Socio-demographic distribution of vestibular schwannomas in Denmark.

CONCLUSION

Vestibular schwannomas (VSs) are diagnosed less frequently in the remote parts of Denmark, whereas the diagnostic age and tumor size is the same across the different socio-demographic areas of Denmark.

OBJECTIVE

To determine whether VSs are diagnosed equally often in different socio-demographic areas of Denmark and whether a change has occurred during the period 1976-2012. In addition, differences in diagnostic age and tumor size between areas were explored.

METHODS

Since 1976, all patients diagnosed with a VS in Denmark have been registered in a national database, in which information on, for example, the size of the tumor and the age and address of the patient has been registered. Up to 2012, 2739 patients were diagnosed with a VS. Patient distribution according to area of habitat was determined by subgrouping into urban, suburban, rural, and remote municipalities, using the definitions of socio-demographic areas elaborated by Demarks Statistic.

RESULTS

The mean national incidence increased almost linearly over the time period from 6.1 per million per year in the first period from 1976 to 1984, to 22.1 per million per year in the last period from 2003 to 2012. There was a lower incidence at the end of the period in the remote areas compared with the other socio-demographic areas (1976-1984, p = 0.05 and 2003-2011, p = 0.001). The mean age at diagnosis increased during the period, from 52.6 years in the first period to 58.6 years in the last period. There was no significant difference in the age distribution between socio- demographic areas. The mean diagnostic tumor size decreased during the period, from 28.6 mm in the first period to about 10 mm in the last period. There was no significant difference in the size of the tumor between socio- demographic areas.