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:12/7/2016)... ... December 07, 2016 , ... A. Kevin Spann Insurance, a ... throughout the Five Boroughs, is launching a charity drive to raise funds that will ... traditions and spirit of marines and Navy FMF Corpsmen. Working closely with the MCL, ...
(Date:12/7/2016)... ... December 07, 2016 , ... Facial plastic surgeon, Dr. John ... by donating a portion of proceeds to two local organizations: North Chicago Animal Control ... & Friends is a team of authorized and trained volunteers who support rescued ...
(Date:12/7/2016)... ... ... The medical profession is well aware that heart attacks do indeed increase ... attacks among 138,602 people recorded a 35% higher number of heart attacks in December ... course–no time of year is a good time for a heart attack! In the ...
(Date:12/7/2016)... ... December 07, 2016 , ... ... (IFW) Program at Reproductive Medicine Associates of Connecticut (RMACT). McLaughlin brings nearly 20 ... of three acupuncturists to help patients realize their family building goals. Acupuncture ...
(Date:12/7/2016)... ... December 07, 2016 , ... “Fred Rides a Train” allows readers to ... , “Fred Rides a Train” is the creation of published author, Janet Morrison, ... teen years in Michigan. The "Fred, the Dog" series is her first attempt at ...
Breaking Medicine News(10 mins):
(Date:12/7/2016)... Kan. , Dec. 7, 2016   Rx Savings ... West Virginia and its Public Employees Insurance Agency ... members access to their innovative healthcare software, ultimately saving money ... with PEIA and provide its members with access to our ... or a more effective, affordable therapy can be found," says ...
(Date:12/7/2016)... Dec. 7, 2016  Varian Medical Systems (NYSE: ... previously announced plans to separate its Imaging Components business.  ... tax-free distribution to Varian stockholders of common stock in ... will hold the Imaging Components business.  As part of ... by the end of January 2017, Varian will receive ...
(Date:12/7/2016)... 7,2016  Based on its recent analysis ... & Sullivan recognizes Nemaura Pharma Limited with ... for Enabling Technology Leadership. Nemaura Pharma,s transdermal ... traditional drug delivery technologies, especially in delivering ... delivery technologies, Memspatch and Micropatch respectively, facilitate ...
Breaking Medicine Technology: