Transplant-linked cancer deaths pose questions about safety
Cancer transmission is less than 1 percent across all cases. UW Medicine transplant chief describes precautionary measures.
“4 get cancer from donated organ,” blared the headline above a news story last week. It described the case of a woman in Europe who died in 2007. Her undetected breast cancer was transmitted via transplant to four individuals who received her lungs, liver and kidneys. Only one recipient is alive today, after the donor kidney was removed in a subsequent surgery.
The story raises questions about the risk of cancer transmission from a transplant and what precautions exist to make such horrifying outcomes a rarity. Jorge Reyes, UW Medicine’s chief of transplant surgery, provided context:
“It’s not unusual for us to get (organ) offers from a prospective donor who has a history of breast cancer, and we (UW Medicine) reject them every time. Breast cancer, melanoma and certain brain cancers are the three tumor types we reject every time it is part of a donor’s medical history, no matter how far in the past.”
The donor in the news story, however, had no history of breast cancer. It’s plausible that her undetected tumor had dispersed small amounts of cancer cells to each of the transplanted organs, according to a formal review of the donation and the four recipients’ outcomes. At that early stage of development, the cancer could have gone undetected, even with a comprehensive screening of the donor’s health, Reyes suggested.
Across all U.S. transplant surgeries, cancer transmission is low, affecting less than 1 percent of recipients, per research studies (Transplantation, 2002; American Journal of Transplantation, 2017). That figure is equally low in the UK.
Policies of the U.S. Organ Procurement and Transplantation Network dictate that all deceased donors are subject to a comprehensive physical exam and a review of medical records. A regional organ procurement organization, which facilitates organ donations, also attempts to gather information about the deceased donor’s medical and behavioral history from family members and friends.
This upfront work is uniformly helpful, Reyes said, but he acknowledged that physical exams can miss evidence. The nature of organ donation is that, once their availability is confirmed, there is a flurry of activity among teams working to recover individual organs. Priority tests focus on potential infection transmission of bacteria and viruses such as hepatitis B and C, and HIV.
In that on-deadline, task-oriented environment, a “head-to-toe, behind-the-ears” exam of the donor may not be prioritized, Reyes said. And, of course, health risks are not always as obvious as a scar.
“About 10 percent of the time we’re confronted with unknowns,” Reyes said. “For instance we had a prospective lung donor and our team ordered a CT scan to check for infection, pulmonary edema, and nodules. This showed masses in the spleen, which led to a second CT scan and questions about whether the donor could have lymphoma or another cancer. So we withdrew from that offer. But if the lungs had not been involved in the original donation, the CT wouldn’t have been done. Then it would’ve been up to the surgeon doing the procurement, in their exam of the donor’s abdomen, to recognize any visual clues that might be there.”
Much more frequently than cancer, Reyes added, transplant precautionary tests turns up viruses and bacterial and fungal infections.
By and large, existing measures keep transplant recipients safe from disease in the vast majority of cases. Nonetheless, Reyes suggested that a checklist, akin to one that surgeons use to begin a procedure, could provide additional screening benefit to the organ-donation process.
-- Brian Donohue