Science is Hard (breast cancer edition)

Two studies/stories caught my attention this week with respect to breast cancer.  The first is a study in the Annals of Internal Medicine which found that the risk of an overdiagnosis of breast cancer - meaning the breast cancer was not likely to cause any symptoms in the remaining years of life given that some other ailment would likely cause mortality before the breast cancer progressed to a symptomatic stage- increased significantly with age (e.g. for women age 70-74 it was a 31% overdiagnosis, for agef overdiagnosis increased significantly with age. They report that among women aged 70 to 74, up to an estimated 31 percent of breast cancer found among screened women was over diagnosed, over age 85 the rate of overdiagnosis rises to 54%. 

The other story I came across was this Nature news piece  on the unintended consequences of the FDAs accelerated-approval process for life saving drugs.  The story focuses on a breast cancer drug that was initially approved for the accelerated approval in the US but, when subsequent studies demonstrated it was not effective, that accelerated approval was retracted. However, the drug is still offered as treatment in India because drug approval is regulated by local health authorities.  A sample from the story:

Accelerated approvals in the United States are granted on the basis of clinical studies that suggest a health benefit without necessarily demonstrating it fully. The process prioritizes speed over certainty, and it requires companies to complete follow-up studies to confirm a treatment’s benefits. This is a “very reasonable compromise”, says bioethicist Holly Fernandez Lynch at the University of Pennsylvania in Philadelphia, “so long as we can get the confirmatory evidence quickly and reliably”.

Cheers, 

Colin