From Anal Dysplasia to Anal Cancer
This fact-filled essay is essential reading for every man or woman who receives anal intercourse. The facts become terribly interesting as you realize that knowing them could save your life or the life of someone you love
by Ted Voloyiannis, MD, FACS, FASCRS
One of the gastrointestinal cancers that drew a lot of attention in the last decade among the GLBT community is anal-canal cancer and its precursor, anal-canal dysplasia. There are numerous publications regarding the diagnosis, classification, treatment, and prevention of the different stages of dysplasia and cancer of the anus. Multiple guidelines can be found in the literature, and sometimes can cause confusion among doctors in the fields of internal medicine, gynecology, gastroenterology, oncology, and colon and rectal surgery. In addition, new technology has evolved in the diagnosis and treatment of anal dysplasia—to name a few: anal canal cytology (equivalent to the cervical Pap test for women), high-resolution anoscopy, and infrared coagulation. Regarding anal-canal cancer treatment guidelines, we have new technology in radiation treatment modalities (with fewer side effects) and new surgical procedures, including the single-port laparoscopic and robotic-assisted laparoscopic surgery for anal-canal cancer that cannot be cured completely after medical treatment with chemotherapy or radiation. The anus, or anal canal, is a passage that connects the rectum (the last segment of the gastrointestinal tract) to the outside of the body. It is surrounded by several muscles that help us control a bowel movement, the anal sphincter muscle being the most important.
Dysplasia, and subsequently anal cancer, arises from squamous cells (skins cells) in the lining of the anal canal that lose their ability to control their growth and may invade the sphincter muscle and surrounding tissues, spreading to other locations of the body—often the lymph nodes, bones, and organs such as the liver. This process of spreading from the primary location of the cancer (distal spread) to non-adjoining areas of the body is called metastasis, and the resulting tumors are called metastases.
Anal-canal cancer is fairly uncommon. It accounts for 2 percent or less of all gastrointestinal cancers. About 5,000 new cases are diagnosed each year in the U.S., more than half in women. Each year, approximately 700 people succumb to the disease. This is compared to 147,000 new cases of colon and rectal cancer per year, with 50,000 deaths.
However, there has been a significant increase in the incidence of anal-canal cancer among men who have sex with men. The present rate ranges from 60 to 160 per 100,000, compared to 20 to 30 years ago, when the rate was less than 30 per 100,000.
Who is at risk?
Many risk factors have been associated with anal dysplasia and anal-canal “skin” or squamous cancer. The most common risk factor is certain types of the human papilloma virus (HPV) that can cause genital warts or growths inside and around the cervix in women and the anus in both men and women. Several serotypes, or variations, of this virus are associated with increased risk of cervical cancer in women and anal dysplasia and cancer in men and women.
HPV is transmitted with sexual skin-to-skin contact, and it is a very common virus in the general population. It is estimated that almost half of the sexually active general population has HPV, although many types of the virus are harmless and do not cause warts or dysplasia. However, HPV is detected in 72–92 percent of HIV-positive and 57–61 percent of HIV-negative men who have sex with men! ?
Another risk factor for dysplasia and cancer of the anus is being over the age of 50. That makes sense when we consider the aging gay male HIV-positive population who have been responding successfully to antiretroviral therapy.
Both men and women who have receptive anal intercourse are also at increased risk. Epidemiological studies also found that smoking increases risk for anal-canal dysplasia and cancer, as does conditions that cause immune-suppression, such as HIV or immune-suppressing drugs that are necessarily taken by transplant patients.
Patients who have had pelvic irradiation for cancer of the cervix, rectum, bladder, or prostate could also develop anal dysplasia and cancer. Last, chronic inflammation of the anus from conditions such as fistula may lead to another type of anal-canal cancer, adenocarcinoma. In this case the cancer develops when the condition is left untreated for many years, and the risk is only around 1 percent.
What are the symptoms?
Anal-canal warts caused by the HPV can be detected by feeling lumps or small growths around the anus that may cause persistent or recurrent itching and bleeding when wiping or during a bowel movement. Warts that grow inside the anal canal over the skin lining may not be detected until they have grown significantly and start prolapsing or coming out via the anus (or causing discomfort, burning, and bleeding during a bowel movement or during intercourse). The warts may range from a few millimeters to several centimeters in size (from a small fraction of an inch to more than one inch).
