ABSTRACT
Since quality of life [QoL] is subjective, self-reported QoL is the main source of assessment; however, in some situations the patient cannot evaluate his/her own status. In this cross-sectional study, 148 patients with breast cancer referred to the Cancer Institute of the Islamic Republic of Iran and their caregivers were selected through the consecutive sampling method. Five oncologists from this centre also evaluated the QoL of these patients. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire was completed by these 3 groups and the results compared. The patient-caregiver intra-class correlation coefficient [ICC] for all 15 QLQ.C30 domains was moderate to good [ICC = 0.41-0.76]. Agreements between QoL scores of patients and those of oncologists were moderate to good, except in the 4 domains. In the patient-caregiver comparison there was 55% exact agreement, and for the patient-physician comparison agreement was 45%. The findings can be used in the patients' decision-making process and care planning when patients with breast cancer are unable to self-report the QoL