Despite risks, imaging is the trend for lung cancer screens
For years, the chest x-ray has served as the standard tool to diagnose lung cancer. However, the high incidence of false positive results often left patients and their physicians taking a hit or miss approach to treatment. Now, many lung cancer researchers and advocacy groups are recommending another option -- low dose CT scans.
But as with many new technologies, questions abound over who should be screened using this screening tool and how to pay for them.
Second to prostate cancer in men and breast cancer in women, lung cancer is the next most commonly diagnosed form of the disease in the United States. Each year, 220,000 people in the U.S. are diagnosed with lung cancer, according to the National Lung Cancer Partnership and 27 percent of all cancer deaths are attributable to lung cancer according to the American Cancer Society.
Given these statistics, it's not a stretch to see why researchers sought a more reliable diagnostic tool. Thus, the development of low-dose helical computed tomography (CT) scans.
Researchers and advocates were encouraged with the release in 2011 of the National Lung Screening Trial (NLST), which revealed there was a 20 percent reduction in lung cancer deaths among current or former heavy smokers who were screened use the new technology versus those screened with a chest x-ray.
Funded by the National Cancer Institute (NCI), a division of the National Institutes of Health, "...the NLST is a nearly decade-long study that establishes low-dose helical CT as the first validated screening test which can reduce mortality due to lung cancer," according to an NCI press release.
Yet, despite the encouraging results, questions remain over who gets screened using low-dose CT scans and how to pay for them.
The American Lung Association is among those groups recommending low-dose CT screening for people who meet the following criteria: current or former smokers (aged 55 to 74 years), with a smoking history of at least 30 pack-years (that is, an average of a pack a day for 30 years) and with no history of lung cancer.
Therein is the problem as the estimated number of those who should be screened is so high that there are not enough facilities to perform annual screens on everyone. An additional problem is the exposure to radiation, although advocates say the health risk of exposure is small compared to the benefits gained.
On the other hand, the American College of Chest Physicians, the American Society of Clinical Oncology and the American Thoracic Society took a more cautious approach to low-dose CT scans, pointing to the recent stories about the effectiveness of prostate cancer screening.
The debate then over the effectiveness of low-dose CT scans then leads to the question of payment. In particular, since United States Preventive Services Task Force, an independent group of experts that makes recommendations on the effectiveness of treatments has determined that the evidence is inconclusive regarding these scans, Medicare and insurance companies do not include this scan as a covered service for payment.
Still, the debate over the effectiveness of low-dose CT scans doesn't stop the work of researchers like Dr. Tokihiro Yamamoto of the Department of Radiation Oncology at the Stanford University School of Medicine. Yamamoto recently received a grant from the National Lung Cancer Partnership to further his research on a new method for imaging the healthy and unhealthy portions of the lung using four-dimensional computed tomography.
According to a press release announcing the grant, this method could "...help doctors perform better targeting of lung cancer tumors during radiation treatment."
"Success of this project will ultimately lead to the improved quality of life of lung cancer patients through toxicity reduction and survival improvement," said Yamamoto in an e-mail explaining his research. "Furthermore, 4D CT ventilation imaging may be useful in diagnosis pulmonary diseases such as chronic obstructive pulmonary disease (COPD) and asthma."
There could be other benefits as well.
Yamamoto also pointed out that four-dimensional imaging has "...high potential to be translated into the clinic..." because of its increased availability over the past decade. In addition, he said the "...images can be considered 'free' information for lung cancer radiotherapy patients, since 4D CT ventilation calculation involves only image processing/analysis and does not require any additional scan." Finally, he added that the method has a higher image quality and costs less than other lung imaging methods.
Despite the advances to better detection of lung cancer, don't smoke or stop smoking remains the best advice from the American Cancer Society and the American Lung Association.