Incidence of Merkel cell carcinoma in Olmsted County, Minnesota: a population-based study.

Background: Merkel cell carcinoma (MCC) is a rare, aggressive, often cutaneous malignancy. The incidence has been estimated from national registries in the USA and elsewhere, and data indicate variations depending on the region studied. The objective of this study was to determine the incidence of MCC in Olmsted County (MN, USA).

Methods: Using the Rochester Epidemiology Project, which contains health records for all the residents of Olmsted County, we retrospectively reviewed the records for all cases of MCC from 1976 to 2011.

Results: The overall annual age- and sex-adjusted incidence of MCC in Olmsted County during 1976-2011 was 0.35 per 100,000 person-years (95% CI, 0.14-0.57). The incidence tended to be higher among men than women with 0.69 per 100,000 (95% CI, 0.24-1.14) and 0.10 per 100,000 (95% CI, 0-0.24), respectively.

Conclusions: These data are within the range of previous MCC incidence reports, and the incidence of MCC in Olmsted County is consistent with rates reported in the remainder of the USA.