KAHULUI - Half of the United States' population of men and a third of its women will develop cancer in their lifetimes, according to the American Cancer Society.
And, while many people believe a family history of cancer or fate will determine whether they get the disease, it's now "pretty clear" that environmental and lifestyle factors, such as smoking or excessive exposure to sun, lead to most cancers - not heredity, according to Dr. Laurence Kolonel, a Harvard Medical School-trained epidemiologist and a professor of public health at the John A. Burns School of Medicine in Honolulu.
"Most people think they're doomed" because cancer runs in their families, Kolonel said. So many are surprised that fewer than 5 percent of cases of cancer stem directly from inheritance and most of those occur early in life.
While a person's genetic makeup still plays an important role in determining whether he or she will be susceptible to cancer, anyone can do much to reduce the risk by not smoking, limiting time in the sun, being physically active and eating a diet with more fruits and vegetables, Kolonel said.
Kolonel will be on a panel of four experts and a cancer survivor speaking about the latest research on cancer prevention and care from 8:30 to 9:30 a.m. Tuesday at the University of Hawaii Maui College. The free panel discussion on "New Frontiers: Unraveling Cancer in Hawaii" will be in the college's Class Act Restaurant in the Pa'ina Building. Registration begins at 8 a.m., and a continental breakfast will be served.
The panel will discuss the role of genetics, nutrition and other factors in cancer prevention.
Smoking alone is linked to a third of all cancer diagnoses, including lung cancer and cancer of the larynx, esophagus, pancreas and kidney, Kolonel said. A number of those cancers also have a "very poor survival rate," including cancers of the pancreas and esophagus.
The more people smoke and the longer they do it increases their chances of getting cancer, he said. Also, smoking and alcohol consumption have a synergistic effect, making it a "very bad combination." Secondhand smoke exposes others to risk, he added.
Poor weight management combined with a lack of exercise contributes to another third of all cancers, he said. And, the remainder of cancer cases stem from exposure to too much sunlight and to lengthy periods spent working in heavy industries involving toxic chemicals or occupations such as painting or furniture-making.
While many cancers can be tied to environmental factors, one that puzzles researchers is prostate cancer, one of the most common cancers to affect men, Kolonel said.
It is "a really tough nut to crack," he said. "It's very hard to find any risk factors in the environment, food or lifestyle that can contribute to prostate cancer."
Being overweight may be a contributing factor to prostate cancer, but scientists are unsure, he said.
Another member of Tuesday's panel will be Dr. Shane Morita, director of the Queen's Medical Center/Queen's Cancer Center Surgical Oncology Research Program. He has researched melanoma (skin cancer) in Hawaii.
While it's not surprising that more than 85 percent of patients diagnosed with melanoma in Hawaii are fair-skinned Caucasians, what was unexpected was that a disproportionately high percentage of people who die from such skin cancers were not Caucasian, he said.
While the reason for that is being researched, Morita said it might be because non-Caucasians are unaware they can get skin cancer and are not watching out for it. Caucasians, on the other hand, know they are at risk, watch out for unusual skin growths and seek treatment earlier.
"Early detection is the key to an improved prognosis," Morita said.
Telltale signs to watch out for in spots on skin include asymmetry, an irregular border, a change in color, a diameter of 6 millimeters or more and rapid growth, he said.
Protection from the sun's rays with clothing and sunscreen and regular medical checkups are important ways to catch skin cancer early, Morita said.
Kolonel said drug manufacturers are developing newer and better drugs to target specific cancer cells without being toxic to other body tissues.
However, "all these drugs don't work equally well in everybody," he said.
In the future, there may be a way to use genetic testing to tailor drugs specifically for individual cancer patients, but that treatment won't likely be available in the near future, Kolonel said.
Preventing cancer from gaining a foothold remains the best approach, he said.
Kolonel recommends people abstain from smoking, eat a diet of mostly fruits and vegetables and get 30 to 60 minutes daily of moderate-to-vigorous intensity exercise.
"People are surprised to know how preventable cancer is," he said.
Other panel speakers include Dr. Michele Carbone, director of the University of Hawaii Cancer Center and an international expert in thoracic oncology; Dr. David Ward, a leading authority on cancer and genetics; and Maui resident Jennifer Spotts Mabellos, a breast cancer survivor.
The event is part of a Neighbor Island outreach series hosted by the UH Cancer Center, with support from the Friends of the UH Cancer Center.
* Brian Perry can be reached at firstname.lastname@example.org.