Pathological Upstaging of Clinical T1 to Pathological T3a Renal Cell Carcinoma: A Multi-institutional Analysis of Short-term Outcomes.

ABSTRACT

OBJECTIVE: To determine the oncological impact of pathological upstaging among patients with clinical T1 (cT1) disease treated by partial nephrectomy or radical nephrectomy. METHODS: The Canadian Kidney Cancer Information System comprises a prospectively maintained multi-institutional database for patients with renal cell carcinoma. Nonmetastatic, cT1 renal cell carcinoma cases were evaluated. Upstaging was defined as pathological T3a disease. Multivariate Cox regression analysis identified predictors for recurrence (local recurrence and/or metastatic disease) whereas logistic regression identified predictors of pathological upstaging. Kaplan-Meier methods estimated survival. RESULTS: Of 1448 eligible cT1 patients, upstaging was observed in 134 (9%). One thousand fifty-eight (73%) were treated by partial nephrectomy. After a median follow-up of 23 months, the 3-year recurrence-free survival was 76% in upstaged patients compared with 93% in those not upstaged (P < .001). Controlling for age, gender, year of surgery, histology, tumor size, surgical approach, and margin status, pathological upstaging was independently associated with disease recurrence (hazard ratio 2.03, 95% confidence interval [CI] 1.12-3.68). Increasing age (odds ratio [OR] 1.02, 95% CI 1.00-1.05), Fuhrman grade (OR 2.47, 95% CI 1.47-4.14), and tumor size (OR 1.16, 95% CI 1.00-1.36) were independently associated with a risk of pathological upstaging. CONCLUSION: Pathological upstaging confers a negative prognosis and highlights the importance of accurate clinical staging. A number of factors have been identified, including some attainable by renal biopsy, which may predict upstaging and provide valuable adjunct information to inform risk stratification and management decisions among patients with cT1 renal masses.