Predictive value of renal tumor contour irregularity score in pathological T3a upstaging of clinical T1 renal cell carcinoma: A multi-institutional study

To explore the predictive value of renal tumor contour irregular degree (CID) in pathological T3a upstaging of clinical T1 renal cell carcinoma (RCC). We performed a retrospective multi-institutional review of 1,487 patients with clinical T1N0M0 RCC between January 2009 and June 2019. Kaplan-Meier survival curve and Cox regressions were used to analyze the prognostic factors of disease-free survival (DFS). Logistic regressions were performed to determine predictors of pathological T3a upstaging in clinical T1 RCC. Among 1,487 patients with cT1 RCC, 96 (6.5%) were pathological T3a upstaging. Multivariable logistic regression analysis showed that age (odds ratio [OR] = 1.022, 95% confidence interval [CI] = 1.001–1.042, P = 0.036), tumor maximum diameter(OR = 1.242, 95% CI = 1.042-–1.480, P = 0.015) and CID (OR = 1.067, 95% CI = 1.051–1.083, P < 0.001) were independent predictors of pathological T3a upstaging. The area under the curve (AUC) of the prediction model that included the CID was 0.846, while the AUC of the prediction model that did not include CID was only 0.741, the difference was statistically significant (P < 0.001). Kaplan-Meier survival curve showed that patients with pathological T3a upstaging had significantly worse DFS than patients without pathological T3a upstaging (P < 0.001). Multivariable Cox analysis showed that pathological T3a upstaging (HR = 1.836, 95% CI = 1.013–3.329, P = 0.002) is an independent prognostic factor for DFS in patients with cT1N0M0 RCC. The predictive model of CID combined with tumor maximum diameter and age significantly improved the ability to predict pathological T3a upstaging in clinical T1 RCC, compared with the prediction model of tumor maximum diameter combined with age. The predictive model of CID combined with tumor maximum diameter and age may be applicable to patients considering partial vs. radical nephrectomy.