Although smoking is a well-known risk factor for lung cancer, the results of a recent study indicate that smokers with chronic obstructive pulmonary disease (COPD) face a significantly higher risk of developing lung cancer than smokers without the respiratory condition.
The study, published in EBioMedicine, analyzed data from 24 previous studies that enrolled a total of 4346 patients with small cell lung cancer (SCLC), which accounts for 15% to 18% of lung cancers worldwide, and 37,942 individuals without the disease.
After examining the participants’ smoking history, the researchers determined that patients who smoked a pack a day for less than 20 years were 4 times as likely to develop SCLC as nonsmokers, while those who smoked a pack a day for more than 80 years had a nearly 70-fold higher SCLC risk. Additionally, smokers with COPD were 1.86 times more likely to develop SCLC than smokers without COPD, with COPD accounting for 8% of SCLC cases among smokers.
“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 senior author David Christiani, MD, in a press release.