Eleven Years of Oral Neoplasm Diagnosis in Brazil and Canada: A Cross‐National Epidemiological Comparison

The oral cavity comprises a wide range of neoplastic subtypes influenced by intrinsic etiopathogenetic mechanisms and social, cultural, and geographic factors. Comparative analyses between countries with distinct backgrounds provide insight into the distribution of oral neoplasms. This study aimed to evaluate the distribution of oral neoplasms over an 11-year period in two cities in Brazil and Canada. A retrospective analysis of biopsy cases from the Faculty of Dentistry, University of Toronto (UofT), Canada, and the São Leopoldo Mandic (SLM), Campinas, Brazil, was conducted. Data from UofT had been previously reported by Abadeh et al. (2019). All cases were classified according to the 2024 WHO Classification of Head and Neck Tumors. At UofT, 61,598 diagnostic cases were recorded, including 4402 neoplastic lesions (7%), whereas at SLM, 2270 of 11,331 cases (23%) were neoplastic. Clinical and histopathological data are summarized in Table 1. Benign neoplasms predominated at both institutions, comprising 76% of cases at UofT and 63% at SLM, whereas malignant neoplasms accounted for 24% and 37%, respectively. Oral squamous cell carcinoma (OSCC) was the most prevalent malignant neoplasm in both centers, representing 0.4% at UofT and 1.6% at SLM. Most patients with OSCC were male, with a mean age of approximately 60 years. This finding was expected, as OSCC is well established as the most common malignant neoplasm of the oral cavity. Tobacco use, particularly when combined with alcohol consumption, represents the primary risk factor for OSCC and it is prevalent in both populations (Abadeh et al. 2019; Georgaki et al. 2021; WHO 2024). In Canada, betel use is relatively common due to immigrant communities; however, this habit is virtually absent in Brazil. Therefore, differences in established risk factor prevalence alone do not account for the higher OSCC proportion in the Brazilian cohort. It is well established that geographic, socioeconomic, and cultural factors, as well as access to healthcare, can directly influence the prevalence of certain lesions. Although Toronto and Campinas are multicultural cities with heterogeneous populations, these factors alone do not explain the differences observed in this study (Statistique Canada n.d.). (statcan.gc.ca; IBGE). Although healthcare is universal in both countries, dental coverage remains limited. The number of biopsies performed at UofT is proportionally higher than at SLM, which may reflect differences in patient behavior and dental practice patterns. Greater access to dental care and a stronger emphasis on surveillance in Canada likely contribute to higher biopsy rates. According to the Canadian Oral Health Survey, 72.2% of Canadians reported at least one annual dental visit (Statistics Canada 2024), compared with 49.4% of the Brazilian population (IBGE 2020). In Brazil, socioeconomic factors, limited healthcare access, and resource constraints may lead to biopsies being performed only after malignant transformation. In conclusion, despite geographic and socioeconomic-cultural differences between UofT and SLM, oral neoplasms showed a similar distribution in terms of prevalence. However, SLM exhibited a higher overall proportion of neoplasms, particularly malignant lesions. These findings indicate that both clinicians and patients in Brazil should be aware of the prevalence of oral lesions. Andresa Borges Soares: conceptualization, methodology, investigation, visualization, writing – original draft, writing – review and editing, validation, formal analysis, data curation. André Luis Santana de Freitas: investigation, data curation, visualization, writing – original draft, formal analysis. Vera Cavalcanti de Araujo: investigation, data curation. Grace Bradley: investigation, data curation. Marco Magalhaes: conceptualization, investigation, writing – original draft, methodology, data curation, writing – review and editing, visualization, formal analysis, supervision. The authors declare no conflicts of interest. The data that support the findings of this study are available from the corresponding author upon reasonable request.