Clinical outcome among nasopharyngeal cancer patients in a multi-ethnic society in Singapore

Abstract

Background: Nasopharyngeal cancer (NPC) is endemic among Chinese populations in Southeast Asia. However, the outcomes of non-Chinese NPC patients in Singapore are not well reported. Aim: To determine if non-Chinese NPC patients have a different prognosis and examine the clinical outcomes of NPC patients in a multi-ethnic society. Methods: Retrospective chart review of 558 NPC patients treated at a single academic tertiary hospital from 2002 to 2012. Survival and recurrence rates were analysed and predictive factors identified using the Kaplan-Meier method and Cox regression model. Results: Our cohort comprised 409 males (73.3%) and 149 females (26.7%) with a median age of 52 years. There were 476 Chinese (85.3%), 57 Malays (10.2%), and 25 of other ethnic groups (4.5%). Non-Chinese patients were more likely to be associated with advanced nodal disease at initial presentation (p = 0.049), compared with the Chinese. However, there were no statistical differences in their overall survival (OS) or disease specific survival (DSS) (p = 0.934 and p = 0.857 respectively). The 3-year and 5-year cohort OS and DSS rates were 79.3%, 70.7%, and 83.2%, 77.4% respectively. Advanced age (p<0.001), N2 disease (p = 0.036), N3 disease (p<0.001), and metastatic disease (p<0.001) at presentation were independently associated with poor overall survival. N2 disease (p = 0.032), N3 disease (p<0.001) and metastatic disease (p<0.001) were also independently associated with poor DSS. No predictive factors were associated with loco-regional recurrence after definitive treatment. Advanced age (p = 0.044), N2 disease (p = 0.033) and N3 disease (p<0.001) were independently associated with distant relapse. Conclusion: In a multi-ethnic society in Singapore, non-Chinese are more likely to present with advanced nodal disease. This however did not translate into poorer survival outcomes. Older patients with N2 or N3 disease are associated with a higher risk of distant relapse and poor overall survival.