Occult Primary Head and Neck Squamous Cell Carcinoma

Abstract

Objective Cancer of an unknown primary (CUP) squamous cell carcinoma metastatic to cervical lymph nodes is a challenging problem for the treating physician. Our aim is to determine if identification of the primary tumor is associated with improved oncologic outcomes and/or tumor characteristics including human papilloma virus (HPV) status. Study Design Retrospective, matched-pairs analysis contrasting 2 cohorts based upon discovery of primary lesion. Setting Tertiary teaching hospital. Subjects and Methods Records of 136 patients initially diagnosed as carcinoma of unknown primary were retrospectively reviewed (1980-2010) and divided into 2 cohorts based on discovery of the primary lesion. Primary outcome measures were overall survival and time to recurrence according to Kaplan-Meier analysis. A nested subset of 22 patients in which the primary was discovered were matched to 22 patients remaining undiscovered according to nodal stage and age. Results Discovered lesions were more likely to exhibit HPV positivity ( P < .001). Matched-pairs analyses demonstrated that discovery of the primary was associated with better overall survival (HR = 0.125; 95% confidence interval [CI], 0.019-0.822; P = .030). Discovery of the primary was associated with improved cause-specific survival (HR = 0.142; 95% CI, 0.021-0.93; P = .0418) and disease-free survival (HR = 0.25; 95% CI, 0.069-0.91; P = .03). Conclusion HPV positivity is associated with discovery of the primary tumor. Discovery of the primary lesion is associated with improved overall survival, cause-specific survival, and disease-free survival in patients initially presenting as CUP in matched-pair and cohort comparison analyses.