Anal cancer begins when healthy cells in or on the anus change and grow out of control, forming a mass called a tumor.
Types of anal cancer
The anus is made up of different types of cells, and each type can become cancerous. There are several different types of anal cancer based on the type of cell where the cancer began:
- Squamous cell carcinoma is the most common type of anal cancer. This cancer begins in the outer lining of the anal canal.
- Cloacogenic carcinoma accounts for about 1-quarter of all anal cancer. This type of cancer arises between the outer part of the anus and the lower part of the rectum. Cloacogenic cell cancer likely starts from cells that are similar to squamous cell cancer, and it is treated similarly.
- Adenocarcinoma arises from the glands that make mucous located under the anal lining.
- Basal cell carcinoma is a type of skin cancer that can appear in the perianal (around the anus) skin.
- Melanoma begins in cells that produce color found in the skin or anal lining.
Anal Cancer: Treatment
In cancer care, different types of doctors often work together to create a patient’s overall treatment plan that combines different types of treatments. This is called a multidisciplinary team. Cancer care teams also include a variety of other health care professionals, including physician assistants, oncology nurses, social workers, pharmacists, counselors, dietitians and others.
Making treatment decisions
For anal cancer, there are 3 main types of treatment: surgery, radiation therapy, and chemotherapy. Treatment options and recommendations depend on several factors, including:
- The type, stage and grade of cancer
- Possible side effects
- The patient’s preferences
- The patient’s overall health
Descriptions of each treatment option are listed below.
Your care plan may also include treatment for symptoms and side effects, an important part of cancer care. Take time to learn about all of your treatment options and be sure to ask questions about things that are unclear. Also, talk about the goals of each treatment with your doctor and what you can expect while receiving the treatment, including possible bowel function, urinary function, and sexual side effects of the specific treatment plan.
Surgery is the removal of the tumor and some surrounding healthy tissue during an operation. The type of surgery for anal cancer depends on the stage of the cancer. A surgical oncologist is a doctor who specializes in treating cancer using surgery. Surgery for anal cancer may also be performed by a colorectal surgeon, who specializes in surgery on the colon or rectum.
Anal carcinoma in situ or early-stage cancer can often be treated by removing the abnormal cells and a small area of the surrounding healthy tissue, which is called a margin. Afterward, patients should regularly receive follow-up screening to watch for and remove any new abnormal cells.
Previously, most patients with later stages of anal cancer were treated surgically before effective chemotherapy and radiation therapy were developed for anal cancer. However, studies have shown similar cure rates between surgical treatment and the combination of radiation therapy and chemotherapy. Now, most patients have a biopsy (which may require some level of surgery; see Diagnosis) followed by chemotherapy and radiation therapy without further surgery. Many patients can avoid major surgery with this type of combined treatment.
If a patient cannot have chemotherapy or radiation therapy, surgery may be recommended. Surgery may also be recommended if the cancer remains after initial treatment or returns after treatment has been completed.
A persistent or recurring tumor may be treated with an abdominoperineal resection, which is the surgical removal of the anus, rectum, and part of the colon. This procedure results in the patient needing a colostomy, which is an opening on the abdominal wall to allow feces to be collected in a bag. During this procedure, lymph nodes may also be removed, which is called a lymph node dissection.
Radiation therapy is the use of high-energy x-rays or other particles to destroy cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist.
The most common type of radiation treatment is called external-beam radiation therapy, which is radiation given from a machine outside the body. When radiation treatment is given using implants, it is called internal radiation therapy or brachytherapy.
A radiation therapy regimen (schedule) usually consists of a specific number of treatments given over a set period of time. Radiation therapy for anal cancer is often combined with chemotherapy. Typically, patients receive 5 to 6 weeks of radiation therapy which is given daily, Monday through Friday. If there is irritation of the skin, sometimes a break from radiation is needed for several days.
