Colon cancer locations
Colon cancer
Colon cancer is a type of cancer that starts in the large intestine (colon). The colon is the last part of the digestive system.
Colon cancer typically affects older adults, but can occur at any age. It usually begins as small, non-cancerous (benign) clusters of cells called polyps that form inside the colon. Over time, some of these polyps can turn into colon cancer.
Polyps can be small and produce few, if any, symptoms. That’s why doctors recommend regular screening tests to help prevent colon cancer by identifying and removing polyps before they turn into cancer.
If colon cancer develops, many treatments are available, including surgery, radiation therapy and drug therapies such as chemotherapy, targeted therapy, and immunotherapy.
Colon cancer is sometimes referred to as colorectal cancer, a term that combines colon cancer that begins in the rectum and rectal cancer.
The symptoms
Signs and symptoms of colon cancer include:
- A persistent change in your bowel habits or a change in the consistency of your stools, including diarrhea or constipation
- Rectal bleeding or blood in the stool
- Persistent abdominal discomfort such as cramping, gas, or pain
- A feeling that your bowels are not completely emptied
- Weakness or fatigue
- Unexplained weight loss
Many people with colon cancer experience no symptoms in the early stages of the disease. When symptoms occur, they will likely change depending on the size of the cancer and its location in your large intestine.
When to see a doctor
Make an appointment with your doctor if you notice persistent symptoms that worry you.
Talk to your doctor about when to begin colon cancer screening. Guidelines generally recommend that colon cancer screenings begin around 50. If you have other risk factors, such as a family history of the disease, your doctor may recommend screening more often or sooner.
Reasons
Doctors aren’t sure what causes most colon cancer.
Generally, colon cancer begins when healthy cells in the colon develop changes (mutations) in their DNA. A cell’s DNA contains a series of instructions that tell a cell what to do.
Healthy cells grow and divide in an orderly way to keep your body functioning normally. But when a cell’s DNA is damaged and becomes cancerous, cells continue to divide even when new cells are not needed. As the cells accumulate, they form a tumor.
Over time, cancer cells can grow and invade and destroy nearby normal tissue. And cancerous cells can travel to other parts of the body, forming deposits (metastasis) there.
Risk factors
- Factors that can increase your risk of colon cancer include:
- Senile. Colon cancer can be diagnosed at any age, but most people with colon cancer are over the age of 50. Colon cancer rates are increasing in people under 50, but doctors don’t know why.
- African-American race. African-Americans are at greater risk of colon cancer than people of other races.
- A personal history of colorectal cancer or polyps. If you already have colon cancer or noncancerous colon polyps, your risk of colon cancer in the future is higher.
- Inflammatory bowel conditions. Chronic inflammatory diseases of the colon, such as ulcerative colitis and Crohn’s disease, can increase your risk of colon cancer.
- Hereditary syndromes that increase the risk of colon cancer. Certain gene mutations, passed down the generations of your family, can significantly increase your risk of colon cancer. Only a small percentage of colon cancers are linked to inherited genes. The most common inherited syndromes that increase the risk of colon cancer are familial adenomatous polyposis (FAP) and Lynch syndrome, also known as hereditary non-polyposis colorectal cancer (HNPCC).
- Colon cancer history in the family. You are more likely to develop colon cancer if you have a blood relative with the disease. Your risk is even greater if more than one family member has colon cancer or rectal cancer.
- Low fiber, high fat diet. Colon cancer and rectal cancer can be associated with a typical Western diet that is low in fiber and high in fat and calories. Research in this area has yielded mixed results. Some studies have found that people who eat diets rich in red meat and processed meat have an increased risk of colon cancer.
- A sedentary lifestyle. People who are sedentary are more likely to develop colon cancer. Regular physical activity can reduce your risk of colon cancer.
- Diabetes. People with diabetes or insulin resistance have an increased risk of colon cancer.
- Obesity. Compared to normal weight people, obese people have an increased risk of colon cancer and dying from colon cancer.
- To smoke. Colon cancer risk may increase in people who smoke.
- Alcohol. Heavy alcohol use increases your risk of colon cancer.
- Radiation therapy for cancer
