Risk Stratification for the Prognosis of Patients With pT3aN0M0 Clear Cell Renal Cell Carcinoma.

Background: Predicting postoperative recurrence in patients with pathological T3aN0M0 clear cell renal cell carcinoma (pT3a ccRCC) is important to identify patients suitable for adjuvant immunotherapy. This study aimed to develop a novel predictive model for postoperative recurrence of pT3a ccRCC.

Materials And Methods: Patients diagnosed with pT3a ccRCC between 2010 and 2022 were retrospectively enrolled from 19 institutions. Multivariable Cox proportional hazards regression was used to identify clinical factors associated with poor disease-free survival (DFS). A risk model was established based on the hazard ratios of the identified factors. DFS and overall survival were calculated using the Kaplan-Meier method according to the risk group. The association between the risk model categories and the International Metastatic RCC Database Consortium (IMDC) score at recurrence was also evaluated using the chi-square test.

Results: This study included 541 patients with pT3a ccRCC. With a median follow-up of 46 months, postoperative recurrence occurred in 165 (30.5%) patients and death occurred in 81 (15.0%) patients. Multivariate analysis identified 6 variables associated with shorter DFS: male sex, ≥3 extrarenal tumor extension patterns, tumor size >70 mm, nuclear grade 3 or 4, sarcomatoid differentiation, and C-reactive protein ≥1.0 mg/L. The predictive model classified patients into low-, intermediate-, and high-risk categories, with 5-year DFS rates of 88%, 67%, and 39%, respectively. The area under the curve for the 5-year DFS was 0.752. At recurrence, half of the patients in the low-risk group were classified in the IMDC-favorable group, compared to 23.1% in the high-risk group.

Conclusions: This risk model can predict postoperative recurrence risk in patients with pT3a ccRCC. This model may help in selecting candidates for adjuvant therapy for pT3aN0M0 ccRCC.