Abstract 4677: The differences among various age groups of oral cancers in British Columbia
Authors: Lubpairee Tarinee , Zhang Lewei , Rosin Miriam , Poh Catherine F. 
Published: June 2012

Abstract
Oral squamous cell carcinoma (OSCC) is a disease commonly in those who are older and/or heavily smoke. However, the incidence of younger group is increasing world-wide. Research to understand this shift can have significant impact on oral cancer control.
Objectives: 1) To determine the characteristics of OSCC in different age groups in a longitudinal study and 2) To compare the differences among groups.
Methods: From 1990 to 2008, we recruited 536 OSCCs for the BC Oral Cancer Prediction and Longitudinal (OCPL) Study. We have arbitrarily put them into groups based on the age at initial OSCC diagnosis: 43 (8%) were equal to or under age 40 years (Young group); 212 (40%) were diagnosed between age 50 to 65 (Conventional group); 91 (17%) were age 75 or older (Old group). To better define the difference among various age groups, we excluded those between ages 41-49 (12%) and 66-74 (24%). Demographics, smoking habit, clinicopathological features of the lesion, treatment modalities, and outcome data were collected. The data were also compared with those from the BC Cancer Registry in the same period years to determine the representativeness of the BC population.
Results: The Young OSCC from the OCPL Study had no significant differences from those in Registry in gender, anatomical location, tumor staging, and differentiation. When compared to the Conventional group, the Young group showed less Caucasian (66% vs. 86%, P = 0.005), less smokers (35% vs. 77%, P &lt; 0.0001), tongue predilection (88% vs. 51%, P &lt; 0.0001), more treated with combined chemotherapy (12% vs. 4%, P = 0.05), and better prognosis in distant metastases or death (16% vs. 47%, P &lt; 0.0001). When compared to Conventional group, the Old group had more cancers involving more than one anatomical site (P = 0.028) and showed frequently distant metastasis (P = 0.0003). When comparing between the Young and Old groups, we found that the Old group had more Caucasians (86% vs. 66%, P = 0.02), ever smokers (66% vs. 35%, P = 0.001), less tongue location (42% vs. 88%, P &lt; 0.0001) and significantly worse clinical outcome in local recurrence, regional recurrence and distant metastasis.
Conclusion: Various age groups of early-staged oral cancer show different clinical behaviors. Nonsmokers and tongue-located tumor characterize the Young group which has a better prognosis in survival. More molecular studies are needed for better understanding the underlying driven force. An attempt to characterize the difference using-molecular tools is ongoing. This might shed the light in difference among different age groups.
(Supported by grant R01 DE17013 from the National Institute of Dental and Craniofacial Research and grant CCSRI-20336 from Canadian Cancer Society Research Institute)
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4677. doi:10.1158/1538-7445.AM2011-4677