Table 1.

Summary of findings table presenting the results of the GRADE synthesis and rating process. Table created with the GRADEpro Guideline Development Tool: GRADEpro GDT: GRADEpro Guideline Development Tool [Software]. McMaster University, 2020 (developed by Evidence Prime, Inc.). Available from gradepro.org. Table modified. Full information presented in Online Resource 4

Certainty assessment							Certainty
No of studies	Study design	Risk of bias	Inconsistency	Indirectness	Imprecision	Other considerations
Second primary malignancies
8	Observational studies	Serious	Not serious	Not serious	Serious	Dose–response gradient	⨁◯◯◯ VERY LOW
Secondary hematologic malignancies
3	Observational studies	Not serious	Not serious	Not serious	Serious	Dose–response gradient	⨁⨁◯◯ LOW
Dose response gradient
8	Observational studies	Serious	Not serious	Not serious	Serious	Dose–response gradient	⨁◯◯◯ VERY LOW