Wednesday, May 23, 2012

Does Fever Help Prevent Cancer?


An interesting study which suggests that occasional bouts of infectious diseases that cause fevers leads to a reduction in cancer:
Information on potential breast cancer risk factors, history of fever during the last 10 years, and blood specimens were collected from 839 incident breast cancer cases and 863 age-matched controls between October 2008 and June 2010 in Guangzhou, China...
The effect of the fever appears to be dependent on which genetic variant of interferon gamma the women carried. Interferons play roles in immune regulation. So this comparison of interferon gamma variants was not randomly chosen.
This association only occurred in women with CT/TT genotypes [0.54 (0.37–0.77)] but not in those with the CC genotype [1.09 (0.77–1.55)].
So there appears to be a genetic connection as well; if you have the right genes, fever can help keep you cancer free,
The idea that lower infectious disease incidence is associated with higher rates of cancer is not new.

Since the 19th century, it has been repeatedly observed that spontaneous cancer regressions were coincided with acute infections and the cancer patients had a remarkable disease-free history before the onset of cancer. In the 20th century, an inverse association between infectious diseases, particularly febrile ones, and cancer risk has also been consistently found for malignant melanoma and glioma using modern epidemiological methods.

With the widespread introduction of antibiotics and antipyretics since the beginning of the last century, however, the critical role played by fever has often been overlooked, resulting in considerable changes to the clinical course and magnitude of the immune response that develops following acute infections. These changes may be part of the reasons for the substantial increase in the age-adjusted incidences or mortalities of malignant diseases during the early part of the last century in western countries and in the late of the last century in China. It has been observed that every 2% reduction in infectious disease mortality was followed by a 2% increase in cancer mortality over a 10-year interval from 1895 to 1963 in Italy.
An important question is whether the drop in deaths due to the treatment of infectious diseases is greater than the increase in deaths due to higher cancer rates in treated populations?  I would think that it would.  Fever producing diseases are mankind's ancient enemies, and the ability to treat fevers is one of the great advances in medicine.  I'm not giving up my Aspirin or Tylenol when I'm burning up from some random virus to prevent some hypothetical cancer years later, and I would be even less likely to not take an antibiotic that could halt a potentially fatal bacterial infection.

Another slightly related article on cancer:

 "What does it mean to say that something causes 16% of cancers?"

I can't do this one justice by cutting excerpts.   Read the whole thing, and remember that this applies to more than just cancer statistics, it applies to a wide array of science, particularly the way science is portrayed in the media.

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