Development and validation of a nomogram for predicting survival of breast cancer patients with ipsilateral supraclavicular lymph node metastasis

Background: Breast cancer patients with ipsilateral supraclavicular lymph node metastasis (ISLNM) but without distant metastasis are considered to have a poor prognosis. This study aimed to develop a nomogram to predict the overall survival (OS) of breast cancer patients with ISLNM but without distant metastasis. Methods: Medical records of breast cancer patients who received surgical treatment at the Affiliated Cancer Hospital of Zhengzhou University, Jiyuan People's Hospital and Huaxian People's Hospital between December 21, 2012 and June 30, 2020 were reviewed retrospectively. Overall, 345 patients with pathologically confirmed ISLNM and without evidence of distant metastasis were identified. They were further randomized 2:1 and divided into training (n = 231) and validation (n = 114) cohorts. A nomogram to predict the probability of OS was constructed based on clinicopathologic variables identified by the univariable and multivariable analyses. The predictive accuracy and discriminative ability were measured by calibration plots, concordance index (C-index), and risk group stratification. Results: Univariable analysis showed that estrogen receptor-positive (ER+), progesterone receptor-positive (PR+), human epidermal growth factor receptor 2-positive (HER2+) with Herceptin treatment, and a low axillary lymph node ratio (ALNR) were prognostic factors for better OS. PR+, HER2+ with Herceptin treatment, and a low ALNR remained independent prognostic factors for better OS on multivariable analysis. These variables were incorporated into a nomogram to predict the 1-, 3-, and 5-year OS of breast cancer patients with ISLNM. The C-indexes of the nomogram were 0.737 (95% confidence interval [CI]: 0.660-0.813) and 0.759 (95% CI: 0.636-0.881) for the training and the validation cohorts, respectively. The calibration plots presented excellent agreement between the nomogram prediction and actual observation for 3 and 5 years, but not 1 year, OS in both the cohorts. The nomogram was also able to stratify patients into different risk groups. Conclusions: In this study, we established and validated a novel nomogram for predicting survival of patients with ISLNM. This nomogram may, to some extent, allow clinicians to more accurately estimate prognosis and to make personalized therapeutic decisions for individual patients with ISLNM.