Predictive factors for the occurrence of four or more axillary lymph node metastases in ER-positive and HER2-negative breast cancer patients with positive sentinel node: A retrospective cohort study.

INTRODUCTION

Patients with four or more axillary lymph node metastases have benefited from postmastectomy radiotherapy to the supraclavicular region. However, when metastatic sentinel nodes (SNs) are present, information regarding the total number of node metastases cannot be obtained if axillary lymph node dissection (ALND) is omitted from the treatment protocol. It is important to determine the indication for additional chemotherapy in ER-positive and HER2-negative breast cancer patients. We investigated the predictive factors for the occurrence of four or more metastases in patients with ER-positive and HER2-negative breast cancer in the presence of macrometastasis in the SNs.

METHODS

We reviewed 83 patients with ER-positive and HER2-negative breast cancer, who had macrometastasis in the SN and had undergone ALND. The clinicopathological findings and prognosis between patients with pN1 disease and those with pN2 disease were also compared.

RESULTS

Nineteen percent of patients had pN2-3 disease. The predictive factor for poor prognosis in these patients was the presence of pN2-3 disease. The independent predictive factors for pN2-3 disease were the T stage and the ratio of the number positive SNs to the number of removed SNs (SN ratio). Patients with both T2 tumors and a high SN ratio had a 50% risk of having pN2-3 disease.

CONCLUSION

The presence of four or more metastases was found to be the strongest prognostic factor in ER-positive and HER2-negative breast cancer patients with macrometastasis in the SN. The T stage and SN ratio determined before surgery or during surgery were useful in predicting pN2-3 disease in these patients.