Researchers say environmental exposures and behavior weigh heavily on the development of 70 to 90 percent of cancers.

The research, by a group at Stony Brook University in New York, shows only 10 to 30 percent of cancers are attributed to random cell mutations.

Kentucky leads the U.S. in the rate of deaths from cancer. Lung, breast, cervical and colorectal cancer are the most common forms of the disease in the state.

Obesity, smoking and lack of screening are the driving factors of the state’s high cancer rates, according to a recent report about cancer in Kentucky.

Dr. Yusuf Hannun, who led the study, said the research is important for the future of cancer prevention, research and public health.

“We could build on that study and begin to tackle what we always thought was an important question, which was what’s the contribution of extrinsic versus intrinsic factors in cancer pathogenesis,” he said.

The study was prompted by a January 2015 research paper that concluded that much of the variation in cancer risk is simply due to “bad luck.” The team at Stony Brook used the same data to examine what leads to the risk of developing cancer.

Hannun said smoking and exposure to UV rays are well-known extrinsic factors that lead to cancer, but there are many others.

“We suspect many are not known, and our approaches prompt us to propose there should be more study to actually define those factors specifically,” he said.

The team of researchers also found few forms of cancers had greater than 50 percent intrinsic mutations. Their research shows cancers such as colorectal, lung, bladder and thyroid had large proportions of mutations likely caused by extrinsic factors.