At a forum in March at the Harvard School of Public Health in Boston, physicians and policy officials debated the question “Mammograms: Who in the world are they good for?” I was the moderator, and at the end of the afternoon, I came away concluding that it’s time to rethink our policies on screening.
Mette Kalager, a surgeon at Oslo University Hospital and a visiting scientist at the Harvard School of Public Health, told the forum about a study she had led in Norway.
The researchers looked at the records of 40,075 women who received diagnoses of breast cancer between 1986 and 2005. Some had been screened every two years. Others had not been screened; their cancers were been detected by physical examination. Both groups were treated by teams of specialists. Over the 20-year period of the study, both groups saw a decline in death rates from the disease.
By comparing the groups, researchers determined that only about a third of this decline was due to screening. Most of it was due to state-of-the art treatment and comprehensive care. Previous studies had suggested a greater impact from screening, and the study, published in the New England Journal of Medicine in September, caused a stir in the breast cancer community.
A little history is in order. When mammography screening got underway in the United States 40 years ago, it put breast cancer on the public agenda. Catch-it-early-when-it’s-curable became a mantra of hope. Since then, treatments have improved, and the understanding of breast cancer has changed. Perhaps more important than the timing of detection is the biology of the cells. “There are some very tiny cancers that are just bad biology and are destined to relapse, no matter how early you find them,” Julie Gralow, a professor of oncology at the University of Washington Medical School, told the Harvard forum.