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ORIGINAL RESEARCH article

Front. Oncol.

Sec. Genitourinary Oncology

Prognostic Value of the GRANT Score and Development of a Nomogram in Papillary Renal Cell Carcinoma: A SEER-Based Study with External Validation in a Chinese Cohort

Provisionally accepted
Tongpeng  LiuTongpeng LiuWei  ChenWei ChenYu  YaoYu YaoYang  HuYang HuLijiang  SunLijiang SunGuiming  ZhangGuiming Zhang*
  • The Affiliated Hospital of Qingdao University, Qingdao, China

The final, formatted version of the article will be published soon.

Background: Papillary renal cell carcinoma (pRCC) exhibits significant heterogeneity, and robust prognostic tools specifically validated for this subtype are lacking. The GRANT score, incorporating grade, age, nodes, and tumor stage, shows promise but requires extensive validation in pRCC-specific cohorts. This study aimed to evaluate the prognostic value of the GRANT score and develop a novel nomogram for predicting survival in pRCC patients. Methods: A multi-center retrospective study was conducted. Patients undergoing surgery for pRCC were identified from the SEER database (2004-2015) and formed the training (n=4,001) and internal validation (n=1,689) cohorts. An external validation cohort (n=151) was sourced from a Chinese institution. Overall survival (OS) and cancer-specific survival (CSS) were primary endpoints. The GRANT score was calculated for all patients. Univariate and multivariate Cox analyses identified independent prognostic factors, which were incorporated into nomograms for predicting 1-, 3-, and 5-year OS and CSS. Model performance was assessed using the concordance index (C-index), time-dependent receiver operating characteristic curves, and calibration plots. Results: Multivariate analysis confirmed the GRANT score as an independent prognostic factor for both OS and CSS. The prognostic nomograms integrated key variables, including surgical approach, marital status, TNM stage, tumor size, Fuhrman grade, and the GRANT score. For OS prediction, the nomogram achieved C-indices of 0.711 (training), 0.720 (internal validation), and 0.740 (external validation). For CSS prediction, the model demonstrated superior performance, with C-indices of 0.860 (training), 0.873 (internal validation), and 0.826 (external validation). Calibration curves showed excellent agreement between predicted and observed outcomes. Risk stratification based on nomogram scores effectively distinguished low-, intermediate-, and high-risk patient groups with significantly different survival. Conclusion: This study validates the GRANT score as an independent prognostic factor in a large pRCC cohort. The developed and externally validated nomogram provides a clinically useful tool with robust performance, particularly for predicting CSS, facilitating personalized risk assessment and postoperative management for pRCC patients.

Keywords: Papillary renal cell carcinoma, GRANT score, nomogram, prognosis, SEER database, External validation, Cancer-specific survival

Received: 03 Jul 2025; Accepted: 24 Oct 2025.

Copyright: © 2025 Liu, Chen, Yao, Hu, Sun and Zhang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Guiming Zhang, zhangguiming9@126.com

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