Demographic data and tumour location
Most of the studies that have compared patients treated in the pre-pandemic and pandemic periods have not found any significant demographic differences in sex or age, similar to our results7,9,10. However, we did find a significantly higher proportion of patients diagnosed with oral cancer in the pre-Covid period (45.3% vs. 32.1%; Table 2), but the reason for this difference is difficult to determine. Kiong et al. found no significant differences in the main head and neck cancer locations at their centre between the two periods, nor did they find any other studies reporting such differences 8. In contrast, Thomson and colleagues found a substantial increase in the percentage of patients diagnosed with oral cancer (from 23% to 44.4%), but they did not explain the potential reasons for this difference 7. Interestingly, we observed a significant increase in the number of nasopharyngeal cancer patients (from 1 to 11), perhaps because most of the symptoms and side effects of Covid-19 affect the nasal cavity and paranasal sinuses, which could have led to early detection of nasopharyngeal cancer during the diagnostic process for Covid-19. Alternatively, virus-mediated stimulation of the immunological system may have initiated the disease process leading to nasopharyngeal cancer. However, this hypothesis is only speculative given the small sample size and considering that this finding has not been reported elsewhere. Nonetheless, this question could merit further research.