Final answer:
Metastasis is the process where cancer cells spread from the primary tumor to distant parts of the body, establishing new tumors in different locations, which is indicative of advanced cancer.
Step-by-step explanation:
The term metastasis refers to the process whereby cancer cells spread from the original, or primary, tumor to distant parts of the body. This spread occurs via the bloodstream, lymphatic system, or direct cellular invasion of nearby tissue. Once these cancer cells reach a new location, they can establish new tumors, called metastases. Such progression is characteristic of malignant tumors as they possess the ability to invade other tissues, unlike benign (non-cancerous) tumors. Metastasis confirms that cancer has advanced and often indicates a poorer prognosis for the patient. Therefore, the correct answer to the question is B) The spread of cancer cells to distant parts of the body.