Areas in the country that spend more on new screening technologies such as digital mammography are seeing more women diagnosed in the early stages of breast cancer but no corresponding drop in late-stage breast cancer diagnoses, according to a study published last Monday that raises questions about the benefits of the new tools.

Yale University researchers reviewed a 2006 government Medicare database of more than 137,000 women ages 66 to 100 who hadn’t been diagnosed with breast cancer and found that the Medicare program spent more than $1 billion that year on mammography screening, they reported in the journal JAMA Internal Medicine.