Malignancy rates of salivary gland tumors in Greenlandic Inuit comparable to non-endemic populations; epidemiological mapping of salivary gland tumors 1990–2019

Abstract

Background

Salivary gland tumors are assumed to be predominantly malignant in the Greenlandic Inuit population, but there is limited literature on the subject. We conducted a retrospective cohort study using national registers to describe the histological tumor types, location, incidence, and survival of benign and malignant salivary gland tumors.

Methods

We analyzed data on all Greenlandic Inuit with an epithelial-derived salivary gland tumor from 1990 to 2019. We extracted data from the Central Personal Registry and crossmatched it with the Danish Pathology Data Bank. All specimens were reviewed by a specialized pathologist. We noted patient and histological characteristics, calculated crude and age-adjusted incidence rates, overall survival, and excess mortality.

Results

Our study found that 76% of salivary gland tumors in the Greenlandic Inuit population were benign, with pleomorphic adenoma being the most common. Malignant tumors accounted for 24% of cases, with lymphoepithelial carcinoma being the most common type. The most common place of origin for malignant tumors was the parotid gland (71%) and the submandibular gland (15%). The median age of onset for malignant tumors was 47 years. Age-adjusted incidence rates of malignant tumors for men and women were 3.00 and 4.12 per 100,000 person-years, respectively.

Conclusion

Our findings suggest that the proportion of malignant salivary gland tumors in the Greenlandic Inuit population is similar to other nonendemic populations. Our incidence rates are higher than previously reported, likely due to differences in methodology and definitions of the Inuit population. This study provides valuable insights into the epidemiology of salivary gland tumors in the Greenlandic Inuit population and may have implications for other Inuit populations as well.