Effects of upstaging from PET scan on survival in head and neck squamous cell carcinoma

Background. Stage migration occurs when new diagnostic modalities provide additional information, leading to reclassification of disease stage. Our objective was to examine whether stage migration occurs with inclusion of positron emission tomography (PET) scans in staging head and neck squamous cell carcinoma (HNSCC). Methods. In a retrospective cohort study, subjects were identified through university hospital and Veterans Affairs Medical Center cancer registries with incident HNSCC from 2000 to 2003. American Joint Committee on Cancer (AJCC 6th edition) criteria were used for TNM staging with and without PET scan results. Five-year survival data were acquired from medical records and the Social Security Death Index. Results. Addition of PET changed TNM classification in 13/65 patients (20%) with stage reclassification in 5/65 patients (8%, p =.03). Apparent stage-specific 5-year survival was altered, although these changes were not statistically significant. Conclusions. Although stage migration was documented by inclusion of PET scan information in this series, stage-specific survival was not significantly changed. Prospective investigation of this phenomenon is necessary.