Predictors of Clinicopathologic Stage Discrepancy in Oropharyngeal Squamous Cell Carcinoma: A National Cancer Database Study

Objective: To determine the frequency, associated factors, and prognosis of clinicopathologic stage discrepancy in oropharyngeal squamous cell carcinoma (OPSCC). Study Design: Retrospective study using a national database. Setting: National Cancer Database. Subjects and Methods: Cases of OPSCC diagnosed between January 1, 2004, and December 31, 2013, with full clinical and pathologic staging information available were identified. Demographic, clinicopathologic, and treatment variables associated with overall stage discrepancy were identified by multivariate logistic regression analysis. Results: In total, 7731 cases of OPSCC were identified. Overall stage discrepancy was present in 30.2% of cases (21.9% upstaging, 8.2% downstaging). A total of 13.1% of cases were T-upstaged, and 10.5% of cases were T-downstaged; 22.9% of cases were N-upstaged, and 8.6% of cases were N-downstaged. Upstaging by overall stage was associated with a high Charlson-Deyo score, high tumor grade, number of lymph nodes examined, and increasing tumor size. No factors were positively associated with downstaging. High tumor grade was negatively associated with downstaging. For stage II, III, and IVA tumors, upstaging was associated with poorer OS. Conclusion: Clinicopathologic stage discrepancy is common in OPSCC and is likely attributable to insensitive clinical staging techniques as well as to intrinsic tumor biologic properties. Upstaging is associated with poorer prognosis, which is likely due to advancement of disease.