Improved prognosis for patients with oral cavity squamous cell carcinoma: Analysis of the National Cancer Database 1998-2006.

BACKGROUND: Improvements in prognosis have been reported for oral cavity squamous cell carcinoma (OCSCC) in international cohorts. We sought to quantify improvement in survival of OCSCC and to determine factors associated with survival in the United States using a large administrative database.

METHODS: Retrospective cohort study of 13,655 patients with OCSCC in the National Cancer Database diagnosed during time periods 1998-2003 and 2004-2006. Statistical methods included chi-square and Cox regression.

RESULTS: Patients with early (Stages I and II) and late stage (Stages III and IV) disease had improvements of 36.2% and 16.0% in three-year overall survival, respectively. Receipt of adjuvant chemoradiation increased from 8.3% to 36.4% for late stage disease, while receipt of adjuvant therapy in early stage disease remained stable. Patients with early stage disease increased from 64.1% for years 1998-2003 to 67.4% during 2004-2006 (p<.001). Being diagnosed between 2004 and 2006 was associated with decreased mortality in early and late stage disease (HR 0.67 and 0.87, p<.001, respectively). Other treatment factors associated with improved survival for patients of all stages included treatment in a high-volume center (HR 0.91, p=.002) and undergoing neck dissection (HR 0.90, p=.001).

CONCLUSIONS: Three-year overall survival has increased dramatically for OCSCC patients. Advanced stage patients have been increasingly treated with chemoradiotherapy, while treatment of early stage patients has remained relatively unchanged. While other factors such as negative surgical margins and undergoing neck dissection may be partly responsible for improvements in early stage patients, further study is needed to understand the observed survival improvements.