Development and validation of nomograms predicting cancer-specific survival of vulvar cancer patients: based on the Surveillance, Epidemiology, and End Results Program

Objective To explore potential prognostic factors and develop nomograms to predict the cancer-specific survival of patients with vulvar squamous cell carcinoma (SCC) and patients with vulvar melanoma. Methods Cases of vulvar SCC and melanoma were retrieved from the Surveillance, Epidemiology, and End Results (SEER) Program, and randomly segregated into training and test sets. Based on the training set, univariate and multivariate Cox proportional hazard regressions evaluate the association between key demographic/clinical characteristics and vulvar cancer survival. Potential prognostic factors were included to construct nomograms for the prediction of 3-year and 5-year survival probabilities. Results Age, tumor size, stage, surgery, and chemotherapy were potential factors associated with vulvar cancer survival. The C-indices for the training and test sets were 0.82 and 0.81 for SCC, and 0.73 and 0.70 for melanoma. Calibration curves revealed correlated agreements between nomogram-based probability and actual survival status. Conclusion Nomograms were developed to predict cancer-specific survival of patients with vulvar cancer, accordingly identifying the subgroup at high risk of cancer-specific mortality.