Tuesday, April 08, 2008

Malignancy from organ transplants?

I've always wondered about this: Is it possible to get cancer from a donated organ? In theory the organs are inspected and come from healthy donors, but microscopic lesions would be undetectable. Furthermore, the recipients are on immune suppressants, making the cancer even more likely to develop. In fact it's a common occurrence in recipients to develop de-novo tumours after transplantation, but it's usually from their own tissue and a direct result from the drugs. For example, melanomas are 1.6-2.5 times more likely in the transplant population. Well a story this week explains how a 15y old boy who was mis-diagnosed with meningitis but who in fact had lymphoma, ended up causing the death of 2 of the four recipients of his tainted organs. The other two had the organs removed and are undergoing chemo. I wonder if they have improved chances of survival once they are off the immunosuppressants since the cancers are mismatched or whether the match required for transplantation is close enough for the tumour to behave like a de-novo host tumour... The Lancet has a great review on how to threat both types of malignancies:

"Transmission of an undetected tumour in the donor is rare (incidence 0·02%).77 The question of whether a tumour in the recipient has arisen de novo or by transmittance from the donor can be answered by doing a biopsy of the tumour and cross karyotyping the recipient and donor tissue to establish tumour origin. [...] The overall mortality from donor-related malignancies is calculated at 38%, with that of transmitted tumours at 46% and derived de-novo tumours at 33%. Cadaveric-donor-related tumour mortality is 0·007% (8 of 108 062 recipients).77"


Bayman said...

"4 get cancer from teen’s donated organs"
There wasn't any mention in the news article of evidence or studies that demonstrated this was the case. As you alluded to, it's possible the lymphomas happened to arise de novo in the recipient as a result of immunosuppresants inactivating antitumor surveillance mechanisms. Or was the recipient's lymphoma caused by transfer of a virus like HHV-8 that readily induced tumorigenesis de novo in the immunosuppresed milieu?

It would be interesting to know whether (allogeneic)lymphoma cells can really be transferred between people when simply a pancreas or a liver is transplanted...

Anonymous Coward said...

Yeah it was a sensationalized bit of news, and I was disappointed by the lack of case reports about it on pubmed, but the fact that the organs were removed from the two other recipients suggests the doctors strongly suspected that the transplant was the cause. Although I did see some mention on pubmed of viral-related transplant malignancies... In any case, as the Lancet review explained, such tumours DO occur and it can be confirmed by karyotyping.