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Cancer Is Partly Caused By Bad Luck, Study Finds

Nearly two-thirds of cell mutations that cause cancer are caused by random error, a study found.
Steve Gschmeissner
Science Source







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.


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.




Vogelstein says parents often think they, somehow, are responsible for their child's cancer, but that is not the case. "They need to understand that these cancers would have happened no matter what they did," he says. "We don't need to add guilt to an already tragic situation."


So, what can people do? "Nothing. Right now, nothing," Vogelstein says.

But, he's hopeful that if scientists focus on that question, they will have a more encouraging answer someday.

Even without an action plan, the question of how much human cancer is caused by bad luck and how much is caused by bad things we do "is super fascinating," says Martin Nowak, a biologist and mathematician at Harvard who wrote a commentary about the study for Science.

He says the findings are stirring up the field, and that's a good thing.

"It's very unclear to me about whether we have the tools to answer these questions," he says. And, rather than settling the controversy raised by the scientists' previous paper, "I think it will raise an even bigger controversy," Nowak says.

One of the new sticking points is that mutations, while necessary for cancer to develop, aren't the whole story. For example, some scientists say the study doesn't fully account for how hormones can influence cancer.

Dr. Graham Colditz, an epidemiologist at Washington University in St. Louis isn't convinced that hazards can been neatly sorted into the categories of hereditary, environmental and unavoidable mutations. "How these interplay with each other, I think is potentially more complex," he says.


"We're not saying the only thing that determines the seriousness of the cancer, or its aggressiveness, or its likelihood to cause the patient's death, are these mutations," Vogelstein tells Shots. "We're simply saying that they are necessary to get the cancer."

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