Cancer exodus hypothesis
The cancer exodus hypothesis establishes that circulating tumor cell (CTC) clusters maintain their multicellular structure throughout the metastatic process. It was previously thought that these clusters must dissociate into single cells during metastasis. According to the hypothesis, CTC clusters intravasate (enter the bloodstream), travel through circulation as a cohesive unit, and extravasate (exit the bloodstream) at distant sites without disaggregating, significantly enhancing their metastatic potential. This concept is considered a key advancement in understanding of cancer biology and CTCs role in cancer metastasis.