Psychosocial Factors and Cancer

Psychological and social aspects of life, which have been collectively called psychosocial factors, have long been known to play an influential role in shaping physical health and disease. Included in this relatively broad “umbrella” term are processes that involve a person’s mental state, psychological tendencies, and surrounding social environment. Some examples of psychosocial factors include acute stress, chronic stress, coping, perceived control, neuroticism, hostility, anxiety, rumination, hopelessness, negative affect, depression, social class, social conflict, social isolation, self-efficacy, and selfesteem. This article provides an overview of research on psychosocial factors and cancer. More specifically, it summarizes different types of cancer, known associations between psychosocial factors and cancer, biological pathways that link psychosocial factors and cancer, and psychosocial interventions that have been shown to alter these biological processes and improve clinical outcomes. Cancer is not a singular disease. Rather, cancer is a term that describes a group of diseases that, while similar in gross phenotype, are quite heterogeneous in etiology and pathophysiology. Cancers are broadly categorized according to the type of tissue in the body where they originate. Cancers that originate in epithelial cells – that is, cells that line the outer surface of an organ, such as skin cells – are called carcinomas and are the most prevalent; sarcomas are cancers that originate in the connective or supportive tissues of the body (e.g., bone, muscle); lymphomas are cancers that stem from abnormal immune cells in the body’s lymphatic vessels; finally, leukemias are cancers that stem from malignant immune cells in blood (i.e., white blood cells) or other blood-forming cells that occupy the bone marrow. All told, the National Cancer Institute currently recognizes the existence of more than 100 distinct cancers that can occur in the human body. An association between psychosocial factors and cancer has been pondered at least since the 2nd century. At that time the Greek physician, Claudius Galen, believed that women with a depressed or “melancholic” disposition were more prone to getting cancer. When examined prospectively over time, the majority of modern research suggests that no reliable link exists between psychosocial factors and cancer incidence – that is, the onset of cancer. However, a growing body of research shows that stressrelated psychosocial factors play a role in cancer progression – that is, the rate at which an existing cancer in the body worsens or causes mortality. In this latter regard, studies of breast cancer are by far the most common. This research has shown that several psychosocial factors including psychological distress, anxiety, hostility, lack of emotional expression, low overall quality of life, and