Development and internal validation of nomograms for the prediction of postoperative survival of patients with grade 4 renal cell carcinoma (RCC)

Jun Zhu; Zhifu Liu; Zhongyuan Zhang; Yu Fan; Yuke Chen; Zhisong He; Liqun Zhou; Jie Jin; Cheng Shen; Wei Yu

doi:10.21037/tau-19-687

Development and internal validation of nomograms for the prediction of postoperative survival of patients with grade 4 renal cell carcinoma (RCC)

Transl Androl Urol. 2020 Dec;9(6):2629-2639. doi: 10.21037/tau-19-687.

Authors

Jun Zhu^{1

2

3}, Zhifu Liu^{1

2

3}, Zhongyuan Zhang^{1

2

3}, Yu Fan^{1

2

3}, Yuke Chen^{1

2

3}, Zhisong He^{1

2

3}, Liqun Zhou^{1

2

3}, Jie Jin^{1

2

3}, Cheng Shen^{1

2

3}, Wei Yu^{1

2

3}

Affiliations

¹ Department of Urology, Peking University First Hospital, Beijing, China.
² National Urological Cancer Center, Institute of Urology, Peking University, Beijing, China.
³ Beijing Key Laboratory of Urogenital Diseases (male) Molecular Diagnosis and Treatment Center, Beijing, China.

Abstract

Background: To develop successful prognostic models for grade 4 renal cell carcinoma (RCC) following partial nephrectomy and radical nephrectomy.

Methods: The nomograms were established based on a retrospective study of 135 patients who underwent partial and radical nephrectomy for grade 4 RCC at the Department of Urology, Peking University First Hospital from January 2013 to October 2018. The predictive performance of the nomograms was assessed by the calibration plot and C-index. The results were validated using bootstrap resampling.

Results: Aspartate transaminase (AST), the maximum diameter of tumor (cutoff value =7 cm), lymph node metastasis, and the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk group were independent factors for determining the overall survival (OS) and cancer-specific survival (CSS) in multivariate analysis. AST, the maximum diameter of the tumor (cutoff value =7 cm), and lymph node metastasis were found to be independent variables for progression-free survival (PFS) in multivariate analysis. These variables were used for the studies to establish nomograms. All calibration plots revealed excellent predictive accuracy of the models. The C-indexes of the nomograms for predicting OS, CSS and PFS were 0.729 (95% CI, 0.659-0.799), 0.725 (95% CI, 0.654-0.796) and 0.702 (95% CI, 0.626-0.778), respectively. Moreover, the recurrence rate was not associated with open or laparoscopic radical nephrectomy in our cohort (P=0.126).

Conclusions: We have developed easy-to-use models that are internally validated to predict postoperative 1-, 3-, and 5-year OS, CSS, and PFS rates of grade 4 RCC patients. The new models could aid in identifying high-risk patients, making postoperative therapeutic and follow-up strategies as well as predicting patients' survival after externally validated. Besides, our study shows that the recurrence rate is not associated with open or laparoscopic radical nephrectomy.

Keywords: Carcinoma; nomograms; prognosis; renal cell; survival analysis.