Prognostic impact of extensive parenchymal invasion pattern in pT3 renal pelvic transitional cell carcinoma

BACKGROUND. Pathologic T3 renal pelvic transitional cell carcinoma exhibits various patterns of invasion. The authors investigated the prognostic impact of three patterns of invasion of pT3 renal pelvic transitional cell carcinoma. METHODS. Of 212 patients who underwent surgery for renal pelvic transitional cell carcinoma, 70 with pT3 disease were eligible for the main analyses. The candidate predictors of prognosis included patient age, gender, lesion laterality, tumor grade. perioperative cisplatin-based systemic chemotherapy, lymph node involvement. vascular involvement, and patterns of invasion. Invasion patterns were classified as fat invasion, ductal involvement, or parenchymal invasion. RESULTS. Mean postoperative followup was 33.5 months (range, 1-136 months). On univariate analysis, gender, lymph node involvement, vascular involvement, and extensive parenchymal invasion each had a significant impact on the cause specific survival rate. A multivariate analysis using Cox stepwise regression revealed that extensive parenchymal involvement was the strongest prognostic predictor (P = 0.0004, hazard ratio = 5.59). Lymph node involvement (P = 0.0175, hazard ratio = 3.14) and gender (P = 0.0361, hazard ratio = 2.42) were other weaker predictors. Statistically, pT3 disease without extensive parenchymal invasion had a prognosis similar to that of lower stage disease, and pT3 disease with extensive parenchymal invasion had a prognosis similar to that of pT4 disease. CONCLUSIONS. Extensive parenchymal invasion has a strong prognostic impact in renal pelvic transitional cell carcinoma. pT3 disease should be subclassified into two separate entities, that with and that without extensive parenchymal invasion, in view of prognosis.