Ultrasound effective for breast cancer screening, study says; separate analysis questions benefit vs harm

In In The News by Barbara Jacoby

By: Angela Townsend

From: cleveland.com

A study presented this week at a national breast cancer research conference is adding to the body of evidence showing the benefit of using ultrasound along with mammography as a breast cancer screening tool for women with dense breast tissue.

“The fact that we’ve been accumulating the data now for four years is significant,” said Dr. Jean Weigert, a clinical radiologist and director of breast imaging at The Hospital of Central Connecticut in New Britain. “Most studies don’t go beyond two years. I think that’s a limitation.”

Weigert is presenting the findings Tuesday at the 2014 San Antonio Breast Cancer Symposium, a partnership between the University of Texas Health Science Center, the American Association for Cancer Research and Baylor College of Medicine.

In 2009, Connecticut was the first state to require that women be notified if they have dense breast tissue, and to mandate that insurance pay for a screening ultrasound. A handful of the 19 states with notification laws also mandate insurance coverage.

“Most of us were not happy with this,” Weigert, who testified against the law in 2007, told The Plain Dealer. “I didn’t think we had enough data.”

When the law passed, Weigert said her reaction was, “OK, if we’re forced to do this, let’s collect the data.”

She led a team of researchers that found that the number of breast cancers detected in women with dense breasts – whose screening mammogram showed no signs of cancer — was increased when handheld ultrasound directed to a specific spot to provide a sonogram, or picture of body tissue, was done as well.

he study analyzed four years of data from screenings, from October 2009 through December 2013, of women ages 40 to upper 70s, with dense breast tissue. Approximately 30,000 screening mammograms were conducted each year at two practices in Connecticut; of those, just under 13,6000 screening ultrasounds were conducted.

The ultrasound screening detected 46 breast cancers, or between three and four breast cancers per 1,000 women screened over the four-year period.

And over that time period, the positive predictive value — the proportion of women with breast cancer among those whose ultrasound results showed abnormalities that might be cancer – improved from 7.1 percent in the first year to 17.2 percent in the fourth year.

“Our positive predictive value is getting better and better,” Weigert said. “The big drawback was the fact that we were doing a lot of biopsies for negative findings. Our learning curve has improved. We’re getting better at deciding who needs a biopsy.”

Earlier this year, SB 54 was passed in the Ohio Senate. If the bill is passed into law as expected, it would make it mandatory for a woman to be notified if the results of her mammogram show that she has dense breast tissue. She could then choose if she wanted to receive the supplemental ultrasound screening.

But unnecessary biopsy is just one of the results of ultrasound that raises the question of whether using the technology does more harm than good.

In an article published online Monday in the journal Annals of Internal Medicine, researchers provided the results of an analysis they said shows that notification laws and the added ultrasound screening following the results of a normal mammogram significantly increases the cost of care, and saves relatively few lives.

Using computer simulation models, and the most recent data available on the effectiveness of mammography and ultrasound, they found that if ultrasound was performed following mammography for all women with dense breasts, it would prevent about four breast cancer deaths in every 10,000 women. It also would result in 3,500 extra biopsies in women who would end up not having breast cancer.

Cost-effectiveness, the researchers said, could be improved by restricting such screening to women with extremely dense breasts, based on a breast density scale that runs from 1 to 4, with 4 being the most dense.

“The balance of benefits and harms is one issue,” said Brian Sprague, assistant professor of surgery at the University of Vermont College of Medicine who led the analysis. “If we’re deciding which strategies we want to use to produce the greatest benefit in breast cancer screening, it’s helpful to find out how much it costs.”

The cost of a digital mammography screen was $138 based on the 2013 Medicare reimbursement rate. Because screening ultrasound doesn’t have a specific reimbursement rate, the researchers used the reimbursement rate for diagnostic breast ultrasound, which is $100.

“Providing notification and advising women to discuss [the option] with their health care provider is not in itself going to solve the problem,” Sprague said. “I hope our study will highlight some of limitations of existing options and show we really need to do better to identify alternative strategies that can offer benefits with less harm.”

One strategy may lie in three-dimensional mammography, or digital breast tomosynthesis, which Sprague and his colleagues are currently studying.

Earlier this month, researchers from Norway presented the findings of a large study, involving data from more than 25,000 women, showing that tomosynthesis – when used with mammography — has the potential to significantly increase the breast cancer detection rate in women with dense breasts.