Multiple primary lung cancer (MPLC) has become a worldwide problem due to the difficulty in diagnosis, treatment and surveillance. Although exploring tumour clonal heterogeneity and microenvironment can help understand cancer evolution and impact therapeutic outcome, study is still lacking in this field on MPLC. Circulating tumor DNA (ctDNA) are short DNA fragments, which can be obtained conveniently and non-invasively, providing comprehensive views of the tumor as were shed by tumor cells from multiple tumor regions. Therefore, we design a prospective study of patients with surgically treated MPLC, aiming to use ctDNA technique to define the evolutionary landscape of MPLC through inter-tumor and intra-tumor heterogeneity by multi-region sampling and genetic analysis. We will also explore the the microenvironment by RNA sequencing and T cell receptor sequencing. This study may help understand the genetic evolution and microenvironment of MPLC, and provide evidence for the diagnosis, treatment and surveillance of these patients.
