How important is screening for colon cancer? It’s very important, according to a study in the July issue of GIE: Gastrointestinal Endoscopy, the monthly peer-reviewed scientific journal of the American Society for Gastrointestinal Endoscopy (ASGE), and reported in Science Daily (https://www.sciencedaily.com/releases/2015/07/150713143655.htm).
The study. "Survival in patients with colorectal cancer diagnosed by screening colonoscopy," revealed that patients whose colorectal cancer (CRC) is detected during a screening colonoscopy are likely to survive longer than those who wait until they have symptoms before having the test. Conducted in 10 gastroenterology practices in Germany, the study examined 312 patients aged 55 or older, who were diagnosed with CRC between 2003 and 2005. Sixty of them were diagnosed during a screening colonoscopy, having had no symptoms and/or only a negative fecal occult blood test (FOBT). The others had their cancers detected during a diagnostic colonoscopy, after a positive FOBT and/or symptoms including abdominal pain, iron deficiency anemia, weight loss, changes in bowel habits or rectal bleeding.
The patients had not had a previous colonoscopy. They all received endoscopic follow-up care and were followed for as long as 10 years after diagnosis. Patients whose cancer was detected during a screening colonoscopy lived an average of 20.2 months longer than those who had the test after noticing symptoms or having a positive FOBT (diagnostic colonoscopy). Because the latter group was likely to have more advanced stage tumors, people in it had shorter survival times.
Approximately 55 percent of the patients with diagnostic colonoscopy and about 77 percent of the screening colonoscopy patients survived beyond the study time frame. As explained by the lead author, Kilian Friedrich, MD, "We know that screening colonoscopy can prevent cancer by detecting and removing precancerous polyps. Independent of that, this study shows that screening colonoscopy also can contribute to reduced mortality from colorectal cancer by catching tumors at earlier and more treatable stages."
The researchers concluded that, although screening approaches differ between nations, this finding of increased survival among recipients of screening colonoscopy likely applies to other countries. The research corroborated the findings of other organizations.
According to the American Cancer Society, preventing colorectal cancer (and not just finding it early) should be a major reason for getting a screening colonoscopy. Some people can avoid colorectal cancer by having their polyps found and removed. Tests that have the best chance of finding both polyps and cancer are preferred if available. Beginning at age 50, both men and women at average risk for developing colorectal cancer should be tested. Those at an increased or high risk of colorectal cancer -- personal history of colorectal cancer or adenomatous polyps, personal history of inflammatory bowel disease (ulcerative colitis or Crohn's disease) and known family history of a hereditary colorectal cancer syndrome such as familial adenomatous polyposis (FAP) or hereditary non-polyposis colon cancer (HNPCC) -- should begin colorectal cancer screening before age 50 and/or be screened more often (https://www.cancer.org/cancer/colonandrectumcancer/moreinformation/colonandrectumcancerearlydetection/colorectal-cancer-early-detection-acs-recommendations).