectum or anus
  • A mass near the anal opening
  • Persistent, recurring pain or itching in the anus
  • Drainage from the anus
  • Swollen lymph nodes in the anus or groin
  • Narrowing of stool
  • Increased or decreased frequency of bowel movements
  • Increased straining during bowel movements

Treatments
Generally, there are three treatment methods used to mitigate or effectively cure anal cancer. Surgery, chemotherapy, and radiation therapy are usually recommended for the best long-term survival rate from anal cancer.

Surgery
Small, early stage tumors are typically removed during a surgical operation to limit the risk of metastases (the spread of cancer to other areas of the body). Major surgery is often necessary for extensive anal cancer tumors. Should you require major surgery to remove your anus and rectum, your surgeon will attach a permanent colostomy to a stoma created out of your large intestine.

Chemotherapy
Chemotherapy uses specific medications, delivered either orally or intravenously (most common), to kill cancer cells in the anus. 5-fluorouracil or 5-FU, mitomycin C, and cisplatin are common medications used to treat anal cancer.

Radiation Therapy
Radiation therapy uses high-powered x-ray devices to kill cancer cells. According to the American Society of Colon and Rectal Surgeons, anal cancer typically responds well to radiation therapy.