Alphabet Soup of Breast Cancer Screening: Guidelines, Risk Assessment, and Shared Decision Making (Notes from Dr. Schrager, UW)

Screening Rationale and Outcomes

• Mammograms are evidence-based to save lives, especially in older women; the exact magnitude varies by population, but there is consensus that baseline mammograms save lives.
• Balancing benefit and harm is central: benefits (lives saved) come with harms (false positives, callbacks, biopsies, anxiety; overdiagnosis; pain; potential insurance issues).
• False positives and radiologic workups:
  • Additional views, biopsies, ultrasounds
  • Anxiety and insomnia: a study found significant anxiety and insomnia for eighteen months after recall for extra views.
• Overdiagnosis: detecting a cancer that would not have caused clinical harm during the patient’s lifetime; leads to overtreatment and unnecessary harm.
• Practical harms beyond medical risks: pain of the procedure; insurance coverage gaps when a recall shifts from preventive to diagnostic.
• Population-level trade-off schematic (illustrative, per 1000 women, 10-year horizon):
  • Without screening: about 5 deaths from breast cancer.
  • With screening: about 4 deaths from breast cancer.
  • Therefore, screening saves roughly
    $ext{Deaths averted} \,\approx\, 1 \,/\, 1000$
  • Additionally, among 1000 women screened over the period:
    $\text{Callbacks for extra views} = 100$
    $\text{Overdiagnosed cancers} = 5$
• Screening decisions depend on individual risk and preferences; the best approach is shared decision making (SDM) to discuss benefits, harms, and patient values.

Guideline Landscape and Practical Implications

• Major guideline groups and their orientation:
  • USPSTF: considered the least biased, evidence-based core; emphasizes shared decision making for starting screening before age 50 in average-risk women; biennial screening 50–74; 40–49 may reduce breast cancer death but with smaller absolute benefit.
  • American Cancer Society (ACS): more variable, broader age-based options with yearly vs biennial choices; emphasizes life expectancy (>10 years) as a criterion for continuing screening; guidelines emphasize patient education.
  • American College of Radiology (ACR): historically aggressive on screening; emphasizes starting at age 40 and frequent annual screening; notes higher recalls with more frequent screening but also greater potential life-years gained.
  • American College of Obstetricians and Gynecologists (ACOG): start at age 40 for average risk; continue every 1–2 years; most guidelines advocate shared decision making; stop recommendations often around age 75.
  • NCCN (oncologists): start at 40 annually; increased risk factors may justify earlier screening; risk assessment suggested from age 25; annual mammography starting at 40 tied to higher mortality reduction (contextualized with risks).
  • American College of Physicians (ACP): emphasizes discussion of benefits, harms, and patient values; supports starting before 40 only via SDM.
  • American Academy of Family Physicians (AAFP) / others: generally align with USPSTF and emphasize SDM; variability exists across guidelines due to different aims and patient populations.
• Updated draft USPSTF recommendations (not yet finalized at time of talk):
  • For women aged 40–74: screening every 2 years (level B); continued uncertainty about screening in those 75+, and about adjunctive screening for dense breasts.
  • Removal of some language emphasizing explicit balance of benefits/harms and SDM in the final text could affect implementation and patient-centered care if adopted without safeguards.
  • For dense breasts: insufficient evidence to routinely recommend adjunct screening; decision to use ultrasound or MRI should be contextual and discussed via SDM.
• ACS specifics (simplified):
  • 40–44: option to start screening
  • 45–54: annual mammography
  • 55+: every 1–2 years (can continue annual screening)
  • Continue screening as long as a woman is in good health and expected to live at least 10 more years.
  • Emphasis on patient understanding of what to expect from screening.
• ACOG specifics: average-risk women should begin screening at 40; continue every 1–2 years; stop around age 75; shared decision making recommended.
• NCCN specifics: annual screening from age 40 is associated with the highest mortality reduction for average-risk women; risk-based screening may start earlier with other risk factors; risk assessment recommended from age 25.
• Practical takeaway: guidelines vary, but the consensus supports SDM to tailor screening to individual risk and preferences.

