Trends of Salivary Gland Cancer Among Whites in the US

Objectives: About 85% of salivary gland cancers (SGC) occur in White population. The incidence rate of SGC is also the highest among Whites compared to other races in the United States. Due to the diversity and complexity of salivary gland cancers, the etiology of SGC is poorly understood. The objective of the study is to better understand the development of SGC by utilizing the population-based cancer registry database to analyze the disease patterns in the population. To eliminate the confounding issues of race and subtypes of disease, our study was focused on the Whites and by histological details.

Methods: Using the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) database, we examined the SGC incidence rates and survivals by the six most common histology types among Whites in the U.S. during 1973-2004. Time trends as well as age-specific risk patterns were analyzed by gender and tumor grade for each of the histology types.

Results: SGC in Whites typically occurs in both genders beginning in the fifth decade of life with incidence steadily increasing with age. The six most common SGC are mucoepidermoid carcinoma, squamous cell carcinoma, adenoid cystic carcinoma, acinar cell carcinoma, adenocarcinoma NOS (not otherwise specified), and carcinoma in situ or NOS. Squamous cell carcinoma occurs most often in White males with lowest survival followed by mucoepidermoid carcinoma. Mucoepidermoid carcinoma followed by adenoid cystic carcinoma are the most common forms of salivary gland malignancy among White females.

Conclusions: In general, SGC incidence has been the same in the last 20 years or has shown slight increase in certain groups such as acinar cell carcinoma in White males and females. Studying the SGC incidence, distribution and survival as presented here is important to understand the reason for the high incidence of these uncommon malignancies among the White population.