Clinical verification of the superiority of the current International Union Against Cancer staging criteria in an Australian population of patients with nasopharyngeal carcinoma

Abstract

The purpose of this study is to assess the prognostic abilities of the fourth and fifth edition International Union Against Cancer (UICC) staging systems for nasopharyngeal carcinoma (NPC) in Australian patients. All patients planned for curative treatment at the Peter MacCallum Cancer Centre from April 1985 to December 1999 were included in this study. There were 181 patients eligible for this study. The median follow up was 7.6 years. Histological subgroups were World Health Organization (WHO) 1 (23), WHO 2 (12), and WHO 3 (146). Presentation with stage IV disease was 83% by UICC fourth edition staging and 34% by UICC fifth edition staging. The 5 years failure-free survival (FFS) rates for stage 1, 2, 3 and 4 disease by the fourth edition was 77, 100, 93, and 49% respectively,and by the fifth edition was 85, 76, 57 and 36%, respectively. The 5 years overall survival (OS) for stage 1, 2, 3, and 4 disease by the fourth edition was 77, 100, 100 and 61%; respectively, and by the fifth edition was 85, 82, 67 and 53%, respectively. Stage 4 patients by the fourth edition were reclassified as stages 2, 3 and 4 by the fifth edition with hazard ratios of 0.77, 1.01 and 1.79, respectively. In multifactor analysis, the fifth edition staging system was significantly related to FFS and OS after allowing for the fourth edition (FFS: P = 0.002; OS: P = 0.005), but the fourth edition was not significantly related to FFS or OS after allowing for the fifth edition (FFS: P = 0.96; OS: P = 0.96). This study confirms the prognostic superiority of the fifth edition UICC staging system over the fourth edition staging system in an Australian NPC population.