It’s not new news that lung cancer causes more deaths each year than breast, prostate, colon and pancreatic cancers combined. And it’s older news that cigarette smoking is a leading cause of lung cancer. The correlation was the basis for the National Lung Screening Test, launched in 2002 by the National Cancer Institute.
Designed to compare two alternatives for detecting lung cancer – low-dose helical CT scan and chest X-ray – the test screened more than 53,000 former and current heavy smokers ages 55-74, with histories of at least 30-pack years, over a 20-month period. Pack years are calculated by multiplying the average number of cigarette packs smoked per day by the number of years smoked.
Earlier this month, the institute suspended the study because sufficient data affirmed the low-dose CT detected more cancers earlier, resulting in 20 percent fewer deaths among the test’s participants.
The obvious conclusion for increasing smokers’ mortality: consistent CT screening of current and former smokers, who number more than 94 million in the U.S. The obvious conflict: many false positives. The obvious conundrum: insurers may balk at the costs.
The solution? Screen smokers at highest risk for developing lung cancer so that CT scans are cost-effective in identifying early stages of the disease.
Enter Dr. Elwyn Cabebe, a hematologist/oncologist at El Camino Hospital, who created and will oversee the REACT clinical trial, studying 200 20-pack year or more smokers, former and current smokers who are more than 50 years old.
Because researchers have identified genes in DNA that put people at higher risk for lung cancer, Cabebe said a simple cheek swab – and a CT scan that reveals nodules – could help doctors pinpoint whether further testing is needed.
REACT combines genetic testing and low-dose CT screening to identify high-risk individuals susceptible to lung cancer who should be regularly monitored for the disease.
“This is the first study of its kind in the country,” Cabebe said.
Low-dose CT scanning alone often photographs benign nodules – false positives, according to the National Institutes of Health. Between 20 and 60 percent of the scans will show abnormalities, including smoking scars, inflammation and other noncancerous tumors.
According to the institute’s Nov. 4 report, “National Lung Screening Trial: Questions and Answers,” lung biopsies to confirm a cancerous tumor are risky.
“This phenomenon, called over-diagnosis, puts some screening recipients at risk from unnecessary diagnostic biopsies or additional surgeries … unnecessary treatments for cancer, such as chemotherapy or radiation therapy,” the report stated.
The REACT trial will track participants for three years, Cabebe said, and if definitive results come from the trial, he’s hoping to expand the study to other institutions for more data in a larger population.
Cabebe is conducting the trial at both of El Camino’s campuses, Mountain View and Los Gatos, and is accepting participants.
And, of course, smokers will be encouraged to attend smoking-cessation classes.
For more information, call 988-7623 or visit www.elcaminohospital.org.