Detection of human papillomavirus DNA in primary lung carcinoma by nested polymerase chain reaction

Human papillomaviruses (HPV) have been implicated in the pathogenesis of human squamous cell carcinoma, especially of cervical carcinomas. In two previous studies concerning squamous cell carcinomas of the lung, DNA of HPV subtypes 6/11/16/18 (and 31/33/35 for one study) was detected by in situ hybridization in 7% to 30% of the cases. A series of 31 frozen biopsies of lung carcinomas were examined for the presence of HPVDNA by nested polymerase chain reaction (PCR). Type-specific primers (6/11, 16 and 18; Amplicis HPV(R)) located in the E6 or E7 transforming region of HPV were used. HPV DNA was found in 2 of 18 cases (11%) of squamous cell carcinoma, in 1 of 4 cases of adenocarcinoma and in 2 of 7 cases of neuro-endocrine cancers. The two large cell undifferentiated carcinomas were HPV negative. There were three cases of HPV 6/11, one case of HPV 16, and one sample positive for HPV 6/11 and HPV 18. No any consistent morphologic change with HPV lesions could be observed whereas squamous metaplasia could be seen only in squamous cell carcinomas. The frequency of 11% among the squamous cell carcinomas is comparable to those previously reported in studies utilizing in situ hybridization. To our knowledge HPV DNA had never been detected previously in adenocarcinomas or neuro-endocrine tumors. This finding should be confirmed by the investigation of larger series, but suggests that HPV could play a role in carcinogenesis of different types of lung carcinoma, although at low frequency.