Analysis of tumor-draining vein secretome: A direct access to tumor-derived extracellular vesicles in surgical lung cancer patients

Tumor-secreted extracellular vesicles (EVs) participate in the metastasis process through different mechanisms, including the preparation of the pre-metastatic niche to grant circulating tumor cells (CTCs) implantation and growth. The study of the metastasis process through the analysis of CTCs and tumor-derived EVs is difficult because of the dilution grade of these elements in peripheral blood. In early-stage lung cancer patients, the tumor-secreted products are even more diluted. An attractive strategy in surgical lung cancer patients is to purify them from a pulmonary tumor-draining vein where they are enriched. The information obtained from the analysis of EVs and CTCs purified from this source could give more accurate information about tumor biology and could be an important source of biomarkers to identify patients at high risk of relapse after curative surgery.