Let's determine the effectiveness of mammograms to detect breast cancer. Not to be too simplistic but lets consider how we might gather the necessary statistics. If we identify a positive mammogram what is the probability that we indeed detected cancer? According to the American Cancer Society there are about 231,840 new cases of invasive breast cancer detected each year. Each year there are 38,770,390 mammographies performed. Since the accuracy of mammograms varies from 80% to 90% let's assume 90% for purposes of calculations. By adding the 10% of false positives to the estimated 231, 840 cases per year we have the probability of a positive mammogram indicating breast cancer to be 231,840/4108879 or roughly about 5%.
The cost of US mammograms vary from $100 with a reported average of $243 reported by a copay data aggregator, so those 38,770,390 mammograms cost about 3.8 billion dollars if we are using the low cost range. Each case of breast cancer would cost about $18000 to diagnose and that does not even account for the biopsy required for confirmation which would likely double the 3.8 billion figure to above 7 billion yielding $34,000 dollars for the average cost of initial diagnosis.
One more step here. Since only one out of every 2000 women screened will have their life extended--if 38,770,390 women are screened each year that means that 19,385 women will have their lives extended by early screening to the cost of $361,103 per mammogram. This figure does not include treatment costs or other indirect costs related to the lives extended each year due to screenings.
National Expenditure For False-Positive Mammograms And Breast Cancer Overdiagnoses Estimated At $4 Billion A Year
This article presented by Kenneth D. Mandell featured in the Cost and Quality of Cancer Care Health Affairs April Issue describes the cost of false-positive mammograms and overdiagnosis.
The additional costs of additional diagnostic work-ups are substantial.
The costs of false-positive mammography results and breast cancer overdiagnosis in women ages 40–59 are substantial. More than one in ten women who received mammography screening underwent further diagnostic workup. As noted above, if we assume a false-positive rate of 11 percent and an overdiagnosis rate of 22 percent and 86 percent for invasive breast cancer and DCIS, respectively, the estimated annual national expenditure for false-positive mammo- grams and overdiagnoses of breast cancer is about $4 billion.