ANAL CANCER
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.
Q. What Is Anal Cancer?
Anal cancer is when cancer cells form within the tissues of the anus. Benign and malignant tumors in this area are signs of anal cancer. Some non-cancerous forms of anal cancer can turn cancerous over time.
Q. What are anal cancer statistics?
Anal cancers are rare, accounting for about 4% to 5% of the GI tract cancers. The risk of developing anal cancer appears to be increasing. In 2015, there will be about 7270 new cases of anal cancer in the US. In 2015, there will be about 1010 deaths due to anal cancer in the US.
Q. What Are the Symptoms of Anal Cancer?
Anal cancer symptoms are similar to those of hemorrhoids, irritable bowel syndrome, and many gastrointestinal diseases. They include:
Changes in bowel habits
Bleeding from the rectum
Pain, pressure, or the formation of a lump near the anus.
Sometimes, patients may experience discharge from the anus or itching.
Q. What are the types of Anal Cancer?
There are various forms of anal cancer, which are defined by the types of tumors that develop. Examples include benign tumors, pre-cancerous conditions, Bowen's disease, Squamous cell carcinomas, Basal cell carcinomas, Gastrointestinal stromal tumors.
Q. What Causes Anal Cancer?
Anal cancer is caused by the development of abnormal cells in the body. These cells can grow uncontrollably. As these abnormal cells accumulate, they form masses known as tumors. Cancer cells can metastasize, or spread through the body, and begin to infect nearby tissues.
Anal cancer is thought to be caused by the human papillomavirus (HPV), a sexually transmitted disease detected in most anal cancer cases.
Anal cancer may be the result of other cancers in the body spreading through the anal canal.
Q. What Are Risk Factors for Anal Cancer?
Like most cancers, anal cancer can occur in any person. Some patients are more at risk of developing anal cancer than others. Risk factors for anal cancer include:
Human papillomavirus infection (HPV): HPV is present in most cases of anal cancer. Having anal sex or more than five sexual partners in a lifetime significantly increases the risk of anal HPV infections.
Human immunodeficiency virus (HIV): HIV, the precursor to AIDS, puts patients at a higher risk of anal cancer.
Sexual activity: Promiscuity and receptive anal intercourse can increase your risk of getting anal cancer. Not using condoms may also put you at risk.
Smoking: Smokers are much more likely to develop cancer of the anus, even if they quit smoking.
Weak immune systems: Weakened immune systems may prevent the body from fighting off anal cancer. This is most common in patients who take immune suppressants or who have had an organ transplant.
Old age: Most cases of anal cancer occur in patients over the age of 50.
Q. What are the complications of anal cancer?
Anal cancer rarely spreads (metastasizes) to distant parts of the body. Only a small percentage of tumors are found to have spread, but those that do are especially difficult to treat. Anal cancer that metastasizes most commonly spreads to the liver and the lungs.
Q. How Is Anal Cancer Diagnosed?
Anal cancer is often spotted early on as it develops in the digestive tract. Patients 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.
Anal Pap smears can be used to test for anal cancer.
A doctor may biopsy a set of cells or tissues to test for anal cancer if an abnormality is detected.
Q. What is the Stage of anal cancer?
Tests and procedures used in the staging of your cancer may include:
Computerized tomography (CT) scan
Magnetic resonance imaging (MRI)
Positron emission tomography (PET)
Your doctor uses the information from the procedures to assign your cancer a stage. The stages of anal cancer are:
Stage I. The tumor is 2 centimeters (about 3/4 inch) or less — about the size of a peanut or smaller.
Stage II. The tumor is larger than 2 centimeters (about 3/4 inch) but has not spread beyond the anal canal.
Stage IIIA. The tumor is any size and has spread either to lymph nodes near the rectum or nearby areas, such as the bladder, urethra, or vagina.
Stage IIIB. The tumor is any size and has spread to nearby areas and lymph nodes or spread to other lymph nodes in the pelvis.
Stage IV. Anal cancer has spread to parts of the body away from the pelvis.
Q. How Is Anal Cancer Treated?
Anal cancer treatment is based on the stage of anal cancer a patient has. Common treatments for anal cancer include:
Medications
Chemotherapy is a drug used to kill cancer cells and stop them from growing. It can be injected into the body or taken by mouth. Pain relievers may be used intermittently to control symptoms as well.
Radiation therapy uses high-powered beams, such as X-rays, to kill cancer cells. Side effects may include skin redness and sores in and around your anus, as well as hardening and shrinking of your anal canal.
You typically undergo radiation therapy for anal cancer for five or six weeks. Chemotherapy is generally administered during the first week and the fifth week. Your doctor tailors your treatment schedule based on the characteristics of your cancer and your overall health. Combining chemotherapy and radiation increases the two treatments' effectiveness, it also makes side effects more likely. Discuss with your doctor what side effects to expect.
Surgeries
Local resection surgery is often used to remove a tumor in the anus, along with some healthy tissue around it. It is most familiar with patients whose cancer is in the lower part of the anus.
Abdominoperineal resection is a more invasive surgery. An incision is made in the abdomen. The anus, rectum, and parts of the sigmoid colon are removed.
Alternative Therapies
Alternative medicine treatments can't cure anal cancer. But some alternative medicine treatments may help you cope with the side effects of cancer treatment. Your doctor can treat many side effects, but sometimes medications aren't enough. Alternative therapies can complement your doctor's treatments and may offer additional comfort.
Options for common side effects include:
Anxiety — massage, meditation, hypnosis, music therapy, exercise or relaxation techniques
Fatigue — gentle exercise or tai chi
Nausea — acupuncture, hypnosis, or music therapy
Pain — acupuncture, massage, music therapy, or hypnosis
Sleep problems — yoga or relaxation techniques
Q. What Is the Outlook for Anal Cancer?
There is currently no cure for anal cancer. However, many patients can live long, healthy lives even after diagnosis. Early detection is the key to sustained health.
According to the Surveillance Epidemiology and End Results (SEER), the overall five-year survival rate for 2003-2009 was 65.6%. Patients with localized anal cancer reported a 79.6% survival rate (SEER, 2013).
Q. How can I Prevent Anal Cancer?
There is no guaranteed way to prevent anal cancer. But there are some ways to reduce your risk of anal cancer potentially:
Adjust your sexual habits. Limit the number of sex partners you have. Use protection during intercourse. Avoid receptive anal intercourse. Get tested regularly for sexually transmitted diseases.
Stop smoking and avoid secondhand smoke.
If you have a high risk of anal cancer due to other factors, such as your family history or age, get tested regularly to catch symptoms at the first stage.
Feb 8, 2021
HUNG M. DO, MD, PhD