What is the Difference between Anal and Rectal Cancer?

By Ashlyn Everett, MD

Cancer can occur in any part of the body, and the anal and rectal areas are no exception. Anal and rectal cancers are two different types of cancer that can cause similar symptoms and are often confused with each other. In this blog, we will discuss anal cancer versus rectal cancer, including their symptoms and radiation treatment. 

Anal Cancer:

Anal cancer occurs in the tissues of the anus, which is the opening at the end of the digestive tract through which stool passes. The anus is approximately the last 2 inches of the digestive tract, where stool leaves the body. Anal cancer is more common in women than men and is often linked to the human papillomavirus (HPV) infection or is associated with immune compromise. The most common symptoms of anal cancer include:

1. Pain or discomfort in the anal area

2. Bleeding from the anus

3. Changes in bowel habits

4. Itching or burning sensation in the anal area

5. A lump or swelling near the anus

6. Discharge from the anus

7. Fatigue and unexplained weight loss

Rectal Cancer:

Rectal cancer occurs in the tissues of the rectum, which is the last six inches of the large intestine. The rectum connects with the anus, but the two cancers are different types and treatments are different. Rectal cancer is slightly more common in men than women and is usually found in people over 50 years old. The most common symptoms of rectal cancer include:

1. Bleeding from the rectum

2. Abdominal pain or discomfort

3. Changes in bowel habits, including diarrhea or constipation or thin stools

4. A feeling of incomplete bowel movement

5. Unexplained weight loss

6. Fatigue and weakness

7. Anemia, which is a shortage of red blood cells

Screening:

Rectal cancer screening should begin at the age of 45 for those with normal risk. For patients with family history or those at high risk of cancer, screening will start sooner. Screening helps to detect cancer at an early stage when it is easier to treat and cure. Anal cancer screening can be performed in high risk individuals, or people with known history of pre-invasive anal lesions. The specific tests recommended for screening may vary depending on an individual's age, medical history, and other risk factors.

The following are some of the screening tests that may be recommended for anal and rectal cancer:

1. Digital rectal exam (DRE): During this exam, a healthcare provider inserts a gloved, lubricated finger into the anus and rectum to feel for any abnormalities, such as lumps or growths.

2. High-resolution anoscopy (HRA): This is a procedure in which a healthcare provider uses a special magnifying device to examine the tissues inside the anus and lower rectum for abnormal growths.

3. Fecal occult blood test (FOBT): This test checks for the presence of blood in the stool, which can be a sign of colon or rectal cancer.

4. Colonoscopy: This is a procedure in which a healthcare provider uses a flexible, lighted tube to examine the entire colon and rectum for abnormal growths. Abnormal lesions can also be removed through this procedure. 

5. Flexible sigmoidoscopy: This is a procedure in which a healthcare provider uses a flexible, lighted tube to examine the lower part of the colon and rectum for abnormal growths.

The specific tests and screening intervals recommended for anal and rectal cancer may vary depending on the type of screening performed, an individual's medical history, and other risk factors. It is important to discuss screening options with a healthcare provider to determine the best approach for your individual needs.

Treatment Options: 

Treatment recommendations for anal and rectal cancer will vary, but often includes a combination of chemotherapy, radiation, and sometimes surgery. You will meet with a specialist who will discuss more details with you. 

Radiation Treatment:

If it is found that you have anal or rectal cancer, radiation therapy can be used as a primary treatment, or it may be used in combination with other treatments, such as surgery or chemotherapy. Radiation therapy is typically given externally, using a machine outside the body. 

External radiation therapy is the most common type of radiation treatment for anal or rectal cancer. The radiation is delivered using a machine that aims the radiation beams at the cancer from outside the body. The treatment is typically given in small doses over several weeks, with recovery time (overnight) in between treatments to allow the body to recover.

Prevention:

The best way to prevent anal and rectal cancer is to practice good hygiene and maintain a healthy lifestyle. This includes:

1. Practicing safe sex

2. Quitting smoking

3. Eating a healthy diet that is rich in fruits, vegetables, and whole grains

4. Getting regular exercise

5. Maintaining a healthy weight

6. Getting screened regularly for colorectal cancer

Conclusion:

Anal and rectal cancers are two different types of cancer that share similar symptoms. Radiation therapy is an effective treatment option for both types of cancer and may be used as a standalone treatment for anal cancer, or in combination with other treatments for rectal cancer. More importantly, it is crucial to be screened regularly and is recommended to start screening at the age of 45. If you would like to learn more about anal or rectal cancer or treatment options please contact our team of experts for a consultation.