Family history of cancer as a risk factor for Long COVID among United States adults

Background: Previous research has identified several risk factors for Long COVID, including cancer. This study aims to assess whether adults with a family history of cancer had a higher risk for Long COVID. Methods: This cross-sectional study used data on 25,389 adults, who were not cancer patients or survivors, from the nationally representative 2023 National Health Interview Survey. Multivariable generalized linear models were estimated to assess the prevalence of Long COVID (i.e., having symptoms for ≥ 3 months) for self-reported family history of cancer by sequentially adjusting for demographic and socioeconomic attributes, health behaviors, and underlying health conditions. Karlson–Holm–Breen (KHB) method was applied to assess potential mediating effects of health conditions. Results: Long COVID prevalence in the study population was 8.4%. Adults with a family history of cancer were 1.26 (95% CI 1.15–1.38) times more likely to have Long COVID. The prevalence rate ratio decreased to 1.19 (95% CI 1.08–1.28) when health conditions were accounted for. KHB decomposition suggested that 30.16% of the association was mediated through underlying health conditions. Conclusion: These findings suggest that familial or genetic factors associated with cancer susceptibility may also contribute to Long COVID risk. Further research is needed to explore potential biological mechanisms underlying this association.