Pneumonia may serve as an early warning sign for smokers, as a recent study found heavy smokers who develop pneumonia are one of the highest lung cancer risk groups. The association between lung cancer and pneumonia was strongest for pneumonia in the upper lobe. These findings were reported in The American Journal of Medicine (doi:10.1016/j.amjmed.2015.10.030).
The 5-year survival rate for lung cancer is just 17%, and lung cancer is the leading cause of cancer mortality in the United States. Approximately 85% of all lung cancer cases are caused by smoking, and few (15%) are diagnosed at an early stage.
The researchers suggest that heavy smokers with pneumonia should be screened with chest computed tomography (CT).
This retrospective study examined 381 hospital admissions for community-acquired pneumonia between 2007 and 2011 at a single hospital. During the first year after hospitalization, lung cancer was diagnosed in 31 cases (8.14%). The researchers were surprised at the high number of patients with pneumonia patients who had subsequent diagnoses of lung cancer.
The incidence of lung cancer was 23.8% in patients who had upper-lobe pneumonia, significantly higher than other locations. The lobe involved in the pneumonia was the location of the lung cancer in 75.8% of the patients.
“Lung cancer is truly aggressive,” said Daniel Shepshelovich, MD, of Tel Aviv University Sackler Faculty of Medicine and Rabin Medical Center in Petach Tikva, Israel. “The only chance of recuperation is if it’s caught before it begins to cause any symptoms at all. The idea is to find the tumor well in advance. Previous studies have shown that a low-dose radiation CT scan conducted once a year on heavy smokers has the potential to lower lung cancer mortality rates. But this requires huge resources, and we still don’t know how it will perform outside of strictly conducted clinical trials.
“We want to develop a more realistic and cost-effective strategy targeting a particularly high-risk population,” he said.
Shepshelovich explained the study found that smokers hospitalized with pneumonia have cancer diagnosed after the infection because often the cancer masquerades as pneumonia, physically obstructing the airway and creating such an infection.
“Smokers admitted to the hospital with pneumonia should be considered for chest-computer tomography,” he stated. “Only 15% of lung cancer cases are detected at an early stage. We want to increase that number in order to reduce mortality or, at the very least, extend lives.”