Human papillomavirus-16 presence and physical status in lung carcinomas from Asia.

Background. Although human papillomavirus (HPV) genome has been detected in lung cancer, its prevalence is highly variable around the world. Higher frequencies have been reported in far-east Asian countries, when compared with European countries. The present study analysed the HPV-16 presence in 60 lung carcinomas from the Asian countries China, Pakistan and Papua New Guinea. Results. HPV-16 was present in 8/59 (13%) samples. According to histological type, HPV-16 was detected in 8/18 (44%) squamous cell carcinomas (SQCs), which were mainly from Pakistan; 0/38 (0%) adenocarcinomas (ACs), which were mainly from China; and in 0/4 (0%) small cell carcinomas (SCLCs). The observed histological difference was statistically significant (p < 0.001). HPV-16 viral load was also determined using real-time polymerase chain reaction (qRT-PCR); it ranged between 411 to 2345 copies/100 ng of genomic DNA. HPV-16 genome was found integrated into the host genome in every HPV-16 positive carcinoma. Conclusion. These results support the notion that HPV-16 infection is highly associated with SQCs in Pakistan. Our results show a frequent HPV-16 integration in SQCs, although the low viral load casts doubt respect a direct etiological role of HPV in lung carcinomas from Asia. Additional HPV-16 characterization is necessary to establish a direct or indirect etiological role of HPV in this malignancy.