Background: The possibility of an association of Graves' disease (GD) with subsequent cancers raised by certain studies.
Methods: Using a database on 18 156 hospitalised GD patients, subsequent cancers were ascertained.
Results: Increased risks of thyroid and parathyroid tumours were limited to the early follow-up period, which is probably a surveillance bias. Cancer sites with observed excess included the mouth and breast, in contrast to decreased risks of colon cancer, melanoma and non-Hodgkin's lymphoma.
Conclusion: Increased subsequent cancers in GD patients appeared to be balanced by decreased risks at other sites; chance cannot be excluded.