Human papillomavirus may be common within nasopharyngeal carcinoma of Caucasian Americans: Investigation of Epstein-Barr virus and human papillomavirus in eastern and western nasopharyngeal carcinoma using ligation-dependentpolymerase chain reaction

Background. Nasopharyngeal carcinoma (NPC), particularly those tumors endem ic to the Far East, commonly harbor Epstein-Barr virus (EBV), thought to se rve as an important oncogenic promoter. Human papillomavirus (HPV) is assoc iated with a proportion of upper aerodigestive tract carcinomas. We hypothe sized that HPV might also contribute to the pathogenesis of NPC, and we que ried whether geographic and racial distinctions may be identified between N PC of the Far East versus those diagnosed in Caucasian American patients wi th regard to the interrelationship of histologic subtype and viral infectio n. Materials and Methods. Formalin-fixed paraffin-embedded tissue (FFPET) from 30 patients (6 Caucasian Americans, 1 Chinese American, 14 and 9 patients from Korea and China, respectively) were studied using the ligation-depende nt polymerase chain reaction (LD-PCR). These cases were histologically clas sified according to the World Health Organization (WHO) schema for NPC. Con sensus target probes complementary to the L1 region of over 30 HPV types, a s well as target probes complementary to EBER-1 (EBV-related nontranslated latency-associated RNA), were used to amplify target sequences. Results. Seven of 30 NPC (23%) contained HPV sequences. There were 6 Caucas ian American patients with NPC; 3 cases (50%) were HPV positive (HPV+). Two of these Caucasian Americans had WHO type I tumors: one was HPV+ and EBV n egative (EBV-) and the other was HPV-/EBV+. The remaining Caucasian America n NPCs were WHO-II/III tumors which tested as follows. two were coinfected with HPV and EBV, the other two contained EBER but not HPV sequences. The s ingle Oriental American patient had a WHO-III NPC which was HPV-/EBV+. Of t he Eastern NPC patients, 4 (1 WHO-I, 3 WHO-II/III) of 23 (17%) NPCs contain ed HPV sequences as well as EBV. Conclusion. Human papillomavirus appears to be uncommonly (17%) associated with NPC in patients from the Far East and was detected more often (50%) in NPC from American Caucasian patients. Some of these tumors conformed to ou r perceptions and expectations of NPC (eg, WHO-I tumors being EBV-/HPV+ and WHO-III tumors being EBV+/HPV-), but other tumors did not conform to these expectations (eg, WHO-III NPC occasionally harboring both HPV and EBV). Th ere appears to be a broad profile in the relationship between HPV, EBV, and NPC histologic subtype. Unfortunately, the number of American Caucasian ca ses studied are too small to allow for strong conclusions. (C) 1999 John Wi ley & Sons, Inc.