Familial risk of non-Hodgkin lymphoma by sex, relationship, age at diagnosis and histology: a joint study from five Nordic countries.
We aimed to estimate stratified absolute (cumulative) and relative (standardized incidence ratios; SIRs) risks of non-Hodgkin lymphoma (NHL) in relatives of NHL patients. A cohort of 169 830 first-degree relatives of 45 406 NHL patients who were diagnosed between 1955 and 2010 in five European countries was followed for cancer incidence. The lifetime (0-79 year) cumulative risk of NHL in siblings