In an extremely rare case reported in the Journal of American Transplants, three out of four patients died of breast cancer after receiving tainted organs from a single donor.

The organs of a 53-year-old woman were donated to medicine after she died of a stroke in 2007. Unbeknown to doctors, she had undetectable traces of breast cancer in her body – tests taken at the time (including a physical examination, an X-ray, and an ultrasound) came back entirely negative.

They now suspect the donor had metastasized breast cancer and that tiny, untraceable clumps of cells had made their way to each transplanted organ. These were then able to progress in the new bodies with the help of immunosuppressant drugs.

It was only 16 months after the organs had been transplanted into the donor patients that one became ill and was admitted to the hospital with a transplant dysfunction. Doctors found cancer in the lymph nodes in her chest, and a subsequent analysis examining the DNA of the cancer cells found it had originated from the donor organs – in this case, two lungs.

After a year or so of being diagnosed, she died. The remaining three donor patients were advised to go in for testing to see if their organs had also been infected with cancerous cells.

In 2010, the tests came back negative, but just a year later, a 59-year-old woman who had received the liver transplant was diagnosed with cancer. The cells were found to be breast cancer. Once again, they had originated from the organ donor.

To avoid risking complications, the woman chose not to have a liver transplant and instead began radiation treatment. Initially, it was a success and the disease appeared to remain stable, but in 2014 – seven years after the transplant and three years after diagnosis – she passed away. 

The third patient to die from "donor-derived" cancer was a 62-year-old woman who had undergone a kidney transplant. Breast cancer in the left kidney was diagnosed six years after transplant, at which point it had already spread to the liver, bone, spleen, and digestive tract. 

The fourth patient was a 32-year-old man diagnosed with breast cancer in the right kidney in 2011. In this particular instance, the doctors were able to remove the infected organ. The man stopped taking medication to suppress the immune system and began a process of chemotherapy, which was successful. Today, the man is cancer free. 

While this is an unnerving example of how donor organs can cause negative side effects, it is worth remembering that such cases are very, very rare. According to the authors of the article, there is just a 0.01 to 0.05 percent chance of tumor transmission for any single organ transplant. That is less than one instance per every 2,000 cases. 

"This low incidence implies that current practices of donor screening for malignancy are effective," they add. 

"It remains unclear whether a predonation total-body CT scan of the donor might have revealed the malignancy. The drawback of a routine postmortem CT scan for all donors is that it will increase clinically irrelevant findings, which might lead to more rejection of donors and a decrease of the already scarce donor pool."