Demographic and Clinicopathologic Distribution of Oral Cavity and Oropharyngeal Cancer in Alberta, Canada: A Comparative Analysis.

Objectives: The aims of this study were to determine demographic profiles, tumour characteristics and treatment factors related to oral cavity and oropharyngeal cancer (OCC and OPC) and comparatively analyze these cancers in the adult population of Alberta, Canada, over 12 years.

Methods: Demographic, tumour characteristics and treatment data regarding OCC and OPC incidence in Alberta residents ≥18 years in 2005-2017 were extracted from the Alberta Cancer Registry database. Age-standardized incidence and mortality rates (ASIR and ASMR) were computed.

Results: Among 3448 OCC and OPC cases, mean (standard deviation) age at diagnosis was 63.9 (14.4) and 60.1 (10.2) years, respectively. There was a male predilection for both OCC (58.2%) and OPC (81.7%). With some fluctuations, ASIR remained the same for OCC but increased for OPC. ASMR increased for both. The most common site for OCC was tongue and for OPC tonsil. Squamous cell carcinoma was the most common diagnosis for OCC and OPC. Involvement of at least 1 lymph node was observed in 38.5% of OCC and 85.8% of OPC cases. For 45.2% of OCC and 82.3% of OPC cases, diagnosis occurred at stage IV. The most common initial treatments for OCC were surgery, alone or combined with radiation, whereas radiation with chemotherapy was the main treatment modality for OPC.

Conclusion: The incidence of OPC in younger males was higher than that of OCC. Although incidence of OPC per 100 000 population increased over the 12-year study period, it remained largely unchanged for OCC. For both cancers, initial diagnoses were made at advanced stages, with almost twice as many stage IV OPC cases than OCC cases.