Top 10 Innovations for 2012
#2 CT Scans for Early Detection of Lung Cancer
Lung cancer is the most common cause of death from cancer among American men and women. According to the American Cancer Society, more than 220,500 new cases of lung cancer are diagnosed annually. An estimated 157,000 Americans will die of lung cancer in 2011. This is more than deaths from breast, prostate, colon, and pancreatic cancers combined.
Death rates have remained elevated because there is no effective screening method for early detection of lung cancer. When it is picked up, the cancer has usually spread, making a difficult to treat cancer even more difficult. Most cases of lung cancer occur in people between the ages of 45 and 75 who have been smokers or who have been exposed to cigarette smoke for many years. Sadly, only about 15 percent of people with lung cancer are alive five years after diagnosis. Doctors typically do not recommend general screening for lung cancer in smokers and former smokers because a standard x-ray is not sensitive enough to locate small tumors, nor does this screening method help decrease death from lung cancer. Medicare and most insurance companies do not cover lung cancer screening.
All that has changed now with the introduction of low-radiation-dose spiral computed tomography (spiral CT). This high-tech scan generates a series of detailed cross-sectional images of the lungs that are used to create a three-dimensional image. These scans can not only identify tumors earlier, but also spot them when the tumors are smaller and more treatable by surgery. Surgery is the best treatment for most types of lung cancer.
More than 53,000 men and women age 55 to 74, current and former heavy smokers and former heavy smokers recently participated in the multicenter National Lung Screening Trial (NLST) of spiral CT. Each was randomized to undergo either a CT scan or a standard chest x-ray once a year for three years and then were followed for five years in this study, which was sponsored by the National Cancer Institute.
The NLST results were very surprising, significant, and potentially game changing for the 7 million Americans who are heavy smokers and the 94 million current and former smokers. The study reported 20 percent fewer lung cancer deaths among older, current, or former heavy smokers (an average of a pack a day for at least 30 years) screened with CT compared with chest x-ray. This is the first study to show that screening for lung cancer can save lives. Another unexpected benefit from the lung screening: Testing cut deaths from any cause by 7 percent, a benefit that has yet to be explained.
If caught earlier through screening, the potential to save lives is great: Upwards of 60 to 90 percent of lung cancers are curable in the early stages. Screening for colon, breast, and cervical cancer has been shown to reduce the risk of dying from these cancers compared to those who are not screened. We now wait to see whether the results of the NLST will lead to changes in lung cancer screening guidelines by the Centers for Medicare and Medicaid Services.