Anaplastic lymphoma kinase as a new target for the treatment of non-small-cell lung cancer

Abstract

The anaplastic lymphoma kinase (ALK) gene rearrangement identifies a distinct molecular subset in non-small-cell lung cancer (NSCLC) populations susceptible to targeted inhibition. It consists of a small inversion in the short arm of chromosome 2 between exon 20 of the ALK gene and different exons of the echinoderm microtubule-associated protein-like (EML4) gene. This translocation leads to a chimeric protein with constitutive activation of ALK that possesses an oncogenic activity demonstrated both in vitro and in vivo. Other rare translocation partners for ALK other than EML4 may be found in lung cancers, including TRK-fused gene (TFG) and kinesin family member 5B (KIF5B). ALK-positive patients represent 5–6% of all NSCLCs and they seem to have particular clinicopathological and molecular features. Recently, Phase I–II trial results of crizotinib, a potent dual c-MET and ALK inhibitor, demonstrated its dramatic efficacy in ALK-positive patients with advanced NSCLC. This article will present knowledge on the characteristics of ALK-positive patients, discuss the different methods of ALK rearrangement detection and focus on clinical results of crizotinib.

Keywords::

• ALK rearrangements
• crizotinib
• EML4–ALK gene
• lung adenocarcinoma
• NSCLC

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.