Colon cancer can cause abdominal pain. Most of the colon cancers develop out of colon polyps, which grow like a mushroom out of the lining of the large bowel with a stalk and a fleshy polyp head. It is usually inside the fleshy head of the polyp that the adenocarcinoma (the most common colon cancer) develops.
Apart from lung cancer, colon cancer kills most people with cancer in the Western countries. Both sexes are affected equally and 75,000 people die every year in the U.S. from this disease. The majority of colon cancer occurs in the rectum and the sigmoid colon (located in the left lower abdomen). Some families are at a higher risk for cancer of the colon, particularly familial adenomatous polyposis, but also patients with ulcerative colitis. High risk diets for colon cancer are: high fat, low fiber, high animal protein, high refined carbohydrates (sugar and sweets).
Colon Cancer Symptoms
Unfortunately there are no early symptoms for colon cancer. Blood in stool is already a late sign. A yearly stool for occult blood test might pick up a certain percentage of cancerous lesions that shed blood. But early cancer might be located within the wall of the colon and therefore not shed blood into the stool. Colonoscopy would pick up a very high percentage of early colonic cancer and would pick up 100% of premalignant polyps.
Barium enema X-rays pick up larger expanding masses in the colon before a bowel resection were contemplated by the surgeon. In the late stages when the cancer is spreading through the bowel wall, there is suddenly an irritation of the peritoneal lining of the colon, which the patient feels as a severe abdominal pain. Another dramatic presentation sometimes is when the patient’s colon suddenly closes off through the spreading tumor mass, which at one point can cover the entire opening of the bowel. In this case there is a bowel obstruction with symptoms that might be indistinguishable from an ileus. The treatment would be the same, but in the work-up the colon cancer would be found very quickly. As the majority of colon cancers are in the rectosigmoid region, this pain would be located in the left lower abdomen. There might be constipation as the lumen of the colon might be narrower. Ascites might develop in the later stages of colon cancer with spread of cancer cells into the free abdominal cavity.
Colon Cancer Treatment
The therapy is surgical with a wide resection of the cancer. A general surgeon would be the specialist involved in this. For rectal cancer a combined abdominal perineal surgery (from above and below) or variation thereof can remove the cancer.
Depending on the stage the patient is in, this might leave the patient with a colostomy (a bag) or not. About 70% of patients can be helped with surgery. The 5-year survival rate is about 90% for the best scenario when the cancer is confined to the mucosal lining and about 75% when the cancer is within the bowel wall, but still localized to the area. Once there is lymph gland involvement the 5-year survival rate drops dramatically to about 30%. For the cases where a colon resection is not feasible chemotherapy and radiotherapy can be partially employed, but the survival chances are severely limited. Nevertheless there are a few successes and there is occasionally a palliative value in this type of treatment as well. Like with any cancer in the end stage it is important for the patient to seek the advice of counsellors and work through the grieving process over the incurable disease.
For a more detailed discussion of colon cancer click on the link.
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