Colon cancer (or colorectal cancer) is rare in the underdeveloped world, but is the second leading cause of cancer deaths in Western countries. It occurs commonly in those over the age of 50. Both environmental and genetic factors are important risk factors for colon cancer. Lifestyle factors that predispose you to colon cancer are obesity, sedentary lifestyle, alcohol intake and smoking. High intake of red meat and saturated animal fat increases the risk; and high intake of dietary fiber, fruits and vegetables, calcium and folic acid decreases the risk.
Since colon cancer is preventable, all those over 50 years should undergo periodic screening by fecal occult blood test, colonoscopy and flexible sigmoidoscopy, to detect and remove lesions at an early or pre-cancerous stage.
Signs OF Colon Cancer
Symptoms Of Colon Cancer
You may have colon cancer and yet not have symptoms for several years down the line. The symptoms of colon cancer vary depending on the location of the tumour in the large intestine, that is, whether it is in right colon or left colon.
Blood In Stool
Passing blood in stool does not always mean that you have colon cancer, although it is a fairly common symptom of it. It could be due to other milder problems like inflammatory bowel disease, anal fissures and hemorrhoids. Keep in mind that stools can be red also because of intake of certain food items like beet root, tomato juice and watermelon.
Bright red blood indicates tumour may be closer to rectum. However, often you may not be able to detect the blood with the naked eye because it may be passed in small amounts, as happens with right colon cancer. In such cases, fecal occult blood test can be done to detect it.
Weakness And Fatigue
These symptoms are brought on due to anemia (or less red blood cells in blood). This is more common in right colon cancer because the blood loss is slow and over a prolonged period.
Two-thirds of patients have colicky lower abdominal pain. However, this symptom is not very specific to colon cancer. Obstruction to the passage of gas through colon by the tumour can also bring on pain. Sometimes, abdominal pain, particularly when severe, can point to a more serious complication of colon cancer, that is, perforation of intestine.
Altered Bowel Habits
These are also mainly nonspecific symptoms. Constipation can occur due to obstruction of feces by the tumour mass.
The frequency or character of bowel movements could be altered. You could have persistent feeling of incomplete emptying of bowels due to presence of tumour mass.
Unexplained weight loss can be the sole symptom in about 10 to 20% of patients. There could be abdominal distention, and persistent and unexplained nausea and vomiting if the tumour is large enough.
A Note On Diagnosis And Treatment
Prevention and cure are possible if colon cancer is detected and treated early. So if you are having some of the above symptoms then you should check with your doctor. Colonoscopy and sigmoidoscopy are the important investigations. Once diagnosed, surgical removal of the tumour, followed by chemotherapy and radiotherapy, is the usual line of treatment.