Diagnosing Anal Cancer

About Anal Cancer

At Penn Medicine's Abramson Cancer Center, patients with anal cancer receive their care from a multidisciplinary team of nationally recognized experts in the diagnosis, treatment and research of gastrointestinal cancer.

The anus is at the end of the digestive tract below the rectum. The anal canal is a three- to four-centimeter long structure between the anal sphincter, a muscle that controls bowel continence, and the anal margin, the area of skin just outside of the digestive tract. The anus is the opening of the rectum to the outside of the body.

There are two types of anal cancer:

  • Anal margin: Visible on the skin outside of the anus
  • Anal canal: Cannot be seen on the outside of the anus

Anal cancer is not very common and accounts for only 1 to 2 percent of all gastrointestinal cancers.

Penn Medicine's multidisciplinary approach to cancer diagnosis and treatment provides better outcomes and gives patients access to the most advanced treatment, surgical techniques and clinical trials. This multidisciplinary approach has a dual goal of anal conservation and cure of disease.

Because navigating a cancer diagnosis and treatment options can be difficult, patients who wish to connect with a cancer specialist at Penn Medicine can speak with a cancer nurse, who can help them make an appointment with the right physician.

To connect with a cancer nurse at Penn Medicine, patients should call 800-789-PENN (7366).

Read more About Anal Cancer

Diagnosing Anal Cancer

An accurate cancer diagnosis from trusted cancer specialists is the first step in getting personalized treatment options to treat anal cancer.

Patients who choose Penn's Abramson Cancer Center, benefit from a multidisciplinary team of cancer specialists including medical oncologists, gastroenterologists, radiologists, pathologists and surgeons who work together to provide a diagnosis and treatment plan designed specifically for each patient with anal cancer.

Cancer specialists at Penn Medicine are highly experienced in using the most advanced techniques for diagnosing anal cancer.

Navigating a cancer diagnosis and treatment options can be difficult. Patients who wish to connect with a cancer specialist at Penn Medicine can speak with a cancer nurse who can help them make an appointment with the right person. Penn Medicine’s contact center has experienced cancer nurses available and ready to guide patients in finding the cancer specialist right for them.

To connect with a cancer nurse at Penn Medicine, patients should call 800-789-PENN (7366).


Screening for Anal Cancer

Currently, there are no recommendations for screening the general public for anal cancer, such as mammograms for breast cancer or colonoscopies for colon cancer. However, people who are at increased risk for anal cancer should talk to their physicians about anal cancer screening

Those at increased risk include HIV-positive men, men who have sex with men, individuals with multiple sexual partners and women with a history of cervical warts or precancerous changes identified in the cervix.

Diagnostic Tools for Anal Cancer

Anal cancer can either be seen if it is on the anal skin or if it is within the anal canal. If a physician suspects anal cancer, he may perform or order one or more of these tests to diagnose and stage anal cancer.

  • Medical history and physical exam. An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments is also taken.
  • Lymph node exam. Physicians may examine lymph nodes in the groin to check for swelling. Samples of lymph tissue may also be removed through a needle biopsy.
  • Digital rectal exam. The anus and rectum are examined by the physician or nurse who inserts a lubricated, gloved finger into the lower part of the rectum to feel for lumps or anything else unusual.
  • Proctoscopy. An exam of the rectum using a short, lighted tube called a proctoscope.
  • Imaging tests. Pictures of the inside of the body can help find out whether a suspicious area might be cancerous, to learn how far cancer may have spread, and to help determine if treatment is working.
    • Endoscopic ultrasound (EUS). Ultrasound uses sound waves to create a picture of the internal organs. This procedure is often done at the same time as the upper endoscopy.
    • Computed tomography (CT) scan. A three-dimensional X-ray of the inside of the body in which a series of images are combined by a computer into a detailed, cross-sectional view that shows any abnormalities or tumors. A CT scan is used to see if the tumor has spread. Sometimes, a contrast medium (dye) is used to provide better detail.
    • Chest X-ray. An energy beam passes through the body to create a picture of areas inside the body. If anal cancer is found, a chest X-ray may be done to determine if the cancer has spread to the chest.
  • Biopsy. If other tests find a changed that may be cancer, a sample of the suspicious area is removed and viewed under a microscope. A biopsy is the only way to tell if cancer is really present.
  • Needle biopsy. A thin needle is inserted into the lymph node to remove a small sample of lymph fluid. This is usually done in the groin or anus area if cancer is suspected.

