Bringing back into focus the value of a lifesaving intervention
Article first published online: 30 JUN 2011
Copyright © 2011 American Cancer Society
Volume 117, Issue 14, pages 3062–3063, 15 July 2011
How to Cite
Ganai, S. and Winchester, D. J. (2011), Screening mammography. Cancer, 117: 3062–3063. doi: 10.1002/cncr.26319
- Issue published online: 30 JUN 2011
- Article first published online: 30 JUN 2011
By Sabha Ganai, MD. PhD, Department of Surgery. University of Chicago Pritzker School of Medicine, Chicago, Illinois; and David J. Winchester, MD, Department of Surgery, University of Chicago Pritzker School of Medicine, Chicago, Illinois, and NorthShore University HealthSystem. Evanston, Illinois
Confusion and changes abounded after the release of the US Preventive Services Task Force (USPSTF) recommendations for screening mammography in 2009.1 In their controversial report, the USPSTF recommended against screening mammography for women ages 40 to 49 years; biennial, not annual, screening for women ages 50 to 74 years; and declared that insufficient data exist to recommend for or against screening for women older than age 74 years.2 In 2003,theACS endorsed annual screening mammography for average-risk, asymptomatic women beginning at age 40 years, a recommendation based on randomized controlled trials and observational studies.3-5 Although the ACS has continued to stand firmly behind their guidelines without modifications, the impact of the USPSTF recommendations has been significant for patients and clinicians. In a recent report presented at the American Roentgen Ray Society, the practice patterns of primary care physicians changed dramatically after the publication of the USPSTF recommendations in 2009, with a decrease in the use of screening mammograms noted across all age groups.6 This has led to significant confusion among patients as well, despite a prevalence of disapproval of these guidelines in the lay press and social media.' Perhaps more important, the USPSTF recommendations, which devaluate screening mammography for all age groups, have significantly marred the perceived value of mammograms and will likely decrease compliance with any set of guidelines.
Hendrick and Helvie have recently modeled the risks and benefits of mammography screening strategies, examining the number of lives saved for each screening as well as the harms, including false-positive mammograms, unnecessary biopsies, and missed breast cancers.,7 Their data, based on averaging 6 Cancer Intervention and Survefflance Modeling Network models in which women ages 40 to 84 years were screened, demonstrated an additional 71% breast cancer survival benefit when following ACS screening guidelines (a 39.6% mortality reduction) above and beyond the mortality reduction (2 3.2%) achieved with the USPSTF recommendations. Following the ACS screening guidelines would result in an additional 5 lives saved per 1000 women compared with the less robust strategy. By screening women ages 40 to 49 years, a false-positive mammogram would occur once in every 10 years of screening, and a false-positive biopsy once in every 149 years. Although anxiety-producing recalls occur in this population, most women only require additional imaging without tissue acquisition.
Screening is a concept that relies on early detection to improve outcomes. The method of breast cancer detection in women has an important impact on the stage of disease at diagnosis. In a recent comparison of women ages 40 to 49 years, those who were screened were more likely to have early stage disease compared with symptomatic patients.8 In population-wide breast cancer screening programs in Sweden in which women were invited to participate in screening mammography at ages 40 to 49 years, those undergoing screening mammography had a 29% decrease in breast cancer mortality over a 16-year interval compared with those who were not invited.9 Swedish investigators also demonstrated an optimal annual screening interval for the population of women ages 40 to 49 years, which may be reflective of a more aggressive tumor biology noted in premenopausal women. Comparisons of biennial with annual screening interventions have shown that annual screening results in 30% lower recall rates, the detection of smaller tumors, and a potential impact on stage migration10, 11
Implicit in the USPSTF recommendations for breast cancer screening is a motivation for cost savings by reducing the number of screening mannnograms. As a useful comparison, annual screening mammography of women ages 40 to 79 years is intervention that is more cost-effective than the use of automobile seat belts and air bags with regard to its cost-per-year-of- life gained.12-14 Although screening man'unography is more cost-effective than dmg development as a method of saving lives from breast cancer, the cost-effectiveness of different screening intervals must also take into account cost differences related to the management of early versus more advanced cancers as well as differences in cancer mortality. Unfortunately, reimbursement by Medicare and third-party payers for participation in screening interventions could be linked with the USPSTF recommendations, leading to limitations in access to care and the diagnosis of more advanced disease.
In addition to contradictory guidelines, noncompliance with screening manimography is influenced by the absence of reminders, being “too busy,” and simply forgetting to keep appointments.15 As routine screening behaviors are established earlier in a woman's life, adherence to scheduled mammography improves with time.16 Screening compliance could be affected by a shortened (24-year), biennial schedule. Although the Swedish mammography trials have shown that inviting women to participate in screening mammography has a survival benefit of 32% and results in the detection of disease at an earlier stage, the USPSTF recommendations cloud the issue for both patients and clinicians, stating that any decision to start mammography prior to the age of 50 years should be an individual one, taking the patient's context and values into account.2, 17, 18 Unfortunately, such vague definitions may lead to indecisiveness, even in patients with an above-average risk of breast cancer.
Ultimately, women respond to an endorsement of screening guidelines.19 With any strategy, balance must be achieved between the benefits and harms of the intervention. In the United States, although breast cancer survival has improved over the last 20 years secondary to early detection and fin- proved therapy, it remains the leading cause of cancer mortality in women ages 40 to years.20 Until other screening modalities have been developed and tested, mammography the gold standard. High compliance and preservation life with this established and proven screening test will depend on a unified and supportive perspective from the medical community.
- 3American Cancer Society guidelines for breast cancer screening: update 2003. CA Cancer J CIin. 2003; 54: 141-169., , , et al.
- 5Screening for breast cancer with mammography. Cochrane Database Syst Rev. 2011; ( l): C0001877., .
- 6Survey to screening mammography ordering practices to primary care physicians before and after the release to the November 2009 United States Preventative Services Task Force screening mammography guidelines. AIR Am J Roentgenol. 2011; 196: A1., , , .
- 8Neglecting to screen women aged 4049 years with mammography: what is the impact on breast cancer diagnosis. MR Am J Roentgenol. 2011; 196: A2., , , et al.
- 16Longitudinal predictors to nonadherence to maintenance to mammography. Cancer Epidemiol Biomarkers Prey. 2010; 19: 1103-1111., , , .
- 19Mammography screening to women in their 40s: impact to changes in screening guidelines. Cancer. 2008; 112: 413-480., , , , .