Children with Down syndrome have a significantly increased risk of leukemia, while adults have a lower risk of several common solid tumors, according to a new register study from Karolinska Institutet published in the British Journal of Cancer. The results may contribute to more tailored cancer screening guidelines.

In a large, Swedish population-based register study, the risk of different cancer types in individuals with Down syndrome was mapped across the lifespan. The results show a markedly increased risk of leukemia during childhood, with a nearly 500-fold increased risk of acute myeloid leukemia (AML) before age 5, and a 20-fold increased risk of acute lymphoblastic leukemia (ALL). Despite this, only 2.5% of all individuals with Down syndrome developed leukemia during childhood.

In adulthood, however, a clearly reduced risk was observed for most solid tumors, including breast, prostate, lung, colorectal, and gynecological cancers, as well as melanoma. Although the study showed an overall lower cancer risk in adults, there was an increased risk of testicular cancer, as well as new associations between Down syndrome and certain rare forms of bone cancer.