There would be very few cases of colon cancer if everyone went for screening as prescribed. Colon cancer is one of the most preventable cancers, yet it is one of the least prevented. If precancerous polyps are not discovered and removed, they can silently develop into cancer. Not all polyps will turn cancerous, but you are taking a risk every time you skip a colonoscopy.
Let’s take a look at what happens in the colon if a precancerous polyp begins to grow. Here is a short explanation of how a polyp develops into cancer:
Polyp stage and precancerous stage
A polyp is a small growth on the lining of the colon or rectum. There are two types of polyps: hyperplastic and precancerous. Most polyps that become cancerous originate as precancerous polyps and not hyperplastic polyps.
In the precancerous stage, the cancer cells have begun to divide but the cancer has not grown through the walls of the rectum or colon.
In stage 1, the tumor has begun to grow through the muscles in the colon, but has not affected the lymph nodes or other parts of the body. Patients diagnosed with stage 1 colon cancer have an average 5-year survival rate of 94 percent.
In this stage, the cancer has completely grown through the colon wall but has not spread to tissues or lymph nodes. Patients diagnosed with stage 2 colon cancer have an average 5-year survival rate of 82 percent.
The cancer has grown into the outer layers of the colon or grown beyond the wall of the colon. It may affect lymph nodes and attach itself to nearby organs and tissues. Patients diagnosed with stage 3 colon cancer have an average 5-year survival rate of 67 percent.
This is the most severe stage of colon cancer. To be classified as stage 4 colon cancer, the cancer must have spread to one distant organ. Most often, it is the lungs, liver or lining of the abdominal cavity. Patients diagnosed with stage 4 colon cancer have an average 5-year survival rate of 11 percent (Source: Be Seen Get Screened).
One of the most common questions about colon cancer is, “How long does it take for a polyp to grow into cancer?” Every individual case is different, but current research suggests that it takes about 10 years for a precancerous polyp to develop into cancer. For this reason, the U.S. Preventative Services Task Force recommends a screening colonoscopy every 10 years beginning at 50 years of age. Those who are African American or exhibit risk factors for colon cancer like family history or inflammatory bowel disease may need to get a colonoscopy earlier than 50 years of age and repeat the screenings at shorter intervals. The recommended intervals should be seen as general guidelines (Source: American College of Gastroenterology).
Talk to your doctor about your colon cancer risk. The best defense against colon cancer is regular colonoscopies. Routine screenings offer colon cancer prevention and early detection. Consider this fact: colon cancer is over 90 percent treatable when discovered in the early stages. Call your gastroenterologist for an appointment, or use our locator tool to find a GI center near you.