Breast Cancer Screening II

The meta-analysis conducted by the U.S. Preventive Services Task Force result in these numbers: the relative risk reduction of screening mammography on breast cancer death in women 40-49 is 0.85 (CI 0.75-0.96; 8 trials). Due to the lower incidence of breast cancer in this age group, the number of people needed to invite for a screening mammogram to prevent 1 breast cancer death is 1904.

Therein lies the rub. Are we, as a society, willing to do 1904 mammograms to prevent one breast cancer death? Mammograms aren't completely benign. False-positive results are very common and lead to unnecessary invasive procedures and undue anxiety. This is not trivial; biopsies and surgeries as a result of false positive tests can be extremely costly and entail their own consequences. Other issues include discomfort of the procedure, overdiagnosis, and dangers of radiation exposure.

The problem is this: any woman would rather face the anxiety of a false positive test than have cancer. Furthermore, of the 1904 women screened, if you're the one with the actual cancer, then screening matters. But this kind of reasoning leads to a slippery slope. Why don't we mammogram women 30-39? They get breast cancer too. We'd have to do more mammograms to prevent a single death, but there are potential lives to save.

Where do you set the cut-off? If we do screening mammograms on women 40-49, we pay $190,400 to save one life (based on average cost of mammogram $100). Is that worth it?

Think of how many swine flu vaccines we could buy with that amount of money. (Don't worry, my opinion on the novel H1N1 vaccine is coming soon). My opinion doesn't really matter as I'm not going into primary care. But in looking at the numbers, I think it's reasonable to be ambivalent, and either side can be defended. For me, given a patient from age 40-49, I would assess her risk factors, and absent any red flags, I'd reassure her and schedule her for a mammography when she turns 50.