Circadian rhythm disruption and quality of life in cancer patients

There is a growing body of research indicating that cancer patients have an increased risk of developing sleep disturbances caused by circadian rhythm disruption. Precipitating factors include psychological distress, treatment side effects and the cancer processes themselves, among others. Such sleep disturbances have serious deleterious effects on cancer patients' physical and emotional well-being. Sleep disturbances negatively affect immune functioning making it harder for cancer patients to protect themselves from infection and to fight off the cancer itself. In addition, sleep disturbances in cancer patients have been linked with poorer quality of life. This dissertation reviews the sleep process, sleep disturbances in the general population and sleep disturbances in cancer patients. It then explores the relationship between circadian rhythm disruption and quality of life in cancer patients through a study conducted with 24 cancer patients undergoing chemotherapy. Sleep disturbances were measured subjectively using the Pittsburgh Quality Sleep Index (PSQI) and objectively using the Sensewear Armband. Quality of life was measured using the Functional Assessment of Cancer Therapy - General (FACT-G). Correlational analysis results indicate that there is a significant correlation between the severity of cancer patients sleep disturbances and their global quality of life. More specifically, the physical and functional aspects of quality of life were more strongly correlated with the severity of sleep disturbances than the emotional and social aspects of quality of life. The current study results are discussed, as well as directions for further research.