ASCO Guideline Update Recommends Risk-Based Breast Cancer Surveillance

According to an updated guideline from the American Society of Clinical Oncology (ASCO), breast cancer follow-up and surveillance after primary treatment should be tailored to a patient's individual risk of recurrence rather than a uniform, one-size-fits-all schedule.¹ The guideline, accepted for publication in Journal of Clinical Oncology, stratifies patients into low-, intermediate-, and high-intensity surveillance groups based on disease stage, biomarker status, and time from diagnosis.

The update was developed by a multidisciplinary ASCO Expert Panel co-chaired by Zeina Nahleh, MD, FACP, chair of the Department of Hematology-Oncology and director of the Maroone Cancer Center at Cleveland Clinic Florida, and Maryam Lustberg, MD, MPH, director of the Breast Center at Smilow Cancer Hospital and chief of breast medical oncology at Yale Cancer Center.¹ ASCO first published breast cancer follow-up guidance in 1997, with subsequent updates in 1999, 2006, and 2013; the 2013 review had concluded that no changes to the 2006 recommendations were warranted. The panel's systematic review identified only a single randomized controlled trial that directly informed a surveillance recommendation—the mammography schedule—and no randomized trials evaluating follow-up approaches by recurrence risk in early-stage breast cancer, so most recommendations were generated through a formal modified Delphi consensus process across 3 rounds of panel voting.

Low-, Intermediate-, and High-Intensity Surveillance Groups

The low-intensity group includes patients with ductal carcinoma in situ who are not receiving or have completed endocrine therapy, patients with stage I hormone receptor (HR)-positive breast cancer who have completed systemic therapy, and patients with triple-negative breast cancer (TNBC) or HER2-positive breast cancer who are at least 5 years from diagnosis. For this group, ASCO recommends an annual clinical visit, conducted in person or virtually, that may be managed by a survivorship clinic, an oncology advanced practice provider, or a primary care or gynecology clinician.¹

The intermediate-intensity group includes patients with stage I TNBC or HER2-positive disease within 5 years of diagnosis, those with stage II or III TNBC or HER2-positive disease who achieved a pathologic complete response after neoadjuvant therapy, and patients receiving ongoing endocrine therapy. ASCO recommends clinical follow-up with an oncology team or survivorship clinic every 6 to 12 months for 5 to 10 years after diagnosis, with some patients transitioning to low-intensity follow-up after year 5.

The high-intensity group includes patients with TNBC or HER2-positive disease and residual disease after neoadjuvant therapy within 5 years of diagnosis, inflammatory breast cancer within 10 years of diagnosis, carriers of germline BRCA1, BRCA2, or PALB2 mutations, and patients with HR-positive disease receiving endocrine therapy plus a CDK4/6 inhibitor.¹ This group is recommended to have clinical follow-up with the oncology team every 3 to 6 months for up to 10 years after diagnosis, along with chest wall examinations every 6 months.

Mammography Recommendations Draw on the Mammo-50 Trial

For patients treated with breast-conserving surgery in the low-intensity group, ASCO recommends annual mammography for the first 3 years after treatment, followed by surveillance mammography every 1 to 2 years for selected patients 50 years or older with low-risk features (T1, low-grade, node-negative, estrogen receptor–positive tumors) who remain recurrence-free 3 years after diagnosis.^1,2 Patients who prefer to continue annual mammography may do so after discussing the potential benefits and harms with their clinician. In the intermediate-intensity group, annual mammography is recommended for patients treated with breast-conserving surgery, and annual contralateral mammography is recommended after unilateral mastectomy; mammography is not recommended after bilateral mastectomy unless symptoms warrant evaluation. Among patients with high-risk disease, annual mammography is recommended when residual breast tissue remains.

The de-escalated mammography schedule is informed by the Mammo-50 trial, a UK phase 3 noninferiority trial (ISRCTN48534559) that randomized women 50 years or older who were recurrence-free 3 years after breast cancer surgery to annual mammography or less frequent mammography: every 2 years after breast-conserving surgery or every 3 years after mastectomy.² At a median follow-up of 5.7 years, less frequent mammography was noninferior to annual mammography for recurrence-free interval, overall survival, and breast cancer–specific survival, with no major differences in quality-of-life outcomes between the 2 groups.

Blood-Based Biomarkers and ctDNA Not Recommended Outside Clinical Trials

ASCO does not recommend routine complete blood counts, chemistry panels, or tumor markers such as CEA, CA 15-3, or CA 27.29 for surveillance in asymptomatic patients, consistent with the society's prior guidance. The panel also addressed circulating tumor DNA (ctDNA), stating that ctDNA testing is not recommended for recurrence monitoring outside a clinical trial or research setting.^1,3 The panel noted that although detectable ctDNA can identify patients at higher risk of recurrence, its clinical utility—whether changing treatment in response to a positive result improves outcomes—has not been established, and routine use outside of research could introduce anxiety, unnecessary treatment, and cost without a proven benefit.

Supplemental imaging with breast MRI may be offered through shared decision-making for select patients based on factors including germline mutation status, prior radiation exposure to breast tissue, age younger than 50 years at diagnosis, invasive lobular histology, dense breasts, or cancers not detected by screening mammography. The guideline notes no evidence that MRI surveillance improves overall survival posttreatment, although it may reduce interval cancers in selected higher-risk patients. Routine imaging for distant metastases, including CT, PET, bone scan, liver ultrasound, or chest radiography, is not recommended in asymptomatic patients without symptoms or abnormal clinical findings.

Clinical Context and Limitations

The panel acknowledged that the evidence base for breast cancer surveillance remains limited and cautioned that de-escalating surveillance intensity may feel uncomfortable to some patients and clinicians even where supported by data. ASCO said the risk-adapted approach is intended to better match follow-up intensity to recurrence risk, patient preferences, oncology workforce capacity, and health care costs, and emphasized that shared decision-making conversations should address the purpose of follow-up, recurrence risk, imaging choices, the current lack of evidence for routine tumor marker or ctDNA monitoring, and psychosocial concerns such as fear of recurrence. The panel noted that recommendations will be revisited as additional evidence-based tools become available to further individualize surveillance.

REFERENCES

1. Nahleh Z, Alfano CM, Somerfield MR, et al. Breast Cancer Follow-Up and Surveillance After Primary Treatment: ASCO Guideline Update. J Clin Oncol. Published online July 16, 2026. doi:10.1200/JCO-26-01700

2. Dunn JA, Donnelly P, Elbeltagi N, et al. Annual versus less frequent mammographic surveillance in people with breast cancer aged 50 years and older in the UK (Mammo-50): a multicentre, randomised, phase 3, non-inferiority trial. Lancet. 2025;405(10476):396-407. doi:10.1016/S0140-6736(24)02715-6

3. Lockwood CM, Messersmith HJ, Kim AS, et al. Circulating Tumor DNA Testing in Solid Tumors and Lymphoma: ASCO Guideline. JCO Oncol Pract. Published online June 18, 2026. doi:10.1200/OP-26-00311