Staging Anal Cancer

Staging anal cancer attempts to discover the following:

  • The size of the tumor
  • Whether the cancer has spread to nearby tissues
  • Whether the cancer has spread to other parts of the body

Staging is a way of describing a cancer, such as where it is located, if or where it has spread, and if it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the cancer's stage, so staging may not be complete until all the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's chance of recovery.

  • Stage 0. Abnormal cells are found only in the innermost layer of the anus. Also called carcinoma in situ.
  • Stage I. Cancer has formed and the tumor is 2 cm or smaller. 
  • Stage II. Tumor is larger than 2 cm.
  • Stage III. One of the following:
    • IIIA. Tumor is any size and
      • Has spread to either the lymph nodes near the rectum.
      • Has spread to nearby organs such as the vagina, urethra and bladder.
    • IIIB. Tumor is any size and
      • Has spread to nearby organs and lymph nodes near the rectum.
      • Has spread to lymph nodes on one side of the pelvis and/or groin and may have spread to nearby organs.
      • Has spread to lymph nodes near the rectum and in the groin and/or lymph nodes on both sides of the pelvis and/or groin and may have spread to nearby organs.
  • Stage IV. The cancer has spread (metastasized) from where it started to lymph nodes, nearby organs and distant parts of the body.

Anal Cancer Treatment

Following the diagnosis and staging of anal cancer, cancer specialists at Penn Medicine’s Abramson Cancer Center develop a personalized treatment plan.

Anal margin cancer, otherwise known as “perianal cancer” is treated with surgery to remove the growth.

Anal canal cancer is usually treated with a combination of chemotherapy and radiation.  Surgery is rarely needed in cases of anal canal cancer. 

In all cases of anal cancer, Penn cancer specialists are committed to doing everything they can to conserve the anus and anal tissue.

Penn’s treatment options for anal margin cancer include:

  • Surgery
    • Local resection

Penn’s treatment options for anal canal cancer include:

  • Radiation therapy
    • 3-D conformal radiation
    • Intensity-modulated radiation therapy (IMRT)
    • Volumetric-modulated arc therapy (VMAT)
    • Proton therapy
  • Chemotherapy and biologic therapies
  • Surgery
    • Local resection

Other possible treatment options for anal margin and canal cancer include:

  • Clinical trials
  • Other treatments
    • Integrative medicine and wellness
    • Palliative care
    • Penn Home Care and Hospice

Because navigating a cancer diagnosis and treatment options can be difficult, patients who wish to connect with a cancer specialist at Penn Medicine can speak with a cancer nurse, who can help them make an appointment with the right physician.

To connect with a cancer nurse at Penn Medicine, patients should call 800-789-PENN (7366).

Read more Anal Cancer Treatment

Anal Cancer Survivorship

Survivorship programs at Penn Medicine are a distinct phase of anal cancer care and are designed to help patients transition from their cancer treatment routine to a post-cancer care lifestyle. There are more than 12 million cancer survivors living and thriving today as a result of advances in cancer treatment. However, cancer treatments can result in physical, emotional and financial complications long after the therapy is complete.

Read more Anal Cancer Survivorship


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Clinical Trials

Clinical Trials

Clinical trials are studies to find new ways to prevent, detect and treat cancer. The purpose of each clinical trial is to answer a specific question. Our physicians carefully design these studies to find new ways to improve care and quality of life ... more about clinical trials