Worse characteristics can predict survival effectively in bilateral primary breast cancer: A competing risk nomogram using the SEER database.
OBJECTIVE
There is limited information from population-based cancer registries regarding prognostic features of bilateral primary breast cancer (BPBC).


METHODS
Female patients diagnosed with BPBC between 2004 and 2014 were randomly divided into training (n = 7740) and validation (n = 2579) cohorts from the Surveillance, Epidemiology, and End Results Database. We proposed five various models. Multivariate Cox hazard regression and competing risk analysis were to explore prognosis factors in training cohort. Competing risk nomograms were constructed to combine significant prognostic factors to predict the 3-year and the 5-year survival of patients with BPBC. At last, in the validation cohort, the new score performance was evaluated with respect to the area under curve, concordance index, net reclassification index and calibration curve.


RESULTS
We found out that age, interval time, lymph nodes invasion, tumor size, tumor grade and estrogen receptor status were independent prognostic factors in both multivariate Cox hazard regression analysis and competing risk analysis. Concordance index in the model of the worse characteristics was 0.816 (95% CI: 0.791-0.840), of the bilateral tumors was 0.819 (95% CI: 0.793-0.844), of the worse tumor was 0.807 (0.782-0.832), of the first tumor was 0.744 (0.728-0.763) and of the second tumor was 0.778 (0.762-0.794). Net reclassification index of the 3-year and the 5-year between them was 2.7% and -1.0%. The calibration curves showed high concordance between the nomogram prediction and actual observation.


CONCLUSION
The prognosis of BPBC depended on bilateral tumors. The competing risk nomogram of the model of the worse characteristics may help clinicians predict survival simply and effectively. Metachronous bilateral breast cancer presented poorer survival than synchronous bilateral breast cancer.
['Shen|Kaiwen|K|', 'Yao|Longdi|L|', 'Wei|Jinli|J|0000-0001-8654-8787', 'Luo|Zhou|Z|', 'Yu|Wang|W|', 'Zhai|Huamin|H|', 'Wang|Jianwen|J|', 'Chen|Luhong|L|', 'Fu|Deyuan|D|0000-0003-3636-399X']
D000368:Aged D014408:Biomarkers, Tumor D001943:Breast Neoplasms D005260:Female D006801:Humans D008875:Middle Aged D049451:Nomograms D011379:Prognosis D016016:Proportional Hazards Models D012372:ROC Curve D015203:Reproducibility of Results D018570:Risk Assessment D012307:Risk Factors D018426:SEER Program D047368:Tumor Burden
nomograms surveillance epidemiology prognosis bilateral breast neoplasm end results (SEER) database