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:6/25/2016)... ... 25, 2016 , ... Experts from the American Institutes for ... Meeting June 26-28, 2016, at the Hynes Convention Center in Boston. , AIR ... care planning, healthcare costs and patient and family engagement. , AIR researchers will ...
(Date:6/25/2016)... ... , ... First Choice Emergency Room , the largest network of independent ... Director of its new Mesquite-Samuell Farm facility. , “We are pleased to announce ... Dr. James M. Muzzarelli, Executive Medical Director of First Choice Emergency Room. , ...
(Date:6/25/2016)... Canada (PRWEB) , ... June 25, 2016 , ... Conventional ... pursuit of success. In terms of the latter, setting the bar too high can ... risk more than just slow progress toward their goal. , Research from ...
(Date:6/24/2016)... ... ... Marcy was in a crisis. Her son James, eight, was out of control. Prone to ... , “When something upset him, he couldn’t control his emotions,” remembers Marcy. “If there ... my other children and say he was going to kill them. If we were ...
(Date:6/24/2016)... ... 2016 , ... Comfort Keepers® of San Diego, CA is excited to announce ... program to drive cancer patients to and from their cancer treatments. Comfort Keepers ... of life and ongoing independence. Getting to and from medical treatments is one ...
Breaking Medicine News(10 mins):
(Date:6/26/2016)... June 27, 2016  VMS Rehab Systems, Inc. ( ... take whatever measures required to build a strong and ... is currently listed on the OTC Markets-pink current trading ... and CEO, "We are seeing an anomaly in market ... not only by the Company, but shareholders and market ...
(Date:6/24/2016)... , June 24, 2016  Global Blood Therapeutics, ... company developing novel therapeutics for the treatment of ... announced the closing of its previously announced underwritten ... at the public offering price of $18.75 per ... were offered by GBT. GBT estimates net proceeds ...
(Date:6/24/2016)... The Academy of Managed Care Pharmacy (AMCP) ... would allow biopharmaceutical companies to more easily share health ... and coverage decisions, a move that addresses the growing ... The recommendations address restrictions in the sharing of ... label, a prohibition that hinders decision makers from accessing ...
Breaking Medicine Technology: