Lung cancer is the leading cause of cancer mortality among both men and women in the US, and yet the disease is rarely diagnosed early. Now, a new Israeli study proposes that screening smokers admitted to the hospital with pneumonia could facilitate the early diagnosis of lung cancer and thereby save – or prolong – many lives.
The study, which was conducted by researchers from Israel’s Tel Aviv University and Rabin Medical Center, was recently published in the prestigious scientific journal The American Journal of Medicine.
“Lung cancer is truly aggressive,” TAU‘s Dr. Daniel Shepshelovich, who led the study, said in a statement. “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.”
According to the researchers, “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.”
Heavy smokers face greater risks
Smoking causes approximately 85 percent of all lung cancer cases, only 15 percent of which are diagnosed at an early stage. Thus, Dr. Shepshelovich and his team examined Rabin Medical Center‘s cases of heavy smokers with community-acquired pneumonia — a form of pneumonia contracted by a person with little contact with the health care system. They reviewed every patient’s medical file for demographics, smoking history, lung cancer risk factors and the anatomical location of the pneumonia. The data was then crosschecked with the database at Israel’s National Cancer Registry for new diagnoses of cancer.
The researchers found that out of 381 admissions of heavy smokers with pneumonia between 2007-2011, 31 patients were diagnosed with lung cancer within a year of being hospitalized. Moreover, lung cancer incidence was found to be 23.8 percent higher in patients admitted with upper-lobe pneumonia. They also found that the lung cancer was located in the lobe affected by pneumonia in 75.8 percent of cases.
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“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,” Dr. Shepshelovich explains. “Considering that only 0.5 – 1 percent of smokers without pneumonia have a chance of being diagnosed with lung cancer every year, the fact that 8 percent of our study group developed lung cancer is alarming.”
“Only 15 percent of lung cancer cases are detected at an early stage”
Existing diagnostic methods, such as chest X-rays, “sometimes find the cancerous tumors, but they do not change mortality rates,” he 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.”
He continued to say that smokers admitted to the hospital with pneumonia should be considered for chest CT scans: “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.”
The researchers are currently considering a larger nationwide retrospective study on the subject.