March 24, 2017

Study finds a lot of cancer arises randomly

NPR - Cancer can be caused by tobacco smoke or by an inherited trait, but new research finds that most of the mutations that lead to cancer crop up naturally.

The authors of the study poked a hornet's nest by suggesting that many cancers are unavoidable.

The provocative findings by Bert Vogelstein and Cristian Tomasetti at the Johns Hopkins Kimmel Cancer Center, have stirred up a heated scientific debate that started two years ago, when they published a report along similar lines.

Back then, critics said they were undercutting important messages about cancer prevention. So when these scientists had new results to report, Vogelstein addressed that concern head-on.

"We all agree that 40 percent of cancers are preventable," he said at a news conference. "The question is, what about the other cancers that aren't known to be preventable?"

Vogelstein, who is also an investigator with the Howard Hughes Medical Institute, explained how he and Tomasetti have refined that question. He notes that every time a perfectly normal cell divides, it makes several mistakes when it copies its DNA. These are naturally occurring mutations.

Most of the time, those mutations are in unimportant bits of DNA. That's good luck. "But occasionally they occur in a cancer driver gene. That's bad luck," Vogelstein says.

After two or three of these driver genes get mutated in the same cell, they can transform that healthy cell into a cancer cell.

In their new paper in Science, the researchers set out to quantify how often those random errors are an inevitable part of cell division, how often they're caused by nasty chemicals like tobacco smoke and how often they're inherited.

The answer: 66 percent of the total mutations are random, about 29 percent are due to the environment and the remaining five percent are due to heredity.


Anonymous said...

There is an inherent and glaring flaw in this study, that being the assumption current mutation rates represent a historic constant. Can it be that the increased mutation rates are an early effect environmentally induced? The data could actually be suggestive that the impacts of carcinogen exposure may well be nearly universal. Many of the chemicals used today in agriculture, for example, are intended to function through the alteration of RNA messaging. As near 90% of the cereal grains ingested by folks in the United States have been treated in some way with herbicides such as glyphosate, a suspected carcinogen, it seems the researches on this study have been somewhat negligent in not pursuing deeper the possibilities of these high percentages of mutation rates just might be attributable to other factors, and therefore, are not necessarily natural. That cancers previously unheard of in the past have now become common suggests there is something erroneous about this study. One would like to know what funding and grants were provided to the researchers? On first impression, this seems more intended as cover-up, dissemblance, or misdirection.

Anonymous said...

If 66% of cancer can't be helped, then why do we need environmental laws or the FDA?

I smell a rat.

Something about this rings hollow. Did the researchers check for novel chemicals, industrial byproducts, and similar? There are many pollutants that cause cancer, that probably didn't get a look at for this study. I haven't read the study, but if they did, it would be a first.

Corporate Polluters are slavering over the opportunities 45's deregulation will bring them, and Big Pharma look forward to managing all the illness that ensues. Seems like paying off a few scientists to find that cancer is YOUR fault, might be a good financial move.