Cancer risk elevated in mild-to-moderate CKD patients, transplant recipients

There appears to be a substantial cancer incidence in the setting of kidney disease, with cancer risk heightened among patients with mild-to-moderate chronic kidney disease (CKD) and transplant recipients, but not among those with advanced kidney disease, according to a study.

The study included 5,882,388 individuals with estimated glomerular filtration rate (eGFR) data, 29,809 who were receiving maintenance dialysis, and 4,951 who had received a kidney transplant. EGFR levels were categorized as ≥60, 45–59, 30–44, 15–29, or <15 mL/min/1.73 m² consistent with KDIGO stages G1/2, G3a, G3b, G4, and G5, respectively.

A total of 325,895 incident cancer cases were documented over 29,993,847 person-years of follow-up. The cumulative incidence of cancer ranged from 10.8 percent to 15.3 percent among patients with kidney disease.

The adjusted hazard ratios (aHR) for a cancer diagnosis relative to patients with eGFR ≥60 mL/min/1.73 m² were 1.08 (95 percent confidence interval [CI], 1.07–1.10), 0.99 (95 percent CI, 0.97–1.01), 0.85 (95 percent CI, 0.81–0.88), and 0.81 (95 percent CI, 0.73–0.90) among patients with CKD stages G3a, G3b, G4, and G5, respectively.

Among patients receiving dialysis and those who had received a transplant, the aHRs for cancer were 1.01 (95 percent CI, 0.96–1.07) and 1.25 (95 percent CI, 1.12–1.39), respectively.

Stage 4 cancers at diagnosis were most frequent among patients with kidney disease. The risk of cancer-specific mortality was high among those with CKD stages G3a (aHR, 1.27, 95 percent CI, 1.23–1.32), G3b (aHR, 1.29, 95 percent CI, 1.24–1.35), and G4 (aHR, 1.25, 95 percent CI, 1.18–1.33), as well as transplant recipients (aHR, 1.48, 95 percent CI, 1.18–1.87).

The risks of bladder cancer, kidney cancer, and multiple myeloma were particularly elevated in CKD, and mortality from these malignancies increased with worsening kidney function.

The study was limited by possible unmeasured confounding.

The findings highlight the need for strategies to detect and manage these cancers in the CKD population.