As the debate rages among experts about whether women are unnecessarily over-screened for breast cancer, a new study may provide more ammunition to suggest frequent mammograms may not increase the chance of survival as much as once thought.
Timely care and, "the widespread use of adjuvant therapy have probably combined to make screening now less important," said Dr. Gilbert Welch, professor of medicine at Dartmouth Medical School, in an accompanying editorial.
But many experts still aren't buying it.
"Our recommendations remain the same -- annual screening mammograms for women at average risk beginning at age 40," said Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society.
Such advice may have helped Rebecca Sutphen, 53, of St. Petersburg, Fla. With no family history of breast cancer, Sutphen thought she was in the clear -- until a routine mammogram detected breast cancer.
"I was hoping praying expecting it would be normal," she said. "I was completely shocked and scared and I felt very fragile."
Although Sutphen's doctor recommended she undergo yearly mammograms even without history of the disease, some experts do not.
Annual mammograms are recommended for women starting at age 50, and are thought to reduce the likelihood of dying from breast cancer by 15 to 23 percent, according to the U.S. Preventative Services Task Force.
But the study published Thursday in the New England Journal of Medicine suggested that mammograms reduce the chance of death by only 10 percent.
Researchers analyzed medical records from more than 40,000 women ages 50 to 69 with breast cancer in Norway and found that mammogram detection of breast cancer was responsible for only one-third of the women who survived.
Researchers said they used data to follow up with each patient after about two years. However, many experts said that is not enough time to track whether or not the mammogram helped the patient.
"It takes about 7 to 10 years to see the full benefit of mammographic screening," said Dr. Therese Bevers, director of the cancer prevention clinic at University of Texas M.D. Anderson Cancer Center.
In the new study, Bevers said, "the benefit is just starting to emerge."
Dr. Daniel Kopans, director of the breast imaging division at Massachusetts General Hospital, agreed.
"No one presents data on breast cancer with only 2.2 years of follow-up," he said.
And while the study suggests that treatment rather than screening contributed to most women's chance of survival, many experts, including Kopans, said screening plays as strong a role in survival.
"There are large, published studies from Sweden and the Netherlands that disagree with these results and show that most of the decrease in deaths is due to screening and not therapy."
In fact, for most women, early stages of breast cancer are more likely to be detected by mammogram, said Lillie Shockney, associate professor of breast cancer at Johns Hopkins University.
"The earlier [we] find it, usually the smaller it will be and less treatment will be needed," said Shockney.