The final step in metastasis is the colonization of new tissues, a process known as homing. Cancer cells exit the bloodstream through extravasation, migrate through the new tissue, and establish secondary tumors. Histologically, metastatic tumors often resemble the primary tumor but can show adaptations to the new tissue environment. For example, metastatic breast cancer in the bone may stimulate osteoclast activity, leading to bone resorption.
