A startling new study from Duke University has determined that 1 out of every five 5 lung tumors detected by CT scans may actually be “harmless,” according to lead researcher Dr. Edward Patz, Jr.
“People have to understand that we are going to find some cancers, which if we never looked, we never would have to treat,” stated Patz, a radiologist at the school. “This is something not commonly known about lung cancer among many doctors, let alone patients.
Still, he conceded that the results of his study are not likely to alter how the disease is treated. “For one thing, the disease is usually diagnosed after symptoms develop. When tumors show up on an ordinary chest x-ray, they are potentially life-threatening, and it is hard to determine which symptom less tumors found on CT scans might be dangerous so they automatically treat the cancer aggressively.
The Duke study is based on data from the National Lung Cancer Screening Trial sponsored by the National Cancer Institute, and involved more than 53,400 people at high risk for lung cancer. 50% received three annual low-dose CT scans (the only test shown to reduce lung cancer deaths in high-risk smokers), while the other half were given three annual conventional chest X-rays. During six years of follow-up, 1,089 lung cancers were diagnosed in CT scan patients, opposed to 969 in those who got chest X-rays.
What this means is “that for every 10 lives saved by CT lung cancer screening, almost 14 people will have been diagnosed with a lung cancer that would never have caused any harm, said Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society.
Lung cancer still remains the most common form of the disease (followed by skin cancer) in the US, with more than 200,000 people here diagnosed with it annually, and more than half of the cases end up being fatal. In addition, WHO reports that more than 1.5 million lung cancer deaths worldwide each year.