A simple blood test could guide personalized treatments for lung cancer

French researchers identify genetic alterations in the blood of patients with lung cancer that could be used to make a personalized therapy crizotinib, without tumor lung biopsy.

In the last decade, advances in the knowledge of the molecular biology of lung cancer have made it possible to treat some patients with the variety of pulmonary adenocarcinoma -a frequent subtype- in a personalized manner. Thus, all patients with this diagnosis must undergo a study of alterations in the genes known as EGFR and ALK in the tumoural biopsy of the lung obtained in cruel tests such as fibrobronchoscopy or pulmonary puncture. When mutations or rearrangements are identified in those genes, something that happens in small subgroups of patients, there are non-chemotherapy treatments with new drugs against those therapeutic targets, such as erlotinib, gefitinib or crizotinib, which significantly improve the prognosis of these patients. However, lung biopsy material in inoperable patients is usually very scarce or insufficient, forcing more and more to raise new and bloody biopsies.

Researchers at the Gustave Roussy Institute of Cancérology, as published this week in the Journal of Clinical Oncology (www.jco.org) , have isolated circulating tumour cells (CTCs) in blood, through a simple blood extraction, and applying a subsequent method of enrichment in these cells and an adaptation of the analysis technique (filter adapted-FISH) have managed to differentiate precisely those patients who are candidates for treatment with crizotinib from those who are not. While this is not a validated technology for immediate clinical application, it clearly shows that minimally invasive analysis of blood samples allows the analysis of markers or targets that guide treatment. Considering the rapid expansion of molecular markers and new drugs applicable to the therapy of these patients, it is of great interest to be able to carry out the necessary molecular studies without having to resort to aggressive procedures such as pulmonary biopsies.