RESUMEN
PURPOSE: Multimodal therapies affect the quality of life (QoL) of patients with primary breast cancer (PBC). The objectives of this prospective study were to explore the changes in QoL from diagnosis to conclusion of adjuvant therapy and to identify predictive factors of QoL. METHODS: Before surgery (t1), before onset of adjuvant treatment (t2) and after completion of adjuvant chemo- or radiotherapy (t3), patients with PBC (n = 759) completed the European Organization for Research and Treatment of Cancer Quality of Life Core Questionnaire, Charlson Comorbidity Index, Patient Health Questionnaire and Perceived Involvement in Care Scales. Predictors of the course of global QoL were estimated using multinomial logistic regression. Effect estimates are odds ratios (OR) and their 95% confidence intervals (CIs). RESULTS: Global QoL improved between t1 and t3, while physical functioning, emotional functioning and fatigue deteriorated. QoL before surgery was more often poor in patients <60 years (OR 2.2, 95% CI 1.5-3.1) and in those with comorbid mental illnesses (OR 8.6, CI 5.4-13.7). Forty-seven percentage reported good global QoL both at t1 and at t3. QoL improved in 28%, worsened in 10% and remained poor in 15%. Compared to patients with consistently good global QoL, a course of improving QoL was more often seen in patients who had received a mastectomy and in those with intense fear of treatment before surgery. A course of decreasing QoL was more often found in patients who were treated with chemotherapy. QoL stayed poor in patients with chemotherapy, mastectomy and intense fear. There was no evidence that radiotherapy, progressive disease or perceived involvement impact the course of QoL. CONCLUSIONS: Younger age and comorbid mental illnesses are associated with poor QoL pre-therapeutically. QoL is more likely to stay or become poor in patients who receive chemotherapy.