This application discloses methods for prevention and treatment of cancers. Due to the larger size of human white blood cells compared to red blood cells, a decrease in the diameter of a part of a blood vessel can block the flow of white blood cells while allowing the flow of red blood cells. As a result, in tissues with such reduction in the diameter of blood vessels, there are areas where red blood cells are present, while there is a lack of white blood cells to fight the parasites and cancer cells. Therefore, cancer cells and other parasites can reside in such areas, replicate, and develop into diseases.The disclosed methods provide for widening of the blood vessels in which a reduction in the diameter of a part of the vessel blocks the flow of white blood cells, while allowing the flow of red blood cells. As a result of this widening, white blood cells may pass through the vessel, reach to the parasites or cancer cells, and confront them. The disclosed methods include administration of vasodilators, blood fat-reducing drugs, anti-inflammatory agents, or blood clot-reducing medications. The claimed methods may be used in combination with other conventional methods for treating cancers.
