“Metastasis” is the process by which:
✓ Correct answer: b) cancer cells spread through the blood or lymphatic system to other sites or organs
ExplanationMetastasis is the process through which cancer cells spread from the primary tumor to distant parts of the body, forming secondary tumors in organs such as the lungs, liver, bones, or brain.This process is responsible for nearly 90% of cancer-related deaths, showcasing the aggressive and life- threatening nature of malignant tumors.The process begins with Epithelial-to-Mesenchymal Transition (EMT), where cancer cells gain the ability to migrate and invade surrounding tissues.These cells then enter the bloodstream or lymphatic system (intravasation) and travel to other parts of the body.While in circulation, they evade immune system attacks and other hostile conditions.Upon reaching a new site, the cells exit blood vessels (extravasation) and adapt to the local environment to form secondary tumors.Interestingly, some metastatic cells can remain dormant for years before becoming active again, contributing to cancer recurrence.473
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