57OA nomogram for predicting the likelihood of axillary lymph node metastasis in breast cancer patients based on ultrasonographic-pathologic features

Background: Axillary lymph node status is an important prognostic factor of breast cancer patients. Several variables have been confirmed as predictors of axillary lymph node metastasis in breast cancer. However, it is rather difficult to apply the nomogram for predicting the likelihood of axillary lymph node metastasis before surgery. This study aimed to construct a novel nomogram to predict the risk of axillary metastasis preoperatively in breast cancer patients based on ultrasonographic-pathologic features. Methods: Data were collected from 1,273 patients who were histologically proven breast cancer between January 2012 and March 2017, and divided them into the training set and the validation set. Besides, the prospective validation study was registered at Clinicaltrials.gov. Statistically significant independent predictors were identified in multivariate logistic regression analysis. A receiver operating characteristic curve was implemented to evaluate the discriminative ability of the nomogram. Furthermore, a calibration plot was executed to compare actual versus predicted probability. Finally, decision curve analysis was used to assess the clinical usefulness of the nomogram. Results: Based on the multivariate logistic regression analysis, axillary lymph node status was associated markedly with clinical tumor size, histological grade, longitudinal diameter, cortical thickness and hilum status. The area under the receiver operating characteristic curve was 0.876(95% confidence interval[CI]=0.830-0.923) in the validation set as compared to 0.873(95% confidence interval[CI]=0.851-0.896) in the training set. The predictive model was well-calibrated in the patient population. The decision curve suggested the clinical usefulness of our nomogram. Conclusions: We have constructed a user-friendly tool that utilizes variables preoperatively available to clinicians and accurately predict the risk of axillary lymph node metastasis for individual patients based on ultrasonographic-pathologic features. Clinical trial indentification: The prospective validation study was registered at Clinicaltrials.gov (NCT02992769). Legal entity responsible for the study: Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University Funding: None Disclosure: All authors have declared no conflicts of interest.