A feeling of a lump or mass at the anal opening, palpable groin lumps, constant pain in the anal area, change in bowel habits (such as constipation or diarrhea, more or fewer bowel movements, increased straining, or narrowing of stools) may also be worrisome signs of anal-canal cancer. Discharge of mucous, blood, or pus may also be indicative of cancer of the anal canal.
All these symptoms may also be caused by less serious, non-cancerous conditions such as hemorrhoids! This is what leads most patients to try many different over-the-counter remedies, because they attribute their symptoms to hemorrhoids. When the symptoms fail to go away, they finally seek medical advice. Many patients cope with these symptoms for months and sometimes years before they see their doctors. Some people may not see a doctor early enough because of fear or embarrassment about disclosing the condition to partners, families, or friends, thus delaying the diagnosis and treatment.
On the other hand, anal-canal dysplasia usually does not display any symptoms. Many lesions are not visible and are detected only with anal cytology or with high-resolution anoscopy. It is therefore very important that sexually active men who have sex with men, as well as women who have anal intercourse, seek medical advice when they detect
an anal-canal lesion or have a new symptom, especially if they are being treated for HIV.
How do we diagnose and treat anal-canal dysplasia?
As previously mentioned, anal-canal dysplasia can be diagnosed with anal cytology. The exam is fairly simple. It is performed with a wetted swab that is used to collect cells for cytology; sometimes a second swab may be used to collect additional cells for HPV typing. This test can be performed by a primary-care physician and in many anal-dysplasia clinics.
Cytology results may have a confusing terminology for someone without specific medical knowledge. The classification is based on what is called the Bethesda system. The range includes benign, atypical squamous cells of undetermined significance, low-grade intraepithelial lesion and high-grade intraepithelial lesion, and squamous-cell anal-canal cancer.
Following a cytology that is positive for low- or high-grade dysplasia (especially in a HIV-, HPV-positive man who has sex with men), a digital (gloved finger) exam and anoscopy is essential. A colon and rectal surgeon may diagnose visible or suspicious lesion of the anal canal and perform excision (cutting out the lesion) or biopsy (cutting a piece of tissue for testing).
In the case of a positive cytology for low- or high-grade dysplasia with non-palpable, non-visible lesions in the anal canal, a high-resolution anoscopy is the next step. This is a fairly simple exam, where the anus is wetted with a medication called acetic acid that allows non-visible skin changes to become visible with different colors under lens magnification—thus the term high-resolution anoscopy.
Skin changes of the anal canal that may be suspicious for high-grade dysplasia may be treated with infrared coagulation in the office setting under local anesthesia during the anoscopy. Infrared coagulation is a technique that allows a suspicious dysplastic lesion to be fulgurated (destroyed/removed) with infrared light that does not cause a deeper injury to the tissues. This procedure can be repeated as necessary after future cytology. It has been shown that infrared coagulation may reduce the rate of anal-canal dysplasia by 50 percent in HIV-positive men who have sex with men. If the lesions are larger or multiple and the patient cannot tolerate the procedure in the office setting, a short outpatient procedure under general anesthesia may be necessary.
How is anal canal cancer diagnosed?
Anal-canal cancer may present with any of the symptoms of bleeding, itching, pain, fluid discharge, or change in bowel habits and a palpable mass, as was mentioned earlier. The most difficult step is for the person suffering symptoms to decide to visit his physician. A biopsy of the mass will lead to diagnosis. A squamous-cell cancer growth may sometimes be detected over a large chronic hemorrhoid, and that may confuse the patient and the primary-care physician.
Following the diagnosis of cancer, several other studies may be necessary to determine the local depth of the tumor in the surrounding tissues (local invasion) and the distal spread (metastases). An ultrasound of the anal canal or a MRI may be performed to determine the local invasion, and a CT of the abdomen and pelvis and a chest X-ray may be ordered to assess for metastasis. Blood work may also be necessary.
How is anal canal cancer treated?
The treatment for most cases of anal cancer is very effective without the need for surgery. However a colon and rectal surgeon should preferably establish the diagnosis and guide the treatment by doctors of other specialties. It is very important that a surgeon determine the initial appearance and stage of the tumor for local invasion and distal spread. Tumors that invade deeper into the sphincter muscle may be more resistant to treatment and may require surgery.
