How to make mammogram testing cheaper and more effective.

New recommendations concerning mammogram testing have upset a lot of people.   Previously, doctors recommended that women be tested yearly starting at age 40. The new recommendations say that most women should start mammogram testing at age 50, and only do it every other year.  The analysis relied on the following empirical result: one cancer death is prevented for every 1,904 women age 40 to 49 who are screened for 10 years, compared with one death for every 1,339 women age 50 to 59, and one death for every 377 women age 60 to 69.  (These recommendation make sense, as pointed out by Mike Trick.)   However, if the ratio of cancer deaths prevented per mammogram could be improved for women aged 40, then mammograms would be recommended.

What this highlights is the importance of a cheap preliminary test with reliability that is pretty good.   For example, suppose that there was a test for which no women with breast cancer had false negatives, and where 1 out of 10 women with no breast cancer had a false positive.  With such a test, approximately 90% of women would be screened out as negative, with all of them having no cancer.  The remaining 10% would test as positive, with the vast majority of them being false positives.  These women would be given mammograms.  (Women would need to be reassured that the preliminary test is not a test for cancer but a test on who should be screened using mammograms.)    Since only 1/10th as many women would be given mammograms, this would result in cancer death prevented for every 190 women being tested, a huge improvement over the current system, with huge savings in terms of health outcomes and dollars.

Even if the test had a false negative rate of 10%, the prevention of cancer deaths would be almost as high.  There would be 1 cancer death prevented for approximately 210 mammograms.  Unfortunately, the false negative could lead to 1 cancer death for every 17,000 women not given mammograms (because of a negative test.)   At the same time, it would eliminate the health risks of mammogram testing for 17,000 women who didn’t have cancer.

The conclusion is that a cheap test with pretty good reliability (say around 90%) can dramatically improve the health outcome of mammogram testing,  while dramatically decreasing the cost of health care.   The NIH should dedicate research funding to find such tests.


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