Metastatic disease is the leading cause of cancer associated deaths. Circulating tumour cells
(CTCs) are responsible for tumoral dissemination, as they are able to be released from the primary
tumour and establish distal metastatic foci. The objective of this doctoral thesis is to increase the
knowledge of CTCs, through the use of liquid biopsy. To this aim, with the use of blood samples
from metastatic cancer patients we identified key biomarkers for cancer progression. In this
context, different experimental approaches were considered: the validation of new technologies for
the study of CTCs, the isolation and molecular analysis of CTCs and the establishment of in vivo
models