Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How often should women get mammograms?

22.02.2005


New mathematical model predicts live-saving benefits of different screening schedules



Researchers at Dana-Farber Cancer Institute in Boston have devised a mathematical tool that predicts how the frequency of mammograms affects the number of lives saved by detecting breast cancers at an earlier stage. With screening guidelines and financial coverage varying among health systems and insurers – sometimes dramatically – the model provides quantitative predictions of the mortality benefits, on average, in populations of women over the course of 40 years.

"We’re not advocating any particular interval for mammography screening," says Sandra Lee, ScD, a biostatistician at Dana-Farber who developed the model along with Marvin Zelen, PhD, of Dana-Farber and the Harvard School of Public Health. "This is a preliminary tool to show policymakers the kind of information they can draw on to help them make decisions."


Lee will describe the development of the mathematical model, which made use of data from several past clinical trials of mammography screening and from cancer databases, in a presentation at the annual meeting of the American Association for the Advancement of Science on Sunday, Feb. 20, 8:30 am (Marriott Wardman Park Hotel, Lobby Level, Maryland Suite C). She also will present that data at a press briefing later that day at 2 pm (Marriott Wardman Park Hotel, Mezzanine Level).

The mathematical tool generates comparative information that’s impossible to obtain in the real world, say the scientists, because clinical trials would require hundreds of thousands of volunteers following a variety of schedules over many years to demonstrate small mortality differences – and would be prohibitively expensive. Moreover, adds Lee, such trials would be ethically questionable because of the need for unscreened control groups.

At present, American Cancer Society guidelines recommend that women age 40 and older have a screening mammogram every year and that they "should continue to do so for as long as they are in good health."

But payors differ in their coverage for the tests: in Great Britain, said Zelen, the National Health System pays for mammograms only at three-year intervals and doesn’t cover any screening whatsoever for women younger than 50, when the incidence of breast cancer is lower and mammograms are effective.

The model can be helpful to women, he said, by eliminating unnecessary screening exams when the chance of detecting an unknown breast cancer is too low to warrant them. "It’s clear that the more mammograms you give, the more able you are to locate disease that a person didn’t know about," Zelen says. But, testing with increasing frequency has diminishing returns, while boosting the odds of "false positives" that can be traumatic to women and lead to unneeded biopsies that drive up health costs.

Lee and Zelen, along with Hui Huang, MS, of Dana-Farber, described the model in 2004 in Statistical Methods in Medical Research. Among their conclusions:

  • Annual screening from age 50 to 79 of women with average breast cancer risk would reduce mortality by 37 percent – compared to 30 percent with screenings every two years, and 26 percent with mammograms every three years.
  • Beginning mammograms at age 40 – when breast cancer risk is low – rather than at 50, reduces overall risk of death by five percent because the incidence of cancer in the younger women is very low. However, Zelen said he believes screening women between 40 and 50 has merit because their breast cancers are more aggressive.
  • If women underwent mammograms every two years beginning at 40 and then annually starting at 50, there would still be a 33 percent reduction in mortality.
  • Because breast cancer risk increases with age, an alternative screening schedule derived from the model calls for fewer mammograms at early ages, but increasingly often later on. This "threshold" method provides for 18 screenings between 40 and 79, and predicts a mortality reduction of 26 percent.

Women who have a higher breast cancer risk because of their family history are advised to begin mammography at an early age. Using the model, say the researchers, health care providers can determine when to schedule mammograms depending on the amount of a woman’s extra risk.

The model also provides estimates of the relative costs incurred by screening populations of women at greater or lesser intervals – an important issue for health policymakers.

Richard Saltus | EurekAlert!
Further information:
http://www.danafarber.org

More articles from Health and Medicine:

nachricht TSRI researchers develop new method to 'fingerprint' HIV
29.03.2017 | Scripps Research Institute

nachricht Periodic ventilation keeps more pollen out than tilted-open windows
29.03.2017 | Technische Universität München

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: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

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...

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

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>