Contribution of shared environmental factors to familial aggregation of common cancers: an adoption study in Sweden.
Cancer runs in families, suggesting a heritable component, but the contribution of environmental factors cannot be neglected. Studies on spousal risk can partly disentangle the environmental contribution but miss shared environmental factors during childhood and adolescence. Here, we examined the familial aggregation of common cancers among 80 281 Swedish-born adoptees, identified from the nationa
