An epidemiological study published earlier this week in the British Journal of Cancer by NYU School of Medicine researchers shows an association between regular use of aspirin and reduced risk of a common type of lung cancer in women. But the NYU researchers emphasized today that until large clinical trials establish aspirin's beneficial effect, women shouldn't start taking the painkiller to prevent cancer.
"The results of our study suggest that aspirin may have even wider benefits than previously thought," says Arslan Akhmedkhanov, M.D., Assistant Professor of Obstetrics and Gynecology at NYU School of Medicine, one of the study's authors. "However, we consider our results preliminary. Larger studies are needed to confirm our study's results before any recommendations about aspirin use for the prevention of lung cancer can be made," he says.
The new study found that taking aspirin three or more times each week for at least six months appears to substantially lower a woman's risk of developing non-small cell lung cancer, the most common type of lung cancer. The study involved 81 women with lung cancer who were compared to 808 healthy women of the same age and menopausal status. The women responded to questions about their use of painkillers as part of an ongoing, long-term study called the NYU Women's Health Study (WHS). The WHS began in the late 1980s and was originally designed to evaluate the effects of hormones and diet on breast cancer and was later expanded to other cancers.
From 1994 to 1996, the researchers collected information on aspirin use for women enrolled in the WHS. Follow-up information on aspirin use was obtained from questionnaires distributed between 1994 and 1996.
It isn't known how aspirin could act to lower cancer risk. By reducing local inflammation, aspirin may be preventing the release of certain molecules that stimulate mutations in epithelial cells leading to out-of-control cellular growth, says Dr. Akhmedkhanov. There is some evidence from animal studies that chronic inflammation could be related to the development of cancers arising in the epithelium, the cellular lining, of organs.
Women should not begin taking aspirin to prevent lung cancer, cautions Dr. Akhmedkhanov. Aspirin can cause gastrointestinal bleeding and raise the risk of other bleeding disorders, especially in those with a family history of bleeding disorders. The exact dose of aspirin that should be taken also needs to be determined. Any woman who decides to take aspirin routinely should first consult her primary care physician, he advises.
"Aspirin definitely has side effects," says Dr. Akhmedkhanov. "By far, the best way to avoid lung cancer is to not smoke," he says.
June 14, 2002 - Study Finds Genetic Aberrations Linked to Lung Cancer; Could Help in Early Diagnosis
Researchers at Ohio State University have identified more than two dozen genes that behave abnormally in cancerous lung cells. The finding could lead to new tests for diagnosing lung cancer.
Led by Ming You, a professor of molecular virology, immunology and medical genetics, the researchers found 14 genes that are over-expressed - meaning they are too active - in lung cells stricken by cancer. They also identified 12 genes that are under-expressed (not active enough) in these cells.
You and his colleagues reported their findings in a recent issue of the journal Neoplasia. About half of the 26 genes pinpointed in the study have never been linked to lung cancer before.
"In the past five years, lung cancer has killed more people in the U.S. than breast cancer, prostate cancer and colon cancer combined," You said. "We must find methods for early detection of the disease."
For the study, You and his colleagues analyzed samples of cancerous lung tissue taken from patients who had died of the ailment. (Some of these victims had been heavy smokers and one had suffered exposure to asbestos.) The researchers compared the samples to normal lung tissue from the same patients.
Using standard tests, the researchers found that the level of certain proteins in the tumor cells was higher than normal. They traced the increased level of these proteins to the over-expression of 14 genes. In the same way, the researchers traced the low level of another set of proteins to 12 genes that were under-expressed in the tumor cells.
Among the genes identified in the study are ones that regulate intra-cellular communication, cell growth and apoptosis, or programmed cell death. The list includes some known oncogenes - genes that promote cancer when they go into overdrive - and some known tumor-suppressor genes, which fail to check tumor growth when they are under-expressed.
"The over-expression and under-expression of certain genes in lung cells may directly contribute to the initiation or progression of lung cancer," You said. "Alternately, the abnormal expression of these genes may be secondary effects of the tumor development process."
The next step in You's research will be to find out which of the 26 genes identified in this study start behaving abnormally at a relatively early stage in the onset of lung cancer.
"In order to find diagnostic markers for the disease, we need to identify genes that show aberrant behavior before it is too late for treatment," You said.
Successful treatment of lung cancer hinges on early diagnosis - more so than in other cancers - because the continuous flow of blood through the lungs makes the disease very easy to spread inside the body. Most diagnostic methods of today don't do a very good job of spotting lung tumors at a treatable stage, You said.
"We estimate that about 20 percent of the genes identified in our study show signs of alteration at a very early stage of tumor development," You said. To spot these early changes, the researchers plan to analyze lung tissue samples from patients who have been diagnosed at an early stage of their illness - through positron emission tomography (PET) or other imaging techniques.
Equipped with a profile of genetic aberrations that are linked to early tumor growth, it would be possible to distinguish potentially dangerous nodules in a patient's lung from the benign ones. "If you know which lesions are likely to become cancerous, you could start treating them right away," You said. "That would give you enough lead time to halt the progression of the illness."