Colon Cancer
What is Colon Cancer?
Colon cancer is a type of cancer that starts in the large intestine, also called the colon. It typically begins as small growths called polyps on the inner lining of the colon. Over time, some polyps can become cancerous. Most colon cancers develop slowly over several years.
The colon is the final part of your digestive system where your body absorbs water and nutrients. It also stores waste before elimination. When cells in the colon start growing out of control, they can form tumors that interfere with normal digestive function.
Colon cancer is one of the most common cancers in the United States. The good news is that when caught early, it is highly treatable. Regular screening starting at age 45 can prevent most cases by finding and removing polyps before they turn into cancer.
Symptoms
- Changes in bowel habits lasting more than a few days, including diarrhea or constipation
- Blood in the stool or rectal bleeding
- Persistent abdominal cramping, pain, or gas
- Feeling that your bowel does not empty completely
- Unexplained weight loss
- Weakness and fatigue
- Narrow stools
- Anemia or low red blood cell count
Many people with early colon cancer have no symptoms at all. This is why screening is so important even when you feel perfectly healthy. Symptoms typically appear only after the cancer has grown or spread.
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Causes and risk factors
Colon cancer develops when genetic changes occur in colon cells that cause them to grow uncontrollably. Age is the biggest risk factor, with most cases occurring after age 50. A diet high in red and processed meats and low in fiber may increase risk. Smoking, heavy alcohol use, obesity, and lack of physical activity also raise your chances. Some people inherit gene mutations that increase colon cancer risk significantly.
People with inflammatory bowel disease like Crohn's disease or ulcerative colitis have higher risk. A family history of colon cancer or polyps means you should start screening earlier. Diabetes and insulin resistance are also linked to increased colon cancer rates. Some research suggests that folate levels may play a role, though the relationship is complex and still being studied.
How it's diagnosed
Colon cancer is diagnosed through several methods. Colonoscopy is the gold standard, allowing doctors to view the entire colon and remove polyps during the procedure. Other imaging tests include CT colonography and flexible sigmoidoscopy. Stool-based tests can detect blood or DNA markers that suggest cancer or precancerous polyps.
Blood tests can provide supporting information about your health status. Rite Aid offers testing that includes folate and red blood cell count, which may reveal anemia or nutritional factors related to colon health. These blood markers are not diagnostic for colon cancer but can help your doctor understand your overall health picture. If you have symptoms or risk factors, talk to your doctor about colonoscopy screening.
Treatment options
- Surgery to remove cancerous sections of the colon and nearby lymph nodes
- Chemotherapy using drugs like 5-fluorouracil, oxaliplatin, or irinotecan to kill cancer cells
- Radiation therapy to shrink tumors, often used for rectal cancer
- Targeted therapy drugs that attack specific cancer cell characteristics
- Immunotherapy to help your immune system fight cancer cells
- Eating a high-fiber diet with plenty of fruits, vegetables, and whole grains
- Maintaining a healthy weight through regular physical activity
- Limiting red meat and avoiding processed meats
- Avoiding tobacco and limiting alcohol consumption
- Regular follow-up care and surveillance colonoscopies after treatment
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- Simple blood draw at your nearest lab
- Results in days, not weeks
- Share results with your doctor
Frequently asked questions
Early colon cancer often has no symptoms, which is why screening is critical. When symptoms do appear, they may include changes in bowel habits, blood in stool, abdominal pain, or unexplained weight loss. Many people feel perfectly fine in early stages. Regular screening starting at age 45 can catch cancer before symptoms develop.
Most people should begin colon cancer screening at age 45. If you have a family history of colon cancer or polyps, you may need to start earlier. People with inflammatory bowel disease or inherited genetic conditions need screening at younger ages. Talk to your doctor about the right screening schedule for your personal risk factors.
Blood tests alone cannot diagnose colon cancer. However, they can reveal anemia from chronic bleeding or nutritional markers that may warrant further investigation. Tests like folate and red blood cell count provide helpful context about your overall health. Colonoscopy remains the most reliable way to detect colon cancer and precancerous polyps.
Survival rates depend heavily on what stage the cancer is found. When caught early and confined to the colon lining, the 5-year survival rate exceeds 90%. Survival drops significantly once cancer spreads to distant organs. This dramatic difference highlights why early detection through screening saves lives.
Diet plays a significant role in colon cancer risk. Eating lots of red and processed meats increases risk, while high-fiber foods like fruits, vegetables, and whole grains are protective. Obesity and physical inactivity also raise your chances. Limiting alcohol, avoiding tobacco, and maintaining a healthy weight all help reduce risk.
About 5 to 10 percent of colon cancers are caused by inherited genetic mutations. Conditions like Lynch syndrome and familial adenomatous polyposis greatly increase risk. Having a parent or sibling with colon cancer doubles your risk even without a known genetic syndrome. If you have a family history, talk to your doctor about earlier and more frequent screening.
A polyp is a growth on the colon lining that is usually benign. Most polyps never become cancer, but some types can turn cancerous over many years. Removing polyps during colonoscopy prevents them from becoming cancer. This is why regular screening is so effective at preventing colon cancer.
Colon cancer typically develops slowly over 10 to 15 years. It usually starts as a small polyp that gradually grows and may become cancerous. This slow progression gives you a large window for screening to catch and remove polyps before they turn into cancer. Regular screening takes advantage of this long timeline.
Yes, lifestyle changes can significantly lower colon cancer risk. Exercising regularly, maintaining a healthy weight, and eating a high-fiber diet all help. Limiting red and processed meats, avoiding tobacco, and drinking alcohol in moderation are also important. These changes work best when combined with regular screening starting at age 45.
If screening finds polyps, your doctor will remove them during the colonoscopy. Most polyps are benign and removal prevents cancer from developing. If cancer is found, additional tests will determine the stage and guide treatment. Early-stage colon cancer is highly treatable, with many people achieving complete recovery after surgery.