A recent study from the Karolinska Institutet has uncovered distinct cancer risk profiles in individuals with Down syndrome, highlighting both increased and decreased risks for various cancer types throughout their lives. Published in the British Journal of Cancer, the findings may influence future cancer screening guidelines for this population.
Researchers conducted a comprehensive analysis of cancer risk among nearly 10,000 individuals with Down syndrome born between 1930 and 2017. By linking data from several national registers, including the National Patient Register and the Swedish Childhood Cancer Register, the study meticulously tracked the incidence of different cancers across the lifespan.
The study revealed a strikingly elevated risk of leukemia in childhood, with a nearly 500-fold increase in cases of acute myeloid leukemia (AML) before the age of five, alongside a 20-fold increase in acute lymphoblastic leukemia (ALL). Despite these alarming statistics, only 2.5% of children with Down syndrome ultimately developed leukemia during their early years.
In contrast, the research found a significantly reduced risk of several common solid tumors in adults with Down syndrome. This includes cancers such as breast, prostate, lung, colorectal, and gynecological cancers, as well as melanoma. Interestingly, while the overall cancer risk was lower in adults, an increased risk of testicular cancer was noted, along with new associations with rare forms of bone cancer.
Ann Nordgren, adjunct professor of clinical genetics at the Department of Molecular Medicine and Surgery at Karolinska Institutet, led the study. She emphasized the dual nature of the findings: “Our results show the very high risk of leukemia early in life, but at the same time show that the majority of children with Down syndrome never develop cancer.”
The implications of this research extend beyond individual patients. Nordgren indicated that the data could lead to more tailored cancer screening protocols. She suggested modifications to existing practices, such as targeted testicular examinations and potentially different approaches to breast cancer screening for those with Down syndrome.
Furthermore, the study opens avenues for future research into the protective mechanisms associated with trisomy 21, which may explain the reduced risk of various solid tumors. “This opens new opportunities for in-depth research into cancer-suppressive mechanisms,” Nordgren stated, noting that the findings could benefit not only individuals with Down syndrome but also broader cancer research efforts.
The study was supported by multiple organizations, including the Swedish Childhood Cancer Fund, the Swedish Research Council, and the Swedish Cancer Society, among others. As the research continues, next steps will involve the development of consensus cancer screening guidelines specifically tailored for individuals with Down syndrome, alongside further biological studies to explore the protective effects of chromosome 21.
Overall, this pioneering research offers critical insights into the cancer risks faced by individuals with Down syndrome, paving the way for improvements in care and screening tailored to their unique health profiles.
