Reduced Immune System Activity
Stress can reduce the Immune System activity, many type of immune system cells cannot perform their defense performance against any threat (low performance of NK, DC and T-cells Activity).
Faulty DNA Repair Mechanisms
Stress reduces the DNA repair mechanism; this mechanism can fix any mutation taken place in the Cell DNA located in the nucleus of the cell, therefore mutations can be accumulated without being fixed, letting DNA mutations create more tumor cells constantly.
Faulty Apoptosis (death cell mechanism)
It blocks Apoptosis function, the natural necessary function so any old cell terminates itself in order to be replaced by a new one, normal process of death cell. Tumor cells don’t terminate themselves because this function is deactivated due to high levels of stress.
Oncogenes are proteins with the information of cancer to be manifested. They must be inhibited so they don’t create tumor cells. Stress activates oncogenes to be expressed.
Tumor Suppressor Genes De-activation
Stress deactivates Tumor Suppressor Genes/Proteins; those proteins can suppress the creation of tumor cells and can block those oncogenes.
Increased Susceptibility to have viral infections
Stress can increase the susceptibility and some of them can generate more cancer, because there are viruses that are carcinogenic. They introduce within a healthy cell their own DNA code, and therefore they produce mutations after mutations creating eventually tumor cells. Those types of viruses can be: Epstein – Barr virus (EBV), Papilloma Virus (HPV), Hepatitis B and C, Cytomegalovirus (CMV), etc.
Increased Cortisol Levels
Psychological Stress can increase Cortisol (Stress Hormone) levels in blood that promotes angiogenesis (which is the process of creation of blood vessels) also around the tumor area, a process that makes glucose available to feed the tumor encouraging the tumor growth.
Hypoxia (low levels of oxygen)
Stress can interfere the distribution of oxygen in the body which can creates hypoxia or low levels of oxygen in certain parts of the body, It is proven that when a healthy cell is in hypoxia, has to adapt to that new environment creating mutations and therefore becoming a tumor cell eventually.