Tumor Cell Anaplasia and Multinucleation Are Predictors of Disease Recurrence in Oropharyngeal Squamous Cell Carcinoma, Including Among Just the Human Papillomavirus-Related Cancers

Oropharyngeal squamous cell carcinoma (SCC) is frequently related to high risk human papillomavirus. This tumor expresses p16, frequently has a nonkeratinizing morphology, and has improved outcomes. Despite having a good prognosis, tumors can have focal or diffuse nuclear anaplasia or multinucleation, the significance of which is unknown. From a database of 270 oropharyngeal SCCs with known histologic typing (using our established system) and p16 immunohistochemistry, all surgically resected cases (149) were reviewed. Anaplasia was defined as any x 40 field with >= 3 tumor nuclei with diameters >= 5 lymphocyte nuclei (similar to 25 mu m), and multinucleation was defined as any x 40 field with >= 3 tumor cells with multiple nuclei. p16 was positive in 128 cases (85.9%), 64 cases (43.0%) showed anaplasia, and 71 (47.7%) showed multinucleation. Anaplasia and multinucleation were highly related (P < 0.001), and both also correlated with histologic type (P < 0.001 and P = 0.01, respectively), p16 status (P = 0.09 and 0.03, respectively), and partially with nodal extracapsular extension. There was no correlation with any of the other variables. In univariate analysis, cases showing anaplasia or multinucleation had worse overall, disease-specific, and disease-free survival (P < 0.006 for all). Higher T-stage, keratinizing histologic type, extracapsular extension, and smoking also all correlated with worse survival. In multivariate analysis, anaplasia and multinucleation both predicted worse disease-specific survival (hazard ratio 9.9, P = 0.04; and hazard ratio 11.9, P = 0.02, respectively) independent of the other variables. In summary, among surgically resectable oropharyngeal SCC (including among just the p16-positive cohort), tumor cell anaplasia and multinucleation independently correlated with disease recurrence and poorer survival.