Adding 3-D Mammography or Ultrasound to Regular Screening Finds More Cancers in Dense Breasts

Dense breasts have less fatty tissue and more non-fatty tissue compared to breasts that aren’t dense.

One way to measure breast density is the thickness of tissue on a mammogram. The BI-RADS (Breast Imaging Reporting and Database System), which reports the findings of mammograms, also includes information on breast density. Still, no one method of measuring breast density has been agreed upon by doctors. Breast density is not based on how your breasts feel during your self-exam or your doctor’s physical exam. Dense breasts have more gland tissue that makes and drains milk and supportive tissue (also called stroma) that surrounds the gland. Breast density can be inherited, so if your mother has dense breasts, it’s likely you will, too.

Research has shown that dense breasts:

  • can be 6 times more likely to develop cancer
  • can make it harder for mammograms to detect breast cancer; breast cancers (which look white like breast gland tissue) are easier to see on a mammogram when they’re surrounded by fatty tissue (which looks dark).

About 43% of women ages 40 to 74 years old in the United States are classified as having dense breasts.

As of September 2015, 24 states have passed legislation requiring that women be notified of their breast density with mammography results.

Because mammograms don’t always find cancers in dense breasts, researchers have been studying the effectiveness other screening methods for dense breasts.

A study has found that adding 3-D mammography (also called digital tomosynthesis) or breast ultrasound to regular screening mammograms can detect more cancers in dense breasts. Ultrasound was slightly better at detecting cancers in dense breasts than 3-D mammography and both screening methods had similar false-positive rates.

The study was published online on March 9, 2016 by the Journal of Clinical Oncology. Read the abstract of “Adjunct Screening With Tomosynthesis or Ultrasound in Women With Mammography-Negative Dense Breasts: Interim Report of a Prospective Comparative Trial.”

The study also was presented on March 9, 2016 at the 2016 European Breast Cancer Conference. Read the abstract of “Interim results of the Adjunct Screening with Tomosynthesis or Ultrasound in Mammography-negative Dense Breasts (ASTOUND) trial.”

The ASTOUND study was started in December 2012 and included 3,231 women with breasts classified by BI-RADS as either consistently dense or extremely dense. The women were 44 to 78 years old, and screening mammograms had found no cancer in their breasts.

After their last regular screening mammogram, the women also had a 3-D mammogram and breast ultrasound. The 3-D mammograms and ultrasounds were read by different radiologists who knew that the standard screening mammogram had found no cancer, but didn’t know the result of the other additional screening test.

The additional screening tests found 24 breast cancers:

  • 12 were detected by both 3-D mammogram and ultrasound
  • one was detected only by 3-D mammogram
  • 11 were detected only by ultrasound

“These results mean that tomosynthesis detected an additional four breast cancers per 1,000 women screened and ultrasound detected an additional seven breast cancers per 1,000,” said Dr. Nehmat Houssami, professor of public health at the University of Sydney, who presented the study at the European Breast Cancer Conference.

There were 107 false-positive results:

  • 53 for 3-D mammograms
  • 65 for ultrasound

This difference wasn’t statistically significant, which means that it was likely due to chance and not because of the difference in screening methods.

In an editorial in the Journal of Clinical Oncology that ran with the paper, Wendie Berg, M.D., of the Magee Women’s Hospital at the University of Pittsburgh Medical Center, wrote that a high false-positive rate is why many doctors have been reluctant to use ultrasound for breast cancer screening. The ASTOUND study may start to change that.

“Importantly, in preliminary results from the ASTOUND trial, false-positive recalls (2.0%) and biopsies (0.7%) were acceptably low,” Dr. Berg wrote.

“…Our study does not provide all the answers on this issue but provides the first critical piece of information on how these two tests compare,” Dr. Houssami added. “If a woman is concerned that her breasts are very dense on the mammogram (or has been told her breasts are very dense and would like more testing), I can use the data from ASTOUND to discuss with her the option of having the ultrasound or the tomosynthesis screen; I would discuss with her the pros and cons of adding another test to improve sensitivity for detecting cancer, but would also point out this could have additional harms such as more false alarms.”

