Nasopharyngeal carcinoma: differences in presentation between different ethnicities in the New Zealand setting Ilia Ianovski,*† Mark Izzard,* Randall P. Morton† and Lindsay D. Plank‡ *ORL Department, Auckland City Hospital †ORL Department, Counties Manukau DHB ‡Department of Surgery, School of Medicine, University of Auckland, Auckland, New Zealand Key words Nasopharyngeal carcinoma, TNM stage, ethnicity, New Zealand. Abbreviations AJCC, American Joint Committee on Cancer; CT, computed tomography; MPI, Maori and Pacific Island; MRI, magnetic resonance imaging; NPC, nasopharyngeal carcinoma. Correspondence Dr Ilia Ianovski, 2-9 Bowling Ave, Epsom, Auckland, New Zealand. Email: blindrevelations@gmail.com I. Ianovski MBChB, BHB; M. Izzard MBBS, FRACS; R. P. Morton MBBS, FRACS, MSc (Med); L. D. Plank D.Phil. The corresponding author is not a recipient of a research scholarship. The following paper is not based on a previous communication to a society or meeting. Accepted for publication 17 August 2008. doi: 10.1111/j.1445-2197.2009.05132.x Abstract Introduction: There is an elevated incidence of nasopharyngeal carcinoma (NPC) in the Maori and Pacific Island (MPI) population as well as the Asian population in New Zealand; however, no studies have been conducted to evaluate how the two populations differ in their clinical presentation according to the TNM stage. Methods: A retrospective review was conducted of all patients presenting to the Auckland City Hospital ENT department with a newly diagnosed NPC between the years 1995 and 2007 inclusive. The patient’s radiological and biopsy results were reviewed, and each patient was staged according to the TNM stage at presentation as per the revised 2002 American Joint Committee on Cancer staging criteria. The Fisher’s exact test was used to compare the differences between ethnicities in the T and N stages of the disease at presentation; the Cochran–Armitage Trend test was used to look for statistically significant trends. Results: There was a statistically significant difference in T stage at presentation between MPIs and Asians (P < 0.0001), with a positive, statistically significant (P < 0.0001) trend indicating that MPIs present with greater T stage. A statistically signifi- cant difference in the N stage at diagnosis between MPIs and Asians, independent of the T stage, was found at stages T2 (P = 0.046) and T4 (P = 0.0083), with a statistically significant trend (T2 – P = 0.009; T4 – P = 0.026). Conclusions: These results show that MPIs have a more advanced local NPC disease than Asians at presentation, and that for specific T stages, the nodal disease is also more advanced than that found in Asians. Introduction Nasopharyngeal carcinoma (NPC) is an aggressive tumour of the head and neck, with a variable incidence rate around the world. In the Western world (United States and Europe), the annual incidence is estimated at 1/100 000, 1 but in Southern China, parts of South East Asia, the Mediterranean basin and Alaska, the annual incidence is 10–30/100 000. 2 These epidemiological differences have been attributed to three aetiological factors: genetic susceptibility, expo- sure to dietary or environmental carcinogens and latent Epstein-Barr Virus (EBV) infection. 3 In New Zealand, the main ethnic groups are Europeans (67.6%), Maori (14.6%), Pacific Islanders (6.9%) and Asians (9.2%). 4 The New Zealand Europeans have the same incidence of NPC as do their counterparts in Europe and North America. However, Maori and Pacific Islanders (MPIs) have a much higher incidence of NPC, estimated at 10/100 000. 5,6 There is evidence that Pacific Islanders inhabiting the South Pacific region are descended from the Asian population that once inhabited Southern China. 6 Thus, the higher incidence of NPC in MPIs may be attributed to a shared ancestral genetic susceptibility. The Asian population of New Zealand is mostly made up of immigrants from China (Including Hong Kong and Taiwan). 7 The reported incidence of NPC in Hong Kong and the Guangdong province of China (geographically adjacent regions), where it is most prevalent, is 20–30/100 000 for men and 15–20/100 000 for women, 8 and the incidence of NPC remains the same in Chinese immigrants to United States, UK and Australia but decreases in the next generation that is born in the country of immigration. 8,9 The Asian population in New Zealand is mostly made up of ORIGINAL ARTICLE ANZJSurg.com © 2009 The Authors Journal compilation © 2009 Royal Australasian College of Surgeons ANZ J Surg 80 (2010) 254–257