An update on cancer after kidney transplantation.

The emergence of onconephrology in recent years highlights the importance of the interaction between kidney disease and cancer. Chronic kidney disease (CKD) and cancer are linked with each other in different ways bidirectionally: cancer can cause CKD, whereas CKD itself may be a risk factor for cancer. Kidney transplant recipients (KTRs) have a 2- to 3-fold increased cancer risk when compared with the general population. The elevated risk covers a wide range of cancers. Some are related to CKD, including cancers of the kidney, urinary tract and thyroid, whereas others are related to oncogenic viruses that include non-Hodgkin lymphoma, cervical cancer, nonmelanoma skin cancer and Kaposi's sarcoma. There is no standard protocol regarding how immunosuppressive drugs should be adjusted in patients who develop posttransplant cancers. However, any modification of immunosuppressive regimens should be balanced against the risk of allograft rejection or deterioration in kidney function. Cancer surveillance can be used as a strategy to improve the clinical outcome in KTRs. Although guidelines adopted in the general population have been used as the reference, a personalized approach based on individual cancer risk, life expectancy and concurrent comorbidities has to be adopted.