Current staging paradigms from the American Joint Committee on Cancer (AJCC) staging system for upper urinary tract carcinomas treat locoregionally advanced (T4 and N+) and metastatic (M1) patients as a single entity (stage IV). The current study proposes a modification of the AJCC staging system where these 2 entities are separated.
The Surveillance, Epidemiology, and End Results (SEER) database (2004-2014) was accessed through SEER*Stat program. Overall survival (OS) analyses according to AJCC and modified staging systems were conducted through Kaplan-Meier analysis. Moreover, cancer-specific survival analysis was conducted through a Cox proportional hazard model.
OS was compared according to AJCC and modified AJCC staging systems. The P value for OS trend for both staging systems was < .0001. This was also found when OS was stratified by the site of the primary (renal pelvis vs. ureter) as well as when stratified by the staging approach (pathologic vs. clinical) (P < .0001). Cancer-specific Cox proportional hazard analysis (adjusted for age, grade, histology, and surgical treatment) was conducted for both staging systems. Pairwise hazard ratio comparisons between different stage categories for both staging systems were significant (P < .0001). The c index for cancer-specific survival for the AJCC staging system was 0.706 with standard error 0.006 (95% confidence interval, 0.695-0.717), while the c index for cancer-specific survival for the modified AJCC staging system was 0.714 with standard error 0.006 (95% confidence interval, 0.702-0.725).
Dividing stage IV upper urinary tract carcinomas into locoregionally advanced and metastatic disease subcategories improves the prognostic utility of the staging system compared to the current AJCC staging system. Given the limitations of a SEER-based study, this concept needs to be externally validated in various settings.
Clinical genitourinary cancer. 2018 Feb 22 [Epub ahead of print]
Department of Clinical Oncology, Faculty Of Medicine, Ain Shams University, Cairo, Egypt; Department of Oncology, University of Calgary and Tom Baker Cancer Center, Alberta, Canada. Electronic address: .