Validation of the Tenon breast cancer score for predicting non-sentinel lymph node status in breast cancer patients with sentinel lymph node metastasis: a prospective multicenter study

Background Axillary lymph node dissection (ALND) is the standard treatment for patients with sentinel node (SN) metastasis, but most of these patients have negative non-sentinel nodes (non-SN). We have developed a scoring system (the Tenon score) to help identify a subgroup of patients who have a low risk of having non-SN metastases and who may thus forgo ALND. Here we validated the Tenon score in an independent cohort of SN-positive patients. Patients and methods We tested the accuracy of the Tenon score for predicting non-SN status in a prospective multicenter study of 226 SN-positive breast cancer patients. We calculated the false-negative rate, sensitivity, specificity, and positive (PPV) and negative predictive values (NPV). Receiver operating characteristics (ROC) curves were constructed and the areas under the curve (AUC) were calculated as a measure of discriminatory capacity. Results At least one non-SN was positive in 63 patients (27.9%). One hundred and twenty (53.1%) of the 226 patients had a Tenon score of 3.5 or less. Among these 120 patients, five had at least one positive non-SN. With a score cut-off of 3.5, the negative predictive value was 95.8% and the false-negative rate was 4.2%. Overall, the Tenon score accurately predicted non-SN status, with an AUC of 0.82 (95% confidence interval, 0.77–0.88). Conclusion In this multicenter study of an independent patient population, the Tenon score was accurate and reproducible for predicting non-SN status in breast cancer patients. The simplicity and reliability of the variables on which the Tenon score is based may be an advantage over other scoring systems.