Rectal Cancer

Causes

Cancer is when cells in the body split without control or order. These cells form a growth or tumor. Cancer refers to harmful growths. These growths attack nearby tissues and can spread to other parts of the body. It is not clear exactly what causes these problems. It is likely a mix of genes and the environment.

Risk Factors

Rectal cancer is more common in men and people 60 years old or older. Other things that raise the risk are:

• Inherited diseases such as familial adenomatous polyposis
• Prior colon or rectal cancer, or polyps
• Having certain genes
• Colon or rectal cancer in the family—mainly a parent, sibling, or child
• Ulcerative colitis or Crohn disease
• Obesity
• Habits such as:
  • Smoking
  • A diet high in red meat, and low in fruits, vegetables, and whole grains
  • Drinking excess alcohol
  • Little or no exercise

Symptoms

Rectal cancer may not have symptoms at first. When symptoms happen, they may be:

• Rectal bleeding without other problems
• A change in bowel habits
• Blood in the stool (poop) that is either bright red, or black and tarry
• Pain, pressure, or feeling of a mass
• Itching
• Belly pain
• Weight loss
• Feeling tired, breathing problems and pale skin—signs of anemia

Diagnosis

The doctor will ask about symptoms and past health. A physical exam will be done. The doctor will insert a gloved finger into the rectum to check for problems. Diagnosis of rectal cancer is based on symptoms and:

• A digital rectal exam—the doctor will feel for lumps with a lubricated, gloved finger in the rectum
• Endoscopy such as:
  • Colonoscopy
  • Sigmoidoscopy
• Biopsy—Tissue samples taken during endoscopy and tested in a lab

Other tests may include:

• Blood tests
• Imaging tests, such as:
  • CT scan
  • CT colonography
  • MRI scan
  • Transrectal ultrasound
  • Barium enema
  • PET/CT scan

The exam and test results will help find the stage of cancer. Rectal cancer is staged from 0 to 4. Stage 0 is a very localized cancer. Stage 4 is a spread to other parts of the body

Treatment

Treatment is based on the size and stage of the cancer and the person's health. Rectal cancer is treated with more than one method.

Surgery is the main way to treat rectal cancer. There are many ways this can be done. It depends on where the cancer is and how much it has spread.

• Polypectomy and local excision—Cancer is removed during endoscopy.
• Local transanal resection—A border of healthy tissue along with the cancer is removed.
• Transanal endoscopic microsurgery (TEM)—A border of healthy tissue along with the cancer is removed. The hole in the wall is sewn back together.
• Low anterior resection—A border of healthy tissue along with the cancer is removed.
• Proctectomy—The rectum is removed. The end of the colon and the anal canal are attached. Bowel use will stay.
• Abdominoperineal resection—The rectum, anal canal, and surrounding tissue are removed.
• Pelvic exenteration—Removal of rectum, anal canal, and nearby organs with cancer. This may include the prostate, uterus, or bladder.

A colostomy is a path for solid waste to pass from the body. It is made through the belly wall. A special bag is needed to collect the waste. This may be needed for some procedures on the rectum.

If the bladder is removed, a urostomy is needed. This is a path for urine to pass out of the body through the belly wall. Some, but not all types, need a bag to collect the waste.

Instead of surgery, small tumors and tumors in other places may be destroyed with:

• Ablation methods, such as:
• High-energy radio waves
• Electromagnetic microwaves
• A concentrated alcohol injection
• Freezing
• Embolization—uses an injection or IV to treat tumors that have spread to the liver

Other treatments may include:

• Radiation therapy—uses radiation to kill cancer cells and shrink tumors.
• Chemotherapy—uses drugs to kill cancer cells. It may be given by mouth, shots, or IV.

Radiation and chemo are sometimes given together. Depending on the problems, they may be used:

• Before, after, or instead of surgery
• For cancers that have spread—to help shrink tumors and ease symptoms

Other medicines may include:

The doctor may also advise counseling and support groups. This can help with coping and easing stress.

Prevention

Screening

The purpose of these tests is to find and treat cancer early. Common screening options are:

• Colonoscopy—every 10 years
• Fecal immunochemical test (FIT)—every year
• Fecal occult blood test (FOBT)—every year
• Sigmoidoscopy—every 5-10 years
• CT colonography—every 5 years
• Barium enema—every 5 years
• Stool DNA test every 3 years

Talk to the doctor about testing after age 40 if you are Black, Asian, or a native of Alaska.

Talk to the doctor about how often you should be tested if you have:

• People in your family with:
• Colon or rectal cancer, or polyps
• Inherited diseases of the colon or rectum
• Had colon or rectal cancer, or polyps
• Inflammatory bowel diseases

Lifestyle Changes

To help lower the risk of colon cancer:

• Quit smoking—ask the doctor about programs that help
• Eat a well-balanced, healthful diet.
• Get at least 30 minutes of activity a day on most days of the week.
• Alcohol—Do not drink more than 2 drinks a day if you are a man or more than 1 a day if you are a woman.
• Keep a healthy weight.