An epidemiological evaluation of salivary gland cancer in the Netherlands (1989-2010)

Background: The relative 5-year survival rate of salivary gland cancer is moderate at best. This study was set up to evaluate whether the improvements in diagnosis and treatment in the last decades impacted the incidence, mortality and survival of salivary gland cancer. Methods: Data on patients with salivary gland cancer from 1989 through 2010 were extracted from the Netherlands Cancer Registry (NCR); we examined incidence, mortality and relative survival. Furthermore, information on sex, age, tumor stage, histology, and treatment was taken into account. Results: A total of 2737 patients were included. Fifty-three percent (53%) were males and 47% were females with a significant higher proportion of early stages in women. In 2010, the incidence rate (European Standardized Rate (ESR)) of salivary gland cancer was 0.9 per 100,000 per year. The estimated annual percentage change in incidence rate since 1989 equaled 0.6% (95% CI: -0.2-1.4). Mortality rates (ESR) decreased in men until 1997 and increased thereafter. Mortality in women remained stable at 1.5 per 100,000. Over time more patients were treated by surgery and radiotherapy (p < 0.001). The relative five-year survival rate equaled 69% and did not change in time. Conclusion: We observed no relevant changes in incidence or mortality rates in the last two decades. Despite the increased combined treatment by surgery and radiotherapy, survival did not improve. This implies an urgent need for the development of new effective treatment modalities. (C) 2014 Elsevier Ltd. All rights reserved.