Physiological Principles

Once a malignant tumor grows as large as approximately 2 cubic mm in size, oxygen and nutrients have difficulty diffusing the cells in the center of the tumor, causing a state of cellular hypoxia that marks the onset of tumoral angiogenesis - the excess formation of blood vessels that bring oxygen and nutrients and remove metabolic waste, without which the tumor cannot continue growing.

Enhanced angiogenesis is one of the causes for the increased temperature surrounding a malignant tumor.

Other causes include:

• Enhanced metabolism of tumor cells
• Higher concentration of Nitric Oxide which:
  • Increases blood flow
  • Affects the responsiveness to vasoconstriction stimulation.

Cold Stress Challenge

One of the fascinating physiological phenomena in the human body is the reaction to a Cold Stress Challenge (CSC) test. During drastic and sudden temperature decrease, the autonomic nervous system acts to constrict peripheral blood vessels (Vasoconstriction) while keeping regular blood flow to vital organs. It is a sophisticated way in which the body preserves heat and prevents any heat loss.

The high concentration of Nitric Oxide in a malignant breast diminishes the responsiveness of the breast's peripheral vessels to vasoconstriction stimulation.

During the procedure, the patient holds cold packs (~10°C; 50°F) in both hands for 1 minute, which stimulates the vasoconstriction reaction. Pre and post CSC images are acquired and compared to detect the presence of malignancy.

Cold Stress Challenge Process

• Cold pack held for 1 minute
• Stimulation of peripheral vasoconstriction
• Malignant breast's peripheral vasoconstriction impaired due to Nitric Oxide presence.