Risk assessment model for overall survival in patients with locally advanced cervical cancer treated with definitive concurrent chemoradiotherapy.

To develop a nomogram for predicting the probability of 5year survival after definitive concurrent chemoradiotherapy (CCRT) in locally advanced cervical cancer (LACC). Between 1998 and 2008, 209 patients with LACC were treated with definitive CCRT. Multivariate analysis using Cox proportional hazards regression model was performed. A nomogram based on this Cox model was developed and internally validated by bootstrapping. Its performance was assessed by using the concordance index and a calibration curve. The median age was 55years (range, 26-78). Of the patients, 9, 16, 129, 3, 42 and 10 had FIGO stage IB2, IIA, IIB, IIIA, IIIB, and IVA disease, respectively. Histology revealed that 190, 13, 4, and 2 patients had squamous, adenocarcinoma, adenosquamous, and small cell cervical cancer, respectively. In 91 patients, PET/CT was performed before CCRT. The median follow-up period was 51months (range, 6-151) and there were 50 (23.9%) disease-related deaths. Multivariate regression analysis revealed that histology, tumor size, and paraaortic lymph node metastasis (defined by MRI), but not PET/CT before CCRT, were independent predictors of overall survival. A nomogram for predicting the 5year survival incorporating these three significant variables was constructed. The concordance index was 0.69. The predictive ability of the nomogram proved to be superior to that of the FIGO staging system (p<0.05). The nomogram was a better predictive model for overall survival than the FIGO staging system. If externally validated, it could be used to counsel patients with LACC who must choose additional treatment modalities after definitive CCRT.