What term describes the invasion of cancer cells into adjacent tissues, a hallmark of malignant breast tumors?

Infiltration is the term that accurately describes the process of cancer cells invading adjacent tissues, which is a defining characteristic of malignant tumors, including breast cancer. This invasive behavior allows cancer cells to breach the boundaries of the tissue they originated from, disrupting normal tissue architecture and function. Invasive cancer often spreads beyond its original site, leading to the potential for further complications and treatment challenges.

Metastasis, while also a key aspect of cancer progression, specifically refers to the spread of cancer cells from the primary tumor site to distant organs or tissues, rather than the local invasion into neighboring tissues. Excision pertains to the surgical removal of tumors and other tissue, which does not describe the invasive behavior itself. Encapsulation refers to the formation of a fibrous capsule around a tumor, indicative of a benign tumor, rather than the aggressive invasion seen in malignant tumors.

Understanding these terms is crucial to grasp the nature of breast cancer and its management.