The link between cytokines and cancer appears to be that cancer increases cytokine levels, and both are connected to depression symptoms. Patients who receive cancer treatments to get rid of tumors tend to experience higher incidences of depression. This is due to the cytokines contained in the medications. In addition, levels of cytokines are known to naturally increase in the body due to prolonged physical or emotional stress.
A type of protein, cytokines essentially regulate hormones that communicate with the body's immune system. The link between cytokines and cancer seems to be related to the increase in the amount of cytokines actively circulating within a patient's bloodstream. They are considered to be pro-inflammatory and tend to irritate the body.
Cytokines and cancer are related as cancer puts a great amount of strain on the immune system. A surge in cytokines may be the body's inflammatory response to the infection. Higher levels of these proteins result in many emotional and physical symptoms that resemble depression. These symptoms include suicidal thoughts, lethargy, loss of interest in hobbies and activities, and decreased sex drive.
It is somewhat difficult to pinpoint whether the depression comes as a result of an increased level of cytokines or if the depression originates as a side effect of having cancer. Increased levels of cytokines are seen in individuals who experience long-term physical or emotional stress, including disease. What is certain is that the link between cytokines and cancer results in the progression of the symptoms commonly associated with depression.
Patients with some forms of cancer receive therapy medications and treatment protocols that contain cytokine proteins. They are usually referred to as TH2 cytokines and are sometimes used to treat conditions such as leukemia and melanoma. TH2 cytokine treatments are aimed at destroying tumors and cancerous cells that could later develop into tumors. When these types of treatments are administered, patients are at a greater risk for developing depression in addition to what is sometimes referred to as "sickness syndrome."
Symptoms of "sickness syndrome" include fever, chills, nausea, vomiting and hypotension. Depression symptoms may or may not accompany these, but there is a 50 percent likelihood that they will. When TH2 cytokine treatments are stopped, the depression and "sickness syndrome" symptoms usually subside.
Some think that the medications elevate the body's cytokine levels even more by releasing the proteins from tumors or cancerous cells. Regardless of how they become elevated, the primary link between cytokines and cancer is that the disease or its treatments lead to abnormal levels. It is these higher levels that contribute to uncomfortable side-effects.