Tobacco consumption is related causally to cancer of the lung, mouth, larynx, esophagus, bladder, kidney, and pancreas. Smoking also is related to colon polyps, precursors of colon cancer. Smokers may have a greater risk for developing a type of colorectal polyp that could increase their risk of colon cancer, according to researchers at the Ohio State University Comprehensive Cancer Center.
Scientists have studied general patterns of cancer in the population to learn what things around us and what things we do in our lives may increase our chance of developing cancer.
Both smoking and inheriting specific genes could be considered risk factors for certain kinds of cancer, but only smoking can be avoided. Some people are more sensitive than others to factors that can cause cancer.
Cancer of the colon or rectum is often called colorectal cancer. The colon and the rectum are part of the large intestine, which is part of the digestive system.
Diet and Lifestyle
Diet appears to be associated with colorectal cancer risk. Among populations that consume a diet high in fat, protein, calories, alcohol, and meat (both red and white) and low in calcium and folate, colorectal cancer is more likely to develop than among populations that consume a low-fat, high-fiber diet. A diet low in vitamin D may also increase the risk of colorectal cancer.
One study has found that a diet low in fat and high in fiber, fruits, and vegetables does not reduce the risk of colorectal cancer recurrence during a three to four year period. A diet high in saturated fat combined with a sedentary lifestyle may increase the risk of colorectal cancer. There is also evidence that smoking cigarettes may be associated with an increased risk of colorectal cancer.
Signs and Symptoms
Unfortunately, most people with colorectal cancer will not begin to experience symptoms until the disease is already at a late stage. In fact, some people may experience no symptoms at all. This is the reason that screening tests, such as a colonoscopy, are so important.
In general, signs and symptoms of colorectal cancer can include the following:
- Changes in bowel habits
- Blood in the stool
- Problems related to blood loss (anemia, weakness, fatigue, shortness of breath, pounding or racing heart, chest pain, and intolerance to exercise)
- Abdominal discomfort (frequent gas, bloating, fullness, cramps, and pain)
- Unexplained weight loss
- Pain with defecation
- Stools that are narrower than usual
- Urgent desire to defecate (and the passage of little matter)
These symptoms may be caused by colorectal cancer or by other conditions such as infections, hemorrhoids, and inflammatory bowel disease. It is important to bring any of these symptoms to the attention of your health care provider to determine the cause of your symptoms.
- Family history (genetic factors) of colorectal cancer or polyps in the colon
- Older age (over 50 years)
- Living in an industrialized country like the United States
- Polyps on the inner lining of the colon or rectum
- Diets high in meat and low in fruits and vegetables
- Overweight or obesity
- Regular consumption of alcohol
- Smoking cigarettes regularly
- Inflammatory bowel disease (such as irritable bowel syndrome, Crohn’s disease, and ulcerative colitis)