A New Era in Breast Cancer Screening – Mammography Every 2 Years Under the ACP 2026 Guideline
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Annals of Internal Medicine, April 2026 · ACP Clinical Guidance Statement, Continuing the 2019 Update
The American College of Physicians (ACP) has substantially updated its breast cancer screening guideline after a seven-year interval. The new guideline's most striking message is very clear: Annual mammography is no longer recommended for asymptomatic, average-risk women. Mammography every two years is considered sufficient for women aged 50–74; a shared decision-making approach is recommended for those aged 40–49 and over 75. Perhaps most striking is the explicit opposition to routine supplemental MRI or ultrasound screening in women with dense breast tissue. This guideline symbolizes an era in which the long-standing paradigm of "more screening means more benefit" is being scientifically questioned.
Why Another Update? Changing Evidence After Seven Years
Because more than seven years have passed since the ACP's previous guideline in 2019, the panel conducted a new update. It systematically reviewed the latest guidelines from specialist societies around the world and high-quality evidence. This resulted in five core recommendations — each shaped by age group and breast density category.
⚠ WHO DOES IT APPLY TO? WHO DOES IT NOT APPLY TO?
This guideline applies to asymptomatic, average-risk adult women only. Women with symptoms of breast cancer, those with a history of high-risk breast lesions, carriers of known genetic mutations such as BRCA1/BRCA2, those with a family history of high-risk genetic syndromes, and people who received high-dose chest radiation at a young age fall outside its scope. Screening strategies for these groups should be planned within a completely different framework.
The Five Recommendations of the ACP 2026 Guideline
🎯 RECOMMENDATION 1 — AGES 50–74: Mammography Every Two Years
Mammography every two years (biennial) is recommended for asymptomatic, average-risk women in this age group. In the US, approximately %80 of women in this age group already participate in screening every two years.
🤝 RECOMMENDATION 2 — AGES 40–49: Shared Decision-Making
In this age group, the screening decision should be made through shared decision-making. Individual risk, personal values and preferences, and uncertainty about benefits and harms should be discussed openly. Women undergoing annual mammography have a %50–60 probability of a false-positive result over 10 years.
⏸ RECOMMENDATION 3 — AGE 75 AND OVER: Reassessment
For women aged 75 and over or those with limited life expectancy, whether to continue screening should be determined through shared decision-making. Uncertainty about the balance of benefits and harms increases at these ages.
📊 RECOMMENDATION 4 — Dense Breasts: Tomosynthesis
In women with BI-RADS category C or D (heterogeneously dense or dense breast tissue), supplemental digital breast tomosynthesis (DBT) should be considered because of the potential to mask lesions.
❌ RECOMMENDATION 5 — MRI/Ultrasound Should NOT Be Used ROUTINELY in Dense Breasts
In women with BI-RADS C or D density, supplemental MRI or ultrasound screening is recommended against. This directly challenges a practice routinely used for years, particularly in some US centers. The ACP also maintains its previous position against breast self-examination.
Qaseem et al., Ann Intern Med 2026 · For asymptomatic, average-risk women
The Hidden Cost of Annual Mammography: False Positives and Overdiagnosis
A major emphasis of current guidelines is the explicit recognition that screening can bring harms as well as benefits. A woman undergoing annual mammography has a %50–60 probability of encountering at least one false-positive result over a 10-year period . This figure has practical significance: Despite being healthy, more than half of women will experience additional imaging, a biopsy, or a period of uncertainty at least once.
Screening Harms: The List Is Not Short
- Overdiagnosis: Detection of cancer that would never affect quality of life
- Overtreatment: Unnecessary surgery, radiotherapy, hormonal therapy
- False negative: Missing an actual cancer
- Need for additional imaging and biopsies
- Cumulative radiation exposure
- Psychological distress caused by false positives
- Reduced adherence to future screening
- Moderate reduction in breast cancer mortality (in certain age ranges)
- Diagnosis at an early stage
- Possibility of less invasive treatment in some cases
- A sense of psychosocial reassurance
- Ages 40–49: No statistically significant difference in advanced-stage cancers was demonstrated
Shared Decision-Making: A Woman Can Make Her Own Decision
The philosophical change behind the guideline may be at least as important as its technical recommendations. For years, the approach was: "Every woman should have annual mammography starting at age 40." The new paradigm places a model based on women's own preferences, values, and risk perceptions and on informed shared decision-making at its center.
