trends of oral cancer rates in isfahan, iran during 1991-2010

background: there is a variation in trends of oral cancers all over the world. many studies have reported evidence of increasing incidence in oral cancers during recent years. the purpose of this study was to investigate time trends and changes in demographic distribution of oral cancers incidence in isfahan during 1991-2010. materials and methods: in this retrospective analytic study, we collected and recorded data on patients with oral cancers at oral pathology department of dental school of isfahan university of medical sciences during 1991-2010. collected data include age at presentation, gender, primary site, and histologic type of cancer. statistical analysis performed using jointpoint regression program version 3 and spss version 18. results: we analyzed data from 231 pathology reports. the most frequent cancer was squamous cell carcinoma. comparing the two time intervals (1991-2000) and (2001-2010), we found that carcinomas and salivary gland tumors had decreased while there was an increase in incidence of sarcomas and lymphomas. gingiva was the most common site (46%) of oral cancers followed by tongue with (18%) through these 20 years. male to female ratio was decreased from 1.4 to 1.1 during these two decades of study. conclusions: according to this study, there might be some changes in risk factors as well as changes in the diagnosis of oral cancers in isfahan that calls for further investigations.