Cancers caught during screening colonoscopy are more survivable

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, according to a study.

The study looked at 312 patients in 10 gastroenterology practices in Germany, all aged 55 or older, who were diagnosed with CRC in 2003-2005. Of those, 60 patients were diagnosed during a screening colonoscopy, meaning they had no symptoms and/or only a negative faecal occult blood test (FOBT). The other 252 patients had their cancers detected during a diagnostic colonoscopy,
following a positive FOBT and/or symptoms including abdominal pain, iron deficiency anaemia, weight loss, changes in bowel habits, or rectal bleeding. None of the patients had had a previous colonoscopy, and all received endoscopic follow-up care. The patients were followed for as long as 10 years after diagnosis.

Patients whose cancer was detected during screening colonoscopy lived 20.2 months longer, on average, than those who had the test after noticing symptoms or having a positive FOBT (diagnostic colonoscopy). The latter group tended to have more advanced stage tumors; as expected, those whose cancer was in a more advanced stage had shorter survival times. About 55 percent of the patients with diagnostic colonoscopy, and about 77 percent of the screening
colonoscopy patients, survived beyond the time period of the study.

According to the lead author, Kilian Friedrich, MD,