Clinicopathological factors and nomograms predicting nonsentinel lymph node metastases after neoadjuvant chemotherapy in breast cancer patients

Non-sentinel node metastasis prediction during surgery in breast cancer patients with one to three positive sentinel node(s) following neoadjuvant chemotherapy

Our aim was to develop a tool to accurately predict the possibility of non-sentinel lymph node metastasis (NSLNM) during surgery so that a surgeon might decide the extent of further axillary lymph node dissection intraoperatively for patients with 1-3 positive sentinel lymph node(s) (SLN) after neoadjuvant chemotherapy. After retrospective analysis of Asan Medical Center (AMC) database, we included 558 patients' records who were treated between 2005 and 2019. 13 factors were assessed for their utility to predict NSLNM with chi-square and logistic regression with a bootstrapped, backward elimination method. Based on the result of the univariate analysis for statistical significance, number of positive SLN(s), number of frozen nodes, Progesterone Receptor (PR) positivity, clinical N stage were selected for the multivariate analysis and were utilized to generate a nomogram for prediction of residual nodal disease. The resulting nomogram was tested for validation by using a patient group of more recent, different time window at AMC. We designed a nomogram to be predictive of the NSLNM which consisted of 4 components: number of SLN(s), number of frozen nodes, PR positivity, and clinical N stage before neoadjuvant chemotherapy. The Area under the receiver operating characteristics curve (AUC) value of this formula was 0.709 (95% CI, 0.658-0.761) for development set and 0.715 (95% CI, 0.634-0.796) for validation set, respectively. This newly created AMC nomogram may provide a useful information to a surgeon for intraoperative guidance to decide the extent of further axillary surgery.

Sentinel lymph node biopsy after neoadjuvant chemotherapy predicts pathological axillary lymph node status in breast cancer patients with clinically positive axillary lymph nodes at presentation

BACKGROUND

It is still controversial whether axillary lymph node (ALN) dissection (ALND) can be omitted after negative sentinel lymph node (SLN) biopsy (SLNB) in breast cancer (BC) patients with clinically positive ALNs at presentation treated with neoadjuvant chemotherapy (NAC). The study aim was to analyze whether SLNB could be useful in these patients.

METHODS

In a retrospective study, eligible patients were women with invasive BC with clinically positive ALNs at presentation, treated with NAC then a total or partial mastectomy, with an intraoperative histological examination of SLNs and non-SLNs suspicious for metastasis followed by ALND. Non-SLNs suspicious for metastasis were defined as hard or large nodes located in the same level of the axilla where clinically positive ALNs had been initially identified. The results of SLNB and clinicopathological characteristics were analyzed for correlation with pathological ALN status.

RESULTS

In a consecutive series of 105 women with 107 BC cases, 81 (75.7 %) had at least 1 SLN, and the remaining 26 (24.3 %) had at least 1 non-SLN suspicious for metastasis. The intraoperative (or final) histological examination of these nodes revealed that the false-negative (FN) rate and accuracy were 8.2 (or 6.3) % and 95.1 (or 96.3) %, respectively. Estrogen receptor status at presentation, pathological tumor response, lymphovascular invasion after NAC, and NAC regimen were correlated with pathological ALN status.

CONCLUSION

The histological examination of SLNs and that of non-SLNs suspicious for metastasis are useful for predicting pathological ALN status in BC patients with clinically positive ALNs at presentation who are treated with NAC.