Former smokers are still at risk for lung cancer long after they have quit, but have a chance to try and stop the disease before it starts. Study coordinators are now recruiting ex-smokers who had the equivalent of a pack-a-day history for 30 years to test the efficacy of green tea as a cancer prevention agent.

"Many people who have quit smoking don't realize that they are still at risk for lung cancer," explains Sharon Gee, a coordinator of the BC Cancer Agency's Lung Health Study. "Damage occurs to the DNA of cells from prolonged smoking even after quitting."

In fact, one half of newly diagnosed lung cancers occur in former smokers. While there are important and immediate health benefits to quitting – such as the automatic reduction in risk for cardiac disease – the risk of developing lung cancer decreases only marginally.

Green tea as a cancer prevention agent has been the focus of speculation for some time. This is one of the first studies to scientifically document the efficacy of green tea, instead of relying on anecdotal or epidemiologic evidence. The efficacy of botanical extracts in Western medicine is gaining increasing recognition.

There are several benefits to participating in this study, says Gee. Former smokers get an excellent work up with a detailed history of exposure to inhaled substances that can cause lung cancer; computer-assisted image analysis of their sputum cells, and a spiral CT scan to look for early lung cancer. If cancer is discovered during the screening process, they also have the important advantage of early diagnosis and careful follow up if problems are discovered.

"Tea is the second most widely consumed beverage in the world after water," says principal investigator Dr. Stephen Lam. "Despite decades of scientific research, there is still no conclusive evidence that green tea can prevent cancer. This is the world's first double-blind randomized, placebo controlled study to examine the health benefits of green tea."

The study will be double-blind, with half the participants taking the green tea, and half taking a placebo. All participants, however, will have the benefit of thorough lung cancer screening, and close monitoring.

Study participants will be taking decaffeinated tea in capsule form – the equivalent of 10 to 15 cups of green tea per day – for six months to one year. Using a tablet not only makes it more convenient for the volunteers, explains Gee, but it helps the study coordinators to regulate the dose. If people were making their own tea each day, she explains, the strength of brew, steeping time, amount of water would all be variables that could throw off the results.

The $4 million U.S. study is part of a $14 million lung cancer prevention study funded by the U.S. National Cancer Institute. This is an exciting study because it will test the effectiveness of a 'non-traditional' chemopreventive agent.

"People are excited when they see that we're studying something herbal, rather than a man-made product," says Gee. "Green tea has very low toxicity, which is good because people get very nervous about possible side effects."

The study is open to volunteers from across B.C., however, those who are accepted into the program will be responsible for their own transportation to and from Vancouver. The study is not open to current smokers. To receive more information about participating in this trial, please call 604.877.6190 in the Lower Mainland, or 1.800.663.3333, ex. 6190 from out of town.

The BC Cancer Agency, a part of the Provincial Health Services Authority, is committed to reducing the incidence of cancer, reducing the mortality from cancer, and improving the quality of life of those living with cancer. It provides a comprehensive cancer control program for the people of British Columbia by working with community partners to deliver a range of oncology services, including prevention, early detection, diagnosis and treatment, research, education, supportive care, rehabilitation and palliative care. The BC Cancer Research Centre conducts research into the causes and cures for cancer.

For more information, please contact:
Nicole Adams
Public Relations Officer
BC Cancer Agency
Ph: (604) 877-6272