Colon & Rectal Cancer

Rectal cancer is different from colon cancer that is found higher up in the colon, especially when it comes to treating the disease with surgery. Dr. Polcino will go into detail with each patient individually.

Cancer that begins in the colon is called colon cancer, and cancer that begins in the rectum is called rectal cancer. Colorectal cancer occurs when some of the cells that line the colon or the rectum become abnormal and grow out of control. The abnormal growing cells create a tumor, which is the cancer.M

Inside your abdominal cavity is the long, tubular digestive tract. The second part of this tube -- the large intestine -- is composed of the colon and the rectum.

The inner lining of this "colorectal tube" can be a fertile breeding ground for small tumors, called polyps (Figure 1). About a quarter of all adults in the U.S. older than age 50 will have at least one colorectal polyp. Most colorectal cancers develop from polyps in glandular tissue of the intestinal lining.

Most polyps are benign, but at least one type is known to be precancerous. These are called adenomatous polyps.

The size of the polyp correlates with the development of cancer. Larger polyps have a greater chance of developing into a cancer. Most colorectal cancers develop from polyps in glandular tissue of the intestinal lining.

If colorectal cancer is diagnosed and treated early while the tumor is still localized, the disease is highly curable, with five-year survival rates of about 90%. If the tumor continues to grow, cancer can spread directly through the bowel wall to surrounding lymph nodes, tissues, and organs, as well as into the bloodstream.

Once the cancer spreads to lymph nodes or other organs, successful treatment becomes more difficult. Depending on how advanced the disease is, five-year survival rates range from 11% to 87%.

Cancers of the colon and rectum are common, with approximately 140,000 cases diagnosed each year. Like many cancers, colorectal cancer is of particular concern for people older than age 50.

Although diagnosis is often possible at an early stage, many people delay seeking medical care because they are embarrassed or fearful of symptoms related to their bowels. Risk increases significantly after age 50 and continues to increase with age.

The exact cause of colorectal cancer is not known. But there are several risk factors for the disease.

  • Other diseases. Colorectal cancer is strongly associated with certain other diseases. Those people considered at high risk include anyone with a personal or family history of colon polyps or colon cancer, inflammatory disease of the colon such as ulcerative colitis or Crohn's disease, and cancers of the pancreas, breast, ovaries, or uterus.
  • Heredity. As with any cancer, susceptibility to colorectal cancer is at least partly determined by genetic makeup. A few people inherit medical conditions, such as familial adenomatous polyposis (FAP), Lynch Syndrome, MYH-associated polyposis (MAP), Gardner's syndrome, Turcot's syndrome, Peutz-Jagher's syndrome, juvenile polyposis, and Cowden's disease. In all of these disorders, colon polyps develop at an early age, and unless treated, these people are at high risk of developing colorectal cancer.
  • Diet. Diet also contributes to the risk of colorectal cancer, although the cause-and-effect relationship is still unclear. People whose diets are high in fruits and vegetables seem to have a reduced risk. Many studies implicate animal fat and protein as promoters of colorectal cancer, although researchers are cautious about drawing any definite conclusions.
  • Chemical exposure. Heavy exposure to certain chemicals, including chlorine -- which in small amounts is commonly used to purify drinking water -- may increase the risk of colorectal cancer. Exposure to asbestos is thought to be potentially harmful because it has been implicated in causing formation of polyps in the colon.
  • History of colon cancer. A prior case of colon cancer increases the risk of a second colon cancer, especially if the first cancer was diagnosed before the age of 60.
  • Lifestyle. Smoking and alcohol intake of more than 4 drinks per week increases the risk of developing colon cancer.
  • Family history. Those with a first-degree relative with colorectal cancer have an increased risk of the disease. The risk increases if more than one first-degree relative has colon cancer.
  • Radiation . Prior radiation increases the risk of cancer to the radiated tissue only.

In its early stage, colorectal cancer usually doesn’t have symptoms. That’s why it’s so important to keep up with the tests your doctor recommends to see if you have it, when it’s easiest to treat.

If you do have symptoms, the most likely ones include:

  • Changes in bowel movements, including constipation or diarrhea that don’t seem to go away
  • Feeling like you can’t empty your bowels completely or urgently need to have a bowel movement
  • Bleeding or cramping in your rectum
  • Dark patches of blood in or on your stool; or long, thin, "pencil stools"
  • Discomfort or bloating in your belly
  • Unexplained fatigue, loss of appetite, and weight loss
  • Pelvic pain, which can happen in the later stages of the disease

Many things can cause the symptoms listed above and you’ll need to check with your doctor to review these symptoms. Make an appointment if you have any of the symptoms, or if a doctor tells you that you have anemia. Your doctor will most likely do a rectal exam. You may also get a sigmoidoscopy or a colonoscopy -- exams that involve a long flexible tube put into your rectum so that your doctor can look for any cancers or growths that could become cancer.

Once diagnosed,the next step is to determine the best course of treatment. Treatments may include the following, alone, or in combination:

  • Surgery
  • Chemotherapy
  • Radiation
  • Biological therapy

As with many cancers, a team approach to treating colorectal cancer is often used. Your treatment team may involve specialists from the following fields:

  • Colorectal Surgery
  • Hepatobiliary Surgery
  • Gastroenterology
  • Medical Oncology
  • Radiation Oncology