Nasopharyngeal carcinoma: clinicoepidemiology and treatment outcomes at a major Australian tertiary referral hospital

Background: Nasopharyngeal carcinoma (NPC) predominantly occurs in East and Southeast Asia, with significantly lower incidence in non-endemic regions like Australia. Although disease phenotype varies with ethnicity, current knowledge regarding its pathogenesis, management, and long-term outcomes mostly arises from studies of high-risk populations. This retrospective cohort study aimed to characterise the clinicoepidemiological features and long-term outcomes of NPC in a diverse cohort of Australian patients, and identify differences between Asian and non-Asian patients. Methods: Patients diagnosed with a nasopharyngeal tumour were identified retrospectively from the Northern Sydney Cancer Centre database between 2001 and 2024. Demographics, clinicopathological features, and treatment outcomes were compared across ethnicities using Mann-Whitney U , Chi-squared, and Fisher exact tests. Regression analyses were performed to identify prognostic factors and calculate disease-specific survival (DSS) and relapse-free survival (RFS). Results: Of the 103 patients with biopsy-proven NPC, the median age at diagnosis was 55.1 [interquartile range (IQR), 44.2–62.7] years and 75 (72.8%) were of Asian descent. Ethnicity (Asian vs. non-Asian) was significantly associated with poorer RFS, with Asians [hazard ratio (HR) =4.73; 95% confidence interval (CI): 1.01–22.29; P=0.049], T4 tumour stage (HR =4.60, 95% CI: 1.52–13.96; P=0.007), and distant metastases (HR =7.85, 95% CI: 1.45–42.67; P=0.017) having worse outcomes. Seventy-nine patients underwent definitive radiotherapy treatment with or without chemotherapy, yielding a complete metabolic response rate of 94.9%, 5-year DSS of 89.7%, and 5-year RFS of 72.4%. Recurrent disease lowered 5-year DSS to 36.4% and median survival time to 42.6 months (95% CI: 25.8–59.4), although 27.8% of recurrences occurred after 5 years. No statistically significant differences were found between ethnicity groups regarding age (P=0.80), sex (P=0.32), and clinical stage at presentation (P=0.69). However, ethnic differences in risk factors were noted as more non-Asians smoked (P=0.018) and consumed alcohol (P<0.001) whereas positive tumour Epstein-Barr virus (EBV) encoded RNA in-situ hybridisation (EBER-ISH) staining was more prevalent in Asian cases (P=0.033). Keratinising histology was associated with smoking (P=0.017) while undifferentiated non-keratinising NPC was the most common subtype (68.9%) and more frequently EBV positive (P=0.045). Conclusions: NPC in Australia shows notable ethnic disparities, with advanced-stage Asian patients facing worse outcomes, highlighting the need for tailored surveillance and management. With the high risk of late recurrence and its poor associated prognosis, extending follow-up to 7–10 years post-treatment is recommended. Further research into salvage therapies for recurrent NPC is required.