Final answer:
Tumors invade other organs and tissues through a process called metastasis, which is a characteristic of malignant tumors and involves the spread of cancer cells to new areas of the body via the bloodstream.
Step-by-step explanation:
Tumors invade other organs and tissues in a process called metastasis. Malignant tumors, or cancerous growths, have the ability to break beyond their own boundaries and spread to other parts of the body. This happens when tumor cells enter the bloodstream and move to other tissues, where they can initiate new tumor growth. Metastasis is a hallmark of cancers, distinguishing them from benign tumors which do not spread. The process of metastasis involves further somatic mutations which may facilitate the growth and survival of cancer cells in the new location.