The Study of Exosome EML4-ALK Fusion in NSCLC Clinical Diagnosis and Dynamic Monitoring

The application of ALK inhibitors in the first-line cancer treatment can significantly increase the PFS and ORR of patients those with EML4-ALK fusion. The contemporary clinical ALK fusion detection are mainly via FISH and ICH while biopsies are needed. For locations where are difficult to take biopsies, these routine examinations can hardly been adopted. Apart from these, part of ALK fusion patients are resistant to ALK inhibitors, also making an accurate and efficient prognostic indicator for efficacy evaluation and identifying high-risk recurrent population an urgent priority.

The bilayer membrane structure of exosome helps maintain its internal genetic stability, making detection of EML4-ALK fusion via plasma exosomes in advanced NSCLC patients a feasible way, which might provide a non-invasive and more convenient approach for NSCLC diagnosis and efficacy monitoring. Firstly, this study will evaluate the performance of exosome EML4-ALK fusion detection in NSCLC diagnosis, which sensitivity and specificity would be compared with the FDA approved IHC (ALK [D5F3] CDx Assay) test. Subsequently, this study would monitor the dynamic changes of EML4-ALK fusion in exosome examination diagnosed ALK fusion positive NSCLC patients both before and after treatment. It aims to prospectively evaluate the potential value of this approach on efficacy and prognosis prediction in NSCLC therapy and determining whether exosome ALK fusion could assess the curative effect more accurately than imaging examination and tumor markers. Thirdly, FISH diagnosed EML4-ALK positive NSCLC patients will be divided into the positive or negative subgroup according to their post-treatment exosome ALK fusion expression which were determined at 2-3 months after ALK inhibitor were adopted. The prognostic value of monitoring exosome EML4-ALK fusion expression is assessed through the comparison of patients PFS and OS.