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dence suggests that only a minority of the cells in s primary tumor express the constellation of phenotypic traits required to complete the many steps in the metastatic process. |
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In order for cancer to metastasize and develop into distant tumors, several steps must occur. It is here that many natural anticancer agents can play a lifesaving role. These agents include tumor-cell adhesion inhibitors (such as modified citrus pectin), platelet aggregation reducers (such as turmeric and bromelain), angiogenesis inhibitors (such as genistein-rich soy products), and many more that are discussed in chapters 4 and 5. |
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Since metastases are a primary determinant of cancer morbidity and mortality, the use of nutritional and herbal interventions that may inhibit the metastatic process should be considered more seriously by oncologists for their patients with malignancies. |
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The first step of tumor invasion and metastasis occurs with detachment of the cancer cells from the primary tumor. The rumor cells then spread by piercing the protective membranes enclosing all tissue. Next, the cells make their way into the base membrane of a blood vessel and enter the bloodstream. There they secrete certain proteolytic enzymes, which digest the base membrane and enable the cells to slip between vascular endothelial cells and enter the vessel lumen. The cancer cell now lodges in the tiny capillaries and is free to travel to vital organs, such as the liver, brain, and/or lungs, or to remain in the lymph system. At this point, angiogenetic growth factors are secreted by the cancer cell to supply oxygen and blood to the secondary tumor. The tumor continues to grow until it takes over the host organ and starves that organ of its vital nutrients. Eventually, as the cancer proliferates, the organ becomes so infiltrated by the tumor that it can no longer perform its essential functions. |
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The bad news is that metastases are a primary determinant of cancer morbidity and mortality. The good news is that the use of certain nutritional and herbal interventions may inhibit the metastatic process by blocking vascularization. The process is called antiangiogenesis. |
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Cell Adhesion Molecules (CAMs) |
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Cancer cells communicate with each other and proliferate because of certain cell surface receptor molecules called cell adhesion molecules (CAMs). |
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