Occupational exposure and risk of oral and oropharyngeal squamous cell carcinoma: systematic review and 25-year retrospective cohort study of patients.

Social habits such as smoking and drinking alcohol are well-known causative agents for oral and oropharyngeal squamous cell carcinoma (OSCC/OPSCC). Human papillomavirus (HPV) is a known causative agent for OPSCC. However, we often encounter patients with no identifiable risk factors. There is growing evidence of the role of occupational carcinogens in the pathogenesis of oral cancer. The aim of this study therefore was to identify any occupational carcinogens linked to oral cancer. We carried out a systematic review of the literature using PubMed, EMBASE, and Medline, along with a retrospective review of patients treated in a regional unit over 25 years. Occupations were classified based on the UK Standard of Classification 2020. Data analysis was completed using the chi-squared test. A total of 17 papers met the inclusion criteria for review. In our retrospective study a total of 874 patients were identified of whom 31% were blue-collar workers, 32.8% were white-collar workers, 20.2% were unemployed/housewives, and 16% workers in other occupations. The majority of blue-collar workers were in the construction industry and had maximum exposure to hydrocarbons and exhaust fumes. The aetiology of oral and oropharyngeal SCC is multifactorial and there is no consensus on the role of occupational carcinogens. We showcase our patient cohort and discuss the occupational exposures that appear to make them susceptible to OSCC and OPSCC. Further multicentre studies are required to enable us to understand fully the pathogenesis of oral cancer and help us to inform relevant organisations, the aim being to reduce the incidence of occupation-related cancer.