Circadian Rhythm as a Mediator between Sleep Disturbances and Pain Intensity and Its Prognostic Role in Predicting Survival in Advanced Cancer Patients

Pain and sleep disturbance are among the most commonly happened symptoms in advanced cancer patients. Pain and sleep disturbance are intertwined in cancer patients. However, very limited research effort has been directed toward exploring mechanism underlying the relationship between pain and sleep in cancer. The possible biological mechanisms underlying the co-existence of the two symptoms are areas needed rigorously empirical investigations. The PI’s preliminary results indicate that cancer patients suffering from cancer-related pain reported higher levels of sleep disturbances than patients without suffering from pain in a sample of patients receiving chemotherapy. Furthermore, in a sample of advanced cancer patients, the levels of cancer pain were significantly correlated with circadian rhythms parameters, i.e., r24 and I