Malignancies in renal transplant recipients: A retrospective single-center descriptive study

Abstract

The risk of malignancy development in kidney transplant recipients (KTRs) is 2-3 times higher than in the general population. This picture, which emerged with chronic immunosuppressive use, has become more prominent in recent years as the ongoing cause of death in this population. This study aims to determine the common features of KTRs with malignancy in follow-up under a single-center experience. Thus, it is to save time by correctly determining our focus points in patient follow-up.

Methods. The files of 403 patients who underwent kidney transplantation between 2005 and 2020 in our hospital were reviewed retrospectively. The clinical findings at admission were age, gender, primary disease, use of cyclophosphamide before transplant, duration of dialysis, number of human leukocyte antigen mismatch, transplantation time, previous rejection, the existence of associated viral infections, comorbid diseases, used induction therapy, maintenance immunosuppressive therapy, allograft survival, recipient survival, malignancy development time after transplantation, serum creatinine, glomerular filtration rate (GFR) and presence of proteinuria and hematuria. Using these data, we retrospectively analyzed the incidence and types of malignancies in KTRs.

Results. During the follow-up period, 22cancer cases have been developed. The median age of the patient was 60 years (IQR 45-64.3) and patients were mostly male (77.3%) The median follow-up period was 111.5 months (IQR76.3–128.3). The median duration of dialysis was 54 months (IQR 11.5-78). The etiology of primary kidney disease in most KTRs recipients was unknown. The percentage of patients with mismatch 3 and above 3 was 86.3%. While the majority of patients received anti-thymocyte globulin (86.4 %) as induction therapy, maintenance therapy was mostly tacrolimus + mycophenolate mofetil + prednisolone (86.4 %). The median time from transplantation to the initial malignancy was 17.5 months (IQR 5-61.3). The most common initial malignancy was skin cancer (22.7%), followed by renal cell carcinoma originating from the native kidney (18.2%).

Conclusion. Renal transplantation is the most favorable renal replacement therapy. Malignancies are now among the important causes of death in KTRs and these patients have a higher risk of developing cancer than the general population. Therefore, screening for cancer at certain intervals, especially in long-term and elderly recipients after transplantation, will positively affect the survival of the patient and functional renal graft.