Abstract :
[en] Organ Donation and Cancer
Pr Olivier Detry, Dpt of Abdominal Surgery and Transplantation, University of Liege
The risk of transmission of cancer with the transplanted organ has been known since the pioneering years of solid organ transplantation, and is enhanced by immunosuppression and particularly the calcineurin inhibitors. Therefore, classically, potential organ donors with past history of cancer are excluded from donation, with the exception of low-grade malignant tumours of the central nervous system, the skin and the cervix uteri. Despite that policy, every year, some cases of cancer transmission with organ transplantation were regularly reported in transplant medical journals.
At the other hand, there is a clear graft shortage, with long organ transplant waiting lists and inacceptable mortality while waiting for a life saving graft. One mean to increase the number of available grafts could be to accept donation from donors with past history of cancer. Several uncertainties remain: what is the risk of cancer transmission with organ transplantation? This risk depends of course of many donor factors, as the staging and the nature of the donor malignant tumour, the oncological management, the delay between the remission and the organ procurement. This risk may also vary according to the type of organ transplanted, as livers and lungs are more prone to bear occult metastases, compared to the hearts for example. In fact, this risk is unknown, and was clearly overestimated by the old registries as the IPTR, and by the various case reports. All modern prospective registries, as from UNOS or from UK transplant, now report a very low rate of cancer transmission when the donor cancer was known and evaluated before organ donation.
Undiagnosed or occult cancer transmission with transplantation is clearly another issue that should not be mistaken with the donors with past history of cancer. In most of the recent reported cases of cancer transmission with transplantation, the donor cancer was not diagnosed before and during organ donation. And this risk increases in modern organ transplantation, as we are now accepting older and older donors, particularly in transplantation of the liver, an organ particularly at risk of metastases. Therefore surgical donor exploration is an important step of organ procurement. Body CT could be a tool to diagnose some, but not all, of these tumours.
To my view, the risk of cancer transmission with transplantation has to be balanced with the risk of dying on the waiting lists. Donors with active or recent aggressive cancers have to be excluded from donation. Some types of aggressive cancers, as lymphoma or melanoma, are at high risk. In donors with past history of cancer with some years of remission, organ donation should be considered for recipients at high risk of death without a rapid transplantation. Particularly, heart transplantation, an organ with a low risk of cancer transmission but with a severe organ shortage, could benefit from such a policy.