Why Is MRI Not Routinely Recommended for Dense Breasts?
One of the new guideline's most debated points is its opposition to routine supplemental MRI or ultrasound screening in women with BI-RADS category C or D breast density. This issue has been debated for years, especially in the US. Dense breast tissue both reduces mammographic sensitivity and is an independent risk factor for breast cancer. Following this reasoning, many centers recommend routine MRI or ultrasound for women with dense breasts.
However, the ACP panel concluded that current evidence does not support this practice. Routine supplemental screening increases false-positive rates and biopsy frequency, while its benefit for mortality is described as unclear. For this age and density group, the panel instead recommends considering digital breast tomosynthesis(DBT — 3D mammography) as an alternative. Tomosynthesis images breast tissue in multiple layered sections, reducing the masking effect caused by dense breast tissue.
✅ SUPPORTED: Digital Breast Tomosynthesis (DBT)
It has been shown to increase mammographic sensitivity in dense breast tissue. The panel considers it an acceptable supplemental option.
❌ NOT RECOMMENDED: Routine Supplemental MRI
Its role in high-risk women, such as BRCA carriers, remains. However, in women with dense breast tissue alone who are at average risk, routine MRI screening is no longer recommended.
❌ NOT RECOMMENDED: Routine Supplemental Ultrasound
The panel concluded that ultrasound screening in average-risk women with dense breasts increases false-positive rates without demonstrating a clear mortality benefit.
❌ NOT RECOMMENDED: Breast Self-Examination (BSE)
Consistent with its previous guidelines, the ACP maintained its opposition to routine breast self-examination because of false-positive risks. This recommendation has long been controversial.
ACP Is Not Alone: Comparison with Other Organizations
The ACP's new position represents a particular stance in the international guideline landscape. Different organizations offer different recommendations on this issue. In particular, the United States Preventive Services Task Force (USPSTF) lowered the starting age for screening to 40 in its latest update. The American Cancer Society (ACS) recommends annual screening from 40 and screening every two years from 55. This variation can cause confusion for clinicians and patients.
Summary of recommendations from major international organizations
Implications for Practice in Turkey: What Does Our Guideline Say?
Under the Turkish Ministry of Health's national cancer screening program, mammography every two years is recommended for women aged 40–69. Although this approach differs from the ACP's new recommendation in starting age (40 vs 50), it offers a similar framework in frequency (every two years). Offered through KETEM (Cancer Early Diagnosis, Screening, and Education Centers) in Turkey, this program is an important public health tool providing free access, especially for women of low to middle socioeconomic status.
The most direct messages of the ACP guideline for practice in Turkey are as follows: First, annual mammography should not be performed routinely in average-risk women — in Turkey, where annual screening is common in private hospital practice, the information given to patients needs to be reviewed. Second, routinely requested supplemental MRI or ultrasound in dense breasts should be reassessed on an evidence-based foundation. Third, and perhaps most importantly, there is a need to establish a shared decision-making approach that facilitates women's active participation in screening decisions. Paternalistic tendencies remain widespread in physician–patient communication in Turkey; this guideline could serve as an international reference for change.
🎓 DROZDOGAN Academy — Commentary and Discussion
ACP GUIDELINE · BREAST CANCER SCREENING · SHARED DECISION-MAKING · CRITICAL APPRAISAL
Why This Update Matters
The ACP guideline's 2026 update is an important document that systematically synthesizes the breast cancer screening evidence accumulated over the past seven years. In particular, its rejection of routine MRI/ultrasound screening for dense breast tissue directly challenges the trend of "MRI for every woman with dense breasts" followed in some settings for years. Placing shared decision-making at the center for both the 40-49 and 75+ age groups also represents a concrete reflection of a broader move away from the paternalistic model in medical practice. Screening medicine is now moving from "the more, the better" to "how much is enough without causing harm."
