ASTRO 2026 Conference Preview for Breast Cancer Sessions

The 2026 annual meeting of the American Society for Radiation Oncology (ASTRO) is just a few weeks away. From September 26 through September 30, in Boston, Massachusetts, the 2026 ASTRO annual meeting is five days filled with poster presentations, educational sessions, continuing education opportunities, networking events, and more.

Today, we’re previewing the sessions focusing on breast cancer topics that are currently scheduled for the 2026 ASTRO annual meeting. All times and dates are accurate as of August 19, 2026. For the most up-to-date information, and for a look at all the other sessions currently scheduled, view the event’s full schedule.

Breast Cancer Sessions at the ASTRO 2026 Annual Meeting

Saturday, September 26

• Anticipating and Reducing Potential Toxicity in Breast Cancer Treatment: Hypofractionation and Volume Reduction, Planning Objectives and Techniques to Limit Toxicity, and Management of Adverse Effects
  • 7:55 AM – 9:15 AM
  • Description: This session will include three discussants using case-based presentations to examine the ways in which radiation oncologists can anticipate and reduce toxicity when treating breast cancer patients.

Sunday, September 27

• Multidimensional Toxicity in Breast Cancer Radiotherapy: Integrating Clinical, Patient-Reported, and Biological Outcomes
  • 3:00 PM – 4:00 PM
  • Description: This session includes presentations on topics including safety of postoperative concurrent capecitabine and intensity-modulated radiotherapy in triple-negative breast cancer, radiation-induced hypothyroidism in patients with breast cancer after hypofractionated radiotherapy, and more.

• Nonoperative and Preoperative Local Management of Breast Cancer: From Data to Shared Decisions
  • 3:00 PM – 4:00 PM
  • Description: This session will explore emerging strategies for preoperative and nonoperative local management of breast cancer, focusing on when and how radiotherapy or ablative techniques might safely substitute for or reshape surgery in select patients.

Monday, September 28

• Predicting Outcomes in Breast Cancer: From Multi-Omics to AI-Driven Models
  • 8:00 AM – 9:00 AM
  • Description: This session includes presentations on the association of the radiosensitivity index with overall survival in radiotherapy-treated HER2+ and tiiple-negative breast cancer, the association of blood count-derived inflammatory indices with capsular contracture after post-mastectomy radiotherapy in breast cancer patients undergoing direct-to-implant reconstruction, and more.

• Integrating Postmastectomy Radiotherapy (PMRT) with Breast Reconstruction: Insights from Plastic Reconstructive Surgery and the Role of the Radiation Oncologist
  • 10:45 AM – 12:00 PM
  • Description: The integration of postmastectomy radiation therapy (PMRT) with the full spectrum of breast reconstruction techniques remains one of the most complex and heterogeneous areas in breast cancer care.

• Breast Cancer, Patient Reported Outcomes/QoL/Survivorship, Functional Radiation Medicine, Hematologic Malignancies, Palliative Care, and International/Global Oncology
  • 3:00 PM – 4:00 PM
  • Description: This poster session is set to feature topics including the characterization of cannabis use in patients with prostate, lung, and breast cancer enrolled in a statewide multicenter cohort, early-stage breast cancer patient demographic predictors of adjuvant radiation therapy completion in the United States, and more.

• Evolving Paradigms in Axillary Nodal Management: Precision Medicine Refining Regional Breast Cancer Care
  • 5:00 PM – 6:00 PM
  • Description: Presenters will describe in early-stage breast cancer that non-invasive diagnostic assessment of the ipsilateral axilla may allow for safe omission of sentinel nodal mapping in select patients, and describe and discuss how neoadjuvant therapy has changed the role of both radiation and surgical oncology approaches to treatment of the axillary regional nodes in patients achieving a pathological complete response to upfront systemic therapy.

Tuesday, September 29

• Liquid Biopsy: ctDNA in Early Stage and Metastatic Breast Cancer
  • 12:30 PM – 1:45 PM
  • Description: This session will cover a number of topics: 1) Review the current technologies for liquid biopsy in breast cancer. 2) ctDNA in Early Breast Cancer a. rates of ctDNA detection in early stage breast cancer at diagnosis, pre- and post- neoadjuvant chemotherapy, and in the adjuvant setting. b. the utility of ctDNA in detecting MRD and predicting relapse in the adjuvant setting. c. the lead time between ctDNA detection and clinical relapse d. ongoing therapeutic trials using ctDNA in the adjuvant period. 3) ctDNA in stage IV breast cancer. a. uses of ctDNA to track disease and modify therapy b. radiation effect on ctDNA and ongoing trials in this space.

• Evolving Paradigms in High-Risk Breast Cancer: Optimization and Integration of Treatment Modalities Across the Disease Continuum
  • 3:45 PM – 5:00 PM
  • Description: This session features topics including simultaneous integrated boost in hypofractionated regional lymph node irradiotherapy for cN3 breast cancer, TP53 mutations in primary breast tumors predict brain metastases, and more.

• Clinical Potpourri: Navigating Early-Stage RT, N1mi Disease, and Risk Mitigation in Triple Negative and HER2+ Breast Cancer
  • 5:15 PM – 6:15 PM
  • Description: This session will include presentations on adjuvant endocrine therapy adherence and outcomes in early breast cancer patients treated with APBI, local recurrence risk in patients with microinvasive vs. early-stage invasive breast cancer, and more.

Wednesday, September 30

• Breast Cancer – Science Highlights
  • 8:00 AM – 8:30 AM
  • Description: This session focuses on topics including a phase 1,2 study of concurrent abemaciclib and adjuvant radiotherapy in patients with HR+, HER2-, and high-risk breast cancer, hypofractionated vs. conventional fractionated postmasectomy radiotherapy in high-risk breast cancer, and more.

• Right-Sizing Radiation in Early Breast Cancer: Omission, Shortening, and Targeted Approaches
  • 9:15 AM – 10:30 AM
  • Description: This session includes presentations on the prospective evaluation of a once per day regimen of accelerated partial breast irradiation in low-risk, hormone-responsive breast cancer, validation of a multi-omic biosignature in a multi-institutional cohort to predict locoregional recurrence risk and differential RT effect in early-stage invasive breast cancer, and more.

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