Colorectal cancer is a major health concern and public health problem in most of the Western countries despite widespread use of screening technique to detect early stages of this disease. In the United States alone more than 148,000 people are diagnosed with colorectal cancer each year. Over 55,000 deaths occur in the United States due to colorectal cancer. Colon cancer is a very common disease and it is the third most common type of cancer in both sexes. In men it ranks third after prostate and lung cancer and in women after lung and breast cancer.
Colorectal cancer ranks second after lung cancer in terms of number of deaths from cancer. Majority of colorectal cancers (72%) start in the colon and smaller fraction (28%) arises in the rectum. The lifetime risk of being diagnosed with colorectal cancer in the United States is 5.9% for men and 5.5% for women.
There are several known risk factors for colorectal cancer. Being a male poses higher risk of colorectal cancer compared to being female. Increasing age is associated with an increase in the risk of colorectal cancer. Incidence of colorectal cancer is higher among African Americans compared to Caucasians. Risk of developing colorectal cancer is much higher for people living in the industrialized nations compared to less industrialized nations.
Diet, rich in fat and cholesterol, is linked to higher risk of developing colorectal cancer. Lack of proper exercise, presence of inflammatory bowel disease, some types of polyps and history of family members with diagnosis of colorectal cancer have been associated with higher risk of development of colorectal cancer. Early stages of colorectal cancer may not cause any symptoms. Some people might experience vague symptoms like mild abdominal pain, flatulence or diarrhea. Occasionally there might be microscopic bleeding and the diagnosis of colorectal cancer would be suspected because of presence of anemia from chronic bleeding.
Some people might develop frank bleeding or symptoms of bowel obstruction. Screening for colorectal cancer can detect the disease at an early stage. A rectal examination and examination of the stool specimen for the presence of microscopic quantity of blood are very common screening tools. Sigmoidocopy and colonoscopy are more invasive investigations, which can detect and remove some polyps that might be precursors of cancer. Less invasive techniques like barium enema, virtual colonoscopy using a CT scan machine are also often used in screening and diagnosis of colorectal cancer. Adults having an average risk of colorectal cancer should start colorectal cancer screening beginning at age 50.
Treatment of colorectal cancer depends upon the stage of the disease. Early stages of colorectal cancers are treated with surgery alone, later stages of colorectal cancer are treated with surgery followed by chemotherapy with or without radiation treatment. Rectal cancers are more often treated with radiation therapy compared to colon cancer.
Advanced stages of colorectal cancer, where the disease has spread to other organs, are usually treated with chemotherapy alone. There are several new chemotherapeutic agents and biological drugs available for the treatment of colorectal cancer. Treatment of colorectal cancer has undergone marked changes in the last 10 years. The newer drugs are showing much improved efficacy and prolonging life expectancy in patients with advanced stage colorectal cancer.
The author is a paramedical professional and a freelance health informaiton writer. Author contributes work on various websites including Medicineworld.