Bottom line: For women with dense breasts, the addition of 3D mammography or bilateral whole breast ultrasound improves the early detection of breast cancer.

About the author: Raja P. Reddy, MD is a board certified diagnostic radiologist specializing in breast imaging. He is also a contributing editor for Women’s Imaging Specialists, a leading provider of outpatient women’s imaging services in the greater Atlanta, GA area.


Adding 3-D Whole Breast Ultrasound to Mammography Improves Detection of Breast Cancer!

Women with dense (less fatty) breast tissue represent 40 percent of all U.S. women, and they are four to six times more likely to develop breast cancer than women with non-dense breast tissue. Cancers in these women are also more likely to go undetected after having a mammogram.

A recent study published in the American Journal of Roentgenology, conclude that for women with dense breast tissue, combining mammography with a 3-D automated breast ultrasound system can improve the detection of breast cancer by 29 percent.

The study analyzed the performance of 17 radiologists in their detection of breast cancer using full-field digital mammography only versus full-field digital mammography followed by 3-D automated breast ultrasound.

The radiologists looked at 185 cases collected from prior clinical studies in which both imaging methodologies had been used. Out of the 52 cases in which cancer was identified, 31 had been interpreted in the prior clinical studies as negative for cancer on the mammogram.

When comparing the mammogram and 3-D ultrasound results to results from the mammogram only, the radiologists enhanced their ability to detect cancer by what the study’s researchers termed a “statistically significant relative improvement.”

“The improved detection in nearly a third of women with dense breasts is significant because it means those are cancers that might not have been found until it became more apparent on a mammogram,” Giger said. “And by the time they were discovered, the cancer might have been at a more advanced stage.

“The takeaway here is women with dense breasts should augment traditional mammographic screening with another type of imaging modality, such as 3-D ultrasound (or MRI), in order to avoid missing cancerous lesions,” Giger added.

Giger is the A.N. Pritzker Professor of Radiology for the Committee on Medical Physics and the College at the University of Chicago, as well as the vice-chair for Basic Science Research in the Department of Radiology. She is a member of the National Academy of Engineering and is considered one of the pioneers in the development of computer-aided diagnosis, authoring or co-authoring more than 300 scientific manuscripts. She also is the inventor/co-inventor of 25 patents, and serves as a reviewer for various national and international granting agencies, including the National Institutes of Health and the U.S. Army. In the breast cancer study, she served as an independent evaluator for the Food and Drug Administration’s approval of the Automated Breast Ultrasound System from GE Healthcare.

Bottom line: For women with dense breasts, the addition of 3D bilateral whole breast ultrasound improves the early detection of breast cancer.

About the author: Raja P. Reddy, MD is a board certified diagnostic radiologist specializing in breast imaging. He is also a contributing editor for Women’s Imaging Specialists, a leading provider of outpatient women’s imaging services in the greater Atlanta, GA area.


Half of Women Can Benefit from Mammography at Age 40.

A new study shows that women at the age of 40 should undergo a mammogram, as nearly half of them would benefit from the breast cancer screening. For the review, the researchers found that half of the women aged 40 to 44 had above average risk for breast cancer, which made them eligible for yearly screenings.

The findings presented at the American Society of Breast Surgeons annual meeting in Dallas is important because the latest guidelines on mammograms advise that most women can wait until the age of 45 or 50 to start having annual screenings.

But the review of female patients between the ages of 40 and 44 found that 50 percent had an above-average risk for breast cancer, and therefore would be eligible to begin screening mammography at age 40, said lead researcher Dr. Jennifer Plichta. The study also found a significant percentage of women would qualify for other breast screening methods, including breast MRI and genetic testing, Plichta said. “We believe formal risk assessment is essential for women ages 40 to 44 in order to identify those who require screening mammography to start at the age of 40, and those who would qualify for screening MRIs and genetic testing,” Plichta said.

