Third malignant brain tumor transmitted by liver transplant raises concern in U.K.
The third confirmed case of a malignant brain tumor transmitted via a
liver transplant, reported in the July 4 issue of the British medical
journal The Lancet, raises new questions about organ donation policies.
The donor was a 47-year-old German woman who died from recurrent
glioblastoma multiforme. Five months after receiving her liver, the
29-year-old recipient died, with autopsy showing multiple liver, adrenal
gland, lymph node, and brain and spinal cord metastases of a gliomatous
tumor. Both kidney recipients, by contrast, continue to do well four
years after receiving their transplants. Cancer is a general
contraindication to organ donation. The only exceptions are low-grade
skin cancers and primary central nervous system (CNS) tumors, both of
which have low metastatic rates. Glioblastoma multiforme accounts for
about one-quarter of all primary CNS cancers in US adults. Biologically,
it is the most malignant of glial tumors and also is the most likely to
metastasize, primarily to the lymph nodes, lung, bone, and liver.
Neither the true incidence nor risk of CNS tumor transmission via
transplants is known. But since 1 994, when the United Network for Organ
Sharing (UNOS) began recording primary brain tumors as a cause of brain
death, between 33 and 47 liver transplants per year have been donated by
individuals who died of primary CNS tumors. None has transmitted the
disease to a recipient. Whether patients with CNS tumors should be
organ donors is a difficult clinical and ethical problem. Currently,
over 9,000 patients are on US liver transplant waiting lists. In 1 996,
the median waiting time was 366 days, and 953 patients died without ever
receiving a suitable organ. Prohibiting all individuals with primary CNS
cancers from organ donation would, each year, deny up to 0.5% of this
waiting list--30% of status I patients--the opportunity for life, write
Drs. Patrick Healey and Connie Davis in a commentary accompanying the
case report. If only persons with glioblastomas were ineligible to
become donors, approximately 10 patients per year would not receive an
allograft. Excluding just those with metastatic disease would cause
perhaps two to three patients to miss out on a transplant each year.
To maintain the donor pool while at the same time limiting CNS tumor
transmission, Healey and Davis suggest that liver donors with CNS
cancers, especially a glioblastoma, be considered "marginal"
donors." Their organs would be offered only to patients who would
die without an immediate transplant. To increase safety, the authors
recommend that the transplant team review donor records with special
attention to physical and radiologic evidence of metastatic disease and
seek out asymptomatic liver metastases radiologically or by lymph node
biopsy preoperatively, intraoperatively, or both. The commentators
conclude that while the case report justifies caution with and further
investigation of the use of patients with brain tumors as organ donors,
transplant policy should not be changed without more specific data on
the risk tumor transmission. "There are too few organs for
transplantation," they write, "for 1% of the total organ donor
pool to be dispensed with."