The very therapy used to treat prostate cancer patients in the early stage of the disease actually promotes the second, more deadly wave of the disease, according to a new study.
Men with prostate cancer often take drugs to shut down the body’s production of testosterone, the hormone that feeds the initial tumors. But when those tumor cells die, they trigger an inflammatory response that draws in immune cells called B cells. Those B cells, in turn, secrete a molecule that paves the way for the growth of a second wave of deadlier prostate cancer cells that are resistant to the hormone therapy.
The researchers – from UC San Diego, Scripps Research Institute-Florida and the Engelhardt Institute of Molecular Biology in Moscow – pieced this together by studying the progression of prostate cancer in a variety of genetically modified mice. Here’s how they put it in their report, published in Thursday’s edition of the journal Nature:
“The inflammatory response elicited by the dying primary tumor contributes to the failure rather than the previously proposed success of anti-cancer therapy.” (emphasis added)
It sounds like bad news, but there may be a silver lining. Now that the mechanism is understood, the researchers say that any interference with this sequence of events ought to delay the onset of the dangerous secondary tumors.
In their experiments, such interventions reliably delayed those tumors by three to four weeks. Converting that from “mouse time” to “human time,” they calculated that equivalent interventions in people would slow the development of secondary prostate cancer tumors by 2.3 to 3.1 years.
— Karen Kaplan
Photo credit: Advanced Cell Technology Inc.