Background
Oral and oropharyngeal cancer (commonly referred to collectively as oral cancer, or OC) is the sixth most common cancer. Cancer Registry records show that the incidence of OC in New Zealand (NZ) has increased over the last 50 years, and distinct incidence patterns persist by gender, age, ethnicity and anatomical site. Despite advances in treatment, a poor prognosis persists for those diagnosed. Improving survival rates will need better rates of early diagnosis. Little is known about the factors leading to delays in OC diagnosis in NZ or whether clinicians’ deficiencies in knowledge contribute to delays in diagnosis. International studies have observed regular dental care to be associated with an earlier stage of OC diagnosis, but whether this holds in NZ is not known.
This study explored factors which may contribute to the stage of diagnosis of OC in NZ. It had two main aims: to assess the OC knowledge, beliefs and practices of NZ dentists and clinical dental technicians (CDTs); and to determine whether regular dental care affects the stage of OC diagnosis in the Canterbury region.
Methods
A self-administered questionnaire was developed and sent to all general dentists and CDTs registered with the Dental Council of NZ. The questionnaire data were compared with those from the NZ Cancer Registry (cases diagnosed with OC from 1 January 2012 until 31 December 2013), to determine whether clinicians have adequate knowledge to enable early detection of suspicious oral lesions. Data from the OC cases from the Canterbury District Health Board (CDHB) were analysed for associations of tumour extent by regular dental attendance.
Results
Dental clinicians were found to be knowledgeable about many aspects of OC, but differences in knowledge exist among clinicians, suggesting that some are more able to detect early OCs than others. Time from graduation, the type of clinician and the graduation country may influence some beliefs and practices about OC, thereby affecting clinicians’ ability to detect malignant lesions. Most clinicians reported providing OC screening (OCS) examinations for all patients, but one-third identified barriers to doing so. Consequently, it is likely that a proportion of dentists and CDTs do not provide routine OCS examinations.
Non-smokers and those of higher socio-economic status were more likely than others to be routine users of dental care. However, there was a lack of data on the dental history of cases, and so, whether differential access to dental care impacts on stage of diagnosis of OC could not be explored in this study. It was noteworthy that general medical practitioners (GMPs) continue to detect most of the OC in NZ, but their knowledge, beliefs and practices in respect of OC have yet to be explored.
Conclusion
Missed opportunities for early diagnosis of OC may result from identified deficiencies in dental clinicians’ knowledge of OC, their failure to provide an OCS examination for all patients, and high-risk patients not seeking regular dental care. A better understanding of these is required to increase rates for early diagnosis of OC and ultimately improve patient outcomes
