KERRY’S STORY
Kerry was a 42-year-old executive in excellent health. She was married but had no children and had never been pregnant. She was a non-smoker with no medical history or family history of cancer. Specifically, Kerry had no history of sexually transmitted diseases and was HIV negative. When he noticed blood on the toilet paper after having a bowel movement, he first thought the problem was due to hemorrhoids. However, after two weeks, the bleeding increased and was accompanied by pain and itching around the anus. He went to his GP, whose examination revealed a 2 x 2-inch mass in the anal sphincter. His doctor did not feel any abnormal lymph nodes in his groin. He referred her to a colorectal surgeon who performed a colonoscopy. That exam confirmed the mass seen by his GP, but no other injuries. The biopsy revealed a squamous cell carcinoma, anal cancer.
After her diagnosis, Kerry’s surgeon palpated her for a PET / CT scan that revealed an abnormality only in the anal mass. There was no distant activity to suggest metastatic (distant, incurable) spread of her cancer. Her surgeon referred her to a radiation oncologist and a medical oncologist. They recommended radiation therapy (RT) and chemotherapy administered together (concurrent chemoRT) which he underwent over a 6-week period. Kerry was treated with intensity modulated radiation therapy (IMRT) to minimize the dose of RT to critical organs such as the small intestine and bladder, while treating possible microscopic cancer cells within the lymph nodes of the pelvis and groin and the anal tumor. He simultaneously received mitomycin and fluorouracial chemotherapy by intravenous infusion on an outpatient basis. Kerry had expected the side effects of the treatment, including severe irritation and redness of the skin in the groin and anus, but did not require a break during the IMRT. She had significant fatigue that kept her out of work for most of her chemoRT. He had some loose intestines that were well controlled after adjusting his diet. Near the completion of his treatment, there was no evidence of any remaining tumor. He recovered from the side effects of the treatment for about six weeks. Kerry has seen one of her cancer doctors every three to six months for the past five years and remains cancer free.
THE ESSENTIAL
Although it is one of the less common cancers of the gastrointestinal tract, about 5,000 cases of anal cancer are still diagnosed in the US each year. There are more women than men diagnosed. The average age at diagnosis is around 60 years, but it can occur in patients between the ages of 30 and 40. If the disease is localized, which is the case in 50% of patients, the cure rate is approximately 80%.
RISKS AND CAUSES
Most patients who are diagnosed with anal cancer do not have a clearly defined risk factor. However, factors that increase the risk of developing anal cancer are associated with the risk of infection with the human papillomavirus (HPV). This virus is the same type that causes genital warts. Certain strains of the HPV virus are associated with a high risk of developing anal cancer, as well as cervical cancer and some types of throat cancer. Activities that put people at risk for HPV, such as receptive anal intercourse, also put them at risk for developing anal cancer later on.
SIGNS AND SYMPTOMS
Patients often come to their doctors with complaints of anal pain or bleeding. Many patients ignore or downplay the symptoms, often initially attributing them to hemorrhoids. While most people with these symptoms do not have anal cancer, persistent pain or bleeding should always require medical attention. Less frequently, patients will complain of itchiness or a painless lump in the groin. A lump in the groin can develop as a result of anal cancer that spreads to the lymph nodes and causes them to enlarge.
DIAGNOSIS
Diagnosis of anal cancer is usually made by biopsy of the anal mass or the area of ​​ulceration. This procedure is usually performed by a surgeon or a gastroenterologist. These doctors can directly look at the anal canal and rectum by proctoscopy (or the entire colon by colonoscopy) with special instruments after administering medications to minimize discomfort. Biopsies are performed during these procedures, after sedation and / or injection of an anesthetic. Most anal cancers (80%) are squamous cell carcinomas. A complete evaluation of a person suspected of having anal cancer should also include an examination of the pelvis, particularly of both groins. If the lymph nodes are enlarged, a biopsy may also be done. Many enlarged lymph nodes are just swollen, with no evidence of cancer. Blood tests that may be ordered include complete blood count, kidney function tests, and possibly HIV tests, depending on the patient’s risk factors for the virus.
STAGING
The American Joint Committee on Cancer (AJCC) TNM staging system is used to determine whether anal cancer is localized (early stage) or has spread to other sites (advanced or late stage). Early-stage disease is limited to the anus, while advanced disease refers to cancers that have invaded nearby organs or lymph nodes in the pelvis or groin. Imaging studies should include a CT scan of the abdomen and pelvis and a chest X-ray at a minimum. Staging may also include a PET / CT scan. This imaging test allows the radiologist, as well as the cancer specialists who treat you, to see if anal cancer has spread to the lymph nodes in the groin or pelvis, or has metastasized to other sites in the body. like the liver or lungs.
TREATMENT
Standard treatment for anal cancer does not involve surgery, which is both a surprise and a relief for many patients. Since most anal cancers invade the sphincter that controls defecation, surgery to remove such cancer would require the removal of the sphincter and the creation of a colostomy. Therefore, surgery is generally avoided in favor of treatment that keeps the anal sphincter intact. An exception would be very early cancers of the anal margin, on the skin outside the anus.
Concurrent chemoRT is the standard treatment for most anal cancer patients, for the best chance of cure with preservation of the sphincter. RT given for approximately 6 weeks with concurrent chemotherapy with IV fluorouracil (5FU) and mitomycin C (MMC) gives patients the best chance of cure. RT is administered in daily fractions using 3D conformal RT or IMRT. The latter technique can be used to minimize the amount of normal intestine and / or genitalia receiving full dose RT (and therefore minimize side effects).
The main side effects that are possible during RT in the anus and pelvis include a skin reaction that can be severe around the anus and skin folds in the groin, as well as intestinal irritation and diarrhea. Most patients will see that these acute symptoms resolve within 1-2 months after completing treatment. Extremely rare (<1%) but serious side effects include intestinal obstruction or fistula (a hole between the anus and the bladder or urethra). 5FU can also cause intestinal irritation, diarrhea, mouth or lip irritation, poor appetite, and fatigue. Infrequently, skin or nail discoloration or severe peeling of the hands and feet (hand-foot syndrome) or other major side effects may occur. In rare cases, heart problems can occur, including a heart attack. MMC can cause low blood counts, mouth sores, poor appetite, and fatigue. Nausea, vomiting, and urinary irritation can also occur. In rare cases, life-threatening lung or kidney damage can occur.