Albert Einstein famously said “God doesn't play dice” with the universe: Everything is by design.

But could getting cancer be a random roll of dice? Could it be cancer is more about bad luck than heredity, unhealthy behaviors or harmful exposure to a range of environmental toxins and pollutants?

A recent study in the journal Science reached the astonishing conclusion that two-thirds of the risk of getting many cancers is attributable to “random mutations” when healthy cells divide. Mutated cells trigger chaotic growth that leads to cancer.

The researchers' conclusion: Bad luck, not bad behavior or heredity, steers a huge number of cancer diagnoses.

“Getting cancer could be compared to getting into a car accident,” write the authors, Cristian Tomasetti and Bert Vogelstein of Johns Hopkins University School of Medicine. The longer the trip — the more often stem cells divide over a lifetime to replace dying cells — the greater the chance for an accident that triggers cancer.

People who brush aside doctors' warnings that smoking, obesity and other behaviors contribute to cancer may be tempted to say: See? My fate is determined by unpreventable gremlins in the body's cellular machinery. Either I get lucky or I don't. It's all out of my hands.

Not so.

It's true that the study suggests there is a greater dollop of random good or bad luck in cancer than many scientists expected. Tomasetti told The New York Times that the risk was “about double what I would have thought.”

But this study isn't a license to ignore all those warnings. Luck plays a role in cancer. But so do other factors in human control.

Dr. Leonidas Platanias, director of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University, tells us: “The fact that (the Hopkins authors) attribute certain tumors to random mutations doesn't absolutely exclude environmental or other factors that we have not well defined and may be contributing.” In other words, cancer is complicated. There is much scientists don't know. All those tumors now attributed to “bad luck” may actually be prompted by specific factors that doctors haven't pinpointed yet.

People ask doctors what caused their cancer. Doctors often can't answer. This study has been comforting to many cancer patients, and particularly to parents with children stricken by cancer, Vogelstein tells us. “Parents often feel guilty that they should have done something to prevent the cancer,” he said. “We've heard from a lot of people saying, 'I always felt I did something wrong and now you're telling me these are just random things that you could not have prevented, and that's a great comfort.'”

Random luck often plays a role. But that's not an argument to abandon a healthy diet, stop exercising, start a three-pack-a-day cigarette habit, or skip the cancer screening. Remember, some cancers remain highly treatable, even curable, if caught early enough.

Every cigarette shaves seven minutes from your life, researchers say. Maybe every stalk of broccoli you eat adds a few seconds. Your behavior — how you take care of yourself — can help you avoid illness or recover more quickly.

Be smart about risks. Nudge the odds in your favor.