Individual Risk Assessment and Risk Models

• When to start risk assessment: first visit at age 35 (and re-evaluate at well-woman visits thereafter); the risk category informs screening intensity and potential chemoprevention.
• Why assess risk: high-risk individuals may qualify for enhanced screening and chemoprophylaxis; risk assessment can reveal genetic risk not evident from family history.
• Types of risk models:
  • Gale model: quick, widely used; limitations: less accurate for diverse populations; uses only first-degree relatives, not extended family.
  • Breast Cancer Surveillance Consortium (BCSC) model: includes breast density, more data inputs; helpful for refining risk estimates.
  • Tyrer-Cuzick (IBIS) model: most comprehensive; includes detailed family history, breast density, hormonal factors; can guide risk-reducing medications; best accuracy but more data-heavy and less easily integrated everywhere.
• Practical integration: ideal to have risk model embedded in EMR; some centers integrate Tyrer-Cuzick into their EHRs; others rely on external tools.
• Risk categorization (for guiding screening and prevention):
  • Average risk: lifetime risk < 0.15 or 5-year risk < 0.0166
  • High risk: lifetime risk > 0.20 (some groups use >0.25); 5-year risk > 0.025
  • Intermediate risk: between average and high (use SDM to decide on screening intensity; not clearly defined in guidelines)
• Indications for genetic testing:
  • First- or second-degree relative with breast cancer diagnosed < 45
  • Male breast cancer history
  • Pancreatic cancer in a relative
  • Metastatic prostate cancer in a relative
  • More than two primary breast cancers in a single person
  • More than two relatives with breast cancer on the same side of the family
  • Relative with ovarian cancer
• If high-risk genetic variants are present (e.g., BRCA1/BRCA2):
  • Enhanced screening and chemoprophylaxis options apply
  • MRI surveillance becomes central; timing typically starts earlier (e.g., MRI annually; some guidelines start MRI at age 25 for BRCA carriers; mammography typically begins around age 30)
  • Prophylactic mastectomies are common in certain high-risk groups after childbearing
• Enhanced screening for high-risk individuals:
  • MRI screening annually + mammography, typically offset by about six months (e.g., mammogram now, MRI six months later) to provide semiannual assessment
  • Start ten years before the earliest age at cancer onset in affected relatives (not before age 30)
  • NCCN recommends MRI screening for high- and moderate-risk gene variants
• Risk reduction pharmacotherapy (chemoprophylaxis):
  • Tamoxifen for 5 years in premenopausal women
  • Aromatase inhibitors (e.g., anastrozole, letrozole, exemestane) in postmenopausal women
  • Dosing and response illustrated by risk-reducing models; reduces lifetime risk significantly for many patients
• Summary: risk assessment is central to identifying candidates for enhanced screening and chemoprophylaxis; informed by family history, genetic testing, density, and other hormonal and lifestyle factors

Shared Decision Making (SDM): Concept, Tools, and Evidence

• What is SDM?
  • Evolution from paternalistic decision making (we tell you what to do) to informed medical decision making (we explain, and you decide) to shared decision making (joint decision based on patient values and clinical evidence).
  • SDM aims to align medical actions with patient values while still guided by evidence about benefits and harms.
• SDM in breast cancer screening:
  • Involves presenting positives and potential harms of screening (e.g., benefits, false positives, overdiagnosis, anxiety, cost) and eliciting patient preferences.
  • Use of patient decision aids to structure conversations and ensure no significant topic is omitted.
• Evidence supporting SDM (Cochrane review 2017):
  • Increases patient knowledge and accuracy of risk perception
  • Increases likelihood that choices align with patient values
  • Reduces decisional conflict
  • May improve patient satisfaction and clinician-patient communication
  • Time considerations: impact on visit length varies; median around ~2.5 minutes longer, with ranges from much shorter to somewhat longer depending on context
• Practical SDM workflow (COD): a concise framework
  • Choice talk: establish patient’s options and that it is their choice
  • Option talk: discuss pros/cons, risks/benefits, personalized to the patient
  • Decision talk: elicit patient preferences, decide next steps, plan follow-up if needed
• Decision aids in practice:
  • Templates guide clinicians through the conversation; tools like DynaMed Shared Decisions (integrated with Epic) provide risk inputs from family history, age, BMI, race, and breast density to generate personalized risk and options
  • Other tools referenced: Ottawa decision tools, Dartmouth options tool; choice of tool depends on workflow and accessibility
• Clinician role and personal input:
  • There is debate about whether clinicians should share their personal opinion during SDM. Some argue for direct patient autonomy; others believe clinician input can help patients think through harms/benefits. A pragmatic stance: offer your view after presenting all information and patient values, to avoid steering decisions away from patient-centered outcomes.
• Barriers to SDM:
  • Difficulty eliciting values and preferences
  • Time constraints and resource limitations
  • Competing priorities and information overload
  • Perceived or real pressure from payers or guidelines to adopt a specific screening cadence
• Takeaway: SDM is a core component of patient-centered breast cancer screening, but it requires time, tools, and a cultural shift in practice patterns

