[The biological background of the comorbidity of depression and cancer]

Depression is a common comorbid condition in patients with cancer, but the background mechanisms underlying the relationship between depression and cancer are not well clarified. Depression and cancer are prevalent public health problems in the Western world. In this article, I review the recent knowledge regarding possible etiological mechanisms in particular biological contexts. Inflammation and chronic stress play a role in the development of both types of disease, which can explain high comorbidity. Depression in cancer patients increases the time of hospitalization and mortality, lowers quality of life, decreases compliance, and results in worse prognosis.