Nearly all cases of colorectal cancer develop from polyps. They start in the inner lining of the colon and most often affect the left side of the colon and rectum.
The location in the colon where cancer develops is one of the factors that's considered when developing your customized treatment plan.
Diarrhea, constipation, or feeling that the bowel does not empty completely. General abdominal discomfort, such as frequent gas pains, bloating, fullness and/or cramps. Constant feeling of fatigue or tiredness. New onset anemia diagnosed on routine lab work.
Age. As you get older, your risk of getting colon or rectal cancer increases—with the vast majority of cases occurring in people over age 50. The incidence of colorectal cancer in younger adults has risen steadily in recent years, but it's still a very uncommon disease in young people.
A low-fiber and high-fat diet, or a diet high in processed meats. Overweight and obesity. Alcohol consumption. Tobacco use.
Some studies have found an increased risk of colon cancer in people who eat diets high in red meat and processed meat. A sedentary lifestyle. People who are inactive are more likely to develop colon cancer. Getting regular physical activity may reduce your risk of colon cancer.
Colon cancer is considered a silent disease. Most of the time there are no symptoms. The symptoms that people may experience include a change in bowel habits, abdominal pain, blood in the stool, and weight loss. If individuals have these symptoms, the disease may already have advanced.
Abdominal pain, aches, or cramps may be symptoms of colorectal cancer. If you have any symptoms that worry you, be sure to see your doctor right away.
Colon cancer, or cancer that begins in the lower part of the digestive tract, usually forms from a collection of benign (noncancerous) cells called an adenomatous polyp. Most of these polyps will not become malignant (cancerous), but some can slowly turn into cancer over the course of about 10-15 years.
Two thirds of patients (n = 36,066) had right-sided colon cancer, and one third (n = 17,735) had left-sided colon cancer.
Colon cancer most often spreads to the liver, but it can also spread to other places like the lungs, brain, peritoneum (the lining of the abdominal cavity), or to distant lymph nodes. In most cases surgery is unlikely to cure these cancers.
Metastatic Colorectal Cancer May Spread Early in the Disease, Study Finds. Colorectal cancer cells can break away from the original tumor and travel through the blood or lymph system to other parts of the body, including the liver, lungs, and brain.
Colorectal cancer symptoms may be minor or non-existent during the early stages of the disease, although there may be some early warning signs. The symptoms of colorectal cancer may not develop until the disease has progressed into stage 2 or beyond.
In most cases, colon and rectal cancers grow slowly over many years. Most of those cancers start as a growth called a polyp.
Screening for colorectal cancer
Colorectal cancer doesn't just appear suddenly. It starts as a small growth on your colon, called a polyp, which rarely causes symptoms. If left alone over many years, polyps can grow into cancer. The only way to know it's there is to look.
Nausea and vomiting can occur if a colon or rectal tumor is obstructing the bowel and inhibiting the passage of liquid or solid waste or gas. Bowel blockage can also be accompanied by painful abdominal cramps, bloating and constipation.
No blood test can tell you if you have colon cancer. But your doctor may test your blood for clues about your overall health, such as kidney and liver function tests. Your doctor may also test your blood for a chemical sometimes produced by colon cancers (carcinoembryonic antigen, or CEA).
Usually if a suspected colorectal cancer is found by any screening or diagnostic test, it is biopsied during a colonoscopy. In a biopsy, the doctor removes a small piece of tissue with a special instrument passed through the scope. Less often, part of the colon may need to be surgically removed to make the diagnosis.
Myth: I don't need a colonoscopy because I'm not having any symptoms. Fact: Many people are diagnosed with colon cancer when they are feeling just fine. People don't think they can have colon cancer if they feel OK, but they most certainly can.
Research now suggests that chronic stress can actually make cancer spread faster. Stress can speed up the spread of cancer throughout the body, especially in ovarian, breast and colorectal cancer. When the body becomes stressed, neurotransmitters like norepinephrine are released, which stimulate cancer cells.
Cancer of the colon is a highly treatable and often curable disease when localized to the bowel. Surgery is the primary form of treatment and results in cure in approximately 50% of the patients. Recurrence following surgery is a major problem and is often the ultimate cause of death.
By the time the cancer has advanced to stage 4 (metastasized), a number of symptoms may occur depending on where in the body the cancer has spread. However, not everyone will experience symptoms – or the same set of symptoms – as every patient's experience is unique.
Colorectal cancer can occur in young adults and teenagers, but the majority of colorectal cancers occur in people older than 50. For colon cancer, the average age at the time of diagnosis for men is 68 and for women is 72.
In general, colorectal cancers tend to be slow growing, gradually enlarging and eventually penetrating the bowel wall. When they do spread, it is usually through invasion of nearby lymph nodes. In fact, cancer cells may enter a lymph node even before the tumor penetrates through the intestinal wall.
The most common site of metastases for colorectal cancer, which includes colon cancer or rectal cancer is the liver. Colorectal cancer cells may also spread to the lungs, bones, brain or spinal cord.