New Device Provides Real-Time Assessment of Lung Cancer Status

By Anthony J. Brown, MD

NEW YORK JUL 02, 2008 (Reuters Health) - Using a recently developed device, US researchers have shown that mutations in the epidermal growth factor receptor (EGFR) gene may arise in circulating lung cancer cells. The team believes that monitoring for such real-time changes could help guide and improve current cancer therapy.

"The novel microfluidic CTC-chip is a breakthrough technology in that it provides 100-fold increased sensitivity and similar increased purity in detection and isolation of circulating tumor cells in the blood of patients known to have cancer, compared with existing commercial technology," senior researcher Dr. Daniel A. Haber told Reuters Health.

According to Dr. Haber, a researcher with Massachusetts General Hospital Cancer Center in Boston, the biggest finding and surprise in the present study was that cancer cells evolve in their genetic composition as a result of therapy.

"As additional "targeted therapies" become available," he added, "we may face a day when we have to make practical decisions about therapies based on "real time information" about the genetic composition of the cancer. Some day, we may even be able to rapidly monitor responses to therapies, without having to wait for CT scans to show responses."

The study, reported in July 2nd Online First issue of The New England Journal of Medicine, involved an analysis of circulating tumor cells from 27 patients with metastatic non-small-cell lung cancer.

An expected EGFR activating mutation was identified in cells from 11 of 12 patients (92%) and in matched free plasma DNA from four of the patients (33%), the authors note (p = 0.009).

The drug resistance mutation T790M was found in patients with EGFR mutations who had been treated with tyrosine kinase inhibitors. The presence of this mutation in pretreatment tumor-biopsy specimens predicted reduced progression-free survival.

On serial analysis of circulating tumor cells, a drop in the number of captured cells correlated with a radiographic tumor response. Conversely, an increase in captured cells was tied to tumor progression and, in some patients, the development of additional EGFR mutations.

"The CTC-chip is still in a very early phase of development," Dr. Haber noted. "However, we can imagine a time (within 1-2 years) when this becomes a "point of care" technology and that it may be possible to monitor cancer noninvasively, in terms of responses and drug choices. This technological development comes hand in hand with the revolution in targeted cancer therapies, which will require "knowing what you"re treating" in terms of genetic makeup of each individual tumor."

SOURCE:

"Reuters content is the intellectual property of Reuters Limited. Any copying, republication or redistribution of Reuters content, including by caching, framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in content, or for any actions taken in reliance thereon."