Renal Cell Carcinoma in Native Kidney After Kidney Transplantation: A Multicenter Case Control Study With a Focus on Screening Strategy.

Renal cell carcinoma (RCC) of native kidney is more prevalent after kidney transplantation than in the general population. Risk factors and the value of screening remain unclear. We conducted a multicenter case-control study in kidney transplant recipients transplanted between 1989 and 2017. All patients with RCC were included, and two controls were matched to each case. Two centers performed annual screening (AnS group) and the other two had other strategies (OS group). A total of 125 cancers were found in 113 patients. The majority of cancers were stage T1-T2 (92.0%), 1.6% had metastasis at diagnosis and ten (9.0%) had recurrence after nephrectomy. Men [OR 2.2; IC 95% (1.2-4.4); p = 0.02] and acquired cystic kidney disease [OR 3.2; IC 95% (1.8-5.9); p < 0.01] were associated with cancer in multivariate analysis. The 10-year survival was poorer in cases (65.6% vs. 79.1%, p < 0.001). The AnS group had fewer relapses (5.0% vs. 18.2%, p = 0.02) and a lower rate of cancer-related deaths (16.0% vs. 46.1%, p = 0.04). Survival of patients with RCC is lower than in control patients. Annual screening could improve cancer prognosis, its benefit needs to be evaluated in larger studies.