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CHICAGO -- Researchers say a device to standardize the pressure applied during mammography could cut the pain of breast compression, while another group of researchers here found that risk-based screening for women in their 40s likely misses 75% of tumors in that age group.

A third study also presented at the Radiological Society of North America meeting suggested adding a 3-dimensional view to digital mammography would help with detection in dense or fatty breasts.

Pressure-Control Device

While mammography requires breast compression to enhance image quality and minimize radiation absorption, too much causes pain that deters some women from getting screened at all (more common in Europe, especially for women with small breasts) and too little risks an unreadable image (more common in the United States).

, of the Academic Medical Center in Amsterdam and its spin-off company SigmaScreen, and colleagues developed a device to tackle both problems.

Whereas mammography machines typically only display the compression force, theirs shows the actual pressure on the breast during compression by accounting for over how much area the force is applied.

"Depending on the individual technician, the compression force is typically adjusted to breast size, composition, skin tautness and pain tolerance," Branderhorst's group pointed out.

And that has led to a big variation in practice of anywhere from less than 3 kPa to more than 30 kPa, based on a prior study.

Targeting a standardized pressure had no impact on the image quality and a minor increase in the proportion of retakes required (4.2% versus 1.4%, 95% confidence interval 0.4%-4.4%).

But the pain scores were lower with pressure-controlled compression, 10% lower by one measure and 24% by another (P<0.001). Reports of severe pain were 27% to 46% less common than when considering force alone in compression (P<0.001).

The trial randomized 433 asymptomatic women scheduled for screening mammography to get three of their four compressions at a target force standardized to 14 daN and one standardized to a target pressure of 10 kPa in a double-blind fashion.

"For the millions of mammograms obtained yearly this study shows that a large amount of unnecessary pain can be avoided without adversely affecting radiation dose or the proportion of required retakes," Branderhort's group concluded.

Risk-Based Screening in 40s

More than three-quarters of women with breast cancer diagnosed at age 40 to 49 had neither a strong enough family history or breasts dense enough to meet criteria , a single-center study showed.

That approach isn't a safe strategy, unless screening can be targeted more effectively, according to senior author , chief of women's imaging at the University of California San Francisco.

"Notably, we found that almost 90% of the invasive cancers we would have missed using risk-based triage had positive receptor status, meaning they were very treatable and worth finding early," Joe said in a statement.

The retrospective study included all cancers detected by screening mammography among women ages 40 to 49 at a single institution from January 1997 through November 2012.

Among the 194 cancers in the analysis, 53% were invasive cancer (23% with axillae nodal involvement) and 47% were ductal carcinoma in situ (88% intermediate or high grade).

A strong family history -- one first degree relative with breast cancer before age 50 or at least two first degree relatives with breast cancer -- was absent in 90% of the women with cancer in their 40s; 86% didn't have extremely dense breasts (BI-RADS category 4).

Altogether, 78% of the women had neither of these risk factors, a group which accounted for 79% of the cases of invasive disease.

Women with a prior history of breast cancer and those who had been seen for diagnostic mammography due to symptoms were excluded, as were women screened at other centers and then transferred for care.

3D Mammography

One way to improve detection could be adding tomosynthesis to standard digital mammography, according to a study by Per Skaane, MD, of Oslo University Hospital, and colleagues.

In their population-based study of 25,547 women ages of 50 and 69 getting full-field digital mammography alone or with a digital 3D view in Norway, tomosynthesis boosted breast cancer detection by about 30% overall.

Mammography with the 3D view detected 80% of the 132 diagnostically-confirmed cancer cases in women with dense breasts, compared with only 59% using mammography alone.

Considering only invasive cancers, the relative increase in cancer detection was about 40%, Skaane reported.

The 3D view also helped increase detection for women in the "fatty breast" BI-RADS categories (density 1 or 2). It boosted the cancer detection rate to 84% compared with 68% using mammography alone, although all that advantage accrued in the BI-RADS 2 subgroup.

The analysis included two of the trial's four arms (the others offered full-field digital mammography with computer-aided detection and synthetic 2D mammography alone, respectively).