“This is provocative, fairly compelling data that bone-marrow transplantation can induce an effect against a solid tumor type,” says Dr. George Daley, a leukemia specialist at the Massachusetts Institute of Technology’s Whitehead Institute in Cambridge, Mass.
Researchers at several medical centers around the country already are conducting similar research on stem-cell transplants for kidney as well as other solid cancers.
“One problem,” notes Dr. Walter Stadler, an oncologist conducting such research at the University of Chicago. “is that this [requires] a very highly selective patient population — their disease had to be progressing slowly enough that they could wait the necessary times, usually months, to experience a response.”
And many experts warned the work is still preliminary and should not be considered an option for patients with other cancer types.
“Right now, we don’t know the implication for other solid tumors,” says Dr. John Barrett, of the NIH, an investigator on the study. “We are evaluating the approach.”
The kidney was specifically chosen for this treatment because it has been shown in past studies to respond well to immunotherapy treatment, Stadler says. But other forms of cancers that do not respond to immunotherapy may also not respond to stem cell replacement.
Still a Risky Procedure
And the treatment does have potential risks: two of the patients in the NIH study died from transplant complications. Half suffered from graft vs. host disease, when donor cells turned against the patient’s own body. Two of those with an initial response have since had a relapse. And eight of the patients in the study died as their diseases progressed.
“Whether this will be applicable on a general basis is unknown,” notes Len Zwelling, a researcher at the University of Texas Anderson Cancer Center. “This is expensive and obviously risky.”