A Role for HPV Analysis in Distinguishing Second Primary Tumors from Lung Metastases in Patients with Head and Neck Squamous Cell Carcinoma
JA Bishop, PB Illei, WH Westra. The Johns Hopkins Medical Institutions, Baltimore, MD
Background: For patients with head and squamous cell carcinoma (HNSCC), a squamous cell carcinoma in the lung may represent either a primary lung cancer or a metastasis. Although the distinction influences patient prognosis and therapy, it is far from straightforward using standard clinical and histologic parameters. Human papillomavirus (HPV) is an etiologic agent for an important subgroup of HNSCCs, but not for primary lung carcinomas. Detection of HPV could be useful in establishing tumor origin and clarifying other important relationships for patients with HNSCC who develop a squamous cell carcinoma in the lung.
Design: We performed HPV in-situ hybridization on 46 squamous cell carcinomas involving the lungs of patients with a prior history of HNSCC. HPV status was correlated with certain clinical features including anatomic site of the HNSCC and disease free interval.
Results: HPV was detected in 5 of 46 (11%) cancers in the lungs. When stratified by anatomic site of the prior HNSCC, HPV was more common in patients with oropharyngeal carcinomas than in those with non-oropharyngeal carcinomas (25% vs. 0%, p = 0.01). The presence of HPV was confirmed in the corresponding oropharyngeal carcinomas (3 of 3, 100%). Although lung carcinomas in patients with HNSCC are generally believed to represent second primary tumors if they occur more than 3 years after treatment of the HNSCC, 4 of the HPV-positive lung metastases were discovered beyond this time frame. Indeed, 2 patients with HPV-positive oropharyngeal carcinomas developed lung metastases after a disease free interval of 8 years.
Conclusions: For patients with carcinomas of the oropharynx who develop squamous cell carcinomas in their lungs, HPV analysis may be helpful in clarifying tumor relationships. These relationships may not always be obvious on clinical grounds as HPV-related HNSCC may metastasize long after treatment of the primary tumor. Although not previously appreciated, long periods of quiescence is in keeping with the improved 5 year-survival rates associated with HPV-related HNSCC and underscores a need for long term patient follow-up.
Wednesday, March 24, 2010 9:30 AM
Poster Session V # 236, Wednesday Morning