Incidence of HPV in primary and metastatic squamous cell carcinomas of the aerodigestive tract: implications for the establishment of clonal relationships

Human papilloma virus: differentiating new primary lung cancer versus metastatic disease from previous head and neck squamous cell carcinoma

Distinguishing new primary lung tumours from lung metastasis in patients with head and neck squamous cell carcinoma (SCC) is a challenging clinical problem. Histological examination is not always able to distinguish between these scenarios as SCC is common in both sites. Here the authors present a case of metachronous cancers of the head and neck and lung in which human papilloma virus testing was proposed as a mechanism to distinguish primary from metastatic carcinoma.

HPV status in head and neck tumors

HPV infection has been associated with head and neck carcinoma (HNSCC). In the present study, a tumor collective from Middle Germany was analyzed using two HPV-detection methods, i.e., PCR followed by agarose gel electrophoresis and microarray chip hybridization. In addition, the predictive value of tumor morphology was assessed. In total, 76 HNSCCs from 52 patients were examined, including 23 pairs of primaries and corresponding metastases. The highest rate of positive tumors was observed in the tonsils, with 76% of the patients and 81% of tumor samples being positive for high-risk HPV. DNA chip analysis detected significantly more HPV-positive cases than did agarose gel electrophoresis. Except for one HPV-33-positive case, all others tumors harbored HPV 16. There was a good concordance between the HPV status of the primary tumor and its corresponding metastasis (21/23 cases, 91%). In two cases, HPV was found only in the primary tumor but not in the metastasis. Our results clearly confirmed the high prevalence of HR-HPV in tonsillar carcinomas with a rate that was even 20% higher than those reported in the literature. Morphology is a valuable indicator for an HPV association that needs to be confirmed by molecular tests.

Incidence of human papilloma virus in lung cancer

HPV has been identified not only in gynaecological carcinomas but also in tumors of other organs, especially of the oropharynx and upper aero-digestive tract. In this study we focused on the available literature on HPV in lung carcinomas. In total, 53 publications reporting on 4508 cases were reviewed and assessed for the following parameters: continent and region of the study, number of cases, detection method, material type, HPV type, histological subtype and number of the HPV-positive cases. Overall, the mean incidence of HPV in lung cancer was 24.5%. While in Europe and the America the average reported frequencies were 17% and 15%, respectively, the mean number of HPV in asian lung cancer samples was 35.7%. There was a considerable heterogeneity between certain countries and regions. Particular high frequencies of up to 80% were seen in Okinawa (Japan) and Taichung (Taiwan). However, there were also discrepant results within the same region pointing to methodological differences and the need for validation. All lung cancer subtypes were affected and especially the high risk types 16, 18, 31 and 33 as well as the low risk types 6 and 11 were found, the later mainly in association with squamous cell carcinomas. The data suggest that HPV is the second most important cause of lung cancer after cigarette smoking and strongly argues for additional research on this issue.

Prophylactic human papillomavirus vaccines: potential for sea change

Persistent human papillomavirus (HPV) infection is the central cause in the development of anogenital warts, precancers and cancers of uterine cervix, and a major factor in the genesis of other malignancies of the lower anogenital and upper aerodigestive tracts. The burden of disease carries very high medical, financial and psychosocial costs. The role of prophylactic HPV vaccines in reducing the burden of disease is discussed in light of the results of multiple randomized, controlled trials conducted worldwide in thousands of young females. The review discusses some of the issues that are still unknown, with respect to long-term vaccine performance, challenges to be overcome to achieve universal, mass prophylactic HPV vaccination, as well as the potential impact of the vaccines on primary screening for, and management of, HPV-related anogenital infection and disease.