Overall and site-specific cancer before and after diagnosis of idiopathic inflammatory myopathies: A nationwide study 2002–2016

•The cancer types that occur before IIM diagnosis differ from the ones that occur after diagnosis.•Before IIM diagnosis, only colorectal, lung and ovarian cancers were associated with IIM. After IIM diagnosis, the associated malignancies were oropharyngeal, cervical cancers, malignant melanoma and non-melanoma skin cancer. Lymphatic hematopoietic cancers were associated with IIM both before and after IIM diagnosis.•This study gives an up-to-date and comprehensive picture of the association between cancer and IIM before and after IIM diagnosis. This will be of importance when designing accurate malignancy screening programs in patients with IIM.