What happens to tumor cells after they break off during metastasis?

When tumor cells break off during metastasis, they enter the bloodstream or lymphatic system, allowing them to travel to distant sites in the body. Upon reaching these new locations, the tumor cells can adhere to the tissues there and, under the right conditions, they can proliferate and form new tumors. This process is a key characteristic of cancer progression, where cells not only invade local tissues but also spread to establish secondary tumors, leading to more complex and challenging treatment scenarios.

The ability of these cells to survive in the circulation, evade the immune system, and colonize new tissues is vital for the metastatic process, and contributes significantly to the severity and complexity of cancer. Thus, the correct answer highlights the potential for these cells to continue their growth and contribute to the disease after detaching from the original tumor.