Please use this identifier to cite or link to this item: http://hdl.handle.net/1946/18243
Background: The aetiology of nasopharyngeal carcinoma (NPC), a common cancer in certain parts of the world (in particular, SE-Asia), remains unclear although Epstein-Barr virus (EBV) is considered an essential co-factor. This study aimed to delineate the possible role of human papillomaviruses (HPV) in NPC development in a Scottish cohort and assess correlation with single nucleotide polymorphisms (SNPs) and microsatellite markers known to be associated with human malignancies.
Method: Using data from the Scottish and Nordic Cancer Registries, incidence rates were investigated for a median of 23 years up until 2011. Clinical data was collated for 58 patients treated for NPC at the Edinburgh Cancer Centre (NHS Lothian) during the period 2000-2013 and biopsy samples from a subset of 32 patients analysed for HPV infection and SNP/microsatellite markers by molecular methods.
Results: Over a median period of 23 years (up until 2011), NPC incidence has not risen significantly in Scotland or the Nordic countries, which is in contrast to the observed rise in (HPV-associated) oropharyngeal cancer in Scotland. Of the biopsy sample panel examined, 10 out of 32 cases (31%) were HPV+ve (8 HPV16; 2 HPV18/82). All 10 HPV+ve samples, and 19 out of 22 (86.4%) HPV-ve biopsies, comprised of non-keratinising carcinomas (NKC) whilst 3 out of 22 (13.6%) HPV-ve samples were keratinising carcinomas. Patients with HPV+ve NPC tended to be younger at time of diagnosis (mean age 53.4 vs 57.5 years; p=0.405) and had a lower male-to-female ratio (1.5 vs 6.3; p=0.1655) than patients suffering from HPV-ve lesions. No HPV+ve cases were diagnosed in patients of Asian background whereas 3 out of 22 (13.5%) HPV-ve cases were Scottish Asians (p=0.0694). SNP/microsatellite marker analyses did not show any significant correlation with NPC when compared with controls. However, the rs6904029 GG genotype was common in HPV+ve cases (80% vs 55%) and patients of Caucasian background (75.0% vs 28.6%).
Conclusions: The study suggests a possible role for HPV (in particular, HPV16 and 18) and the rs6904029 GG genotype in the development of a subset of NPC, which merits further investigation of a larger sample panel.