Boston – Researchers from a new study, published in the journal EBioMedicine, discovered that smokers who have Chronic Obstructive Pulmonary Disorder (COPD) may be as twice as likely to get Small Cell Lung Cancer (SCLC) than smokers who do not have COPD.

COPD is a progressive disorder that makes it hard to breath, having cigarette smoking as the leading cause of this disease. This new study, considered the largest-ever epidemiologic study of SCLC, is the first to look at how much COPD increases smokers’ risk of getting SCLC.

Small Cell Lung Cancer (SCLC) is also known as oat cell cancer. About 10% to 15% of lung cancers are SCLC, according to the American Cancer Society. Credit: Justin Sullivan/Getty Images

On the other side, SCLC is responsible for only 15-18% of lung cancers worldwide, however, it tends to grow and spread quickly to distant parts of the body before it is found. That is why patients with SCLC live, on average, 14-20 months after diagnosis, or even less than 11 months.

The study

Scientists analyzed data from 24 case-control studies from the International Lung Cancer Consortium-conducted in North America, Europe, Asia and Oceania-that included 4,346 people with SCLC and 37,942 without the disease.

Besides including information on the participants’ health, gender, age, race, education level, and family history of lung cancer, scientists also took into consideration their smoking history. They asked the participants how old they were when they started smoking, how many years they smoked, how many cigarettes they smoke each day, and, for former smokers, how long it had been since they quit.

The results showed that smokers of a daily pack of cigarettes for less than 20 years are at four times higher risk of getting SCLC than non-smokers. However, those who have spent 80 years smoking a daily pack of cigarettes have 70 times higher risk of getting SCLC.

Smokers with COPD had a 1.86-fold higher risk of SCLC than smokers without COPD. Among smokers, having COPD also accounted for 8% of SCLC cases.

“This work suggests that we need to tease out the mechanisms by which COPD may increase lung cancer risk in smokers, and to conduct clinical trials to determine whether treating COPD in former and current smokers lessens that risk,” said in a statement David Christiani, Elkan Blout Professor of Environmental Genetics at Harvard Chan School and senior author of the study.

Source: Harvard University