Kidney function decline in working-age adults with cancer diagnosis: A study utilizing claims and health checkup data

Purpose Cancer survivors have an elevated risk of chronic kidney disease (CKD); however, long-term alterations in kidney function among working-age individuals remain underexplored. This study aimed to evaluate differences in the rate of kidney function decline between working-age cancer survivors who received anticancer drug treatment and non-cancer survivors. Methods This retrospective cohort study used data from the Panasonic Health Insurance Organization (2017–2021). The cancer person (CP) and non-cancer person (NCP) groups were defined based on cancer diagnosis and anticancer drug treatment, respectively. Propensity score matching aligned demographics and health factors. Standardized and individualized eGFR changes from the year before diagnosis (Year F) to F + 4 were evaluated across age groups (≤ 50 and ≥ 51 years). Results Each group comprised 395 matched individuals. The CP group demonstrated significant decreases in both standardized and individualized eGFR by F + 4 ( p  = 0.007 and p  < 0.001, respectively), whereas the NCP group showed no significant decline. The decline was particularly significant in CP ≤ 50 years ( p  < 0.001) but not in those ≥ 51 years. Linear mixed-effects models confirmed a significantly larger annual decline in individualized eGFR in the CP group, particularly among younger individuals. Conclusions Working-age cancer survivors, particularly those aged ≤ 50 years, face a significantly higher risk of impaired kidney function than non-cancer survivors. These findings highlight the need for long-term kidney monitoring and protective strategies, especially among younger cancer survivors, to mitigate CKD progression and preserve quality of life and employment outcomes.