Top 5 Surgical Takeaways from NCCN Breast for Invasive Breast Cancer

The surgical management of invasive breast cancer continues to evolve toward a "less is more" approach, prioritizing de-escalation of local therapy when oncologically safe. At the recent NCCN 2026 Breast Cancer Congress, Meghan R. Flanagan, MD, MPH, a physician at Fred Hutch and assistant professor of surgery at the University of Washington School of Medicine, highlighted critical updates from the 2025 San Antonio Breast Cancer Symposium (SABCS) and recent clinical trials that are reshaping standard care.¹ For oncology clinicians, these updates provide a framework for optimizing patient outcomes through personalized surgical and systemic strategies.

1. Neoadjuvant Endocrine Therapy as a Tool for Breast Conservation

While pathologic complete response (pCR) remains rare with neoadjuvant endocrine therapy (NET), its primary utility lies in increasing eligibility for breast-conserving surgery.² Data from 5 randomized controlled trials, including the phase 3 ALTERNATE trial (NCT01953588), demonstrate an approximately 30% to 40% conversion rate from mastectomy to BCS—results comparable to neoadjuvant chemotherapy for hormone receptor–positive disease. Clinicians should consider neoadjuvant endocrine therapy to improve cosmetic outcomes and assess real-time tumor response and patient adherence.

2. Evidence-Based Omission of Sentinel Lymph Node Biopsy (SLNB)

Recent data from the SOUND (NCT02167490), INSEMA (NCT02466737), and BOOG 2013-08 (NCT02271828) trials suggest that SLNB may be safely omitted in specific populations. These studies focused on patients with cT1 to cT2, cN0 tumors and negative axillary ultrasounds who were planned for lumpectomy and radiation. Results showed axillary recurrence rates as low as 0.4% to 0.9% at 5 years. The 2026 NCCN guidelines now state that omission of SLNB may be considered for patients with hormone receptor–positive/HER2-negative, pT1, N0 (by ultrasound) tumors.³

3. Balancing Surgical De-escalation with Systemic Staging Needs

The omission of SLNB presents a challenge for medical oncologists who rely on nodal status to guide systemic therapy, such as the use of CDK 4/6 inhibitors.⁴ High-risk features such as grade 3 disease or high Ki67 in patients who are node negative may still warrant systemic escalation in trials like the phase 3 NATALEE (NCT03701334) or monarchE trials (NCT03155997). Clinicians must weigh the benefit of reducing surgical morbidity like lymphedema against the potential for undertreatment due to a lack of staging information.

4. Refining Axillary Management After Neoadjuvant Chemotherapy

The observational AXSANA study (NCT04373655) has expanded the cohort of patients who may be eligible for SLNB after neoadjuvant chemotherapy, specifically those transitioning from cN-positive to ycN0 status.⁵ This trial increases the evidence base for avoiding full axillary lymph node dissection (ALND) in patients who show a robust clinical response to systemic treatment, although no single procedure type (SLNB vs targeted axillary dissection) has yet shown clear superiority.

5. Long-term Patient-Reported Outcomes Favor Breast-Conserving Surgery

Long-term data from the Texas Cancer Registry underscore the importance of breast-conserving surgery for patient quality of life.⁶ At 10 years post-surgery, patients who underwent breast-conserving surgery and radiation reported significantly better psychosocial and sexual well-being compared with those who had mastectomies with reconstruction. These findings support the continued push for neoadjuvant strategies that enable breast-conserving surgery whenever possible.

References

1. Flanagan MR. Surgical management of invasive breast cancer with SABCS updates. Presented at: NCCN 2026 Breast Cancer Congress; February 6, 2026. https://tinyurl.com/ysjccw69
2. Leitch AM, Dockter T, Suman VJ, et al. Surgical outcomes in the ALTERNATE trial (Alliance A011106) -a randomized phase 3 neoadjuvant endocrine therapy (NET) trial in postmenopausal women with clinical stage II/III estrogen receptor positive (ER+) and HER2 negative (HER2-) breast cancer (BC). Abstract presented at: 2025 San Antonio Breast Cancer Symposium; December 9-12, 2025; San Antonio, TX. Abstract RF1-02.
3. NCCN Clinical Practice Guidelines in Oncology. Breast Cancer. Version 1.2026. https://tinyurl.com/muz9yye2
4. Kandzi JD, Englisch A, Boeer B, et al. Reconciling sentinel node omission with cdk4/6 inhibitor eligibility in hr+/her2- early breast cancer: a real-world cohort analysis. Clin Breast Cancer. Published online October 13, 2025. doi:10.1016/j.clbc.2025.10.003
5. Kühn T, Banys-Paluchowski M, Ditsch N, et al. More versus less invasive axillary surgical staging procedures in breast cancer patients converting from a clinically node-positive to a clinically node-negative stage through neoadjuvant chemotherapy – primary endpoint analysis of the international prospective multicenter AXSANA/EUBREAST 3(R)study. Presented at 2025 San Antonio Breast Cancer Symposiu;. December 9-12, 2025; San Antonio, TX. Abstract GS2-01.
6. Hanson SE, Lei X, Roubaud MS, et al. Long-term quality of life in patients with breast cancer after breast conservation vs mastectomy and reconstruction. JAMA Surg. 2022;157(6):e220631. doi:10.1001/jamasurg.2022.0631