In cancer, how do abnormal cells behave?

Abnormal cells in cancer are characterized by their ability to spread and invade nearby tissues, which is a key aspect of cancer progression. Unlike normal cells that grow and divide in a regulated manner and respond appropriately to the signals that regulate cell growth, cancer cells often exhibit uncontrolled growth. This means they can proliferate beyond their normal limits and become invasive.

This invasiveness can lead to the destruction of surrounding tissues, as cancer cells can infiltrate through the extracellular matrix and establish secondary growths in new locations, a process known as metastasis. This ability to migrate from the original tumor site into adjacent tissue and even distant organs is a major factor in the severity and complexity of cancer as a disease.

The other options do not align with the behavior of cancerous cells: normal regulation of cell division is lost in cancer (therefore, they do not divide in a controlled manner), they are not dormant (rather, they tend to be highly active and proliferative), and cancer cells can affect various tissues and systems beyond just the bloodstream.