Background: Patients with breast cancer have a poor prognosis. We want to construct a more elaborative and validate nomograms for predicting overall survival in patients with breast cancer.
Methods: A total of 68363 breast cancer patients who underwent surgery between 2011 and 2015 were recruited from the Surveillance Epidemiology, and End Results (SEER) database. After eliminating lacking clinical information, 60445 eligible breast cancer patients were randomly divided into the training corhort(n=42327) and the internal validation corhort(n=18118) in a ratio of 7:3. The endpoint of this study was overall survival(OS). Multivariate Cox proportional hazards regression models was performed to identify independent risk factors of OS in the training corhort, and then the nomogram was constructed. The nomogram predictive performance was evaluated by the Harrell’s concordance index (C-index), the time-dependent receiver operating characteristics (ROC) curve (AUC), calibration curve, decision curve analysis(DCA) and clinical impact curve. Moreover, the nomogram was verified by the internal validation corhort and external validation corhort.
Results: Age, gender, grade, 7th AJCC stage, ER status, PR status, Her-2 Status, breast subtype were found to be independent risk factor of OS(P<0.05). The nomogram integrating these eight factors was constructed and proved excellent discrimination capability in the training corhort(C-index, 0.724 (95%CI, 0.716-0.732)),which was demonstrated in the internal validation corhort(C-index, 0.717 (95% CI, 0.705-0.729) and external validation corhort(C-index, 0.793 (95% CI, 0.724-0.862)). Calibration curve for the probability of 1-, 3- and 5-year OS demonstated good concordance between nomogram prediction and actual observed results in both the training and validation corhort. Besides, the DCA and clinical impact curve indicated the clinical usefulness of our constructed nomogram.
Conclusions: We developed a nomogram that integrate clinicopathological variables, which can precisely predict the 1-, 3- and 5-year OS of breast cancer patients after surgery. Validation uncovered preeminent discrimination power for the nomogram, indicating that it presents satisfactory clinical application. Therefore, the nomogram can help clinicians in formulating the suitable therapy strategies for individual patients.