Proposed tripartite classification of T1 renal cell carcinoma: Comparison with current binary system

Area of Science:

• Urology
• Oncology
• Nephrology

Background:

• Outcomes for stage 1 renal cell carcinoma (RCC) are highly variable.
• Current binary T1 RCC classification may not accurately reflect distinct outcome groups.
• Improved risk stratification is needed for stage 1 RCC patients.

Purpose of the Study:

• To evaluate a proposed tripartite reclassification of T1 RCC based on tumor size (≤3 cm, >3-5 cm, >5-7 cm).
• To compare the predictive ability of the tripartite system versus the current binary T1 classification.
• To assess the impact of this reclassification on cancer-specific survival (CSS) and overall survival (OS).

Main Methods:

• Retrospective multicenter analysis of 2,989 patients with clinical T1N0M0 RCC undergoing radical or partial nephrectomy.
• Patients categorized into proposed tripartite groups: T1a (≤3 cm), T1b (>3-5 cm), and T1c (>5-7 cm).
• Multivariable and Kaplan-Meier analyses assessed outcomes; AUC/ROC analysis compared predictive accuracy.

Main Results:

• Proposed-T1c, increasing age, radical nephrectomy, and high-grade tumors were associated with worse cancer-specific mortality.
• Kaplan-Meier analysis showed significantly worse 10-year OS and CSS with larger tumor sizes in the tripartite groups (p < 0.001).
• The proposed tripartite classification demonstrated superior predictive power for OS (0.567 vs. 0.556) and CSS (0.643 vs. 0.599) compared to the binary system.

Conclusions:

• The proposed tripartite subclassification of T1 RCC (T1a, T1b, T1c) aligns better with distinct patient outcome populations.
• This refined classification enhances risk stratification for stage 1 RCC.
• The tripartite system may improve pretreatment counseling and postoperative follow-up strategies.