Mark R. Somerfield

ASCO Guidelines provide recommendations with comprehensive review and analyses of the relevant literature for each recommendation, following the guideline development process as outlined in the https://www.asco.org/practice-patients/guidelines/guideline-methodology . ASCO Guidelines follow the https://www.asco.org/about-asco/legal/conflict-interest-coi . Clinical Practice Guidelines and other guidance (“Guidance”) provided by ASCO is not a comprehensive or definitive guide to treatment options. It is intended for voluntary use by clinicians and should be used in conjunction with independent professional judgment. Guidance may not be applicable to all patients, interventions, diseases or stages of diseases. Guidance is based on review and analysis of relevant literature, and is not intended as a statement of the standard of care. ASCO does not endorse third-party drugs, devices, services, or therapies and assumes no responsibility for any harm arising from or related to the use of this information. See complete disclaimer in Appendix 1 and Appendix 2 (online only) for more . PURPOSE: To offer clinicians recommendations concerning breast cancer follow-up and surveillance after primary treatment. METHODS: ASCO convened an Expert Panel to develop recommendations based on a systematic review and a formal consensus process. RESULTS: One randomized controlled trial (RCT) was identified and formed the evidentiary basis for the surveillance mammography guideline recommendation. No RCTs were identified that evaluated different follow-up approaches by risk of relapse in patients treated for early-stage breast cancer. Given the dearth of evidence identified in the systematic review of the literature, formal modified Delphi consensus-based recommendations were generated. RECOMMENDATIONS: The guideline offers recommendations on the role of a risk-based approach to the frequency and intensity of follow-up among patients with breast cancer in the adjuvant setting. Regular history, physical examination, and mammography are recommended for breast cancer follow-up. Either virtual or in-person visits can be offered. Certain patients at a high risk of cancer recurrence warrant closer surveillance, such as those patients with locally advanced disease or residual disease following neoadjuvant chemotherapy. Recommendations on the use of blood-based biomarkers and supplemental imaging are provided. Guideline recommendations will be updated once additional evidence-based tools become available to better individualize surveillance. Additional information is available at www.ascopubs.org/topics/asco-guidelines/breast-cancer .

This guideline has been updated. This ASCO Living Guideline is reviewed on an eight-week cycle. Please see the online dynamic version for the latest updates. Living guidelines are developed for selected topic areas with rapidly evolving evidence that drives frequent change in recommended clinical practice. Living guidelines are updated on a regular schedule by a standing expert panel that systematically reviews the health literature on a continuous basis, as described in the ASCO Guidelines Methodology Manual . ASCO Living Guidelines follow the ASCO Conflict of Interest Policy Implementation for Clinical Practice Guidelines . Living Guidelines and updates are not intended to substitute for independent professional judgment of the treating clinician and do not account for individual variation among patients. Clinical Practice Guidelines and other guidance (“Guidance”) provided by ASCO is not a comprehensive or definitive guide to treatment options. It is intended for voluntary use by clinicians and should be used in conjunction with independent professional judgment. Guidance may not be applicable to all patients, interventions, diseases or stages of diseases. Guidance is based on review and analysis of relevant literature, and is not intended as a statement of the standard of care. ASCO does not endorse third-party drugs, devices, services, or therapies and assumes no responsibility for any harm arising from or related to the use of this information. See complete disclaimer in Appendix 1 and Appendix 2 (online only) for more. Purpose: To provide recommendations on use of medical therapies for patients with stage I to III hormone receptor–positive, human epidermal growth factor receptor 2 (HER2)–negative breast cancer. Methods: An Expert Panel including patient representation completed a systematic review of the evidence and formulated recommendations for practice. Eligible studies included patients with stage I to III hormone receptor–positive, HER2-negative breast cancer and evaluated neoadjuvant or adjuvant chemotherapy, endocrine therapy (ET), immunotherapy, or targeted therapy. Outcomes of interest included pathologic complete response, disease-free survival, distant recurrence-free survival, overall survival, health-related quality of life, and treatment-related adverse effects. Results: Forty-five randomized clinical trials (68 references) published from 2018 to 2026 were identified by the broad literature search. Supplemental searches identified six individual patient data meta-analyses and 21 retrospective studies that, combined with the primary clinical trials, informed guidance on which patients should receive treatment, which treatments should be selected, optimal treatment timing, duration of treatment, and approaches to support adherence. A final section addresses estimation of prognosis and treatment benefit to inform decisions across all phases of treatment. Recommendations: The recommendations are organized to follow the longitudinal care of patients with stage I to III hormone receptor–positive, HER2-negative breast cancer, reflecting the sequence of decisions faced by clinicians from diagnosis through completion of systemic therapy. ET remains the foundation of treatment for stage I to III hormone receptor–positive, HER2-negative breast cancer. For selected patients, chemotherapy and targeted therapies can further reduce the risk of recurrence and breast cancer death. Treatment recommendations should integrate clinicopathologic features, genomic assays, patient preferences, treatment tolerability, and estimated recurrence risk. The guideline provides evidence-based recommendations to support individualized treatment selection and sequencing across the continuum of care. Additional information is available on the ASCO Publications website .

