If you’re in your 40s, you may want to consider switching from digital mammography to digital breast tomosynthesis (DBT) for your next breast cancer screening, say the authors of a study published online February 28 by JAMA Oncology.
A review of more than 170,000 screening mammograms using the two technologies determined that DBT — sometimes referred to as 3D mammography — did a better job at accurately detecting cancers in women of all ages. The advantages were most pronounced for women in their 40s. DBT was also better at finding cancers in women with high breast density, which can make cancers more difficult to spot on screening exams. High density indicates a larger proportion of active tissue in the breast and is a risk factor for breast cancer.
“This study contributes to what is already a fair amount of evidence that shows, particularly for younger women and women who have denser breasts, that DBT is probably a better screening test,” says Dr. Jennifer Haas, one of the study’s authors and a professor of medicine at Harvard Medical School.
A new technology
DBT is a relatively new technology, approved by the FDA in 2011. It works by taking a series of images, which a computer then assembles into a 3D-like image of breast slices. Traditional digital mammography creates a two-dimensional image of a flattened breast, and the radiologist must peer through the layers to find abnormalities.
The study authors compared the two technologies using more than 50,000 breast screenings performed with DBT and 129,369 performed with digital mammography. The data represented more than 96,000 women (average age 54 to 56) screened at three different research centers from 2011 to 2014.
The study’s strengths are the large sample size and how it was designed to measure the experience of women in real clinical practice, says Dr. Haas.
“In contrast to participants in a clinical trial, this study examined the outcomes of women receiving care in a variety of clinical practices. It represents a group of women who are typical of those who get annual mammographic screenings,” she says.
Study authors found that DBT produced higher cancer detection rates and fewer unnecessary callbacks in women of all ages. But the technology performed particularly well on women in their 40s. In this group, DBT found 1.7 more cancers than digital mammography for every 1,000 exams of women with normal breast tissue. In addition, 16.3% of women in this age group who were screened using digital mammography received callbacks, versus 11.7% of those screened using DBT. For younger women with dense breasts, the advantage of DBT was even greater: 2.27 more cancers were found for every 1,000 women screened.
Women with high breast density have long represented a challenge for radiologists. Dense tissue and cancers both show up as white areas on screening mammograms, making it difficult for the radiologist reading the exam to distinguish between normal and abnormal tissue. Some radiologists have described looking for cancer on these images as trying to find a polar bear in a snowstorm.
DBT also outperformed digital mammography when it came to finding smaller cancers. When those smaller cancers were an invasive type, the cancers found by DBT were less likely to have already spread to neighboring lymph nodes. This was especially true for invasive cancers found in women ages 40 to 49.
It seems likely that finding an invasive cancer before it spreads will mean a better long-term prognosis. But more research is needed to confirm this theory and to determine whether DBT produces better breast cancer outcomes than screening with digital mammography.
|Does DBT shift the risk-benefit ratio for younger women?There has been controversy in recent years about the right age for women to start breast cancer screening. While the American College of Radiology and the Society of Breast Imaging say that screening should start at age 40, the American Cancer Society recommends starting at age 45, and the U.S. Preventive Services Task Force suggests age 50.Some experts suggest delaying the start of screening beyond age 40 because younger women are more likely to experience a callback for additional testing for findings that are later determined to not be cancerous. These callbacks not only provoke anxiety for women, but also result in unnecessary procedures (including biopsies) and costs. Some organizations concluded that the risks of false-positive results outweigh the benefits of screening for younger women, because breast cancer is less common in this group.However, a new study (see main article) may change that discussion. Because DBT appears to reduce the number of false positives that lead to unnecessary testing, the drawbacks of screening at younger ages may no longer outweigh the benefits, according to an editorial that accompanied the study.|
Should you change to DBT?
While this study adds to the body of evidence regarding the potential value of DBT, it probably won’t change national screening recommendations, says Dr. Haas. Any changes will likely be made after a large-scale trial called the Tomosynthesis Mammographic Imaging Screening Trial (TMIST) is complete. The trial, which is funded by the National Cancer Institute, is comparing screening outcomes in women who are randomly assigned to either digital mammography or DBT.
However, while more information on DBT is pending, this study provides enough evidence that some women, particularly younger women, may want to talk to their doctor about the potential advantages of DBT screening.
There are few disadvantages of using DBT, according to Dr. Haas. Historically there were concerns that DBT exposed women to a slightly larger amount of radiation than digital mammography. “This was the case because DBT was new, and experts recommended an additional view to facilitate comparison to digital mammography,” says Dr. Haas. Today, that additional image is typically not done, so the difference in radiation dose has largely been eliminated, she says.
A dose of caution
However, DBT may not be available to all women. It’s expensive for screening mammography sites to convert to DBT, so while women in major metropolitan areas can likely find a site with the technology, women in smaller towns or rural locations may not have the option. Despite the cost of the technology, the out-of-pocket cost of a DBT or digital mammography exam will likely be the same for most women, but costs could vary in some cases, says Dr. Haas.
While there is evidence that DBT may be better than digital mammography, keep in mind it’s still not a perfect test.
“It can still miss cancers,” says Dr. Haas. Also, like traditional mammography, DBT might not reduce deaths from tumors that are very aggressive and fast-growing. And some women will still be called back unnecessarily for false-positive results.
Below are spiritual recipe for health and wellness: Matthew E. McLaren
Psalm 27:1 “The LORD is my light and my salvation; whom shall I fear? The LORD is the strength of my life; of whom shall I be afraid?”
Psalm 37:39 “But the salvation of the righteous is from the LORD; He is their strength in time of trouble.”
Psalm 138:3 “In the day when I cried out, You answered me, and made me bold with strength in my soul.”
Matthew 19:26 “But Jesus looked at them and said to them, ‘With men this is impossible, but with God all things are possible.’”
2 Corinthians 4:16 “Therefore we do not lose heart. Even though our outward man is perishing, yet the inward man is being renewed day by day.”
Philippians 4:13 “I can do all things through Christ who strengthens me.”
2 Timothy 1:7 “For God has not given us a spirit of fear, but of power and of love and of a sound mind.”
Psalm 8:2 “Out of the mouth of babes and nursing infants You have ordained strength, because of Your enemies, that You may silence the enemy and the avenger.”
Psalm 18:1-2 “I will love You, O LORD, my strength. The LORD is my rock and my fortress and my deliverer; my God, my strength, in whom I will trust; my shield and the horn of my salvation, my stronghold.”
Psalm 18:32 “It is God who arms me with strength, and makes my way perfect.”
Psalm 19:14 “Let the words of my mouth and the meditation of my heart be acceptable in Your sight, O LORD, my strength and my Redeemer.”
Psalm 22:19 “But You, O LORD, do not be far from Me; O My Strength, hasten to help Me!”
Psalm 28:7-8 “The LORD is my strength and my shield; my heart trusted in Him, and I am helped; therefore my heart greatly rejoices, and with my song I will praise Him. The LORD is their strength, and He is the saving refuge of His anointed.”
Psalm 29:11 “The LORD will give strength to His people; the LORD will bless His people with peace.”
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