my remarks concerned only colorectal cancer.
In his book he talks about Minnesota Colon Cancer Control Study[1993].
There were 47,000 adults between the ages of 50 to 80 in the study. They divided them into sections. 1)annual fecal occult blood testing[FOBT] 2)
biennial [FOBT] 3)no [FOBT].The test ran 13 years. Annually the number of deaths from colorectal cancer were1)80 2)120 3)120. There was absolutely NO difference, however, in the all cause mortality across the groups-about 3,300 in each group.So out of 47,000 to spare 40 individual required identifying the true positives among the 75% of those tested who had false positives. 12246 colonoscopies were performed. 4 resulted in a perforation of the colon(surgery required) &11 resulted in bleeding(3 requiring surgery.
Dr Hadler:
If we rely on FOBT as a screening method, we would have to screen 1,000 people over the age of 50 for a decade to spare 1 death by colorectal cancer. In doing so, we would not affect mortality from all causes. And if we relied on colonoscopy to determine if a FOBT was a true or false positive, for every person spared death by colon cancer, a person with a normal bowel would suffer a serious non fatal complication during diagnosis.
Dr Hadler also addresses the accuracy & thoroughness of a colonoscopy.
One study recruited 183 patients with a positive FOBT to undergo two colonoscopies by two different experienced colonoscopists on the same day. The first colonscopist removed all polyps and adenomas that were discovered. The second found another 89 that the first missed.
The odds of dying from colon cancer according to the chart in "Know Your Chances":
how many out of 1,000 men will die in the next 10 years from colon cancer.
50-54-2 for smokers & nonsmokers
55-59-3 for smokers & nonsmokers
60-64-5 for smokers & nonsmokers
65-69-8 for nonsmokers, 7 for smokers
70-74-10 for nonsmokers, 9 for smokers
75-79-13 for nonsmokers, 11 for smokers