High risk organ donors: When is a risk worth taking?

Interviewer: Sam Walter (Interviewer, Ideas Lab)
Guest: Dr Rajeev Desai
Recorded: 18/06/2014
Broadcast: 09/07/2014

Intro VO: Welcome to the Ideas Lab Predictor Podcast from the University of Birmingham. In each edition we hear from an expert in a different field, who gives us insider information on key trends, upcoming events, and what they think the near future holds.

Sam: So we’re here today with Dr Rajeev Desai who is a Clinical Research Fellow in NHS Blood and Transplant and is also doing a PhD here at the University of Birmingham. Hi, Rajeev.

Rajeev: Hello.

Sam: So can you tell us a little bit more about what you’re doing here at the university?

Rajeev: My research involves studying the risk of transmission of cancer from organ donors to the recipients. Organ transplantation can be life saving in the majority of recipients but, like all medical interventions, has a small risk of complications, of which my interest is cancer transmission.  I have studied a large cohort of organ donors in England and their recipients, to assess the risk of cancer transmission and factors associated with cancer transmission, and compared the outcome of recipients of such donors from standard risk donors. 

Sam: So what is a high-risk donor?

Rajeev: A high-risk donor has various different characteristics such as older age, cardiovascular disease, diabetes, obesity.  Particularly with regards to my research, a donor who has had a previous history of cancer prior to organ donation is classed as high risk of cancer transmission. This is not the same for all cancers. This depends on the type of cancer and also the cancer-free period at the time of organ donation. 

Sam: How has the study that you’ve done gone about following transplant patients and cancer in the transplant?

Rajeev: The study was initially thought about after recipients developed cancers from transplanted organs, which were not known about at the time of organ donation. Obviously this received lots of publicity in the media because transplantation is done with the good intention of saving a life, whereas if it results in inadvertent cancer transmission, obviously it’s not good for the particular recipient as well as it is not good for the entire transplantation programme as a whole because it might reflect that there are some cases of cancer which were not anticipated at the time of transplantation, which can happen in the future.  So I have studied at the UK Transplant Registry a cohort of more than 17,000 organ donors and their recipients to look at which of these donors have had a risk of cancer, which of these cancers are classed as high risk of transmission and did we transplant any recipients whose donors had a high risk of transmission and following such transplantation, what happened to the recipients? As a result of my research, I have demonstrated that a small proportion of highly selected donors who are presently classed as high risk donors; do not necessarily result in cancer transmission following organ transplantation.  It is likely that the vast majority of high-risk donors are indeed high-risk donors and we have only selected, after careful assessment, a small cohort of these donors, particularly bearing in mind the fact that there is a severe shortage of organ donors and a lot of patients who are waiting for organ transplantation are dying. The risk of removal from waiting lists due to being too ill or death whilst waiting for a transplantation ranges between 5% to 20% every year, depending on which organ you are waiting for.  At the same time, the risk of a transplanted cancer is in the range of 1 in 2,000 which is extremely small, so we are trying to get the balance right by assessing are there any high risk donors who are traditionally classed as high risk? Can we include such organs from such donors without resulting in significant cancer transmission? 

Sam: So it’s kind of assessing the risk if there’s only limited options for having donors, you should be prepared to take the risk that you might possibly get cancer or you might possibly not.  It’s deciding on that risk, you’re saying. 

Rajeev: Yes. For patients on the transplant waiting list there are very few options. For example, those who are waiting for kidney transplant might go on dialysis. For patients who are waiting for liver transplant, heart transplant or lung transplant, there are no alternatives. Either they keep waiting for an organ or they die, eventually, and the risk assessment in such patients is of a continued wait for a better organ or accept an organ that’s coming your way, because all the organs that are accepted in the UK have undergone standard assessment. The risk of cancer transmission from these organs is very small and the alternative for these recipients is continued wait on the waiting list and a possibility that they might become too ill to survive a transplant operation. So these are the risks that we wanted to balance by assessing what are the risks of accepting an organ from a high-risk donor. 

Sam: So the quicker that they can get a transplant, the better. 

Rajeev: Yes, because one of their important organs has failed, they are at risk of becoming too ill and they are at risk of developing complications and even death as a result of that, which is why they are on a transplant waiting list in the first place.  At the same time they have the risk of transplantation, an operation itself, and also a risk of accepting an organ from a donor, which might come with its own transmissible diseases such as infections or cancer.  So our intention was to study, assess, what this risk is and see how that compares to the risk of continued waiting. 

Sam: And so who are the donors that you’ve followed in your research to study this?

Rajeev: Of the 17,000 donors, 200 had a history of cancer. Of these 200, there were 61 donors who had a high risk of cancer. Organs from these donors had been transplanted into recipients and these recipients had not developed a transmitted cancer. So this is important because in the traditional sense, these donors are high-risk donors, their organs should not have been accepted for transplantation anyway. They have been assessed. I don’t know the circumstances under which they have been accepted for transplantation. It is possible that the recipient was too ill and the risk assessment indicated that accepting a sub-optimal organ is good enough to save a life as opposed to rejecting this organ and waiting for the next offer, which might not come through. On the other hand it is also possible that some of these donors were not known to have a high risk at the time of organ donation because the study I did was a retrospective study in which I got the data from the Cancer Registry. That data may not have been available at the time of accepting these organs for donation and an organ may have been accepted inadvertently without knowing the history and then we went on to find that it doesn’t really result in cancer transmission. So it’s a very small proportion, it’s got this recommendation of accepting certain organ donors with a history of cancer should come with a precaution because the ones that we accepted and showed no cancer transmission, have been assessed by both the donation team as well as transplantation in terms of risk assessment. 

Sam: And as a result of your research, this has actually changed NHS policy hasn’t it? How has that come about and what does it mean for people that need organ donations?

Rajeev: There has been a lot of publicity about those donors who result in cancer transmission. As a result, a certain sub-group of donors have been excluded from organ donation. There has not been many studies about such donors who are traditionally classed as high-risk donors and what happens when organs are accepted from such donors. Our study is one such unique study. So we demonstrated that a few donors who are traditionally classed as high risk can successfully donate and result in a survival benefit to organ transplant recipients. So we have published this paper in the British Journal of Surgery, we have written up national guidelines, which are accepted by the NHS Blood and Transplant. At present we need to implement these practices and this area needs to be studied further to see the outcome of changed practice.

Sam: So when these practices have been evaluated further, how could this impact on global policy? When will we see that change in the future?

Rajeev: A single measure threat to the future of organ transplantation is the availability of donor organs. So as a direct consequence of this study, a small sub-group of donors who are at present not included in transplantation can be included. So this results in increased transplantation activity, reduced waiting periods for patients who are waiting for transplantation, and improved health and survival for patients with organ failure. That’s the idea. How many additional donors can be included as a result of this study needs to be seen.

Sam: That’s really amazing research, so thanks for sharing that with us today and I hope that we can see the results in the policy changes in the future. So Dr Rajeev Desai, thank you very much for joining us.

Rajeev: Thank you for speaking to me.

Outro VO:This podcast and others in the series are available on the Ideas Lab website: www.ideaslabuk.com. There's also information on the free support Ideas Lab has to offer to TV and radio producers, new media producers and journalists. The interviewer and producer for the Ideas Lab Predictor Podcast was Sam Walter.