Aspirin may reduce women's risk of getting lung cancer, according to an article in the British Journal of Cancer (Vol. 87:49-53).

Some earlier studies have suggested that aspirin decreased smokers’ chances of getting lung cancers. Other studies claimed aspirin provided no benefit in people who smoked.

The current study, reported by A. Akhmedkhanov, MD, and colleagues from the New York University School of Medicine in New York City, followed more than 14,000 women from New York City. The women are part of a long-term study that started in March 1985. Researchers are looking at the women's health, and what habits and other factors may make them healthy or ill.

Of the women in the study, 144 developed lung cancer by July 2000. The researchers then examined whether there was any difference in aspirin use between the women who developed lung cancer (all types), and to those who did not.

For women who started using aspirin before they were diagnosed with lung cancer, the risk of getting lung cancer was cut almost in half. And, the risk for getting the most common type of lung cancer, called non-small cell lung cancer was cut by almost 80% for regular aspirin users.

Why the interest in aspirin? There have been reports that some lung cancers produce an excess amount of an enzyme called COX-2. This enzyme is found in several different types of cancers, and is associated with other diseases such as arthritis. Aspirin and similar drugs, called non-steroidal anti-inflammatory drugs, or NSAIDs, decrease the amount
of COX-2.

This may explain why aspirin appears to have helped women in this study.

But, as the authors pointed out, there are some important reasons to be cautious. “Because regular aspirin use may occasionally result in serious side effects, such as (internal) bleeding,…stroke, and aspirin-sensitive asthma, specific recommendations regarding use of aspirin for prevention of lung cancer should be deferred until confirmation of the effect by larger studies and determination of the effective dose and duration of use.”

Michael Thun, MD, vice president of epidemiology and surveillance research at the American Cancer Society in Atlanta, GA, is also cautious. “Smoking is the Mount Everest of risk factors for lung cancer,” he said. “The main way to avoid lung cancer is to avoid smoking.”

Thun added, “The current, relatively small study adds to the limited epidemiologic evidence on this topic. There is currently a clinical trial in progress studying whether novel aspirin-like drugs…are effective in preventing lung cancer recurrence.”

Like all early studies, this one needs to be confirmed by larger trials before it can be demonstrated that aspirin decreases the chances of getting lung cancer. If you are a smoker, there is only one proven way to decrease your chances of getting lung cancer—and that is to quit smoking.