It's a concept that's been used since the time of Hippocrates and beyond -- using heat to treat what ails us.
Now U.S. researchers want to apply that age-old therapy to try to kill certain cancer cells, and they're using the experience of modern-day cycling superhero Lance Armstrong and others cured of advanced testicular cancer as the underpinning for their investigations.
In a commentary in today's Journal of the American Medical Association, researchers from Johns Hopkins University hypothesize that the reason advanced testicular cancer has such a high cure rate -- 80 per cent or more -- is because the tumour cells are sensitive to heat. And they suggest that makes these cells easier to kill with chemotherapy and radiation, even when they have spread to form tumours in other parts of the body.
That's because both healthy and malignant testicular cells start out a few degrees lower than the body's standard temperature of 37 C, part of a built-in system aimed at keeping heat-sensitive sperm cool and safe. (It's why men with fertility problems are advised to wear loose boxer shorts instead of tight, heat-retaining briefs.)
So when cancer cells spread beyond the testicle, they end up in a much warmer environment, said co-author Robert Getzenberg, director of urology research at Johns Hopkins in Baltimore. The excess heat appears to weaken the cells' inner structure, he explained, making them easier to destroy with drugs and radiation.
The researchers plan to test this principle, dubbed the Lance Armstrong Effect after the seven-time winner of the Tour de France, on other types of metastasizing cancers, including those that originate in the prostate and possibly the breast and lung, Dr. Getzenberg said in an interview.
"There are some differences that exist, obviously, between testicular cancer cells and breast cancer cells. But our feeling is that the general principle will be the same, that the temperature differences that go on when a cell metastasizes will make it more susceptible," he said.
The researchers point out that warming up the body with hot baths and compresses has been used since ancient times as a treatment for ailments ranging from back pain to arthritis.
"Heat is at the centre of many cellular changes," added co-author Donald Coffey, a professor of urology, oncology and molecular sciences at Johns Hopkins. "It drives everything from reproduction to fighting infection, and now we'd like to harness its power to fight cancer."
The team isn't the first to do so. Various types of so-called hyperthermia therapy, including one that employs high-frequency radio waves, are already being used by some centres around the world to treat kidney and prostate cancer.
But the Johns Hopkins group wants to try cutting-edge nanotechnology, in which ultra-tiny particles that target cancer cells could be injected into the bloodstream, then heated by exposure to a magnetic field.
"By using alternative magnetic waves . . . we could get these particles to vibrate and heat up," Dr. Getzenberg explained.
He and his colleagues are working on refining the technology and plan to begin their studies by testing it in laboratory animals with prostate cancer.
Commenting on the JAMA paper, Dr. Laurence Klotz of Sunnybrook Health Sciences Centre in Toronto said the nanoparticle concept is "fantastic and has many potential ramifications, of which this could be one."
But at this point, he said, there are no data to show whether heating up cancer cells using nanotechnology would even work.
"The issue is always whether when you apply the concept, it actually benefits the patient," Dr. Klotz said. "And so I think this is a case where in some ways it's technology looking for an application. You've got the nanoparticles and what can you make them do that will help patients?"
It's not clear, he said, that it's possible to translate success in testicular cancer to other cancers.
"It's an interesting concept and it may pan out, but until there's some reasonable experience doing this in patients, then I wouldn't hang my hat on this."
Even so, the Johns Hopkins team thinks it's worth a try.