WASHINGTON (AP) – A better mammogram? Increasingly, women are being asked if they want a 3-D mammogram instead of regular radiography, and now US health officials. UU They are starting a large study to determine whether the newer and sometimes more expensive choice really improves the detection of breast cancer.
It is the last dilemma in a field that already irritates women with contradictory guidelines on when to control: from 40, 45 or 50 years? Annually or every two years?
The problem: mammograms can save lives if they detect aggressive breast cancers early. But they can also cause damage through frequent false alarms and detect tumors that grow so slowly that they would never have posed a threat: an overdiagnosis means that some women undergo unnecessary treatment.
That compromise is a key issue as doctors begin recruiting 165,000 women nationwide to compare potentially beneficial 3-D mammograms, known scientifically as "tomosynthesis," with standard two-dimensional digital mammography.
Related: New report questions Value of mammograms
3-D mammograms have been marketed as being able to find more cancers.
"But the idea is not so much to find more cancers but to find life-threatening cancers," said Dr. Worta McCaskill-Stevens of the National Cancer Institute, which is funding new research to tell whether truly three-dimensional scans identify the tumors that matter most.
It's one of the largest randomized trials of mammography in decades, and scientists designed the research to do more than answer that key question in 3-D. They hope that the findings will also, eventually, help to clear up some of the confusion surrounding the best evaluation practices.
"The most important thing in this study is that it is moving us to an individualized screening compared to what we have now, which is a unique test for all," predicted the study's president, Dr. Etta Pisano, radiologist Beth Israel Deaconess Medical Center of Boston.
"We're going to have a better understanding of how to evaluate women so that we do the least amount of harm."
WHO NEEDS A MAMMOGRAPHY?
That depends on who you ask. The guidelines vary for women at average risk of breast cancer. (Those at higher risk, due to family or genetic background, already receive different advice.)
The American College of Radiology recommends annual mammograms starting at age 40.
The American Cancer Society urges annual check-ups starting at age 45 and changing every two years to 55, although it says that women ages 40 to 44 can still opt for a mammogram.
And the US Preventive Services Task Force. UU., A government advisory group, recommends starting at age 50, with mammograms every two years. It also says that people over 40 can choose an earlier evaluation.
WHAT HAPPENS WITH 3-D MAMMOGRAMS?
Standard mammograms take x-rays of both sides of the breast. With tomosynthesis, additional x-rays are taken at different angles, not truly three-dimensional, but a computer compiles them into an image similar to 3-D. Approved for the first time by the Food and Drug Administration in 2011, they are still not the standard of care in part due to the questions that the new study aims to answer.
Some studies have found that tomosynthesis detects more cancer with fewer false alarms; They are often advertised as particularly useful for the dense breasts of younger women.
HOW TO DECIDE?
Understand that mammograms include pros and cons and weigh them, said Dr. Otis Brawley, medical director of the American Cancer Society.
Breast cancer is much less common at age 40 than at age 50 or older. After menopause, tumors tend to grow more slowly and women's breast tissue becomes less dense and easier for mammograms to provide a clearer picture.
Consider: for every 1,000 women evaluated every two years until age 70, starting at 40 instead of 50 would avoid an additional death, but it would create 576 false alarms and 58 unnecessary additional biopsies, the team estimated. In addition, two additional women would be treated for tumors that would never have become life-threatening: that overdiagnosis problem.
As to which type to choose, some insurers, including Medicare, cover the 3-D version, and a small number of states require coverage. Other insurers may demand that women pay $ 50 to $ 100 more out of pocket. Who finally pays, the additional time to analyze the scans increases the cost.
THE NEW STUDY
About 100 mammography clinics in the USA. UU And some in Canada will enroll healthy women ages 45 to 74 who are already planning to have a routine mammogram. They will be randomly assigned to obtain the regular or 3-D version for five years. Most will be examined annually, but postmenopausal women who do not have certain cancer risk factors will be evaluated every two years.
Researchers will track the results of all women, including biopsy samples plus genetic and other tests, as well as the evolution of cancer patients. The lucky database will hopefully help you get more information about which women benefit most from what type and frequency of screening.
"Mammography has been provocative for many decades, and it's important for women to better understand how mammography is important to them based on their age and other risk factors," said McCaskill-Stevens.
This Associated Press series was produced in association with the Department of Scientific Education of the Howard Hughes Medical Institute. The AP is solely responsible for all content.