metasztázist

Metasztázis is the spread of cancer cells from the place where they first formed to another part of the body. When cancer cells metastasize, they may travel through the blood or lymph systems. These traveling cells can then form new tumors in other organs or tissues. This secondary tumor is called a metastatic tumor. The process of metastasis is a key characteristic of malignant tumors and is the primary cause of death for cancer patients.

The development of metastasis involves several steps. First, cancer cells must break away from the primary tumor. This often involves changes in the cell adhesion molecules that hold tumor cells together. Once detached, these cells invade surrounding tissues, a process that may require the breakdown of the extracellular matrix. After invading, the cancer cells enter the bloodstream or lymphatic vessels. This is known as intravasation. Within the circulation, the cancer cells, or emboli, travel to distant sites. Upon arrival at a new location, these cells must adhere to the vessel wall, exit the circulation (extravasation), and survive in a new microenvironment. Finally, the disseminated tumor cells proliferate and form a new, macroscopic metastatic tumor.

The most common sites for metastasis vary depending on the type of primary cancer. For example, breast cancer often metastasizes to the bones, lungs, liver, and brain. Lung cancer commonly spreads to the brain, bones, liver, and adrenal glands. Understanding the patterns of metastasis is crucial for staging cancer and guiding treatment decisions. Treatments for metastatic cancer aim to control or eliminate the spread of cancer cells and alleviate symptoms.