Difference in Estimation of Side Effects of Chemotherapy between Physicians and Patients with Early-Stage Breast Cancer: The Use of Patient Reported Outcomes (PROs) in the Evaluation of Toxicity in Everyday Clinical Practice.

Knowledge about the patient's experience and perception of side effects and their impact on daily life is crucial for the adequate planning of interventions to provide the highest attainable levels of quality of life during oncology treatment. We conducted a study on consecutive samples of 69 early breast cancer patients treated with four cycles of neoadjuvant or adjuvant anthracycline-based chemotherapy. Patients completed the questionnaire about side effects experienced after the previous cycle of chemotherapy. The questionnaire was a modified PRO for the evaluation of treatment toxicity consisting of 18 questions related to the very common and common side effects of doxorubicin and cyclophosphamide, valued from 0 to 3 according to the subjective assessment of the patient. During the same cycles of therapy, data were also collected by the physician who completed a questionnaire consisting of the same questions as the questionnaire for patients, on the same scale. Most of the side effects reported by patients were mild to moderate in intensity, while physicians reported side effects much less frequently. The results also indicated a disproportionate reporting, in which physicians reported statistically significantly fewer side effects than patients. This study reported a level of disagreement between patients and physicians in the experience of therapy toxicity. In conclusion, use of PRO in clinical practice can help us avoid physician subjectiveness in the estimation of side effects and determine the group of patients who can benefit from additional and individualized supportive care measures, which could lead to better adherence to therapy and ultimately best outcomes.