Healing Heat: harnassing infection to fight cancer
Modern immunology plus historic experiments suggest a better way to gear up the human immune system to battle malignant disease.
Conventional wisdom long held that the human immune system was no match for cancer. Born of native cells, the logic went, cancer fooled the immune system into concluding it was harmless. Thus protected from attack, cancer easily thrived until its host died.
A deeper understanding of our biological defenses has changed that. The human immune system does battle cancer. But we could better optimize our defenses to fend off malignant disease. That’s clear from cancer treatments attempted in New York City and Germany as early as the 19th century. Those experiments and other undervalued evidence from the medical literature suggest that acute infection—in contrast to chronic infection, which sometimes causes cancer—can help a body fight tumors.
It’s not the pathogens that do the good work. But the way our bodies respond to the pathogens is key. Infection events, especially those that produce fever, appear to shift the innate human immune system into higher gear. That ultimately improves the performance of crucial biological machinery in the adaptive immune system. This lesson comes, partly, from doctors who risked making patients sicker to try to make them better.
Read two articles from the Scientific American: Healing Heat: Harnessing Infection to Fight Cancer and from The Newscientist: Fever: Friend or Foe:
TOXIN Therapy:
High temperatures can help you fight infections – or make you much worse. Now doctors are learning when it's better to let a fever burn itself out
It is often the first sign that we're coming down with some bug: we feel groggy, tired - and hot. A thermometer or a hand to the forehead confirms that we have a fever, or as doctors call it, pyrexia.
One of the hallmarks of infectious illness, a fever is not just uncomfortable. In some cases it can trigger fits and perhaps even brain damage. The usual response is to bring down the temperature with antipyretic drugs, such as aspirin, paracetamol (aka acetaminophen) and ibuprofen.
It has long been acknowledged that such drugs could, in theory, be counterproductive - they do, after all, interfere with the body's natural response to infection. But these qualms have been set aside for a variety of reasons: the need to relieve discomfort; fears about brain damage; time-honoured practice; and, some would say, the urge to be doing something rather than nothing.
The upshot is that antipyretics are routinely used for any feverish illness, from the sickest of patients in intensive care to people using over-the-counter medicines at home. The standard advice for people with flu, for example, is to dose up with paracetamol. Parents of young children, who are especially prone to fevers, are well aware of the perils of inaction: febrile convulsions.
But now there's growing concern that these time-honoured approaches are at best misguided and at worst potentially life-threatening. New findings are starting to support a much older view of fever: that it is a key part of the body's disease-fighting strategy. The evidence is coming in from many sources, including insights into how the immune system battles infection, research into how bacteria respond to temperature and studies of critically ill patients. At the same time, the idea that antipyretics can prevent fits in children is looking increasingly shaky. It's not often that decades of clinical practice is overturned, but it looks like the game may be finally up for one of medicine's most basic precepts.
The idea that fever can be beneficial dates to the time of the Greek physician Hippocrates, 2400 years ago. Ironically, it was the emergence of modern medical science during the mid-19th century that led to fever being seen as harmful. The volte-face had its origins in a key concept of medicine: homeostasis. The idea was developed in the 1860s by the French physician Claude Bernard (pictured). It concerns the body's ability to maintain itself within the narrow range of conditions needed for health. Deviations from these ranges were deemed in need of correction. The most obvious deviation was fever - whose severity could be measured with impressive precision by a nifty new gadget: the small, mercury-filled clinical thermometer. Not surprisingly, doctors seized on new antipyretics like paracetamol and aspirin, which rapidly lowered soaring temperatures.
Notwithstanding a fashion in the early 20th century for "pyrotherapy" (see "Fever as cure"), fever has come to be seen as something that should be fought at all costs. Could this be a mistake?
