Patients with advanced cancer frequently experience multiple distressing symptoms. To systematically assess these symptoms, Bruera et al. developed the Edmonton Symptom Assessment Scale (ESAS), which is widely used for patient care and research. However, the magnitude of change in symptom intensity that is considered clinically meaningful (the minimal clinically important difference [MCID]) and the predictors of treatment response have yet to be defined. The overall objectives of this proposed study are to determine the MCID for each ESAS symptom and identify novel predictors of treatment response in cancer patients. Successful completion of this study would allow us to better define ESAS treatment response and pave the way for adequately powered symptom control trials. Furthermore, our study would identify subgroups of patients with symptoms least likely to respond to palliative care interventions, allowing us to further personalized treatments.