EARLY DETECTION AND SCREENING FOR LUNG CANCER
BUFFALO, NY -- Lung cancer is the leading cause of cancer death in the United States. There is a strong push to find methods that may improve survival by diagnosing the disease at an earlier, presumably more curable, stage. However, whether early detection results in a higher number of cured patients remains unclear. A comprehensive review of current lung cancer screening methods and recommendations is featured in the November 30, 2000 issue of the New England Journal of Medicine.
"There is a great need to identify a screening method for high-risk patients because most patients are diagnosed with advanced lung cancer. However, attempts in the 1970s to identify early-stage tumors via chest x-ray and sputum analysis failed to decrease mortality," said Gerold Bepler, MD, PhD, Departments of Medicine and Cancer Genetics at Roswell Park Cancer Institute (RPCI), one of the authors of this review. "Currently, there is interest in the use of computed tomography, laser-induced fluorescent bronchoscopy, molecular technology, and other evolving technologies."
Lung cancer is a significant health problem in the United States. It is estimated that there will be 164,100 new cases diagnosed in 2000, almost 14 percent of all cancer cases diagnosed. There will be an estimated 156,900 deaths from lung cancer, almost 28 percent of all cancer deaths. There has been a slight decline in the incidence of lung cancer in recent years, most likely due to decreased smoking rates over the past 30 years, although, tobacco use among youth has begun to rise again.
This review examined recent attempts to screen high-risk populations for early lung cancer. Three non-randomized trials have published data regarding screening for lung cancer:
* The Early Lung Cancer Action Project (ELCAP), which has enrolled 1,000 high-risk smokers over age 60 and is examining the use of chest x-ray and low-dose CT; and,
* Two studies from Japan that used chest x-ray, low-dose CT and a three-day pooled sputum sample.
"The results from these trials confirmed that CT was more sensitive for detecting lung nodules than chest x-ray, and that some of these nodules were lung cancer. However, to date, there does not appear to be a dramatic impact on survival in patients who participated in these trials. Further studies are needed to analyze morbidity and mortality data as well as a cost/benefit review," continued Dr. Bepler.
The ability of CT to detect smaller nodules than chest x-ray has generated interest in using this method for general cancer screening. However, other diagnostic methods (sputum samples, bronchoalveolar lavage fluid or bronchial biopsy) are also being examined. These methods may end up complementing CT in future screening programs.
"Although there is pressure, based upon these initial studies, to use CT in all high-risk patients, caution should lead the way," said Dr. Bepler. "Additional studies, such as a large-scale project being considered by the National Cancer Institute, should be conducted, completed, analyzed and validated before mass screening programs for lung cancer are initiated and physicians across the country change their clinical practice."
Roswell Park Cancer Institute, founded in 1898, is the nation's first cancer research, treatment and education center and is the only National Cancer Institute-designated comprehensive cancer center in Western New York.
- 30 -
RSS