Strengths
The guideline's methodological strength comes from its systematic appraisal of high-quality international guidelines and current evidence. Each of its five recommendations is presented clearly, with practical applicability and a rationale. In particular, explicitly stating the finding that "early screening did not produce a statistically significant difference in advanced-stage cancer" for the 40-49 age group makes clear that the rationale for enthusiasm about screening at these ages has weakened. Applying shared decision-making to both the 40-49 and 75+ age groups represents a modern medical ethics perspective that respects women's lifestyles and risk preferences. Constructively making room for modern imaging techniques such as tomosynthesis also demonstrates the guideline's balanced approach to technology.
Limitations and Open Questions
The guideline's most serious limitation is its self-defined scope: it applies only to asymptomatic, average-risk women. In real clinical practice, however, "average risk" is not always clearly defined. It is uncertain how to interpret this guideline for women with a marginal family history, atypical hyperplasia, or moderate risk factors in addition to dense breast tissue. Recommending "shared decision-making" for the 40-49 age group is a sound practical principle, but helping women genuinely understand benefit–harm data requires substantial patient education infrastructure — something most health systems lack. The guideline also does not adequately address how BI-RADS density is determined in a standardized way or variation between centers. Finally, it does not explore in depth how screening might have different benefit–harm profiles in women of different ethnicities and socioeconomic backgrounds.
Implications for Clinical Practice
From the perspective of oncology and breast surgery, the guideline's practical messages are clear. First: Annual mammography should cease to be an industry norm in average-risk women; mammography every two years is an approach that is both evidence-based and minimizes harm. Second: Routine MRI/ultrasound is no longer "indispensable" for women with dense breast tissue. MRI unquestionably retains its role in genuinely high-risk patients (BRCA carriers, dense breasts together with a family history) — but the habit of requesting MRI solely because of dense breasts should be reviewed. Third: Patient education materials need updating — the information offered to women should transparently include the risks of false positives, overdiagnosis, and overtreatment. In Turkey, especially in private healthcare institutions, the check-up concept packaged as "MRI every year, annual mammography, routine ultrasound" deserves scrutiny from an evidence-based medicine perspective.
Future Questions
Several critical questions await answers following this guideline: How will the spread of AI-assisted mammography reading systems reshape the screening paradigm? Can the future cancer risk profile of women screened with dense breasts be predicted clearly, and how can the choice of supplemental imaging modality be personalized to identify who will benefit? Could ctDNA and liquid biopsy technologies, discussed in our earlier drozdogan.com article, partly replace mammography in the next decade? What infrastructure does Turkey need to generate comprehensive breast cancer screening data specific to its own population and adapt international guidelines to the national context? How can clinician–patient communication skills be improved so that shared decision-making can be implemented meaningfully in Turkey? The answers will determine how screening medicine evolves over the next decade.
Scientific References
- Qaseem A et al. (American College of Physicians). Screening for Breast Cancer in Asymptomatic, Average-Risk Women: A Guidance Statement From the American College of Physicians. Ann Intern Med 2026. Medscape Medical News and ACP Clinical Guidance Statement, April 2026.
- U.S. Preventive Services Task Force (USPSTF). Breast Cancer Screening: Recommendation Statement. JAMA 2024.
- American Cancer Society (ACS). Breast Cancer Screening Guidelines for Women at Average Risk. 2025 Update.
- Monticciolo DL et al. (American College of Radiology). Breast Cancer Screening for Women at Higher-Than-Average Risk: Updated Recommendations From the ACR. J Am Coll Radiol 2023.
- Republic of Türkiye Ministry of Health. National Cancer Screening Program — Breast Cancer. General Directorate of Public Health.
- Nelson HD et al. Harms of Breast Cancer Screening: Systematic Review to Update the 2009 U.S. Preventive Services Task Force Recommendation. Ann Intern Med 2016;164:256–267.
- Welch HG, Prorok PC, O'Malley AJ, Kramer BS. Breast-cancer tumor size, overdiagnosis, and mammography screening effectiveness. N Engl J Med 2016;375:1438–1447.
- Kerlikowske K, Zhu W, Tosteson ANA et al. Identifying women with dense breasts at high risk for interval cancer. Ann Intern Med 2015;162:673–681.
This article was created using various editorial tools, including artificial intelligence, as part of the process. It was reviewed by human editors before publication.
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