Integration of Intratumoral RASSF10 Expression and Tumor-Associated Macrophages into the Established Clinical Indicators Better Predicts the Prognosis of Clear Cell Renal Cell Carcinoma Patients

Abstract

Background: A helpful evaluation system is crucial for the postoperative prognosis prediction of clear cell renal cell carcinoma (ccRCC) patients. This study determined the prognostic value of combining intratumoral RASSF10 expression and tumor-associated macrophages (TAMs) with the established clinicopathological indicators in ccRCC patients. Methods: RASSF10 expression was analyzed in ccRCC patient data from online databases and ccRCC cell lines. Two independent ccRCC patient cohorts were employed to examine the prognostic value of RASSF10 and other markers by immunohistochemistry (IHC) and statistical analyses. All results were validated in the randomized training and validation ccRCC patient cohorts. Findings: RASSF10 expression was downregulated in most ccRCC specimens from the TCGA datasets and three independent institutions. RASSF10 expression was negatively correlated with disease progression and CD68+ TAM infiltration in ccRCC. IHC was performed in two independent ccRCC patient cohorts, and the results demonstrated that low RASSF10 expression and high CD68 expression predicted a high TNM stage, SSIGN score, Fuhrman nuclear grade, and a poor prognosis. After multivariable adjustment, RASSF10, CD68, TNM stage, and SSIGN score were identified as independent risk factors in predicting the prognosis of ccRCC patients. Time-dependent c-index analyses revealed that the combination of RASSF10 and TAMs resulted in a higher index than that resulting from each alone in the postoperative prognosis of ccRCC patients, and the integration of RASSF10 and TAMs with the TNM stage or SSIGN score achieved the best accuracy in predicting the prognosis of ccRCC patients. These results were validated in the randomized training, validation, and combined cohorts. Interpretation: The combination of the RASSF10-TAM classifier and current clinical parameters yields superior accuracy in predicting the postoperative outcome of ccRCC patients. Funding Statement: Medical Discipline Construction Project of the Pudong New District (No. PWYgf2018-03), National Natural Science Foundation of China (No. 81773154 and 81772747), Outstanding Academic Leader Program of Shanghai Science and Technology Commission (No. 19XD1405100), and the Shanghai Medical Guidance (Chinese and Western Medicine) Science and Technology Support Project (No. 17411960200). Declaration of Interests: The authors declare that they have no potential conflicts of interest to disclose. Ethics Approval Statement: All experiments were approved by the institutional ethical review board from each hospital, and written informed consent was obtained from all ccRCC patients.