An international group of researchers report that cancer DNA circulating in the bloodstream of lung cancer patients can provide doctors with mutation information that can help optimize treatment when tumor tissue is not available. The large international ASSESS study aimed to compare the ability of blood testing to detect EGFR mutations with the more standard method of testing the tumor itself, as noted on a Science Daily news release. The research team presented their findings at the European Lung Cancer Conference (ELCC) in Switzerland.

Dr Martin Reck, who presented the findings at the ELCC, explains, “We were really asking a question on behalf of patients. Is there a valid test that can identify an EGFR mutation and give me the opportunity for superior treatment, even if my lung tumour is not accessible for bronchoscopy or CT-guided biopsy? And, are the results of this blood test in agreement with the results of the ‘gold-standard’ tissue test?”

The study included 1,162 matched tissue and blood samples, and comparison of the outcomes of EGFR testing in the two techniques showed an 89% rate of agreement between the blood test and tissue test. Plasma testing identified about half of the patients with EGFR mutations compared to tissue testing, according to Science Daily. Reck states, “The results mean that for patients who do not have accessible tumor tissue, plasma testing for EGFR mutation turns out to be an attractive option to offer these patients adequate targeted treatment.”

Commenting on the study, Dr Rafael Rosell, an expert on the ESMO Faculty on Lung Cancer, says, “Cell-free DNA detected in the bloodstream of cancer patients represents an excellent tool to examine genetic alterations that are usually found through tumor tissue testing. This represents one of the most astonishing phenomena in biology.”

Rosell adds, “The results of this study validate that the presence of EGFR mutations in circulating DNA from plasma or serum (fractions obtained from whole blood) can be detected in around half of the patients. This work paves the way for further studies and expands the routine use of examining mutations such as EGFR mutations as part of cancer patient care.”

Source: Science Daily