Solid Organ Transplantation in Selected Patients With a History of Lymphoma: Has the Time Come?

A diagnosis of significant malignancy has long been a contraindication to solid organ transplantation. Such patients are typically referred to an oncologist as part of the transplant eligibility screening process. The expectations of such a consultation are often not clearly articulated, and the existing literature offers little guidance. The in-depth review by Bierman1 in this issue of Journal of Oncology Practice addresses a real and no longer rare clinical problem. Although focused on the lymphomas, the general principles are also applicable to the problem of a prior solid tumor. The question may seem straightforward from the perspectives of the patient and the oncologist. Unfortunately, additional factors play a role, including medical uncertainty regarding the effects of long-term immunosuppression, good stewardship of a limited resource, and even concerns about outcome data. The known association between immunodeficiency and malignancy has long generated concerns regarding the effect of immunosuppression on a pre-existing malignancy. Although viral oncogenesis plays a major role in post-transplant malignancies (such as post-transplant lymphoproliferative disorder, squamous carcinomas, and Kaposi’s sarcoma), it does not explain the excess incidence of lymphoma that is not associated with Epstein-Barr virus. Such tumors account for up to half of post-transplant lymphoproliferative disorders ≥ 10 years post-transplant, and a similar excess of Epstein Barr virus–negative lymphomas is observed with HIV-related immunodeficiency. Poorly understood other mechanisms of immunodeficiency-related lymphomagenesis seem to apply to such tumors. It is therefore difficult to conclude on mechanistic grounds that iatrogenic immunodeficiency could not affect the natural history of a pre-existing lymphoma. In the case of a patient who is believed to be cured, concern centers on the possibility that immunosuppression might allow the growth of occult residual disease, abrogating what would otherwise be a functional cure. Although anecdotal or registry-derived, an increasing amount of data has appeared on this subject, as analyzed in detail in the review. The results are reassuring, in that most patients do not seem to relapse, and in that the interval between diagnosis and transplantation was generally short for those who did relapse within the time period when relapse would normally be expected. Histopathology is often not or only poorly described. It is likely that most patients who have been in long remission will have had diffuse large B-cell non-Hodgkin lymphoma or