Many Detected Lung Cancer Tumors are Harmless
Lung cancer is a fatal disease that currently affects around 399,431 people within the United States according to the National Cancer Institute. The five-year survival rate based on data gathered from 2003 to 2009 is 16.6 percent. Due to the mortality rate associated with this disease, doctors recommend people who are high-risk, such as smokers, to get regular CT scans. In a new study, however researchers found that many detected lung cancer tumors end up being harmless. Despite the findings, doctors stated that sticking to the current recommendations to screen frequently is still vital in preventing potentially fatal cases.
"[The study] adds an interesting caution that clinicians ought to think about -- that they will be taking some cancers out that wouldn't go on to kill that patient, commented Dr. Norman Edelman, the senior medical adviser for the American Lung Association.
For this study, the researchers used data collected from the National Lung Screen Trial, which involved 53,452 at-risk people. The trial was a seven-year study aimed to determine whether or not lung CT scans were effective in preventing deaths related to cancer. Half of the participants had received three annual low-dose CT scans and the other half received conventional chest X-rays. During the follow-up section of the study, CT scans diagnosed 1,089 people with lung cancer where as chest X-rays diagnosed 969 cases. From this trial, the researchers had reported that CT scans could have prevented 20 percent of lung cancer deaths in current and ex-smokers between the ages of 55 and 79. People who would qualify for screenings had to have a smoking history of 30 packs or more.
In the latest analysis of the data, researchers, with co-author Dr. Edward Patz Jr., a radiology professor at Duke University Medical Center, found that 18 percent of the cancers that the screenings found were most likely harmless. The researchers explained that these types of tumors tend to be so slow-growing that they never really affect the patient's mortality rate. Instead, these patients would most likely die from other factors caused by smoking, such as heart disease, emphysema or other major heart problems.
"It could be that heavy smokers die of lots of other things before the cancer can kill them," Edleman stated according to HealthDay. Since doctors cannot tell whether or not the detected tumor could be harmless, treatment should still be administered, experts stressed.
"Now we're realizing there's a third kind of cancer -- the kind that doesn't need to be cured but can be cured," Brawley said. "We cure some people who don't need to be cured, but the study clearly shows by treating everyone we cure people who need to be cured," commented Dr. Otis Brawley, the American Cancer Society's chief medical officer.
The study was published in JAMA Internal Medicine.