Cancer that begins in the colon is called a colon cancer, while cancer in the rectum is known as a rectal cancer. Cancers affecting either of these organs also may be referred to as a colorectal cancer. Colorectal cancers generally develop over time from adenomatous (precancerous) polyps — growths — after a series of mutations (abnormalities) arise in their cellular DNA. The exact cause of colorectal cancer is not known. Some of the risk factors for colorectal cancer involve a family history of colon or rectal cancer, diet, alcohol intake, smoking, and inflammatory bowel disease.
Your risk for colorectal cancer may be higher than average if—
- You or a close relative have had colorectal polyps or colorectal cancer.
- You have inflammatory bowel disease (IBD).
- You have hereditary nonpolyposis colorectal cancer, or a genetic syndrome such as familial adenomatous polyposis (FAP).
- You have previous history of bladder or uterine cancer.
Early Detection Critical for Colon and Rectal Cancer
Colon and rectal cancers combined are the second leading cause of cancer-related deaths in the United States. In 2016, an estimated 134, 490 cases in this country are expected to be diagnosed. One of the most important tests for colon cancer is the screening colonoscopy which should be performed starting at age 50, or 10 years before the youngest person in your family to have cancer or polyps. If nothing is found, an individual with normal risk should have a colonoscopy every 10 years. Testing for colon cancer should also be performed as part of the annual physical examination. This requires a rectal exam and a chemical test for occult (invisible) blood in the stool using the guaiac test.
Understanding Colon and Rectal Cancer Risk Factors
Most colon and rectal cancers start as polyps and may show no symptoms for years before detection. This is why colonoscopy screening is important. Symptoms, such as abdominal pain and bloating, indicate a more advanced disease. Screening is even more important in individuals at an increased risk of developing colorectal cancer. A family history of colon cancer is a contributing factor and certain populations have an increased risk including African Americans and Ashkenazi Jews. Also, having diabetes or inflammatory bowel disease increases the risk of cancer. Several other factors increase your risk of cancer, but are within your control, including:
Often times, people with colon cancer experience no symptoms in the early stages. If you begin to experience any of the following symptoms, make an appointment with your doctor:
- A change in your bowel habits, including diarrhea or constipation or a change in the consistency of your stool, that lasts longer than four weeks
- Rectal bleeding or blood in your stool
- Persistent abdominal discomfort, such as cramps, gas or pain
- A feeling that your bowel doesn’t empty completely
- Weakness or fatigue
- Unexplained weight loss
If you begin to experience any of the symptoms for colorectal cancer, your doctor might recommend one or more of the following tests or procedures:
Colonoscopy – During a colonoscopy screening, a physician uses an endoscope (a long, thin, flexible, lighted tube) to check for polyps inside the rectum and entire colon. During the test, your doctor can find and remove most polyps and some cancers.
Physical Exam – A general exam to evaluate signs of health including checking for lumps or anything that seems unusual. Your Physician may also evaluate your past illnesses and health habits.
Fecal Occult Blood Test (FOBT) – A test that is used to check your stool for blood. A small sample of stool is placed under a microscope to check for any traces of blood.
Barium Enema or Lower GI Series – A series of x-rays are taken of the lower gastrointestinal tract. During the x-rays, a liquid that contains barium is added to the rectum. The barium begins to coat the lower gastrointestinal tract making it easier for your physician to see any polyps or abnormal areas.
Sigmoidoscopy – A procedure to look inside the rectum and lower color for any polyps or other abnormalities. During a Sigmoidoscopy, a small tube with a lens and light will be inserted into the rectum. This tube may also have a tool on the end to help your physician remove any polyps or tissue samples which can then be tested for cancerous cells.
Virtual Colonoscopy or CT Colonography – A series of x-rays known as computed tomography (CT) is used to create a detailed image of your colon to help show any polyps or abnormal areas.
Biopsy – The removal of cells or tissue in your colon or rectum so they can be tested under a microscope to check for signs of cancer.
After the initial colon cancer diagnosis, your doctor may order additional test to find out if the cancer cells have spread to other areas of your body. In addition, your physician might test your blood for a chemical that is produced by colon cancer. Your physician can then track the levels of the chemical to evaluate how you are responding to treatments.
The treatment plan that your doctor recommends will depend on a variety of factors including the stage of your cancer, if the cancer has blocked or created a hole in the colon, and your general health. It is important to talk to your doctor about your and understand all of your options moving forward.
For patients with colon cancer, there are six different treatment options available. These include surgery, radiofrequency Ablation, Cryosurgery, Chemotherapy, Radiation Therapy, and Target Therapy.
Surgery – This is the most common form of treatment for patients with colon cancer. Your physician will evaluate which type of surgery is best for you. If caught early, your physician can perform a local excision that involves inserting a tube through the rectum into the colon and removing the cancer. Additional surgical options include removing the cancer and a small amount of healthy tissue around it and connecting the healthy parts of the colon back together or removing the cancer and surrounding tissue and creating a stoma (small opening on the outside of the body) for waste to pass through
Radiofrequency ablation – This procedure uses a special electrode probe to kill cancer cells. This probe can either be inserted directly through the skin or inserted through an incision in the abdomen.
Cryosurgery – A treatment that freezes and destroys an abnormal tissue.
Chemotherapy – This treatment option uses drugs to help stop the growth of cancer cells by either killing them or preventing them from dividing. They way that you receive chemotherapy is dependent upon the type and stage of cancer being treated.
Radiation Therapy – This therapy uses a high-energy x-ray or other forms of radiation to kill cancer cells or prevent them from spreading. Radiation therapy can either be delivered internally (delivered directly into the cancer) or externally (outside of the body).
Targeted Therapy – This therapy delivers drugs or other substances directly to the cancer cells. Through this therapy, your physician can avoid harming any normal cells.
NEW CASES – It is estimated that colorectal cancer makes up eight percent of all new cancer cases.
LIFETIME RISK – Approximately 4.3 percent of men and women will be diagnosed with colon or rectal cancer at some point throughout their life.
MEDIAN AGE – The average age of diagnosis is 67
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- Focus on Cancer – Colorectal Cancer