Anal Cancer

Cancer specialists at UT Southwestern Medical Center have experience treating all types of cancer, even rare types such as anal cancer. Our gastrointestinal cancer experts provide compassionate care using the latest advancements in diagnosis and treatment for the best possible outcomes.

As the only National Cancer Institute (NCI)-designated comprehensive cancer center in North Texas, we deliver the best cancer care available today and push to discover new treatments. NCI designation means we offer patients the ability to participate in the broadest possible range of clinical trials, with access to potential therapies not available at other facilities.

Expert, Compassionate Care for Anal Cancer

In patients with anal cancer, abnormal cells begin developing uncontrollably in the anus, which is the end of the digestive tract. The anus is the opening through which stool exits the body at the end of the rectum, the end of the large intestine. Anal cancer occurs much more rarely than colorectal cancer, which develops in the large intestine and is the third most common cancer in the U.S. 

At Simmons Cancer Center, our specialists take a team approach to anal cancer care. We combine expertise from gastroenterologists and medical, surgical, and radiation oncologists to provide comprehensive care from initial evaluation and diagnosis through treatment and follow-up care.

Causes and Risk Factors of Anal Cancer

Although the exact causes of anal cancer are not fully understood, certain factors can increase a person’s risk of developing it. Risk factors include:

• Human papillomavirus (HPV) infection: HPV is a virus transferred through skin-to-skin contact and can lead to several types of cancer, such as anal and cervical cancer.
• Weakened immune system: HIV/AIDS, organ transplants, immunosuppressive drugs, and certain medical conditions can lower immunity, which makes the body more susceptible to diseases such as anal cancer.
• Smoking: Tobacco use can lead to a number of cancers, such as anal cancer.
• Age: Anal cancer usually develops in people over age 50 but can rarely occur in those under age 35.
• Sexual activity: Having anal sex and having many partners can increase the risk of anal cancer.
• History of cancer: Women who have had cervical, vaginal, or vulvar cancer are at a higher risk of anal cancer.
• Race and gender: Anal cancer is more common among African-American men than women, but it is more common among women than men in other population groups.

Symptoms of Anal Cancer

Anal cancer has symptoms that are similar to those of less serious conditions, such as hemorrhoids or anal warts. It is important for people with any of the following symptoms to see their doctor for an exam to determine the causes. 

Symptoms can include:

• Bleeding from the anus or rectum
• Changes in bowel movements, such as narrowed stool
• Discharge from the anus
• Lump or growth in or near the anus
• Pain and/or itching in and around the anus
• Swollen lymph nodes in the anal or groin areas

Diagnosis of Anal Cancer

At UT Southwestern, our gastrointestinal cancer specialists conduct a thorough examination to diagnose anal cancer. We ask patients about their symptoms, possible risk factors, and medical history and conduct a physical exam.

If our doctors suspect anal cancer, we can confirm a diagnosis with other tests, such as:

Digital rectal exam: The doctor inserts a gloved, lubricated finger into the anus and rectum to feel for lumps or other abnormalities. 

Endoscopy: Doctors use various types of scopes (thin, flexible tubes with a lighted camera at the tip) to look inside the anus, rectum, and lower part of the colon (large intestine). Types of endoscopy that we might use include:

• Anoscopy: A short scope used to examine the anus and lower rectum
• Proctosigmoidoscopy: A longer scope that can examine the rectum and lower colon

Biopsy: During an endoscopic exam, the doctor might take a small tissue sample to examine under a microscope for signs of cancer.

Imaging tests: We use imaging to help detect cancer, see whether it has spread outside the anal area, monitor treatment, and check for signs of recurrence (the cancer coming back) after treatment. Some imaging tests we use are:

• Ultrasound: Using sound waves and a computer, our imaging technicians produce images of internal structures. For anal cancer exams, the transducer (ultrasound scanner) is inserted into the rectum.
• Computed tomography (CT) scan: This technology uses X-rays to create cross-sectional images inside the body. We sometimes use CT scans to guide biopsies performed with a fine needle.
• Positron emission tomography (PET)/CT scan: This imaging exam combines nuclear medicine with CT imaging to produce images of body functions and internal structures. A PET/CT exam uses a small amount of radioactive material to highlight cancerous cells and tissues and determine how far cancer might have spread.
• Magnetic resonance imaging (MRI) scan: Radio waves and a strong magnet produce detailed images of internal structures. We might use MRI scans to check nearby lymph nodes for signs of cancer.

Treatment for Anal Cancer

Treatment options vary depending on factors such as the location of the cancer, whether it has spread outside the anus, and whether the patient has other health conditions that weaken immunity.

We usually begin treatment for anal cancer with a combination of chemotherapy and radiation therapy, known as chemoradiation:

• Chemotherapy is medication that destroys cancer cells or slows their growth; patients can receive the medication either by mouth in pill form or by injection into a vein. This type of chemotherapy is systemic, meaning that it travels through the bloodstream to reach all parts of the body.
  
• Radiation therapy is high-energy X-rays, gamma rays, or other radiation that destroys cancer cells or slows their growth. At UT Southwestern, we use the latest technology for radiation therapy to more precisely target cancer tumors and minimize damage to nearby healthy tissue.

Surgery is also an option to treat either early- or late-stage cancer, generally only after patients have received chemoradiation and the disease has not responded. Depending on each patient’s specific case, we might recommend chemoradiation after surgery. Our experienced cancer surgeons operate on:

• Early-stage anal cancer: Some small tumors can be removed without the risk of damaging the anal sphincter muscles that control bowel movements. The surgeon removes these tumors and a small margin of nearby healthy tissue to ensure that all cancer is removed.
• Late-stage anal cancer: Sometimes, chemoradiation is not enough to destroy anal tumors. For more advanced cancers, the surgeon removes the tumors and surrounding tissue where cancer has spread. These areas might include the anus, rectum, and part of the colon, depending on where the cancer has spread. The surgeon attaches the remaining colon to an opening in the abdomen to allow stool to exit the body into a bag in a procedure known as a colostomy.

Supportive Care

We offer a variety of support services for patients with anal cancer and their families, such as:

• Pelvic floor rehabilitation services at the Physical Medicine and Rehabilitation Clinic
• Integrative therapies
• Nutrition counseling
• Support groups

Clinical Trials

As a medical research institution, UT Southwestern conducts frequent clinical trials, giving our patients access to the newest treatments for anal cancer. Patients should speak with their doctors about the availability of clinical trials.