Optimal management of breast cancer with physical exam negative/radiological abnormal axilla

Abstract

For breast cancer patients with physical exam node negative but radiological finding node abnormal (cN0/rNa), the NCCN and ASCO guidelines recommend sentinel lymph node biopsy (SLNB) as the first-line axillary staging. However, patients who undergo surgery firstly may be upstaged to pathological II–III status, and these patients happen to be the adaptive population of neoadjuvant therapy (NAT). There is no consensus on the optimal management of cN0/rNa patients. The aim is to explore the optimal management strategy of these patients. We performed a retrospective real-world study of 1414 cN0/rNa patients from June 2014 to October 2022. There were 1003 patients underwent surgery first and 411 patients underwent surgery after NAT. We analyzed the real-world conditions of these patients, compared axilla tumor burden between these two groups. In addition, we compared benefit ratio of axillary surgery and regional nodal irradiation (RNI) de-escalation under the two strategies. Among 1003 patients underwent surgery first, the positive and negative rates of fine needle aspiration (FNA) were 18.5% and 81.5%, respectively. There were 66.1% had ≤ 2 lymph nodes+. There were 40.8% of FNA+ patients could be exempted from ALND underwent surgery first. In 411 patients underwent surgery after NAT, the FNA positive and negative rates were 60.8% and 49.2%, respectively. There were 54.4% of FNA+ patients achieved axilla pathologic complete response (apCR) and could omit ALND after NAT. The apCR was 67.3% in HER2+/TNBC subtypes. According to the NSABP-B51 trial, there were 0 and 54.4% of FNA+ patients could omit RNI among surgery first and after NAT, respectively. Among 1–2 sentinel lymph node (SLN)-positive patients underwent surgery first, with a median follow-up 49 months, there was no difference of survival benefit between SLNB-only and SLNB-ALND. Compared with 1–2 SLN+ patients without RNI, RNI could bring better invasive disease-free survival (97.38% vs. 89.36%, P = 0.046) and breast cancer special survival (100% vs. 94.68%, P = 0.020). It is safe to perform SLNB omitting ALND when detected 1–2 positive SLNs in cN0/rNa patients. Patients with HER2+/TNBC subtypes underwent surgery after NAT had more chance to benefit from dual de-escalation, including axillary surgery and RNI de-escalation.