The treatment usually is based on a short-term chemotherapy protocol with radiation therapy directed to the anus for approximately five weeks. If the groin lymph nodes are involved, they may be radiated as well. Following the completion of chemotherapy and radiation, the colorectal surgeon will periodically assess the tumor for regression or complete healing. Resistant or recurrent anal-canal tumors may undergo biopsy again.
If the tumor does not completely respond to therapy, if it recurs after treatment, or if it is an unusual type, radical surgery may be necessary. This operation is called abdominal-perineal resection (APR) and may be performed with an open incision or laparoscopically with the more advanced techniques—via a single laparoscopic port or with the assistance of a robotic system. A colostomy for life is necessary in this case since the rectum and the anus will be removed.
Sometimes the tumor may invade surrounding structures such as part of the vagina in women, thus requiring more extensive surgery for reconstruction of the affected surrounding tissues. If the cancer spreads distally to other organs of the body, it may be difficult to cure.
What is the follow up after treatment for anal cancer?
Most patients with anal cancer will not need surgery since the chemotherapy and radiation is usually highly effective, especially if it is diagnosed early and before it invades into deeper structures or metastasizes. Periodic follow-up by the colon and rectal surgeon (for anoscopy and biopsy as needed) and the radiation oncologist (for CT scans) may be necessary. Sometimes radiation may have side effects causing scarring, burns, rashes, narrowing, and difficulty with sexual intercourse. Medical management is usually very helpful for alleviation of these symptoms.
What are the guidelines for prevention?
After reading about the symptoms and the treatment for anal-canal cancer, one may realize how important it is to prevent this condition that starts with anal-canal dysplasia or a wart and progresses into cancer over the course of years, if it is left undetected and untreated.
There are not yet established guidelines for the prevention of anal-canal dysplasia. Men who have sex with men, as well as women who have anal intercourse, are encouraged to undergo periodic anal cytology. This is especially important in the HIV-positive population who have been diagnosed with the HPV type linked to warts or dysplasia/cancer (types 11, 16, 18, 31, 33, 45), even those who are not sexually active.
The most recent literature published in the journal Diseases of the Colon and Rectum recommends that men who have sex with men, as well as women who have anal intercourse, undergo an anal cytology test once every two years if they are HIV negative and asymptomatic. For the HIV-positive population, the recommendation is an anal cytology or digital exam once a year. If there is an unusual symptom or sign detected by the patient or the doctor, then a digital exam and an anoscopy should be performed by a colon and rectal surgeon. A high-resolution anoscopy may be necessary if dysplasia is detected. If infrared coagulation or excision/biopsy of the lesion is performed and the lesion is eradicated (and provided it is not cancerous), a periodic anoscopy every six months to a year is recommended.
There are two vaccines available for prevention of the low- and high-risk HPV that is responsible for anal-canal dysplasia. Condom use may partially prevent infection with HPV; however, it may not completely protect the sexual partners, since HPV is transmitted with skin-to-skin contact. Avoiding skin shaving before sexual intercourse may help prevent the HPV infection.
As a colon and rectal surgeon, I am accustomed to being the first to diagnose patients with anal-canal cancer and guide them through the treatment modalities, including radical surgery when necessary. However, it is encouraging that in recent years I meet more patients from our city’s GLBT population with early conditions of anal dysplasia or warts that have not yet progressed to cancer. The awareness in the GLBT community is significantly greater in recent years, thus leading to routine anal cytology and anal health checks for suspicious symptoms or signs by primary-care physicians, gastroenterologists, gynecologists, and colorectal surgeons. However, there are relatively few clinics and colon and rectal surgeons, or other specialties, who have experience in anal-canal dysplasia screening treatment. As more men who have sex with men, as well as women who have anal intercourse, seek screening, we may notice a growing demand for trained physicians in this field.
Theodoros “Ted” Voloyiannis, MD, FACS, FASCRS, is Clinical Assistant Professor of Surgery at The University of Texas Health Science Center and Chief of Surgery at Memorial Hermann Hospital Southeast. He works with the Memorial Hermann Medical Group and is board-certified as a colon and rectal surgeon.