Cancer Prevalence Among Large Cohort of Individuals With Down Syndrome: Implications for Screening Guidelines

Introduction It is known that individuals with Down syndrome (DS) have a significantly different spectrum of malignancies and neoplasms. Research shows that most solid tumors are less common among individuals with DS compared to the general population, even when adjusted for age. Conversely, individuals with DS are more likely to develop leukemia and testicular cancer. However, very little of this research has been conducted with a US‐based population or on large sample sizes. Methods This retrospective cohort study analyzed 24 years of EHR data from 5895 unique individuals with DS seen in a Midwestern US health system, with the largest designated DS clinic in the US. We calculated the point prevalence of each cancer type, based on ICD‐10 coding, in our DS cohort, examined co‐occurrence patterns, and compared prevalence within our sample to the US general population using SEER data from 2022. Results Individuals with DS have significantly lower odds of cancer than the general population (OR = 0.88 (0.77–0.99)). Our cohort was 50.2% less likely to have skin cancer, 80.1% less likely to have cervical cancer, 91% less likely to have prostate cancer, and 90% less likely to have breast cancer. Zero people in our DS cohort had lung cancer. Conversely, our cohort was more likely to have leukemia and testicular cancer. Conclusion The differences in prevalences indicate a need to consider modification of the cancer screening recommendations for people with DS and inclusion of the information in shared‐decision making conversations with the patient and their family.