The Prevalence of Human Papillomavirus Infection in Korean Non-Small Cell Lung Cancer Patients

Human papillomavirus (HPV) infection is a co-carcinogen of lung cancer and contributes to its pathogenesis. To evaluate the prevalence of HPV infection, polymerase chain reaction (PCR) was employed to detect HPV 16, 18, and 33 DNA in tumor tissues of 112 patients with non-small cell lung cancer (NSCLC) who underwent curative surgery from Jan. 1995 to Dec. 1998 at Severance Hospital, Seoul, Korea. The patients consisted of 90 men and 22 women. Nineteen patients were under 50 years old (17%), and 92 patients (82%) were smokers. Fifty-three patients had adenocarcinomas, while 59 patients had non-adenocarcinomas. Early stage (I and II) cancer was found in 64 patients (57.1%) and advanced stage (III and IV) found in 48 (42.9%). The prevalence of HPV 16, 18, and 33 were 12 (10.7%), 11 (9.8%), and 37 (33.0%), respectively. Smoking status, sex, and histologic type were not statistically different in the presence of HPV DNA. The presence of HPV 16 was more common in younger patients and HPV 18 was more common in advanced stage patients. This study showed that the prevalence rate of HPV 16 and 18 infections in NSCLC tissue was low, suggesting HPV 16 and 18 infections played a limited role in lung carcinogenesis of Koreans. However, the higher prevalence of HPV 33 infections in Korean lung cancer patients compared to other Asian and Western countries may be important and warrants further investigation

Recent striking changes in histological differentiation and rate of human papillomavirus infection in squamous cell carcinoma of the lung in Okinawa, a subtropical island in southern Japan

Aims—The incidence of lung cancer in Okinawa has been the highest in Japan since 1975, and squamous cell carcinoma (SCC), especially the well differentiated form, is the most prevalent form in Okinawa, although well differentiated SCC is relatively rare in mainland Japan. Furthermore, a high proportion of SCC of the lung in Okinawa was positive for human papillomavirus (HPV). In this study, we report recent striking changes in histological features and in the incidence of HPV infection. Methods—In Okinawa between 1986 and 1998, 1109 surgically resected lung tumours were examined histopathologically. In addition, human papillomavirus infection was detected by the polymerase chain reaction and Southern blot analysis in SCC cases reported in 1993 and 1995–8. Non-isotopic in situ hybridisation of HPV DNA was also carried out. Results—Up until 1994 SCC, especially the well differentiated form, was the most prevalent type of tumour. However, since 1995 the number of such cases has diminished steadily, accompanied by a slight rise in the incidence of adenocarcinoma. Although most present and past patients are heavy smokers, the incidence of SCC, especially the well differentiated form, continues to decrease steadily. Furthermore, in 1993, HPV was detected in 79% of all cases, and was particularly prevalent in the well differentiated form, but the rate fell to 68% in 1995, 35% in 1996, 23% in 1997, and 24% in 1998. The age distribution of patients, the male to female ratio, and the number of tumours overexpressing p53 protein did not change significantly over the study period, and thus did not correlate with changes in the differentiation of SCC. Conclusions—The decreasing incidence of viral infection correlates strongly with the falling numbers of SCC cases, especially well differentiated cases. These findings suggest that HPV might be involved in the development of SCC of the lung, affecting the histological differentiation of SCC in particular, at least in Okinawa, a subtropical island in southern Japan. Key Words: squamous cell carcinoma of the lung • histological differentiation • human papillomaviru