The American Cancer Society advises all women over 40 to get a mammogram once a year to screen for signs of breast cancer. The U.S. Preventive Services Task Force, a panel of experts that advises the federal government, says most women need to get mammograms only once every two years and only when they're between ages 50 and 74.

Who's right? A new study comes down on the side of the task force. Researchers examined the records of about 140,000 women 66 to 89 who had mammograms between 1999 and 2006. Some had mammograms every year, and some of them had them every other year.

It turned out that having annual mammograms did not reduce women's risk of being diagnosed with an aggressive breast cancer. "The proportion [of women] with adverse tumor characteristics was similar among annual and biennial screeners," the researchers wrote in a study published by the Journal of the National Cancer Institute.

But they found that if all American women in the 66-to-89 age group had mammograms every year instead of every other year, the result would be 3.86 million more false-positives and 1.15 million more recommendations for biopsies.


Only 10 percent of men treated for early prostate cancer could sustain an erection sufficient for sex 15 years later, said researchers who found impotence rates were the same whether the treatment was surgery or radiation.

While surgery patients had higher impotence rates two years after treatment, by 15 years erection failure "was nearly universal" with both treatments, said the study in the New England Journal of Medicine. The study of 1,655 men adds to the controversy over whether doctors treat men with early prostate cancer too aggressively. "This is a picture of what really happens in prostate cancer," said senior author David Penson, an urologist at Vanderbilt University Medical Center in Nashville. "It is the most comprehensive portrait of the patient experience in prostate cancer that is out there."


Egg yolks are high in cholesterol, but a new analysis adds to the evidence that they are not the dietary sin we once thought they were.

Researchers reviewed eight prospective studies including 263,938 subjects and pooled the data for analysis. They found no evidence that eating up to an egg a day increased the risk of heart disease or stroke. The results were the same for men and women and in all age ranges.

Diabetic patients were the only exception. For them, high egg consumption was associated with an increased risk of heart disease and a reduced risk for hemorrhagic stroke. But there were too few diabetics in the studies to draw reliable conclusions.

The authors, writing online in the journal BMJ, acknowledge that self-reports are not always reliable. A co-author of the study, Dr. Frank Hu, a professor of nutrition and epidemiology at Harvard, said that eating two or three or more eggs a day might be harmful, in theory, although there are no data on that. "But within the modest range of one a day ... there is no dose-response relationship with higher consumption," Hu said.