More Negative Sentinel Nodes Didn’t Improve Breast Cancer Outcomes
Key Takeaways
- In a 1,551-patient single-center cohort of cT1-2N0M0 breast cancer with negative sentinel nodes, 5-year DFS and OS did not differ significantly across groups with 1-3, 4-6, or at least 7 nodes removed.
- Adjusted analyses did not identify sentinel-node count as an independent factor for DFS, OS, axillary recurrence, or patient-described arm outcomes.
- Short-term postoperative arm outcomes were uncommon, with lymphedema reported in 5.9%, strength limitation in 4.8%, and mobility limitation in 2.5%.
- Among exploratory immune markers, only postoperative change in neutrophil-to-lymphocyte ratio differed significantly across sentinel-node-count groups.
In a single-center cohort, investigators at the First Hospital of Jilin University retrospectively studied patients treated from 2012 through 2019 for clinically staged cT1-T2N0M0 breast cancer who underwent sentinel lymph node biopsy (SLNB) with negative sentinel lymph nodes (SLNs). They excluded patients who underwent axillary lymph node dissection for SLN metastasis or direct axillary dissection, received neoadjuvant therapy, had bilateral breast cancer, had a prior malignant breast tumor or another concurrent malignancy, or had equivocal pathology such as indeterminate HER2 status. Patients were grouped by 1-3, 4-6, or ≥7 excised SLNs, follow-up was truncated at 60 months, the primary endpoint was 5-year disease-free survival (DFS), and secondary endpoints included overall survival (OS), axillary recurrence, self-reported lymphedema, mobility and strength limitation, and exploratory hematologic immune changes.
The final survival cohort included 1,551 patients: 925 in the 1-3-node group, 499 in the 4-6-node group, and 127 in the ≥7-node group. During 60-month follow-up, 82 DFS events (5.3%) and 39 OS events (2.5%) occurred. After multivariable adjustment, higher node yield was not associated with DFS, with hazard ratios of 0.92 (95% CI 0.57-1.48; p = 0.74) for 4-6 versus 1-3 SLNs and 1.02 (95% CI 0.43-2.09; p = 0.95) for ≥7 versus 1-3, and it was not associated with OS, at 0.82 (95% CI 0.39-1.61; p = 0.57) and 0.91 (95% CI 0.24-2.45; p = 0.86), respectively. Other survival comparisons were likewise nonsignificant.
Short-term postoperative arm outcomes were uncommon, with lymphedema reported in 5.9%, strength limitation in 4.8%, and mobility limitation in 2.5%. Adjusted analyses did not identify SLN-count group as an independent factor for axillary recurrence, lymphedema, mobility limitation, or strength limitation. Analyses using alternate node-count thresholds also showed no significant survival differences. In an exploratory immune subset of 906 patients with complete laboratory data, only postoperative change in neutrophil-to-lymphocyte ratio (ΔNLR) differed across groups (p = 0.02).
The authors noted several constraints on interpretation, including the retrospective single-center design, the low event rate, and complication outcomes based on routine patient self-report rather than objective measurement or standardized questionnaires. Residual confounding from treatment patterns and comorbidities across the long study period may remain, and the findings apply most directly to this cT1-2 population with negative SLNs. Some patients in the ≥7 category may have had non-sentinel nodes removed, and the immune analysis remained exploratory because postoperative blood tests were obtained 1 month after surgery after adjuvant chemotherapy and long-acting granulocyte colony-stimulating factor exposure.
Within this selected cohort of early breast cancer with negative SLNs, the investigators found no independent prognostic or morbidity signal tied to higher negative-node counts. They also cautioned that these data do not establish the safety of deliberately minimizing sentinel-node excision in routine practice.
Clinician Questions
Which breast cancer patients do these sentinel-node findings apply to?
These findings apply to patients with clinically staged cT1-T2N0M0 breast cancer and negative sentinel lymph nodes treated at a single center in China. Exclusions included axillary lymph node dissection for SLN metastasis or direct axillary dissection, neoadjuvant therapy, bilateral breast cancer, prior malignant breast tumor, another concurrent malignancy, and equivocal pathology such as indeterminate HER2 status. The authors said the conclusions should not be directly extrapolated to locally advanced breast cancer.
How were lymphedema and arm-function outcomes assessed after sentinel lymph node biopsy in this cohort?
Lymphedema, shoulder mobility limitation, and strength limitation after SLNB were abstracted from routine patient self-report documented in outpatient records at 1- to 2-year follow-up. No standardized questionnaire or objective measurement tool was used, which limits direct comparability with cohorts that used measured arm outcomes.
Why does the group with at least 7 nodes removed need cautious interpretation?
The authors noted that American Joint Committee on Cancer conventionally considers up to 6 nodes a typical sentinel-node range, so some patients in the ≥7 group may have had non-sentinel nodes removed. That makes this category a more heterogeneous marker of surgical extent rather than a pure SLN-count comparison.
Why was the ΔNLR finding considered exploratory rather than definitive?
The ΔNLR analysis was limited to 906 patients with complete preoperative and postoperative laboratory data, and the postoperative blood draw occurred 1 month after surgery after adjuvant chemotherapy and long-acting granulocyte colony-stimulating factor exposure. Other inflammatory confounders such as infection could not be fully excluded, so the authors framed the signal as hypothesis-generating rather than causal.