Survival of patients with squamous cell malignancies of the upper urinary tract

Abstract

Background: Carcinomas of the renal pelvis and ureter are rare diseases, accounting for only about 1% of all urogenital malignancies. Previous reports suggest that squamous cell histology is associated with inferior survival. We present the largest population based analysis to date of survival in patients with upper urinary tract malignancies.

Methods: We analyzed the Surveillance, Epidemiology and End Results database for cancer specific survival rates in patients with renal pelvis and ureteral malignancies who were diagnosed between 1973 and 2003 in the SEER catchment geographic areas. The primary exposure of interest was the underlying histology, squamous cell versus transitional cell differentiation. We performed descriptive statistics, non parametric survival analysis, and cox proportional hazard analysis.

Results: We identified 13,213 eligible patients, 7,716 renal pelvis and 5,497 ureteral carcinomas. Among this cohort, 179 patients had squamous cell carcinoma (SCC), 12,395 had transitional cell carcinoma (TCC), including 121 papillary, and 619 had other histologies. Overall, patients with SCC histology fared worse. The median overall survival time was 10 months for SCC and 63 months for TCC. The cox analysis revealed a HR 3.7 (95% CI 3.0-4.5) for SCC when compared to TCC and corrected for decade of diagnosis, age, gender, prior treatment, and race. The difference between the two groups was entirely attributable to survival differences in patients with loco-regional disease. However, when stratified by lymph node involvement this difference disappeared for patients with locally involved lymph nodes (P = 0.84) and for patients with clear lymph nodes (P = 0.92).

Conclusions: SCCs of the upper urinary tract present at a higher clinical stage and appear to represent more aggressive disease when compared to other histologies. However, when appropriately staged according to lymph node status, the survival of TCC and SCC of the upper urinary tract is identical when compared stage by stage.

Keywords: renal pelvis; squamous cell carcinoma; survival analysis; transitional carcinoma; ureter.

Panel 1

The panel above graphically illustrates the survival of patients with UUT malignancies. Graph A demonstrates the survival by histology. All stages are considered. Graph B considers only the patients presenting with regional disease, ie, patients with malignancies beyond the confinement of the renal pelvis or ureter or positive lymph node involvement. Graph C displays the survival of patients with metastatic disease, by histology. Graph D illustrates the survival of patients with locoregional disease and known lymph node status. All histologies are included. Graph E demonstrates the superior survival of patients with absent lymph node involvement in patients with transitional cell histology and regional disease status. Graph F demonstrates the absence of a significant difference by lymph node status in patients with regional disease status and squamous cell histology.