Patients with both anal cancer and HIV may need to be treated with lower doses of radiation therapy. This depends on the degree to which the patient’s immune system is compromised by the HIV.
Side effects of radiation therapy may include fatigue, mild to modest skin reactions, upset stomach, temporary anal irritation, loose bowel movements, and discomfort when having a bowel movement. Scar tissue may form from the damage to anal tissue, which may interfere with bowel function. Most side effects go away soon after treatment is finished. Talk with the radiation oncologist about what side effects you can expect and how to reduce or relieve them.
Chemotherapy is the use of drugs to destroy cancer cells, usually by stopping the cancer cells’ ability to grow and divide. Chemotherapy is given by a medical oncologist, a doctor who specializes in treating cancer with medication.
Systemic chemotherapy gets into the bloodstream to reach cancer cells throughout the body. Common ways to give chemotherapy include an intravenous (IV) tube placed into a vein using a needle or in a pill or capsule that is swallowed (orally).
A chemotherapy regimen (schedule) usually consists of a specific number of cycles given over a set period of time. A patient may receive 1 drug at a time or combinations of different drugs at the same time.
Chemotherapy for anal cancer usually consists of a combination of drugs. Common drugs for anal cancer include fluorouracil (5-FU, Adrucil) combined with either mitomycin C (Mitozytrex, Mutamycin) or cisplatin (Platinol). Chemotherapy is particularly effective for treating anal cancer when given in combination with radiation therapy, as discussed above. The combined treatment allows the use of lower radiation doses and improves the likelihood of completely destroying the tumor.
Patients with both anal cancer and HIV may need to receive lower doses of chemotherapy. This depends on the degree to which the patient’s immune system is compromised by the HIV.
The side effects of chemotherapy depend on the individual and the dose used, but they can include fatigue, lowering of blood counts, (including cells that fight infection and help stop bleeding as well as anemia) risk of infection, nausea and vomiting, hair loss, loss of appetite, diarrhea. These side effects usually go away once treatment is finished.
Getting care for symptoms and side effects
Cancer and its treatment often cause side effects. In addition to treatment to slow, stop, or eliminate the cancer, an important part of cancer care is relieving a person’s symptoms and side effects. This approach is called palliative or supportive care, and it includes supporting the patient with his or her physical, emotional, and social needs.
Palliative care is any treatment that focuses on reducing symptoms, improving quality of life, and supporting patients and their families. Any person, regardless of age or type and stage of cancer, may receive palliative care. It works best when palliative care is started as early as needed in the cancer treatment process. People often receive treatment for the cancer and treatment to ease side effects at the same time. In fact, patients who receive both often have less severe symptoms, better quality of life, and report they are more satisfied with treatment.
Palliative treatments vary widely and often include medication, nutritional changes, relaxation techniques, emotional support, and other therapies. You may also receive palliative treatments similar to those meant to eliminate the cancer, such as chemotherapy, surgery, or radiation therapy. Talk with your doctor about the goals of each treatment in your treatment plan.
Before treatment begins, talk with your health care team about the possible side effects of your specific treatment plan and palliative care options. And during and after treatment, be sure to tell your doctor or another health care team member if you are experiencing a problem so it can be addressed as quickly as possible.
Metastatic anal cancer
If cancer spreads to another part in the body from where it started, doctors call it metastatic cancer. If this happens, it is a good idea to talk with doctors who have experience in treating it. Doctors can have different opinions about the best standard treatment plan. Also, clinical trials might be an option. Learn more about getting a second opinion before starting treatment, so you are comfortable with your treatment plan chosen.
Your treatment plan may include a combination of surgery, radiation therapy, and chemotherapy. Palliative care will also be important to help relieve symptoms and side effects.
For most patients, a diagnosis of metastatic cancer is very stressful and, at times, difficult to bear. Patients and their families are encouraged to talk about the way they are feeling with doctors, nurses, social workers, or other members of the health care team. It may also be helpful to talk with other patients, including through a support group.