Computed Tomography Measures of Perinephric Adipose Tissue and C-Reactive Protein-to-Albumin Ratio are Associated with Common Prognostic Models for Nonmetastatic Clear Cell Renal Cell Carcinoma Patients.

Background: Renal cell carcinoma (RCC) is a reclusive tumor, usually discovered incidentally on imaging examinations of other abdominal diseases. Although prognosis models based on pathology are more accurate, it is crucial to evaluate tumor prognosis before invasive operations to support the choice of active surveillance and ablation therapy. Thus, non-invasive methods are essential for determining appropriate treatment strategies in patients.

Methods: Data from 106 patients under non-metastatic clear cell RCC (ccRCC) who went through partial/radical nephrectomy from January 2016 to October 2023 were retrospectively evaluated. Basic demographic information, preoperative hematological indicators, pathological data, and computed tomography (CT) measurements of perinephric adipose tissue (PAT) were collected for each patient. The CT assessments of PAT, including thickness, radiodensity, and Mayo adhesive probability (MAP) score, were performed by a radiologist. Univariate and multivariate logistic regression analysis was applied to clarify risk factors of Fuhrman grade, tumor size, and the Stage Size Grade Necrosis (SSIGN) score. The receiver operating characteristic (ROC) curve of SSIGN was then constructed in order to determine discriminatory ability and optimal cut-off values of these risk factors.

Results: The radiodensity of PAT on the tumor side was significantly higher (p < 0.001) compared to the contralateral side. RCCs with higher maximum radiodensity of PAT and elevated C-reactive protein-to-albumin ratio (CAR) were related to a higher Fuhrman grade, larger tumor size, and increased Stage Size Grade Necrosis (SSIGN) scores (all p < 0.05). The area under curve (AUC) of maximum radiodensity of PAT and CAR for higher SSIGN scores was 0.816 (p = 0.003) and 0.811 (p = 0.004) each. The optimal cut-off values of PAT and CAR for higher SSIGN scores were -69.685 and 0.0452, respectively.

Conclusions: The study corroborates that PAT and CAR's maximum radiodensity are independent markers for predicting Fuhrman grade, tumor size and SSIGN. These non-invasive methods are likely to improve traditional prognostic prediction and possibly effect new therapeutic strategies for patients with non-metastatic ccRCC.