When we think of solving mysteries, doctors and researchers aren’t exactly the kind of sleuths who immediately come to mind. Yet when it comes to unraveling the secrets of diseases, they are front and center. Take chronic obstructive pulmonary disease, or COPD, and lung cancer, for example. New research from determined scientists is changing the way we think about these two conditions.
COPD and Lung Cancer: A Look at a Study
Until recently, scientists believed that COPD was an independent risk factor for lung cancer. “This basically means if you develop COPD, you are more likely to develop lung cancer,” says Bilal Piperdi, MD, director of the Thoracic Medical Oncology Program at Montefiore Einstein Center for Cancer Care in the Bronx, New York. “In other words, if there are two people who smoke, the one who develops COPD is more likely to develop lung cancer than the one who does not.”
However, like all good investigators, researchers have continued to delve into the matter from a number of angles and, in the process, have found that there might not be a direct relationship after all.
A recent study published in the Journal of Thoracic Oncology looked at about 12,000 lung cancer cases and 38,000 matched controls in the United Kingdom and compared the timing of diagnosis of COPD, asthma, pneumonia, and lung cancer. The results showed the majority of lung cancer diagnoses were made within six months of a COPD diagnosis. Experts tend to attribute this change in respiratory status to being a preclinical indicator or sign that lung cancer may already be present.
Arguably more interesting is what happens after this six-month mark. The risk of developing lung cancer, although still present, remained constant for patients with a diagnosis of COPD between one to five years, greater than five years, and greater than 10 years. In other words, they did not observe an increase in risk of lung cancer with a longstanding diagnosis of COPD.
Smoking and COPD: The Real Culprit?
Like any good mystery, the link (or lack thereof) between COPD and lung cancer has been muddied by other factors — in this case, smoking.
“It is not a great surprise that smoking is a major risk factor for both diseases and that people who smoke frequently will develop both diagnoses,” says Neil Schachter, MD, member of the COPD Foundation Clinical Advisory Committee and professor of medicine and community medicine at Mount Sinai School of Medicine in New York.
While smoking and COPD can go hand in hand just as smoking and lung cancer can, there are other lung cancer and COPD risks as well. Everything from radon exposure and diesel fumes to dust or chemicals in the workplace or at home can all contribute.
COPD and Lung Cancer: The Sleuthing Continues
Like dogged detectives, researchers are continuing to study both COPD and lung cancer.
“There are studies that suggest both lung cancer and COPD may also reflect another risk factor, systemic inflammation, which may be the reason why some smokers are more likely to develop these lung [and other] diseases,” says Dr. Schachter.
Another area of research vis-à-vis COPD and lung cancer risk is looking into biomarkers in the lungs of people with COPD to see if there are certain proteins in the bloodstream that can shed any light on who might develop lung cancer. Both smokers and non-smokers are being studied so researchers can also learn the impact (if any) of chronic inflammation.
COPD and Lung Cancer: In the Meantime
Solving mysteries takes time, but there are steps you can take now to protect yourself. “For someone diagnosed with COPD, see a physician and a pulmonologist as needed,” advises Mary E. Reid, PhD, associate professor of oncology and director of collaborative research in the department of medicine at the Roswell Park Cancer Institute in Buffalo, New York. Be sure to maintain a regular follow-up schedule with your doctors, she adds.
A chest X-ray can be used to detect larger cancers while a chest CT is able to see a smaller cancer and perhaps improve survival through earlier detection. Discuss all testing options with your medical team to see what’s right for your situation (your age, how long you’ve been a smoker, and so on).
Finally, the one unequivocal step everyone can do for their health is to quit smoking and avoid exposure to secondhand smoke. COPD risks as well as lung cancer risks would decrease — and that’s no mystery.