Epidemiological study of HPV-related cancers in Asia-Pacific region

人乳头瘤病毒（HPV）是宫颈癌的一种广泛接受的危险因素，已在其他类型的癌症（包括食道癌和肺癌）中发现。为了阐明环境因素（包括辐射暴露和生活方式）、病毒因素和遗传因素之间的相互作用对致癌的影响，本研究从流行病学、临床病理学、病毒和分子生物学等方面对病毒的致癌作用进行了研究。HPV（主要是HPV）相关的癌症与非病毒相关的癌症相比，HPV基因组在10-30%的食管癌，肺癌，其检出率因肿瘤的部位和组织学类型而异。HPV-16高危型在所有肿瘤部位中最常见。虽然实时PCR分析表明，在大多数HPV-16阳性标本中存在整合形式的病毒DNA，但估计的病毒载量明显低于宫颈癌（约0.1拷贝/细胞）。这些结果表明，HPV在这些器官和宫颈癌发生中的作用不同。另一方面，我们观察到在吉非替尼敏感的肺腺癌中HPV阳性病例的高频率，以及在高背景辐射地区癌症中HPV高危型和高病毒载量的高频率。进一步的调查是必要的，以检查HPV与遗传和其他环境因素的相互作用。

Detection of human papillomavirus (HPV), a widely-accepted risk factor of cervical cancer, has been reported in other types of carcinomas including cancers of the esophagus and the lung. To clarify the effects of interactions among environmental factors including radiation exposure and lifestyles, viral factors, and genetic factors on carcinogenesis, this study examine epidemiological, clinic-pathological, viral, and molecular biological features of virus (mainly HPV)-related cancers in comparison with those of non-virus-related cancers.HPV genome was detected in 10-30% of carcinomas of the esophagus, the lung, and the breast, and its detection rate varied by regions and histological type of tumors. The most frequent genotype was high-risk type of HPV-16 in all sites of tumors. Although real-time PCR analysis indicated the presence of integrated-form of viral DNA in most of HPV-16-positive specimens, the estimated viral load was significantly lower (around 0.1 copy per cell) than that of cervical cancers. These results suggested that the role of HPV in carcinogenesis differ between these organs and cervix.On the other hand, we observed the high frequency of HPV-positive cases among gefitinib-responsive lung adenocarcinomas, and the high frequency of high-risk types of HPV and high viral load in cancers in a high background radiation area. Further investigations are warranted to examine HPV interactions with genetic and other environmental factors.