MAMMOGRAPHY IN YOUNGER WOMEN

NEW YORK (Reuters Health) Sep 10 - Adding to controversy over when to start screening for breast cancer, a new study suggests women in their 40s may benefit from yearly mammograms.

Researchers who reviewed 609 breast cancer deaths found about half occurred among women who were diagnosed when they were under 50 years old, and most of those women had never had a mammogram.

"You should be (screening) about every year in the 40s," Dr. Blake Cady, a professor emeritus of surgery at Harvard Medical School in Boston who worked on the study, told Reuters Health.

That recommendation echoes screening guidelines from the American Cancer Society, which calls for yearly mammograms starting at age 40 for "as long as a woman is in good health."

But the government-backed U.S. Preventive Services Task Force (USPSTF) recommends that women at average risk for breast cancer get screened every other year starting at 50 years old and says younger women should make their own decision on whether to be screened.

"For women 40 to 49 (years old) we know there is some benefit," said Dr. Virginia Moyer, who chairs the USPSTF and was not involved in the new study.

"The benefit is relatively modest and whenever there is modest benefit you really have to look at the downside," said Dr. Moyer, who is also the vice president for maintenance of certification and quality at the American Board of Pediatrics in Chapel Hill, North Carolina.

Most screening recommendations are based on analyses of randomized controlled trials. Dr. Cady and his colleagues wrote September 9th in the journal Cancer that those analyses may downplay the actual benefit of screening, because - for example - people in the groups who are told not to get screening may get screened anyway.

For their study, the researchers did a so-called failure analysis on data from the medical records of 609 women who died of breast cancer. The women were diagnosed between 1990 and 1999 at one of two Boston hospitals, and they died by 2007.

A failure analysis, according to Dr. Cady, is similar to what aviation officials do when evaluating a plane's black box to determine what went wrong before a crash.

The researchers found that of the 609 breast cancer deaths, 29% occurred in women who had a mammogram within two years of their diagnosis and 71% were in women who were not screened.

Only about 13% of deaths occurred among women who were more than 70 years old when they were diagnosed. About half occurred among women younger than 50 at diagnosis.

Of all the deaths, 30% happened in women who were diagnosed between ages 40 and 49, and 20% were in women diagnosed before age 40, Cady said.

Previous research has found that about 30 of every 1,000 40-year-olds will die from the disease in the absence of screening.

In an interview with Reuters Health in 2011, Dr. Michael LeFevre of the University of Missouri, who co-chairs the USPSTF, said that if screening is started at 50 and done every two years until the women hit 75, seven of those deaths would be prevented. Starting at age 40 instead would prevent one additional death, he said. (See Reuters Health story of May 27, 2011.)

The new findings "are somewhat unsurprising in that essentially if you look backwards in a highly selected population you can find a lot of things and knowing how to interpret them is nearly impossible," Dr. Moyer said.

Just under 2% of 30-year-old women will develop breast cancer by age 50, according to the U.S. Centers for Disease Control and Prevention.

Dr. Cady said the controversy over when to begin screening for breast cancer will not be solved by the new study, "but at least it provides some points of reference."

SOURCE: http://bit.ly/18PaTWL

Cancer 2013.