Prognostic impact of tumor size in low-risk upper tract urothelial carcinoma: A multi-institutional analysis.

PURPOSE: To evaluate the prognostic value of tumor size in patients with low-risk upper tract urothelial carcinoma (UTUC) undergoing radical nephroureterectomy (RNU).

METHODS

A retrospective multicenter European analysis was conducted on 3987 patients treated for UTUC at 17 academic institutions. After applying the exclusion criteria, 328 low-risk UTUC patients (pTaN0M0, low grade, unifocal, without hydronephrosis) were included in the analysis. Patients were stratified by tumor size in the RNU specimen: <1cm, 1-1.9cm, and ≥2cm. Recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) were evaluated using Kaplan-Meier analysis. Univariable Cox regression analysis was used to evaluate the association between tumor size and disease recurrence. Because other confounding factors intrinsic to the study design were excluded, no multivariable analysis was performed.

RESULTS

After a median follow-up of 4.2 [3.9; 4.5] years, 41 (12.5%) patients experienced disease recurrence. Kaplan-Meier analysis showed that tumors ≥2cm were significantly associated with lower RFS compared to tumors of 1-1.9cm and <1cm (81% vs. 95% and 97%, respectively; P<0.05). CSS and OS did not differ significantly among groups (all P>0.05). Univariable Cox regression analysis confirmed that tumor size ≥2cm was a significant predictor of disease recurrence with HR=7.18; 95%CI=[2.94-17.5]; P<0.001.

CONCLUSIONS

Tumor size ≥2cm is associated with an increased disease recurrence in low-risk UTUC. These findings align with the European Association of Urology guidelines, supporting the inclusion of tumors up to 2cm within the low-risk category.