Colon Cancer
According to the definition in the medical dictionary, colon is explained as "The long, coiled, tube-like organ-also called the large bowel or large intestine-that removes water from digested food. The remaining material, solid waste called stool, moves through the colon to the rectum and leaves the body through the anus. The colon has four sections: the ascending colon, the transverse colon, the descending colon and the sigmoid colon."
In the United States, colorectal cancer is the fourth most common cancer in men, after skin, prostate, and lung cancer. It is also the fourth most common cancer in women, after skin, breast, and lung cancer.
Colon cancer is the cancer that forms in the tissues of the colon (the longest part of the large intestine). Such cancer is sometimes referred to as "colorectal cancer." Most colon cancers are adenocarcinomas (cancers that begin in cells that make and release mucus and other fluids).
Other types of colon cancer such as lymphoma, carcinoid tumors, melanoma, and sarcomas are rare. In this website, use of the term "colon cancer" refers to colon carcinoma and not these rare types of colon cancer.
Causes
According to the American Cancer Society, colorectal cancer is one of the leading causes of cancer-related deaths in the United States. However, in almost all cases, early diagnosis can lead to a complete cure.
There is no single cause for colon cancer. Nearly all colon cancers begin as benign polyps, which slowly develop into cancer.
You have a higher risk for colon cancer if you have:
Certain genetic syndromes also increase the risk of developing colon cancer.
What you eat may play a role in your risk of colon cancer. Colon cancer may be associated with a high-fat, low-fiber diet and red meat. However, some studies found that the risk does not drop if you switch to a high-fiber diet, so the cause of the link is not yet clear.
Symptoms
Many cases of colon cancer have no symptoms. The following symptoms, however, may indicate colon cancer:
- Diarrhea, constipation, or other change in bowel habits
- Blood in the stool
- Unexplained anemia
- Abdominal pain and tenderness in the lower abdomen
- Intestinal obstruction
- Weight loss with no known reason
- Narrow stools
With proper screening, colon cancer can be detected BEFORE the development of symptoms, when it is most curable.
Exams and Tests
Your doctor will perform a physical exam and press on your belly area. The physical exam rarely shows any problems, although an abdominal mass may be felt. A rectal exam may reveal a mass in patients with rectal cancer, but not colon cancer.
Imaging tests to diagnose colorectal cancer include:
Note: Only colonoscopy can see the entire colon.
A fecal occult blood test (FOBT) may detect small amounts of blood in the stool, which could suggest colon cancer. However, this test is often negative in patients with colon cancer. For this reason, a FOBT must be done along with colonoscopy or sigmoidoscopy. It is also important to note that a positive FOBT doesn't necessarily mean you have cancer.
A complete blood count may reveal show signs of anemia with low iron levels.
If your doctor learns that you do have colorectal cancer, additional tests will be done to see if the cancer has spread. This is called staging.
- Stage 0: Very early cancer on the innermost layer of the intestine
- Stage I: Cancer is in the inner layers of the colon
- Stage II: Cancer has spread through the muscle wall of the colon
- Stage III: Cancer has spread to the lymph nodes
- Stage IV: Cancer that has spread to other organs
Treatment
Treatment depends partly on the stage of the cancer. In general, treatments may include:
- Chemotherapy medicines to kill cancer cells
- Surgery to remove cancer cells
- Radiation therapy to destroy cancerous tissue
Stage 0 colon cancer may be treated by removing the cancer cells, often during a colonoscopy. For stages I, II, and III cancer, more extensive surgery is needed to remove the part of the colon that is cancerous.
There is some debate as to whether patients with stage II colon cancer should receive chemotherapy after surgery. You should discuss this with your oncologist.
Almost all patients with stage III colon cancer should receive chemotherapy after surgery for approximately 6 - 8 months. The chemotherapy drug 5-fluorouracil given has been shown to increase the chance of a cure in certain patients.
Chemotherapy is also used to treat patients with stage IV colon cancer. Irinotecan, oxaliplatin, and 5-fluorouracil are the three most commonly used drugs. You may receive just one type, or a combination of the drugs. Capecitabine is a chemotherapy drug taken by mouth, and is similar to 5-fluroruracil.
