Promising new tool for monitoring lung cancer

A non-surgical technique that may help doctors monitor how well non-small cell lung cancer patients are responding to treatment is currently being tested. Using a device known as a CTC-chip to analyze circulating tumour cells from patient's blood samples, it was possible to identify whether patients had genetic mutations that would make them less likely to respond to certain therapies.

The research, published in the New England Journal of Medicine, is still in the early stages. However, if future studies confirm it works, the technique could offer lung cancer patients a non-invasive, safe way to monitor their disease and find out which treatments will work. Currently, in order to get that type of information, patients would have to undergo dangerous, invasive procedures to sample tissues and cells.

The current findings will need to be replicated in larger studies before the chip is used widely, since only 27 patients participated in the pilot study.

The CTC-chip opens up a whole new field of studying tumors in real time. When the device is ready for larger clinical trials, it should provide new ways of measuring treatment response, defining prognostic and predictive measures, and studying the biology of blood-borne metastasis, which is the primary method by which cancer spreads and becomes lethal.

Blood samples from 27 patients, 23 of whom had a cell-surface protein mutation known as the epidermal growth factor receptor (EGFR) mutation were tested. Using the CTC-chip, the researchers were able to identify the mutation from the circulating blood tumour cells 92% of the time.

It was also noticed the chip could detect changes over time. Research has shown that tumours with the EGFR mutation are more likely to respond to a class of drugs known as tyrosine kinase inhibitors, or TKIs; Tarceva (erlotinib) and Iressa (gefitinib) are 2 TKIs used to treat lung cancer. However, the patient's tumours eventually come back. Using the CTC-chip, the researchers found out why; it appears that the tumour cell's genetic makeup evolved over the course of treatment.

Biopsy samples taken at the time of diagnosis can never tell us about changes emerging during therapy or genotypic differences that may occur in different sites of the original tumour, but the CTC-chip offers the promise of noninvasive continuous monitoring.

This information could one day help doctors see when a patient was becoming resistant to treatment so that new therapies could be tried earlier. However, there is still work to do to make this technique more efficient on the larger scale outside of the clinical trial setting.

Genetic mutations and lung cancer - new developments in oncology

New results on genetic techniques that are helping doctors diagnose and treat lung cancer were released today at the 1st European Lung Cancer Conference jointly organized by the European Society for Medical Oncology (ESMO) and the International Association for the Study of Lung Cancer (IASLC) in Geneva, Switzerland.

In one report (Abstract No. 81O; 25th April), Israeli researchers from Rosetta Genomics, a biotechnology company developing microRNA-based technologies for diagnostic and therapeutic applications, described a test that may help make crucial distinctions between types of lung cancer. They demonstrated that the method can accurately distinguish between squamous and non-squamous forms of non-small-cell lung cancer, based on the levels of different microRNA molecules found in tissue samples.

MicroRNAs are short RNA molecules that regulate many cancer-related processes. Recently, the launch of new targeted therapies for non-squamous, non-small-cell lung cancer underlines the importance of accurate, objective diagnosis has taken center stage. The ability of physicians to accurately differentiate squamous from non-squamous NSCLC may be used as important treatment guide. For example, some treatments for non-squamous non-small-cell lung cancer can be deadly or ineffective in patients with the squamous form of the disease. Researchers expect the test to be approved for use during 2008.

In another report (Abstract No. 106PD; 25th April), Italian researchers showed that genetic analysis can help identify patients who are at high risk of relapse after surgery to remove lung cancer. The 3 gene signature may allow oncologists to classify patients with stage I non-small-cell lung cancer who underwent curative surgical resection in high or low risk molecular category, beyond conventional predictors and decide which appropriate treatments they should receive.

The test includes the gene LCK, which is an important marker of immune cell anticancer activity, DUSP-6 which regulates a signaling pathway involved in cancer spread, and ERCC1, which is thought to be a significant prognostic and therapeutic biomarker in non-small-cell lung cancer. These findings mean that we can potentially improve not only the prognostic stratification of patients, but also the choice of the more appropriate adjuvant drug after surgery, i.e. which patients will benefit most.


Source: ESMO