Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

For many, mammography every other year has benefits of annual screening, but less harm

17.11.2009
Conclusion represents unanimous consensus of 6 independent research groups from various academic institutions

A comprehensive analysis of various mammography screening schedules suggests that biennial (every two years) screening of average risk women between the ages of 50 and 74 achieves most of the benefits of annual screening, but with less harm. The results represent a unanimous consensus of six independent research groups from various academic institutions. Their findings are published in the November 17, 2009 Annals of Internal Medicine.

Researchers from CISNET, the NCI-funded Cancer Intervention and Surveillance Modeling Network, used independent models to examine 20 screening strategies with different starting and stopping ages and intervals. Modeling estimates the lifetime impact (outcomes including benefits and harms) of breast cancer screening mammography. The CISNET models link known data across the course of life and include national data on age-specific breast cancer incidence, mortality, mammography characteristics and treatment effects.

"It's reassuring that all CISNET modeling groups came to the same conclusion even when applying different models to these data," says the paper's lead author, Jeanne S. Mandelblatt, MD, MPH, of Georgetown Lombardi Comprehensive Cancer Center, a CISNET member. "While the findings represent a comprehensive review of existing data, decisions about the best screening strategy depend on individual and public health goals, resources, and tolerance for false-positive mammograms, unnecessary biopsies and over-diagnosis."

The CISNET analysis shows that screening every other year maintains almost all of the benefit (an average of 81 percent) of annual screening with almost half the number of false-positives. Compared with no screening, mammography screening every other year from ages 50 to 69 achieves a median reduction in breast cancer mortality of 16.5 percent over a life time. If screening is started at age 40 versus 50 and performed every other year, there is a median mortality reduction of 19.5 percent (an additional 1 woman per 1000), but an increase in false-positives, unnecessary biopsies, and anxiety.

"False-positives" represent mammograms read as abnormal that often require further follow-up in women who are found to not have cancer. An "unnecessary biopsy" occurs after a false positive mammogram when the biopsy is normal. "Over-diagnosis" is the detection of a cancer through screening that otherwise never would have produced symptoms or affected the woman's health. Since usually it is not possible to determine which cancers will progress, almost all cancers detected during screening are treated.

Mandelblatt says the benefits of biennial screening are consistent with what is known about the breast cancer's biology. In the majority of women, most tumors are slow growing and this proportion increases with age, so that there is little loss in survival benefit across the population for screening every year versus every other year. For women with aggressive, faster growing tumors, annual screening is not likely to make a difference in survival. For these women, different approaches may be needed and is an important area of on-going research.

While the model results confirmed that mammography saves lives, Mandelblatt explains that there are smaller overall benefits from starting screening earlier than age 50 because few women develop breast cancer in the younger age groups, and screening younger women is accompanied by a large number of false-positive mammograms. "This can lead to stress for women and unnecessary biopsies. We need more research to understand how to tailor screening by individual risk," she says.

"These modeling data represent an average finding regarding the population of women so it can't be emphasized enough that women need to talk to their health care provider for a screening program that is best for them," Mandelblatt concludes.

The CISNET analysis was one of many sources of evidence that the U.S. Preventive Services Task Force (an independent scientific panel convened by the Agency for Healthcare Research and Quality) relied upon in developing the new mammography screening guidelines announced today.

The CISNET study was supported by funding from the National Cancer Institute. The authors report no potential financial conflicts.

In addition to Mandelblatt, authors include: Kathy Cronin and Eric Feuer of the National Cancer Institute; Donald Berry, Mark Munsell, Peter Ravdin and John Venier of the University of Texas MD Anderson Cancer Center; Harry J. de Koning, Gerrit Draisma and Nicolien van Ravesteyn of the Department of Public Health, Rotterdam, the Netherlands; Hui Huang of the Dana-Farber Cancer Institute; Sandra Lee and Marvin Zelen are in the Dana-Farber Cancer Institute and Harvard School of Public Health; Sylvia Plevritis, Bronislava Sigal and Stephanie Bailey of Stanford University; Clyde Schechter of the Albert Einstein College of Medicine; Michael Stoto of Georgetown University Medical Center; Natasha Stout of Harvard Medical School and Harvard Pilgrim Health Care.

About Lombardi Comprehensive Cancer Center

The Lombardi Comprehensive Cancer Center, part of Georgetown University Medical Center and Georgetown University Hospital, seeks to improve the diagnosis, treatment, and prevention of cancer through innovative basic and clinical research, patient care, community education and outreach, and the training of cancer specialists of the future. Lombardi is one of only 41 comprehensive cancer centers in the nation, as designated by the National Cancer Institute, and the only one in the Washington, DC, area. For more information, go to http://lombardi.georgetown.edu.

About Georgetown University Medical Center

Georgetown University Medical Center is an internationally recognized academic medical center with a three-part mission of research, teaching and patient care (through Georgetown's affiliation with MedStar Health). GUMC's mission is carried out with a strong emphasis on public service and a dedication to the Catholic, Jesuit principle of cura personalis -- or "care of the whole person." The Medical Center includes the School of Medicine and the School of Nursing and Health Studies, both nationally ranked, the world-renowned Lombardi Comprehensive Cancer Center and the Biomedical Graduate Research Organization (BGRO), home to 60 percent of the university's sponsored research funding.

National Cancer Institute

NCI leads the National Cancer Program and the NIH effort to dramatically reduce the burden of cancer and improve the lives of cancer patients and their families, through research into prevention and cancer biology, the development of new interventions, and the training and mentoring of new researchers. More information about cancer, screening, and prevention is available on the NCI Web site at http://www.cancer.gov or from NCI's Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).

Karen Mallet | EurekAlert!
Further information:
http://www.georgetown.edu
http://www.cancer.gov

More articles from Health and Medicine:

nachricht The end of pneumonia? New vaccine offers hope
23.10.2017 | University at Buffalo

nachricht Scientists track ovarian cancers to site of origin: Fallopian tubes
23.10.2017 | Johns Hopkins Medicine

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: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>