For almost 30 years, annual mammograms for women over 40 have been a cornerstone of the
US strategy to reduce mortality from breast cancer. A number of advances in the
understanding of breast cancer biology, and screening in general, have led to calls to
revise and improve national screening strategies (Esserman et al., 2014). In 2009, the US
Preventive Services Task Force (USPSTF) introduced changes to screening guidelines,
recommending that annual mammograms for all women 40-75 be replaced by biennial screening
for women ages 50-75, and that screening in the 40's should be individualized by taking
patient context into account, including the patient's values regarding specific benefits
and harms. Despite being based on a thorough review of the scientific literature, these
recommendations continue to spark debate and scientific opinion on the effectiveness of
annual screening is greatly divided. On one hand the radiology and obstetrics/gynecology
community argues that annual mammograms starting at 40 reduce the rate of interval
cancers. On the other hand, primary care physicians and other specialists believe that
annual screening results in more false-positives and unnecessary treatment and that a
more targeted approach could result in fewer false-positives and less over-diagnosis
without increasing the number of interval cancers. In fact it has been estimated that
half of women will receive a false-positive recall over 10 years of annual screening and
that as many as 20% of all breast cancers might be overdiagnosed. Since 2009 this debate
has intensified, paralyzing the system and thwarting any efforts to change or improve
screening. The end result is that women are frustrated and confused, and some have
stopped screening altogether.
Despite a vastly improved understanding of breast cancer risk, the only criteria used to
establish a woman's screening recommendations is her age (and BRCA status if known), but
there are risk models available that incorporate personal and family history of breast
disease, endocrine exposures and breast density to assess breast cancer risk
(Constantino, et al., 1999; Parmigiani, et al., 1998; Tyrer, et al., 2004; Claus, et al.,
2001; Ozanne, et al., 2003). Most recently certain genetic mutations and common genetic
variants (single nucleotide polymorphisms or SNPs) have been confirmed predictors as well
(Darabi, et al., 2012). Therefore, advances in this understanding of breast cancer
biology, risk assessment, and imaging have enabled the creation of better tools and
sufficient knowledge to replace the one-size-fits-all approach to screening and to
implement a new, personalized model; one that provides recommendations on when to start,
when to stop, and how often to screen that depend upon well characterized measures of
risk.
The investigators propose to test a transformational evidence-based approach to breast
screening that educates women about their actual risk, and tailors screening
recommendations to them as individuals. Within the Athena Breast Health Network, the
study will compare comprehensive, patient-centered risk-based screening to annual
screening for women starting at age 40. The comprehensive risk assessment is based on a
widely accepted risk model, the Breast Cancer Surveillance Consortium model, that
includes endocrine exposures, family history and breast density, with additional genomic
risk factors that include rare and uncommon major breast cancer susceptibility alleles as
well as more common and recently validated single nucleotide polymorphisms (SNPs) that
can, cumulatively, contribute significantly to a woman's individual risk. The study's
personalized approach will recommend an age to start and stop screening as well as a
frequency based upon individual risk. Women of highest risk will receive greater
surveillance than those of lowest risk where the lower bound is the USPSTF recommended
guidelines. In this manner, the study will focus the most effort on those most likely to
develop the disease.
In close collaboration with patient advocates, the study has been designed as a 5-year,
preference-tolerant, 65,000 patient, randomized controlled trial of risk-based versus
annual screening. Individuals uncomfortable with the potential to be assigned to a
particular arm in the randomized cohort can participate in the self-assigned
observational cohort, an example of the pragmatic approach taken. Total accrual is
anticipated to be 100,000 women across both cohorts. A broad group of stakeholders have
participated in crafting this approach, including advocates, payers, the entire range of
medical specialists and primary care providers and researchers involved with breast
cancer screening across the entire Athena Network, technology partners, the Office of the
President at the University of California, and policy-making organizations.
The study hypothesizes that risk-based screening will be an improvement over annual
screening because it will be as safe, less morbid, enable more cancer prevention, less
stressful and more readily accepted by women as a result of an improved understanding of
their personal risk.
The Athena Breast Health Network was established across the 5 University of California
medical centers to develop a new, harmonized approach to breast cancer prevention,
screening and treatment. Athena is among the few centers in North America to use
technology to integrate risk assessment into breast screening. The investigators have
developed a cadre of "breast health specialists" who provide women with counseling and
support around risk and prevention. There are currently 100,000 registered Athena
participants, with 30,000 new patients per year and growing with the addition of Sanford
Health, one of the largest rural health networks in the country. The primary research
mission of Athena is to address issues requiring a population-based approach and
translate solutions to clinical practice. Athena is uniquely positioned to address the
screening controversy and provide women with renewed confidence in decisions about their
breast health. Risk-based screening for breast cancer is exactly the advanced,
evidence-based approach to medicine described in the NIH and FDA's "Path to Personalized
Medicine". If these hypotheses prove to be correct, this study will be able to establish
a clear justification for its use, and provide a framework for widespread implementation
that will benefit women across the country.