For patients with stage IV disease that has spread to the liver, various treatments directed specifically at the liver can be used. This may include cutting out the cancer, burning it (ablation), or freezing it (cryotherapy). Chemotherapy or radiation can sometimes be delivered directly into the liver.
While radiation therapy is occasionally used in patients with colon cancer, it is usually used in combination with chemotherapy for patients with stage III rectal cancer.
Outlook (Prognosis)
How well a patient does depends on many things, including the stage of the cancer. In general, when treated at an early stage, more than 90% of patients survive at least 5 years after their diagnosis. (This is called the 5-year survival rate.) However, only about 39% of colorectal cancer is found at an early stage. The 5-year survival rate drops considerably once the cancer has spread.
If the patient's colon cancer does not come back (recur) within 5 years, it is considered cured. Stage I, II, and III cancers are considered potentially curable. In most cases, stage IV cancer is not curable.
Possible Complications
- Cancer spreading to other organs or tissues (metastasis)
- Recurrence of carcinoma within the colon
- Development of a second primary colorectal cancer
When to Contact a Medical Professional
Colon cancer is, in almost all cases, a treatable disease if caught early. Removal of pre-cancerous polyps by colonoscopy essentially prevents colon cancer. If you are age 50 or older and have not yet had a colonoscopy, you should ask your health care provider about scheduling one. Early colon cancer usually has no symptoms, so screening by colonoscopy is important.
You should also call your health care provider if you have blood during a bowel movement, black, tar-like stools, or a change in bowel habits.
Prevention
The death rate for colon cancer has dropped in the last 15 years. This may be due to increased awareness and screening by colonoscopy. Colon cancer can almost always be caught in its earliest and most curable stages by colonoscopy. Almost all men and women age 50 and older should have a colonoscopy. Colonoscopy is almost always painless and most patients are asleep for the entire procedure.
Dietary and lifestyle modifications are important. Some evidence suggests that low-fat and high-fiber diets may reduce your risk of colon cancer.
The U.S. Preventive Services Task Force recommends against taking aspirin or other anti-inflammatory medicines to prevent colon cancer if you have an average risk of the disease -- even if someone in your family has had the condition. Taking more than 300 mg a day of aspirin and similar drugs may cause dangerous gastrointestinal bleeding and heart problems in some people. Although low-dose aspirin may help reduce your risk of other conditions, such as heart disease, it does not lower the rate of colon cancer.
The products of years of consumption and biological processes all end up in one place: the colon. This is the last stop before our body bids the day’s collection of waste bye-bye. However, the process of elimination may not be so clean-cut and easy for some people. In fact, with the increase in the number of bowel diseases, constipation, colon cancer, and stomach pains, there is reason to believe that more are more people are suffering from one type of bowel problem or another.
Because of its silent nature (serious common problems are often not detected until in their later stages), colon health problems are one of the most overlooked health problems today. And with the increase in fast food consumption, most of which are loaded with trans-fats, salt, processed oils and meats, coupled with a sedentary lifestyle, it is no wonder that more and more people are finding it hard to keep themselves healthy. A bad diet coupled with lack of exercise is one sure recipe for constipation. It is estimated that the average American will have between 10-15 pounds of impacted fecal matter by the time he or she reaches her 30’s. All this waste is literally a clump of poison just waiting to get back into the body’s circulation, where it can be reabsorbed by the body and can eventually lead to poisoning. Gradual effects include a reduction on system performance, weakness, weight loss, abdominal pain, gas, bloating, and a host of other ailments, some of which can predispose us to more serious diseases like infection and cancer.
Fortunately, you can take a serious and active role to make sure that anything like this does not happen to you. All it takes is eating the right kind and amount of food, consuming adequate amounts of water, as well as exercising on a regular basis—these three things can mean the difference between a clean, happy colon and a toxic one. In the event that you suffer from these bowel ailments you have natural fiber supplements and therapeutic procedures like colonic hydrotherapy or irrigation, acupuncture, colon flush or colon cleaning sessions, which can provide treatment and relief.
Living right can make the difference between a life plagued by a clod of ailments and a life that is lived with a healthy, fully-functioning body, colon included. The importance of living right to keep the body healthy can never be underestimated. The body is more than able to keep us healthy as long as we keep our end of the bargain.
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