Battling Lung Cancer and Smoking
DURHAM, N.C. - In November, the Great American Smokeout and Lung Cancer Awareness Day focus attention on smoking and lung cancer, the No. 1 cause of cancer death in the United States. Lung cancer deaths have increased dramatically since the 1940s for men and the 1960s for women. But while the death rate for men is now declining - a trend researchers say mirrors a decline in smoking among males - the death rate for women is still increasing.
Overall, 171,600 new cases of lung cancer and 158,900 deaths from the disease are expected in 1999 in the U.S., according to the American Cancer Society (ACS).
Smokers are about 10 times more likely to develop lung cancer than non-smokers. Using tobacco increases the risk of developing other cancers and diseases as well. According to the ACS, which sponsors the Great American Smokeout, an estimated 173,000 cancer deaths in this country alone will be caused by tobacco use this year.
At the Duke Comprehensive Cancer Center, physicians and scientists are tackling lung cancer on many fronts. They are looking for indicators that might reveal how a given patient's cancer will respond to treatment or what the patient's chances for long-term survival might be; are using new techniques to improve patients' quality of life by offering better-tolerated procedures when possible; and are trying to improve the chances that smokers can give up the often deadly habit. Below is a snapshot of what's occurring at Duke:
Helping Pregnant Women Kick the Habit
If the average smoker stops smoking for nine months, they are "home free," says Colleen McBride, director of Cancer Detection, Prevention and Control Program at Duke. But for women who give up smoking during pregnancy, that's not the case. Some of McBride's research is taking aim at this incongruity.
"Our primary question was whether intervention provided during pregnancy would be enough to prevent smoking relapse or if we had to extend into postpartum," says McBride. The results of the study, which tested three different lengths of intervention, were published in May 1999.
The researchers found that postpartum contact delayed relapse of smoking habits, but it wasn't able to prevent relapse entirely. By six months after giving birth, the group who received the longest intervention was less likely to be smoking than others, but by one year all three groups had similar smoking rates.
"We were able to delay relapse in that study, but we need to do more," says McBride. "Cigarette smoking causes a lot of problems for mother and baby, and we need to find ways to encourage women to remain non-smokers after the baby is born."
It's possible that enlisting women's live-in partners as supporters will help improve smoking cessation rates for pregnant women, says McBride, who is leading a study based at Ft. Bragg, a U.S. Army base near Fayetteville, N.C., to test that idea. The final results are expected in a few years.
Women and Lung Cancer
Many people still think breast cancer is the leading cause of cancer death in women. It's not. In 1987, deaths from lung cancer surpassed those from breast cancer, and the gap has been steadily widening.
While men's death rate has been falling in recent years, thanks in large part to the public education campaign against smoking, women's death rate from lung cancer is still increasing. As a result, medical oncologist Dr. Jennifer Garst considers lung cancer to be a women's health issue.
Not only are more young women taking up smoking and doing so at younger ages, there's also growing evidence that women are more susceptible to developing lung cancer.
It appears that dose-for-dose, women smokers have a higher risk of developing lung cancer than men. Possible reasons include differences in the way the sexes process the cancer-causing agents in cigarette smoke and a greater tendency for women to smoke menthol cigarettes, says Garst.
Women smoking menthol cigarettes may inhale more deeply than those smoking other types of cigarettes, she says. The link between menthol cigarettes and increased lung cancer risk is especially important in the African-American community because 65 percent of black female smokers choose mentholated brands.
"The general health consequences of smoking are devastating, ranging from the aesthetic, such as smoke damaged skin and discolored teeth, to the deadly, including heart attacks, stroke and cancer," says Garst. "Overcoming the superficial attraction of cigarette smoking is the biggest challenge for women and their health care providers."
Illuminating Better Treatments
Patients who have a tumor in the trachea or the bronchi - the tubes that carry air to the lungs - aren't candidates for surgical procedures. Now Dr. Thomas D'Amico is using an FDA-approved non-surgical technique to destroy tumors that are blocking airways.
The technique, called photodynamic therapy, or PDT, uses a "cool" laser to help a drug kill cancer cells while leaving normal cells alone.
"For some early-stage lung cancer patients who can't be treated with surgery, this therapy could possibly be curative," says D'Amico.
PDT is also approved to clear the airways of patients with more advanced diseases. And because the procedure is fairly easily tolerated, it can represent a better option even for some patients who could be treated surgically, he says.
A drug called Photofrin, which makes cells sensitive to light, is given to patients and it selectively collects in cancerous cells. Two days later, D'Amico guides an optic fiber through the trachea and to the tumor with the aide of a bronchoscope. A special non-heating laser activates the drug, whose side products are the same damaging oxygen radicals created with radiation treatment. The cancer cells slough off as they die, clearing the airway within a matter of days. The procedure can be repeated as often as necessary because it doesn't involve damaging ionizing radiation or toxic doses of drugs.
The end result of treatment with PDT is the same as with more traditional heating laser, but PDT is less time intensive and less risky, says D'Amico.
New Screening Method not Ready for Routine Use The low cost, low risk and potential benefits of spiral-CT as an early detection method for lung cancer has led some doctors to tout its possible ability as a screening tool, but Duke physicians urge caution.
Spiral-CT, a modified version of the anatomical imaging procedure known as computed tomography, uses a lower dose of radiation and costs only $300 or so Ò compared to around $1,000 for a full-fledged CT of the chest. But Duke radiologist Dr. Ned Patz says they still need to see if low-dose CT will actually improve survival before it is used routinely in clinical practice.
"We need to have the appropriate randomized clinical trial to test low-dose spiral-CT before it becomes of standard practice," says Patz.
Many doctors and researchers across the country echo his sentiment.
Because of patient demand, Duke does offer it. Insurance companies generally won't pay for this imaging examination for lung cancer screening, Patz says, and there isn't enough proof that it's worth the cost to patients at this time.