Colon Cancer / Polyps
The colon is the final part of the digestive tract, also known as the large intestine. Polyps form in the colon and can turn cancerous. Colon cancer is the third most prevalent cancer in U.S. men and women.
At Concorde Gastroenterology, we perform colonoscopies and sigmoidoscopies to screen for colon cancer.
What is colon cancer?
Often grouped with the rectum into colorectal cancer, cancer in the colon usually begins with small noncancerous polyps. Polyps are clumps of cells that can turn into cancer over time. The odds of a person developing colon cancer in his or her lifetime are one in 23 (4.5%). These odds vary with certain risk factors. Of these cancers, 71 percent develop in the colon, and 29 percent in the rectum. If colon cancer is not found until later stages, it is often fatal.
What are polyps?
A colon polyp is a small clump of cells that develop on the lining of the colon. Most polyps are benign, harmless. But these benign polyps can turn into cancer.
Generally, the larger the polyp the greater the risk of cancer.
If you’re over 50, are overweight, smoke, or have a family history of colon polyps or colon cancer, your risks are far greater. Colon polyps usually don’t cause any symptoms. Because of this, regular colonoscopies or other screenings to check for polyps are important.
Are polyps always cancerous?
What are the signs and symptoms of colon cancer?
Many people with colon cancer show no symptoms in the early stages. That is part of the danger of this form of cancer. When symptoms do appear, they include:
- A change in your bowel habits, including diarrhea or constipation or a change in consistency that last at least four weeks
- Blood in the stool
- Rectal bleeding
- Persistent abdominal pain
- A feeling that your bowel can’t be completely emptied
- Weakness or fatigue
- Unexplained weight loss
These are risk factors that increase your odds of developing colon cancer:
- Older age — The majority of colon cancer occurs in those over 50.
- African American heritage
- Native American heritage
- Inflammatory intestinal conditions — Chronic inflammatory diseases such as Crohn’s disease and ulcerative colitis.
- Family history
- High-fat, low-fiber diet
- Sedentary lifestyle
- Heavy alcohol use
- Radiation therapy for cancer
How is colon cancer diagnosed?
The key to successful treatment of colon cancer is to catch it early. This is why it is recommended that everyone begin screening for colon cancer at age 50. Those with more risk factors should begin screening at 45.
These are the six screening options:
- Stool DNA testing — This non-invasive test involves a stool sample that tests for changes in DNA that could be a sign of cancer or polyp growth.
- Colonoscopy — A flexible lighted tube with a small camera on the end is inserted into the rectum and examines the entire length of the colon and rectum.
- Flexible sigmoidoscopy — Like a colonoscopy, but it looks at only a part of the colon and rectum.
- Double-contrast barium enema — An enema delivers barium into the colon, and then x-rays are taken.
- CT colonography — This is a scan of the colon and rectum that produces detailed cross-sectional images.
- Guaiac-based fecal occult blood test — This test looks for tiny amounts of blood in the stool.
Stages of Colon Cancer
If you are diagnosed with colon cancer, the next step is to determine the stage. These are the four stages:
- Stage I — The cancer has grown through the lining of the colon or rectum but hasn’t spread beyond the colon wall or rectum.
- Stage II — The cancer has grown into or through the wall, but hasn’t spread to the lymph nodes.
- Stage III — The cancer has invaded nearby lymph nodes, but isn’t affecting other parts of the body yet.
- Stage IV — The cancer has spread to distant sites.
How is colon cancer treated?
Treatment depends on the stage. Three primary treatment options are surgery, chemotherapy, and radiation.
Surgery for early-stage colon cancer
- Removing polyps during a colonoscopy
- Endoscopic mucosal resection — Removing larger polyps may also involve taking some of the lining of the colon or rectum.
- Minimally invasive surgery — If the polyps can’t be removed during a colonoscopy, they may be removed with a laparoscope inserted through tiny incisions in the abdominal wall.
Surgery for invasive colon cancer
- Partial colectomy — Part of the colon containing the cancer, along with a margin of normal tissue, is removed and the healthy portion reconnected.
- Ostomy — If the colon can’t be reconnected, an opening is created in the abdominal wall, where a portion of the remaining bowel is routed. A bag is attached to catch the eliminated stool.
Chemotherapy, radiation therapy, drug treatment therapy
These treatments for advanced stage colon cancer each seek to destroy cancer cells with different means.
At what age should a person get screened for colon cancer?
Colon cancer can be successfully treated if caught early. The CDC and the American Cancer Society recommend that all people receive regular screening for colon cancer beginning at age 50. For those with high risk factors detailed above, such as inflammatory bowel disease or genetic factors, screening should begin at age 45.