According to the American Cancer Society, anal cancer occurs in the anal canal at the end of the rectum, where the intestines end. Anal cancer cells can form in the lining of the anus, in the glands around the anus, or in the skin surrounding the area.
Squamous cell carcinoma is the most common form of anal cancer. Anal cancer most often spreads to the liver and lungs. About 9,000-9,400 cases of anal cancer are diagnosed per year in the United States.
Anal cancer may cause the following symptoms:
- Rectal bleeding
- A mass or growth at the opening of the anal canal
- Itching and pain in the anal canal and around the rectum (known as pruritus)
- Feeling of fullness in the rectum but no bowel movement
- Changes in shape or texture of bowel movements, indicating gastrointestinal issues that can lead to anal cancer
- Anal leaking and the inability to control bowel movements
- Bloody or smelly discharge
- Swollen, painful lymph node in the groin area
In addition, anal and genital warts can be a symptom of HPV infection.
Who Gets It
Being infected with human papillomavirus (HPV) increases the chances of developing anal cancer. Specifically, HPV refers to a large group of viruses, some of which are considered high-risk. High-risk HPVs are one of the main causes of anal cancer, though most HPV infections don’t cause cancer at all.
Performing unprotected anal sex and having many sexual partners can also contribute to anal cancer.
People who are at high risk for developing anal cancer include people who:
- Perform anal sex, the leading cause of anal cancer.
- Have Human Papillomavirus (HPV). Most anal cancers are linked to a suppressed immune system due to infection from HPV.
- Take prescriptions for Human Immunodeficiency Virus (HIV) or Acquired Immune Deficiency Syndrome (AIDS) as it affects the immune system and increases the risk of anal cancer.
- Have multiple sex partners.
- Have a medical history of colorectal cancer, or cancers of the male and female reproductive organs.
- Have a history of cervical cancer, anal verge, or rectum issues, specifically women. May be susceptible to squamous cell carcinoma and rectum cancer.
- Are over 50.
- Were or are smokers, as it increases the development of some cancers, including anal cancer.
How to Prevent
What Research Says
According to the National Cancer Institute, people of all ages can be at risk for anal cancer, and the demographics change per age group. Anal cancer is more common in men under 35, women over 50, and people over 60.
Early diagnosis is key to treating and curing cancer patients. Survival rates reach 82% with early detection, immunotherapy for anal cancer, and anal cancer treatment five years after diagnosis.
The following are some things you can do to try to prevent anal cancer.
- Avoid having anal sex
- Practice safe sex and use condoms
- Stop having sex with multiple partners
- Check with your doctor about a vaccine option for HPV
- Stop smoking cigarettes
- Get regular checkups
If you are at risk of developing anal cancer, get a regular cancer screening test to catch it before it becomes advanced anal cancer.
Tests & Diagnosis
How is it given?
Anal cancer usually develops in the part of the anal canal that is easily examined. A doctor will perform a digital rectal exam (DRE) to feel for unusual lumps or growths. He may also use a lighted scope to inspect the inside of the anal canal, called an anoscopy.
A type of anal cancer that develops higher up in the rectum may not be diagnosed until a later stage. A doctor can perform a colonoscopy to examine the anal canal and lower intestine. If abnormal tissue is found, a doctor will biopsy a small sample for testing.
An external imaging test like an MRI or ultrasound might be used to examine cancer further or confirm the type of cancer.
If your cancer has spread or metastasized, a CT scanner will be used to create a visual cross-section of your organs and determine if they have been affected by the anal cancer cells.