Kidney transplant recipients (KTRs) with allograft survival times longer than 20 years have a disproportionately high cancer rate, with post-transplant lymphoproliferative disorder (PTLD) the most common cancer type, according to a recent report.
The findings “suggest long-term exposure to maintenance immunosuppression is the most relevant risk factor contributing to the strikingly high cancer rates in the ultra long-term after kidney transplantation,” corresponding author Thomas Schachtner, MD, of University Hospital Zurich in Switzerland, and colleagues reported in Clinical Kidney Journal. “The immunosuppressive medication facilitates cancer and [nonmelanoma skin cancer] through various mechanisms, including reduced immune surveillance of atypical cells, impaired cell repair mechanisms, and proliferation of carcinogenic viruses.”
KTRs with such long-term exposure to immunosuppression require an individually tailored approach to cancer prevention, screening, and surveillance, they concluded.
Dr Schachtner and colleagues studied 293 KTRs with kidney allograft survival times longer than 20 years. By 10, 20, and 30 after transplantation, the KTRs had an overall cancer rate of 4.4%, 14.6%, and 33.2%, respectively. The nonmelanoma skin cancer rates were 10.3%, 33.5%, and 76.8%, respectively.
By 30 years post-transplant, the cancer with the highest incidence was PTLD (8.5%), followed by renal cell carcinoma (RCC; 5.1%). “Not surprising but impressive in terms of scale are the PTLD and RCC rates among KTRs in the ultra long-term, which should raise awareness among clinicians,” the investigators wrote.
According to a multivariate analysis, recipient age further increased the risk of cancer among KTRs in whom prostate and lung cancer developed, Dr Schachtner and colleagues reported. Smoking history further increased cancer risk for those in whom lung cancer developed. Time on dialysis did not affect the risk of any cancer type, according to the investigators. Risk factors for nonmelanoma skin cancer included recipient age and thiazide diuretic use.
Cancer significantly increased the risk of death by 2.4-fold and PTLD increased the risk of kidney allograft loss by 6.5-fold.
Fuhrmann JD, Valkova K, von Moos S, Wüthrich RP, Müller TF, Schachtner T. Cancer among kidney transplant recipients more than 20 years after transplantation: PTLD remains the most common cancer type in the ultra long-term. Clin Kidney J. Published online January 13, 2022. doi:10.1093/ckj/sfac013