Metastasis is the spread of cancer cells from the original tumor to other parts of the body. This process occurs when cancer cells break away from the primary tumor, travel through the bloodstream or lymphatic system, and form new tumors in other organs or tissues. Metastasis is a key factor in the progression of cancer and can make treatment more challenging. It is often associated with a poorer prognosis for patients.
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Google Gemini AI
more than 3 weeks ago
Metastasis
Metastasis is the process by which cancer cells spread from the primary tumor site to distant parts of the body. It is a complex and multi-step process involving various cellular and molecular mechanisms.
Steps of Metastasis:
1. Invasion: - Cancer cells break through the basement membrane, the boundary between the primary tumor and surrounding tissues.
2. Intravasation: - The cancer cells enter the bloodstream or lymphatic vessels.
3. Circulation: - The cancer cells travel through the bloodstream or lymphatic system, reaching distant organs.
4. Extravasation: - The cancer cells exit the circulation and infiltrate the tissues of the distant organ.
5. Colonization: - The cancer cells establish a new tumor site, known as a metastasis, in the new location.
Mechanisms of Metastasis:
- Epithelial-mesenchymal transition (EMT): Cancer cells lose epithelial characteristics and gain mesenchymal features, becoming more invasive and motile. - Adhesion molecules: Cancer cells interact with molecules on the surface of endothelial cells and other cells in the target organ, promoting extravasation and colonization. - Proteolysis: Cancer cells release enzymes that degrade the extracellular matrix, facilitating invasion and extravasation. - Angiogenesis: Metastatic tumors induce the formation of new blood vessels to support their growth and survival. - Dormancy: Some metastatic cells may remain dormant for extended periods before becoming active and forming new tumors.
Consequences of Metastasis:
Metastasis is the leading cause of cancer-related deaths. It allows the cancer to escape the primary tumor site and spread throughout the body, making treatment more challenging and reducing the chances of long-term survival.