The cancer society updated its guidelines in 2015, recommending that women could wait until age 45 to start receiving annual mammograms. Previously, the cancer society had recommended yearly screenings starting at age 40. The American Society of Breast Surgeons (ASBS) subsequently changed its guidelines to mirror the new cancer society recommendation, Plichta said. The American Society of Breast Surgeons (ASBS) also updated their guidelines with a few more details, which included:

  • Women should have mammograms prior to 45 years of age if their risk of developing breast cancer exceeds 15 percent.
  • Women with 20 percent or higher should also undergo MRI.
  • Women with at least a five-percent risk of a breast cancer-related genetic mutation should undergo genetic testing.

 

“Critical to the development and interpretation of both of these new guidelines is formal risk assessment,” Plichta said. “Furthermore, risk assessment is needed not only to determine who qualifies for mammography, but also who may require screening MRIs and/or genetic testing.”

Breast cancer risk assessments are typically not a part of standard care for this age group, the researchers noted. Since the new guidelines lean heavily on knowing breast cancer risk, doctors need to redouble their efforts to make sure risk assessments are done for women in their early 40s, they concluded.

Bottom line: Given that more than half of women between the ages of 40-45 had risk factors for breast cancer, mammogram screenings should begin at age 40, rather than age 45 or 50. Risk assessment is the best way to determine who would benefit from mammography screening at age 40.

About the author: Raja P. Reddy, MD is a board certified diagnostic radiologist specializing in breast imaging. He is also a contributing editor for Women’s Imaging Specialists, a leading provider of outpatient women’s imaging services in the greater Atlanta, GA area.


Never Too Old for a Mammogram?

You are never too old to get a mammogram. According to a new study presented at RSNA 2016 in Chicago, researchers from the University of California, San Francisco (UCSF) found that women between the ages of 75 and 90 continue to benefit from screening.

Lee’s group used data from the National Mammography Database, evaluating more than 5.6 million screening mammograms performed between January 2008 and December 2014. The exams were done at 150 facilities across 31 U.S. states. Lee and her colleagues looked at patient age, mammogram results, recall rates for more testing, biopsy referrals and biopsy results. The investigators also looked at the percentage of breast cancers found when a biopsy was recommended or performed. Ideally, Lee explained, screening should result in a higher cancer detection rate and a low recall rate.

Based on an analysis of nearly 7 million mammograms over a seven-year period, “the benefit continues with increasing age up until 90,” said study author Dr. Cindy Lee. She is an assistant professor in residence at the University of California, San Francisco.

The question of when to stop having mammograms has been widely debated. In 2009, the U.S. Preventive Services Task Force issued new guidelines, saying there wasn’t enough evidence to assess the balance of benefits and harms of screening mammography in women aged 75 and older.

In the analysis, which included data from 39 states from 2008 through 2014, nearly four breast cancers were found for every 1,000 patients screened. The recall rate was 10 percent.

“We are finding more cancers with increasing age,” Lee said, which makes sense because the risk rises with age. “We are doing better at catching them,” she said. And, “we have decreased the recall rate. We are calling back fewer women for additional testing, but are finding more cancers.”

The study authors concluded that “there is no clear age cut-off point” to determine when to stop screening. The study suggests the decision to screen may depend on a woman’s personal choice and health status. Older women with 10 years of life expectancy, for instance, might choose to continue screening, Lee said.

Robert Smith, vice president of screening for the American Cancer Society, said the study findings show that mammograms are still worthwhile after the age of 70.

“Breast cancer incidence and mortality increase as women age, and roughly 30 percent of breast cancer deaths each year occur in women who were diagnosed after the age of 70,” he said.

“Many of these deaths are avoidable, as Lee and colleagues demonstrate in this new report, since mammography screening performs increasingly well as women get older. While incidence is high, the disease is slower growing and density is lower, providing improved opportunity for early detection,” Smith explained.

Bottom line: Older women can benefit from continued mammography screening and no age should be defined as the cut-off for screening. As always, the choice to continue screening should be a shared decision between the patient and her physician.

About the author: Raja P. Reddy, MD is a board certified diagnostic radiologist specializing in breast imaging. He is also a contributing editor for Women’s Imaging Specialists, a leading provider of outpatient women’s imaging services in the greater Atlanta, GA area.