Computerizing tomography (CT) scans are frequently used in the diagnosis of mesothelioma and other types of cancer. However, new research is showing that low-dose CT scans are proving effective in detecting early stage lung cancer — with very few false positives coming through. Could this be the early stage detection technique the mesothelioma community has been waiting for?
What Are Low-Dose CT Scans?
CT scans are widely considered to be quick, painless, and effective. During a CT scan, a patient lies on a long table while a scanner rotates around them, taking multiple pictures. These pictures are combined to create one extremely detailed image of the soft tissues inside the body.
Low-dose CT scans are the same as conventional CT scans, but use approximately 5 times less radiation. The radiation in 1 low-dose CT scan is equal to about 15 traditional X-rays, but many find the benefits to be worth the risk. Traditional X-rays are capable of showing lung cancers the size of a dime, while a low-dose CT scan can zero in on lung cancers the size of a grain of rice.
How Low-Dose CT Scans Are Being Used to Diagnose Lung Cancer
At the beginning of 2015, Medicare announced that it would cover the cost of low-dose CT scans for individuals with a long smoking history. This came after extensive evidence gathered during the National Lung Screening Trial showed that preventative scans decreased the amount of deaths from lung cancer.
Right now, the low-dose CT scans are generally only being used to screen high-risk smokers. This means the individuals are older than 55, have a history of smoking a pack a day for 30 years, and are in generally good health. The screening is about recognizing the risk for lung cancer and catching it before it spreads too far.
“We’re not decreasing the number of lung cancers, at least for now, but what we’re doing is causing this thing called ‘stage migration,’ “said Dr. Elizabeth Kline, a thoracic surgeon for Roper St. Francis in Charleston, South Carolina. “We’re bringing (patients) out of the later stage and we’re pulling them up in the curable, early stage.”
With this type of screening, there have been concerns surrounding false-positives, which could cause patients to undergo unnecessary surgeries. However, a new study from researchers at Lahey Hospital & Medical Center in Burlington, Massachusetts is calming fears a bit. The researchers followed the outcomes of 1,654 patients who underwent low-dose CT scans for lung cancer at their hospital between 2012 and mid-2014.
Of the 1,654 patients screened, 25 underwent surgery. Of those 25, 20 were diagnosed with lung cancer and 18 had an early stage of the cancer.
“Surgical intervention for a non-lung cancer diagnosis was rare — 5 out of 1,654 patients or 0.3%,” study co-leader Bryan Walker said in a news release from The Society of Thoracic Surgeons. “That incidence is comparable to the 0.62% rate found in the National Lung Screening Trial that helped secure screening coverage in the U.S.”
Could Low-Dose CT Scans Help Mesothelioma Victims?
Right now, low-dose CT scans are not a common screening practice when it comes to victims of asbestos exposure — but they should be, and could be, one day.
Over 10 years ago, Italian researchers conducted a study to determine the efficacy of low-dose CT scans in screening for lung cancer and pleural mesothelioma in an asbestos-exposed population. The study’s participants had all definitely been exposed to asbestos, were between the ages of 40 and 75, had no prior cancer or severe concomitant conditions, and no chest CT scans in the past 2 years. All the volunteers then had a chest X-ray and a low-dose CT scan performed.
Overall, low-dose CT scans identified 9 cases of non-small cell lung cancer, none of which were detected by the chest X-ray. No cases of pleural mesothelioma were diagnosed. Because of this, the researchers noted that while they remain uncertain about the role of low-dose CT scans in diagnosing mesothelioma, they did feel their findings suggested low-dose CT scans may at least be as useful in asbestos workers as in heavy smokers for the early diagnosis of lung cancer.
Additionally, there is a current clinical trial recruiting for participants in Canada at the University of Calgary. The goal of their study is to develop and implement a low-dose CT scan screening approach for lung cancer and mesothelioma in asbestos-exposed workers in Alberta.
The dangerous effects of asbestos have been proven time and time again, so hopefully researchers will be able to show the benefits of low-dose CT screening for not just smokers, but individuals who have been exposed to asbestos as well. With regular preventative screening, victims of asbestos-related diseases could have a fighting chance at prolonging survival, improving quality of life, and giving mesothelioma a run for its money.