Study Seeks to Prevent Lung Cancer Among Former Smokers

September 13, 1986, is a day Erma Lundy will never forget. That’s the day she gave up cigarettes after more than 20 years of smoking.

"I enjoyed smoking, and you could smoke in the office back then - it was accepted then - so it was even harder to quit," Lundy said. "They were just starting to designate smoking areas in 1986."

Smoking almost two packs of cigarettes per day, she realized she needed to stop for the sake of her health and for her children. A public service announcement on television prompted her eight-year-old son to say the words that gave her strength to kick the habit.

"As the person on the TV commercial said, ‘It’s a matter of life or breath,’ my son turned to me and said, ‘Mama, please stop smoking, we don’t want you to die.’" Lundy had called an acupuncturist several times over a two-year period to help her quit, but she cancelled right before each scheduled appointment. That day in September when Lundy finally kept the appointment, the acupuncturist immediately recognized her voice and congratulated her for finally making the commitment to stop smoking.

This year, Lundy decided to go one step further to reduce the risk of cancer. She is now participating in a landmark lung cancer prevention study sponsored by The University of Texas M. D. Anderson Cancer Center.

The study, which is currently accepting eligible former smokers, is the first in the nation to identify synthetic vitamin compounds that may help to prevent lung cancer in former smokers who remain at high risk.

According to Dr. Waun Ki Hong, chairman of the Department of Thoracic/Head and Neck Medical Oncology at M. D. Anderson and principal investigator of the study, the good news is that smoking among Americans is on the decline. However, many former smokers remain at high risk for lung cancer, a disease for which there has been little progress in treatment.

The answer, Dr. Hong said, may be to head off the disease in patients at the greatest risk.

"It was an M. D. Anderson study which offered the first proof that former smokers remain at tremendous risk for this deadly and prevalent disease," pointed out Dr. Hong, citing early groundbreaking work published in 1997.

In the first-ever molecular study of the genetic effects of tobacco smoke on the lung tissue of chronic smokers, M. D. Anderson researchers found genetic damage in the lungs of 82% of current smokers. Although they had expected to see high rates of genetic damage in patients who smoked, researchers were surprised to find that 62% of former smokers - some of whom had quit smoking 10 or 20 years before - also showed signs of continued genetic damage. Such genetic damage may lead to lung cancer, researchers reported.

"We have demonstrated that multiple genetic alterations occur in the epithelial cells of the lungs of smokers, and that this damage is prevalent even in people who quit smoking," said Dr. Hong. "In former smokers, some of the genetic damage to lung tissue decreases over time, but only in certain chromosomes. This damage means these genes cannot aggressively fight cancer."

Although the study revealed long-term damage caused by chronic smoking, there is some encouraging news for former smokers and those who are trying to quit. According to a 1990 report from the Surgeon General, smokers who quit before age 50 have half the risk of dying in the next 15 years compared with those who continue to smoke.

However, despite the reduced risk for former smokers, there is little progress to report in the treatment of lung cancer.

According to the American Cancer Society, the five-year survival rate for all stages of lung cancer combined is only 14%. The survival rate is 49% for cases detected when the disease is still localized, but only 15% of lung cancers are discovered that early.

So for former smokers who want to try to cut their risk of lung cancer, chemoprevention may be the best course of action, experts contend. An emerging field at M. D. Anderson, chemoprevention is the use of natural or synthetic agents to intercept and interrupt the biological processes that may lead to cancer.

Of the former smokers who are found to be eligible for this Phase II prevention study, one third will take pills containing a combination of 13-cis retinoic acid, a synthetic vitamin A analogue, plus vitamin E, while another one third will take 9-cis retinoic acid, another synthetic analogue. The remaining patients will receive placebo capsules and serve as a comparison group.

At first apprehensive to enroll in the study, Lundy was glad she did when doctors found sarcoidosis, a nodule in her lungs, during her first bronchoscopy. Continuing on the pills from the study, she was relieved when her third bronchoscopy showed the nodule had dissipated.

Some patients who have either completed or remain on the study report minor side effects from the synthetic agents, including chapped lips and drier eyes and skin.

Three weeks into the study, Erma Lundy reported dry and itchy skin that lasted one week. Now finished with the study, she is concentrating on eating nutritiously and getting regular exercise – other important steps in reducing the risk of cancer.

"Usually when you find out something is wrong with you, it is too late. I was uneasy at first, but I went ahead and entered into this study so I could find out if anything was wrong or try to prevent something from going wrong," Lundy said.

She is encouraging others to participate in medical studies now. The chemoprevention study ultimately will involve 200 former smokers.

A recent - and promising example of chemoprevention -  is the national Breast Cancer Prevention Trial that reported a remarkable 45% reduction in breast cancer incidence among high-risk women who took the drug tamoxifen. Though the drug did increase a woman’s chances of three rare but life threatening health problems, experts said the ability of tamoxifen to reduce risk is a promising complement to early detection strategies.

For more information about the lung cancer prevention study, please call The M. D. Anderson Information Line at 1-800-392-1611, press option "3."