Physicians Caution: Cancer is too complex to blame on a single cause


Mills-Peninsula oncology specialists say the inventory is helpful, but oversimplified.

“We’ve known since the 1930’s that X-rays can cause cancer and must be used with caution, especially in children,” according to Stephen Weller, M.D., medical director of radiation oncology at Mills-Peninsula’s Dorothy E. Schneider Cancer Center.

“It certainly doesn’t mean we should stop X-raying broken bones or having mammograms. The benefits far outweigh the risk.

“Cancer is complex,” Dr. Weller said. “It is not caused by just one issue, but is more likely a combination of genetic predisposition and environment.”
Medical oncologist Kent Adler, M.D., a lung cancer specialist, said the search for environmental factors is important, but you don’t need a government list to know the greatest threat.

“There are about 180,000 cases of lung cancer each year in America,” Dr. Adler said. “If we simply eliminated smoking, we would prevent almost 90 percent of the most fatal cancer.”

Suspicions about cell phones, power transmission towers and plastic water bottles are “intriguing, but the data are not strong,” he said. “Even if they are found to cause cancers, the increased risk is nothing compared to smoking.”
Diet is also part of the debate. While there is a clear link between diet and colon cancer, the physicians said the correlation for other cancers is not as clear.

“For both prostate and breast cancer, there probably are environmental issues, but I don’t believe diet by itself has a high correlation,” Dr. Weller said.

“Environmental factors for breast cancer are not completely understood,” Dr. Adler said. “The evidence linking breast cancer and diet is not as strong as that for colon cancer.”

A healthy diet and adequate exercise are still the right choice, the doctors advised.

“Whatever we do in life, we can’t protect ourselves completely. When we get in a car, there is some risk we can have an accident, but by driving carefully, we minimize that risk,” Dr. Adler said.

“That’s also true for reducing risk of medical problems including cancer. It’s smart to have regular screenings, maintain a good diet, physical activity, and reduce stress. The best part of these recommendations is that they have very few side effects.”