Navigation Links
Probability model estimates proportion of women who survive breast cancer detected through screening
Date:10/24/2011

CHICAGO A model used to estimate breast cancer survival rates found that the probability that a woman with screen-detected breast cancer will avoid a breast cancer death because of screening mammography may be lower than previously thought, according to a report published Online First by Archives of Internal Medicine, one of the JAMA/Archives journals.

"Today, more people are likely to know a cancer survivor than ever before," the authors write. "Between 1971 and 2007, the number of cancer survivors in the United States more than doubled, from 1.5 percent to 4 percent of the population. Breast cancer survivors are particularly common: they now represent approximately 2.5 million, or one-fifth of the current survivor population." The authors also note, however, that although "perhaps the most persuasive messages promoting screening mammography come from women who argue that the test 'saved my life,'" other possibilities for breast cancer survival exist.

H. Gilbert Welch, M.D., M.P.H., and Brittney A. Frankel, both of Dartmouth Institute for Health Policy and Clinical Practice, Hanover, N.H., developed a method to estimate the probability that a woman with screen-detected breast cancer had her life saved because of the screening. The authors used DevCan, the National Cancer Institute's software for analyzing data, to estimate the 10-year risk of diagnosis and the 20-year risk of death. This probability approach also relies on two estimated possibilities for a woman in the general population of the United States: the probability of having breast cancer detected by screening and the probability of avoiding breast cancer mortality (death) because of the screening.

The authors estimated that for a 50-year old woman, the risk of developing breast cancer in the next 10 years is 2,990 per 100,000. In this age group, 64 percent of breast cancers are found by mammography, suggesting that the risk of having a screen-detected breast cancer during the same period is 1,910 per 100,000. The woman's observed 20-year probability of breast cancer death is 990 per 100,000. Assuming that screening mammography has already reduced risk of breast cancer death by 20 percent, the risk of death in the absence of screening would be 1,240 per 100,000, suggesting that the estimated benefit of screening amounted to 250 per 100,000. Therefore, the authors estimate that the probability that a woman with screen-detected breast cancer avoids breast cancer death because of mammography is 13 percent (250/1910).

The probability of the same 50-year-old woman avoiding breast cancer death increases to 17 percent if screening mammography reduces breast cancer mortality by 25 percent; however, probability decreases to 3 percent if screening mammography reduces breast cancer mortality by 5 percent. Similar analyses conducted for women of varying ages all yield probability estimates below 25 percent.

"We considered a range of values: namely, that screening mammography reduces breast cancer mortality anywhere from 5 percent to 25 percent. The values toward the high end (20 to 25 percent) reflect the randomized trial data from more than a quarter century ago," the authors conclude. "Consequently, we believe that readers should focus on the values toward the low end (5 to 10 percent) and recognize that the probability that a woman with screen-detected breast cancer has, in fact, avoided a breast cancer death because of screening mammography is now likely to be well below 10 percent."

(Arch Intern Med. Published online October 24, 2011. doi:10.1001/archinternmed.2011.476. Available pre-embargo to the media at www.jamamedia.org.)

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Invited Commentary: Screening. Simple MessagesSometimes

In an invited commentary, Timothy J. Wilt, M.D., M.P.H., and Melissa R. Partin, Ph.D., both of the Minneapolis Veterans Administration for Chronic Disease Outcomes Research and the University of Minnesota, Minneapolis, note that in their study, Welch and Frankel, "express concerns that overly inflated perceptions of the benefits of mammography may lead to a self-perpetuating cycle of unwarranted demand for screening, overdiagnosis, overtreatment, and a continually growing population of breast cancer survivors who advocate mammography. The demographics of survivorship suggest that their concern is legitimate."

"Preventive health care services like cancer screening can result in tremendous individual and public health benefits by identifying disease at early, more treatable stages or lowering a patient's risk of developing a disease altogether," write Wilt and Partin. However, the authors do caution that, "they do not always provide the expected benefit and cause harms such as overdiagnosis and overtreatment."

"Numerous studies have documented that the strongest predictor of mammography utilization is physician recommendation," the authors write. "Therefore, simple, highly effective and accurate messages can come directly from clinicians."

"In conclusion, a simple science-based message can and should be delivered to many individuals considering early disease detection and treatment," the authors note. "The opportunity and challenge for clinicians is to be that reliable source of information that ensures that our patients are able to make well-informed decisions that incorporate the best evidence into their personal values."

(Arch Intern Med. Published online October 24, 2011. doi:10.1001/archinternmed.2011.509. Available pre-embargo to the media at www.jamamedia.org.)

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.


'/>"/>

Contact: Deborah Kimbell
deborah.g.kimbell@dartmouth.edu
603-650-6694
JAMA and Archives Journals
Source:Eurekalert

Related medicine news :

1. Will my breast cancer spread? Discovery may predict probability of metastasis
2. New online tool predicts probability of death from stroke
3. The probability of surviving nine types of cancer is analyzed
4. BU presents approach to access biorelevant structures by remodeling natural products
5. Researchers get $3 million National Institutes of Health grant for mathematical models of prostate cancer aggressiveness
6. Frazier Rehab, UofL earn $2.2 million grant for Spinal Cord Injury Model System
7. Molecular depth profiling modeled using buckyballs and low-energy argon
8. Nuclear receptors battle it out during metamorphosis in new fruit fly model
9. Computational modeling can help plan vaccine introduction, Pitt study finds
10. New modeling of brains circuitry may bring better understanding of Parkinsons disease
11. Modeling disparities may help with cervical cancer prevention
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/5/2016)... ... ... While the practice and profession of Aging Life Care is not new, there ... and resources. Aging Life Care plays an important role as these professionals are prepared ... Care is a holistic, client-centered approach to caring for older adults or others facing ...
(Date:5/5/2016)... ... May 05, 2016 , ... The ... electronic cigarettes, requiring e-cigarette manufacturers to submit their products through an arduous federal ... all vaping products that entered the market since February 15, 2007. That would ...
(Date:5/5/2016)... ... ... This weekend, from Friday, May 6 - Sunday, May 8, fifteen elite athletes from ... Semper Fi Mountain Bike Camp, hosted in conjunction with WTB and Cannondale ... Jason Moeschler, who’ll share pro tips with the injured veterans as they rip down some ...
(Date:5/5/2016)... ... May 05, 2016 , ... LELO has discovered many ... LELO fans reach out via email, social media and on the Volonté blog seeking ... the way I masturbate ‘normal’ or ‘correct’?” , While some methods are more common ...
(Date:5/5/2016)... ... May 05, 2016 , ... An ... all U.S. states and certain Canadian provinces is now available from the International ... Institute (WCRI). , The report, Workers’ Compensation Laws as of January ...
Breaking Medicine News(10 mins):
(Date:5/4/2016)... , May 4, 2016 ... addition of the  "Global Multiple Myeloma Market ... to their offering.       (Logo: ... Myeloma Market and Competitive Landscape Highlights 2016, ... products, Multiple Myeloma epidemiology, Multiple Myeloma market ...
(Date:5/3/2016)... India , May 4, 2016 ... spreads across 154 pages, profiling 09 key companies ... is a professional and in-depth study on the ... a basic overview of the industry including definitions, ... Needles market analysis is provided for the international ...
(Date:5/3/2016)... , May 3, 2016 ACME ... Whelan and Delaware County Councilman ... Nasal Spray in all ACME pharmacies across ... for Disease Control and Prevention (CDC), naloxone has saved 26,463 lives ... officers in Delaware County were authorized to ...
Breaking Medicine Technology: