The correlation between discrepancies in clinical and pathological T stages and overall survival in upper urinary tract urothelial carcinoma: Analysis of the hospital-based cancer registry data in Japan.

Objective: Our study assessed the correlation between discrepancies in clinical and pathological T stages and overall survival (OS) in patients with upper urinary tract urothelial carcinoma (UTUC), including renal pelvis (UCP) and ureter (UCU) carcinoma, treated with radical surgery.

Methods: We utilized data from the Japanese Hospital-Based Cancer Registry (HBCR) to identify UTUC cases (n = 2376), consisting of UCP cases (n = 1196) and UCU cases (n = 1180), diagnosed with cTa-3N0M0 between 2012 and 2013. All cases were histologically confirmed and treated solely with radical surgery, excluding any chemotherapy or radiotherapy. We investigated the correlation between stage classification discrepancies and OS.

Results: Among UCP and UCU patients, cT2N0M0 had the highest discrepancy rates between clinical and pathological stages (68% and 51%), while cT3N0M0 had the lowest (21% and 20%). Among UCP and UCU patients with cTa/is/1N0M0, those with up-staging showed significantly worse OS compared to same-staging (HR 1.7 and 2.5, p = 0.001 and <0.001, respectively). In UCU patients with cT2N0M0, the 5-year OS rates were 41.9% for up-staging, 63.7% for same-staging, and 76.4% for down-staging, with significantly worse survival in the up-staged group. Among UCP and UCU patients with cT3N0M0, the 5-year OS rates were 29.3% and 7.7% for those with up-staging, 53.7% and 30.6% for those with same staging, and 79.6% and 65.4% for those with down-staging.

Conclusion: Using a large real-world cohort, we found stage discrepancies to be a significant independent prognostic factor in non-metastatic UTUC patients. Treatment should be carefully selected, considering T-staging discrepancies and prognosis.