Letters

I read with considerable interest the article “Experts Divided on New Guidelines for Mammography” (December 2009, p. 1). Discussing this controversy from all sides is important, but I am more favorably influenced by the balance in the advice provided by Secretary Sebelius and Dr. Stubbs, and am pleased we hear no concern that political interference was a factor in releasing the recommendations. Screening is always a matter of trade-offs, and false positives with potential harm from unnecessary evaluation and worry could very well be problematic for some. But I worry that recommending screening every 2 years may result in screening at longer intervals, perhaps an unintended consequence. Several investigators have recommended that patients need explanations regarding absolute risks and benefits in the context of consistent denominators. For example, 38 women may develop breast cancer for every 10,000 taking hormone replacement, and 30 women may develop breast cancer for every 10,000 not taking hormone replacement. For most patients, describing the risks in hormone therapy users and nonusers as 38/10,000 and 30/10,000 is more meaningful than trying to make decisions based on a relative risk increase of 26% and a number needed to harm of 1,285.