Metastatic colonies are secondary tumor masses that form when cancer cells spread from the primary tumor site to distant organs or tissues. This process, known as metastasis, is a hallmark of advanced cancer and is responsible for the majority of cancer-related deaths. The formation of metastatic colonies involves a complex series of steps including local invasion, intravasation into the bloodstream or lymphatic system, survival in circulation, extravasation into a new tissue, and finally, colonization and growth in the new environment.
