Molecular Analysis Monitors Changes in Lung Cancer
Non-invasive procedure detects mutations in EGFR gene in circulating tumor cells from blood
WEDNESDAY, July 2 (HealthDay News) -- In patients with non-small-cell lung cancer, molecular analysis of circulating tumor cells isolated from blood may be a non-invasive procedure that helps physicians monitor changes in epithelial tumor genotypes during treatment, according to the results of a study published online July 2 in the New England Journal of Medicine.
Shyamala Maheswaran, Ph.D., of the Massachusetts General Hospital Cancer Center in Charlestown, Mass., and colleagues performed an epidermal growth factor receptor (EGFR) gene mutational analysis on DNA recovered from circulating tumor cells isolated from 27 patients.
The researchers identified EGFR activating mutations in 92 percent of the subjects. T790M -- a mutation associated with drug resistance -- was found in patients with EGFR mutations who had been given tyrosine kinase inhibitors. In the patients with the T790M mutation, progression-free survival was reduced (7.7 versus 16.5 months).
"The investigators also showed that serial genotyping of circulating tumor cells seemed to have functional significance, since a decrease in the number of cells was correlated with a radiographic response to gefitinib in four patients, whereas an increase in the number of cells was correlated with the emergence of additional EGFR mutations and clinical progression," states the author of an accompanying editorial. "The capture and analysis of circulating tumor cells from patients with lung cancer represents a new diagnostic approach that may bring us closer to an era of individualized medicine."
The authors of the study and the editorial report financial relationships with the pharmaceutical industry.