ASCO Guidelines provide recommendations with comprehensive review and analyses of the relevant literature for each recommendation, following the guideline development process as outlined in the ASCO Guidelines Methodology Manual . ASCO Guidelines follow the ASCO Conflict of Interest Policy for Clinical Practice Guidelines . Clinical Practice Guidelines and other guidance (“Guidance”) provided by ASCO is not a comprehensive or definitive guide to treatment options. It is intended for voluntary use by clinicians and should be used in conjunction with independent professional judgment. Guidance may not be applicable to all patients, interventions, diseases or stages of diseases. Guidance is based on review and analysis of relevant literature, and is not intended as a statement of the standard of care. ASCO does not endorse third-party drugs, devices, services, or therapies and assumes no responsibility for any harm arising from or related to the use of this information. See complete disclaimer in Appendix 1 and 2 (online only) for more. PURPOSE: To update the ASCO evidence-based recommendations on the use of sentinel lymph node biopsy (SLNB) in patients with early-stage breast cancer treated with initial surgery. METHODS: ASCO convened an Expert Panel to develop updated recommendations based on a systematic literature review (January 2016-May 2024). RESULTS: Eleven randomized clinical trials (14 publications), eight meta-analyses and/or systematic reviews, and one prospective cohort study met the inclusion criteria for this systematic review. Expert Panel members used available evidence and informal consensus to develop practice recommendations. RECOMMENDATIONS: Clinicians should not recommend routine SLNB in select patients who are postmenopausal and ≥50 years of age and with negative findings on preoperative axillary ultrasound for grade 1-2, small (≤2 cm), hormone receptor–positive, human epidermal growth factor receptor 2–negative breast cancer and who undergo breast-conserving therapy. Clinicians may offer postmastectomy radiation (RT) with regional nodal irradiation (RNI) and omit axillary lymph node dissection (ALND) in patients with clinically node-negative invasive breast cancer ≤5 cm who receive mastectomy and have one to two positive sentinel nodes. Clinicians may offer SLNB in patients who have cT3-T4c or multicentric tumors (clinically node-negative) or ductal carcinoma in situ treated with mastectomy, and in patients who are obese, male, or pregnant, or who have had prior breast or axillary surgery. Clinicians should not recommend ALND for patients with early-stage breast cancer who do not have nodal metastases, and clinicians should not recommend ALND for patients with early-stage breast cancer who have one or two sentinel lymph node metastases and will receive breast-conserving surgery and whole-breast RT with or without RNI. Additional information is available at www.asco.org/breast-cancer-guidelines . This guideline has been endorsed by the American Society for Radiation Oncology (ASTRO).

ASCO Rapid Recommendation Updates highlight revisions to select ASCO guideline recommendations as a response to the emergence of new and practice-changing data. The rapid updates are supported by an evidence review and follow the guideline development processes outlined in the ASCO Guideline Methodology Manual . The goal of these articles is to disseminate updated recommendations, in a timely manner, to better inform health practitioners and the public on the best available cancer care options. Guidelines and updates are not intended to substitute for independent professional judgment of the treating provider and do not account for individual variation among patients. See appendix for disclaimers and other important information ( Appendix 1 and Appendix 2 , online only).

ASCO Rapid Recommendation Updates highlight revisions to select ASCO guideline recommendations as a response to the emergence of new and practice-changing data. The rapid updates are supported by an evidence review and follow the guideline development processes outlined in the ASCO Guideline Methodology Manual. The goal of these articles is to disseminate updated recommendations, in a timely manner, to better inform health practitioners and the public on the best available cancer care options. Guidelines and updates are not intended to substitute for independent professional judgment of the treating provider and do not account for individual variation among patients. See appendix for disclaimers and other important information ( Appendix 1 and Appendix 2 , online only).

PURPOSE: To develop recommendations for germline mutation testing for patients with breast cancer. METHODS: An ASCO–Society of Surgical Oncology (SSO) panel convened to develop recommendations based on a systematic review and formal consensus process. RESULTS: Forty-seven articles met eligibility criteria for the germline mutation testing recommendations; 18 for the genetic counseling recommendations. RECOMMENDATIONS: BRCA1/ 2 mutation testing should be offered to all newly diagnosed patients with breast cancer ≤65 years and select patients >65 years based on personal history, family history, ancestry, or eligibility for poly(ADP-ribose) polymerase (PARP) inhibitor therapy. All patients with recurrent breast cancer who are candidates for PARP inhibitor therapy should be offered BRCA1/ 2 testing, regardless of family history. BRCA1/ 2 testing should be offered to women who develop a second primary cancer in the ipsilateral or contralateral breast. For patients with prior history of breast cancer and without active disease, testing should be offered to patients diagnosed ≤65 years and selectively in patients diagnosed after 65 years, if it will inform personal and family risk. Testing for high-penetrance cancer susceptibility genes beyond BRCA1/ 2 should be offered to those with supportive family histories; testing for moderate-penetrance genes may be offered if necessary to inform personal and family cancer risk. Patients should be provided enough pretest information for informed consent; those with pathogenic variants should receive individualized post-test counseling. Variants of uncertain significance should not impact management, and patients with such variants should be followed for reclassification. Referral to providers experienced in clinical cancer genetics may help facilitate patient selection and interpretation of expanded testing, and provide counseling of individuals without pathogenic germline variants but with significant family history. Additional information is available at www.asco.org/breast-cancer-guidelines .