A new study led by researchers at Tel Aviv University (TAU) and Rabin Medical Center in Israel suggests that screening heavy smokers who have been admitted to the hospital with pneumonia could facilitate the early diagnosis of lung cancer, helping to reduce mortality.

The study was published in the American Journal of Medicine, and is titled “High Lung Cancer Incidence in Heavy Smokers Following Hospitalization Due to Pneumonia.”

Smoking is responsible for nearly 85 percent of all known lung cancers, of which only 15 percent are diagnosed at an early stage. Most efforts to reach an early disease diagnosis have been unsuccessful, mostly due to the very aggressive nature of the condition. This makes lung cancer the leading cause of cancer mortality in the U.S., with a five-year survival rate of only 17 percent.

Now, researchers reported that one of the highest lung cancer risk groups is heavy smokers who have been diagnosed with pneumonia, suggesting that this particular patient population should be eligible for early screening by chest-computer tomography (CT) scans.

“Lung cancer is truly aggressive. 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,” Daniel Shepshelovich, M.D., said in a press release.

“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 in real-world conditions, outside of strictly conducted clinical trials,” said Shepshelovich, the study’s lead author. “We want to develop a more realistic and cost-effective strategy targeting a particularly high-risk population.”

Shepshelovich and his colleagues examined 381 files of heavy smokers with community-acquired pneumonia (the type one gets when there is little contact with healthcare systems) who were admitted at the Rabin Medical Center between 2007 and 2011. The team cross-checked every patient’s medical file – including anatomical location of the pneumonia, lung cancer risk factors, smoking history and demographics – with the database at Israel’s National Cancer Registry for new cancer diagnoses.

The investigators found that of the 381 admitted heavy smokers analyzed, a surprising 31 (9 percent) were diagnosed with lung cancer within only a year after hospitalization. Lung cancer occurrence was found to be considerably higher among patients with upper lobe pneumonia (23.8 percent). The researchers also observed that in 75.8 percent of the cases, the lung cancer developed in the lobe that was affected by pneumonia.

“We discovered that smokers hospitalized with pneumonia are diagnosed with cancer after the infection because often the cancer masquerades as pneumonia, physically obstructing the airway and creating such an infection,” Shepshelovich said. “Considering that only 0.5 to 1 percent of smokers without pneumonia have a chance of being diagnosed with lung cancer every year, the fact that 9 percent of our study group developed lung cancer is alarming.”

“The current diagnostic methods in place — chest x-rays, sputum cytology — sometimes find the cancerous tumors, but they do not change mortality rates,” Shepshelovich said. “In other words, people are aware that they have cancer for longer periods of time, but do not recover. This is not a solution.”

Shepshelovich and his team are now considering a larger nationwide study to further understand this correlation. “Smokers admitted to the hospital with pneumonia should be considered for chest-computer tomography,” he said. “Only 15 percent 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.”