Fig. 1.

Flowchart of study population. ^aPatients with both cancer recurrence and second primary cancer were categorised according to the first occurring event. bPatients matched on sex, age, comorbidity burden and primary cancer type. In the boxes below, the total number of observations is listed. In brackets, the number of unique patients is stated as patients in remission may serve as comparison subjects for more than one case. ^cMatched comparison patients in remission were also excluded