Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fewer false alarms when mammographers have greater experience screening healthy breasts

02.03.2005


Physicians who specialize in screening mammography and who have at least 25 years of experience are more accurate at interpreting the images and subject fewer women to the anxiety of false positives for cancer, when compared to physicians with less experience or those who don’t have the same focus, according to a new study. The research was led by a UCSF team and is published in the March 2 issue of the Journal of the National Cancer Institute.

Screening mammograms are the type most women get. These images are designed to discover any cancer that might be hidden in women with no breast symptoms. Women who have a history of breast cancer or other symptoms -- or who experience symptoms at the time of their exam -- receive diagnostic mammograms. After two to five asymptomic years, their physicians will usually revert to screening mammography.

Study findings showed that the more experienced physicians not only properly identified cancer, they also were 50 percent less likely to falsely characterize a mammogram as abnormal. In addition, the study found dramatic variability in physician accuracy. For example, physicians on average detected 77 percent of cancers, but for individual physicians the detection rate ranged from 29-97 percent. The average false positive rate was 10 percent, while the rate for individual physicians ranged from 1-29 percent.



According to the UCSF researchers, it has already been well documented in scientific literature that patient characteristics -- such as breast tissue density -- can be negatively associated with mammogram accuracy and those characteristics largely cannot be changed. They chose, therefore, to focus their study on what physician characteristics could be associated with accuracy. They studied more than 1.2 million mammograms paired with data from statewide cancer registries in four states.

The study found that physicians who read a greater number of mammograms identified cancers without mistaking normal tissue for a malignancy with greater accuracy than physicians whose volume was not as high. In general, the false-positive rate declined with increasing physician age, with increasing time since receipt of medical degree, and with increasing annual volume. Additionally, those physicians who focused their practice on screening, as opposed to diagnostic mammography, had a lower false-positive rate.

Study data came from four sites that participate in the National Cancer Institute- funded Breast Cancer Surveillance Consortium. Those sites -- San Francisco, New Mexico, Vermont and Colorado -- prospectively collect mammographic interpretations. Researchers linked the interpretation data to cancer registries and then to physician information from the American Medical Association. They studied 209 physicians who interpreted 1.2 million mammograms from January 1, 1995 through December 31, 2000 including 7143 that were associated with breast cancer.

The minimum number of mammograms a US physician can read and still be considered qualified under FDA regulations is 960 within a two-year period, or approximately 10 mammograms per week, according to the Mammography Quality Standards Act of 1992.

"Raising the annual volume requirements in the Act might improve the overall quality of screening mammography in the US," said principal investigator Rebecca Smith Bindman, MD, UCSF associate professor of radiology, epidemiology/biostatistics, and obstetrics, gynecology and reproductive sciences. She also is director of the UCSF Radiology Outcomes Research Lab and part of the breast oncology program of the UCSF Comprehensive Cancer Center.

The authors hypothesize that physicians who read more mammograms overall and who have been reading them longer develop a higher threshold for identifying cancer and overall do better. Those who read a higher proportion of diagnostic mammograms, they say, may tend to develop a lower threshold, expecting a higher rate of cancer.

"Compared with those who read the minimum number allowed by the Act and who have less focus on screening, physicians who focus on screening and who interpret 2,500-4,000 mammograms annually have 50 percent fewer false-positive diagnoses while detecting approximately one less cancer per 2,500 mammograms," the authors wrote.

Smith Bindman added, "The variation we found was dramatic. We recommend explicit discussion of what the goals of mammography should be, and sooner rather than later."

If the goal is to maximize the identification of cancer while achieving a reasonable false-positive rate, raising the minimum required under the Act would make sense, according to Smith-Bindman. Although fewer doctors would subsequently be available for reading mammograms, any resulting increased barriers to healthcare delivery could be managed, she said. "Change would need to occur slowly to prevent a shortage of physicians. But the payoff would be fewer false alarms for women."

Eve Harris | EurekAlert!
Further information:
http://www.ucsf.edu

More articles from Health and Medicine:

nachricht Laser activated gold pyramids could deliver drugs, DNA into cells without harm
24.03.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences

nachricht What does congenital Zika syndrome look like?
24.03.2017 | University of California - San Diego

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>