New mega-review underscores mammography’s benefits

I’m not a statistician, but the analysis presented by Dr. Smith makes common sense to me.

Basing benefit solely on those women invited to screen will clearly result in an underestimate of mammography’s true benefit if you’re going to count women who weren’t screened as being in the screened group. More and more, we are learning that breast cancer is a more indolent disease than we thought. Particularly in those with estrogen receptor–positive breast cancer, the most common subtype, many patients don’t recur and die for a decade or more. If you’re not following patients long enough to capture all of the recurrences and deaths from the disease, then you don’t get a full assessment of the value of screening earlier in the course of disease. Long-term follow-up is extremely important.

You’d think that point would be universally accepted in the world of breast cancer screening research, but it isn’t. Mammography is controversial. It takes on some of the same features as debates over global warming. Quite often we see that scientists are just as vulnerable to motivated reasoning as anybody else.

Dr. C. Kent Osborne is the SABCS codirector and director of the Dan L. Duncan Cancer Center and the Lester & Sue Smith Breast Center at Baylor College of Medicine, Houston. He made his comments during the post presentation discussion of the research.