U.S. Preventive Services Task Force (USPSTF) recommendations on breast cancer screening (BCS): Are they justified?

1584 Background: Nine randomized population trials (RPTs) on BCS with mammography have been reported. Conclusions based upon mortality (MOR) comparisons in RPTs have long led to uncertainty about whether BCS saves lives, especially in women in their 40s. In Nov 2009, USPSTF recommended against BCS in women 40-49 and biennial BCS for women >50. By 2010, BCS fell by >4% in US. Does the evidence support USPSTF recommendations? Methods: MOR quantifies the effect of intervention across an entire population. However, the key issue is whether BCS reduces MOR among those with disease. This is reflected by survival (SUR), not MOR. While SUR is considered flawed due to conventional screening biases, the confounding influence of these biases is misunderstood. In a RPT, randomization provides an opportunity to eliminate these biases, so that (SUR) may accurately reflect screening efficacy. MOR would be biased if randomization fails to produce populations at equal risk for the target disease. Results: Among 9 RPTs, si...