Factors Predicting Positive Sentinel Lymph Node Biopsy in Clinically Node-Negative Breast Cancer [Letter]

Dear editor

We read with great interest the study entitled “Factors Predicting Positive Sentinel Lymph Node Biopsy in Clinically Node-Negative Breast Cancer” by Alsumai et al.¹ The authors conducted a retrospective study to identify the predictors of positive sentinel lymph node biopsy (SLNB) in patients with clinically node-negative breast cancer. We congratulate Dr Alsumai on the results.

However, we have several concerns from the perspective of data interpretation and extrapolation.

In general, recognizable preoperative characteristics of patients have relatively high predictive values for positive SLNB.² We believe that the characteristics included in this study such as tumor focality in final pathology and locoregional recurrence contribute little to surgical decision-making, as they cannot be identified before surgery. Furthermore, since the discussion part mentioned that the purpose of the study was identifying noninvasive predictors, postoperative features such as tumor size in final pathology should not be included in the analysis. On the other hand, we would like to know which specific variables in the simple logistic regression analysis were included in the multiple regression analysis and what was the cut-off value. If the critical factors in the simple logistic regression are not included in the multiple regression analysis, the potential independent influencing factors may be ignored. In addition, common potential predictors such as menstrual status, body mass index (BMI), comorbidity, and surgical history were not described, which may lead to information bias. By the way, the inclusion and exclusion criteria should be included in the Study Design, not Data Collection Method.

In this study, 128 patients (27.2%) were SLNB positive and 109 patients underwent axillary lymph node dissection (ALND). None of the SLNB-positive patients with micrometastasis had undergone ALND. Given whether sentinel-node micrometastases affect the prognosis of patients and whether patients with sentinel-node micrometastases still need ALND, researchers still have different viewpoints.³ We would be interested in the comparison of prognosis between patients with sentinel-node micrometastases and patients with negative sentinel lymph nodes in the author’s institution, as it is not mentioned. Besides, the authors described in their conclusion that their findings can significantly contribute to therapeutic decisions. We would like to know what guidance and adjustments the author team has made to the therapeutic decisions based on these predictors.

Finally, all patients in this study received a uniform management procedure from a single medical institution. While this helped control for selection bias, it also limited the generalization of the results to more institutions.

Despite these concerns, we thank the authors for their efforts on this subject, especially in the identification of patients’ clinical, histopathological, and radiological characteristics associated with positive SLNB. In view of the increasing popularity of breast cancer screening programs and the increasing rate of screening-detected breast cancer of early stage, we hope to see long-term prospective studies with larger sample sizes on this topic in the future.