Practical Communication, Implementation, and Real-World Nuances

• How to implement risk-based and SDM-informed screening in practice:
  • Start with a structured risk assessment at age 35 and revisit at each well-woman visit
  • Use a validated risk model (preferably Tyrer-Cuzick for detailed risk and prevention counseling; Gale for quick estimates or where data are sparse; BCSC when density is available)
  • Engage in SDM about whether to screen, when to screen, and how often to screen based on risk level and patient preferences
  • For high-risk individuals, discuss enhanced screening (MRI + mammography cadence) and chemoprophylaxis options; discuss potential side effects and adherence challenges
• Reports and institutional practice changes:
  • Some institutions historically used fixed language in reports (e.g., “annual mammograms are recommended”) but efforts exist to align reporting with guideline-based screening; change requires hospital or radiology department-wide work groups and leadership.
• Special considerations in imaging:
  • Implants: document implant status in orders; radiology may need special views; implants do not change guideline-based screening but may require tailored imaging views
  • Dense breasts: density letters are common in some states; evidence for adjunct screening (ultrasound, MRI) is not strong; density should factor into SDM, especially for risk assessment and potential density-related risk elevation
  • Breast MRI: high sensitivity but high false-positive rate; requires experienced interpretation; recommended primarily for high-risk populations
• Transgender considerations (trans folks):
  • Trans women who meet cisgender screening criteria (e.g., age 40+) should follow standard guidelines
  • Trans men: if no chest surgery, follow cis-female guidelines; if chest reduction surgery (mastectomy) performed, routine breast cancer screening may not be required; if mastectomy not performed, guidelines depend on residual breast tissue
• COVID-19 vaccination guidance (relevant to imaging timing):
  • Do not delay mammography after COVID vaccination; initial guidance to delay has expired (no longer recommended to wait 6 weeks post-vaccination)
• Breast reports and communication to patients:
  • Move away from language emphasizing a fixed “annual” screening expectation; adopt guideline-based screening language in reports to reduce confusion
• Practical patient-facing talking points:
  • Emphasize that screening decisions are individualized based on risk and preferences
  • Clarify the potential benefits and harms of screening, including the possibility of false positives and overdiagnosis
  • Provide a clear plan for next steps, including contact points if there is a recall

Special Topics, Controversies, and Common Questions from Practice

• What to tell patients about screening in transgender individuals:
  • Trans women: screen per cisgender female guidelines if criteria are met (40+ with risk factors)
  • Trans men: if no mastectomy, follow cisgender female guidelines; if mastectomy, screening not required; if breast tissue remains, apply standard guidelines
• COVID vaccine and mammography timing: no need to delay, even after vaccination
• Mammography reports and language:
  • Move away from “annual mammograms are recommended” language to guideline-based statements; emphasize individual risk and SDM
• Implants and screening: document implant status to tailor views; radiologist may need to optimize images around implants
• Pay-for-performance and screening metrics:
  • Some HMOs tie performance metrics to the percentage of eligible women who receive screening; clinicians can advocate for starting screening in appropriate age ranges (e.g., 50+) and recognizing patient choices not to screen as valid outcomes if clinically appropriate
• Is there evidence that mammograms increase breast cancer incidence?
  • No convincing evidence that mammograms themselves cause cancer; theoretical radiation risk exists but not supported by strong evidence in terms of incidence increase
• Do screening guidelines change how I talk to patients about delaying screening for breastfeeding or adult life stage?
  • For breastfeeding, many centers delay screening until 3–6 months post-weaning due to denser tissue and imaging interpretation considerations; decisions should be individualized and discussed in SDM
• Obesity and risk:
  • Obesity increases risk through higher circulating estrogen levels, which can promote breast tissue proliferation and density; BMI is commonly included in risk calculators
• Self-breast exam and clinical breast exam (CBE):
  • Evidence shows little to no impact on outcomes from routine repeat self-exams or CBE in reducing mortality; however, CBE during well-woman visits remains a routine clinical practice for patient education and opportunity to discuss risk
• Pace of SDM conversations in practice:
  • Decision aids can facilitate structured conversations; conversations tend to become more efficient with repetition over time; effective SDM may require a few minutes per visit, but cumulative impact on schedule varies
• Practical takeaway about risk communication: use plain language, explain uncertainty, and tailor the discussion to the patient’s life expectancy, values, and risk tolerance

Key Takeaways for Practice

• There is no one-size-fits-all screening guideline; the core is to use SDM to tailor screening plans to individual risk and preferences while following guideline-based minimums.
• Begin risk assessment early (age 35) and revisit at each well-woman encounter; use validated risk models to stratify risk and guide decisions about enhanced screening and chemoprophylaxis when appropriate.
• For average-risk women, consider USPSTF guidance as a baseline, but adapt to patient preferences, density, and comorbidity profile; SDM is essential when starting screening before age 50 or when considering stopping around age 75.
• Enhanced screening (MRI ± mammography cadence) is appropriate for high-risk individuals; discuss benefits, costs, and potential harms, including MRI’s higher false-positive rate.
• Discuss chemoprophylaxis options (tamoxifen, raloxifene, exemestane) for high-risk individuals where appropriate, with attention to menopausal status and side effect profiles.
• Transgender health requires nuanced application of guidelines and individualized risk assessment; consult specialty guidance as needed.
• Imaging reports should reflect guideline-based screening recommendations rather than a fixed annual mandate; radiology and clinical teams should collaborate to align messages.
• Practical SDM framework (COD): Choice talk, Option talk, Decision talk, with patient values and preferences elicited and incorporated into the final plan.
• Be mindful of practical barriers (time, resources, workflow) and leverage decision aids and EMR integrations to streamline SDM without compromising patient-centered care.