AbstractBackgroundWe aimed to identify changes in quality of life after breast cancer treatment and compare them with the normative population data for the Slovenian population.Patients and methodsA prospective, single-group, cohort design was used. A total of 102 early breast cancer patients treated with chemotherapy at the Institute of Oncology Ljubljana were included. Of those, 71% returned the questionnaires after one-year post-chemotherapy. The Slovenian versions of the European Organisation for Research and Treatment of Cancer (EORTC) QLQ C30 and BR23 questionnaires were used. Primary outcomes were a comparison of global health status/quality of life (GHS) and C30 Summary Score (C30-SumSc) at baseline and one-year post-chemotherapy with the normative Slovenian population. The exploratory analysis evaluated the differences in symptoms and functional scales of QLQ C-30 and QLQ BR-23 between baseline and one-year post-chemotherapy.ResultsAt baseline and one-year post-chemotherapy, C30-SumSc of patients was lower than the predicted C30-SumSc from the normative Slovenian population by 2.6 points (p = 0.04) and 6.5 points (p < 0.001), resp. On the contrary, GHS was not statistically different from predicted either at baseline or after one year. Exploratory analysis revealed that one-year post-chemotherapy compared to the beginning of chemotherapy, patients had statistically significantly and clinically meaningful lower scores in body image and cognitive functioning, and increased symptom scores for pain, fatigue, and arm symptoms.ConclusionsThe C30-SumSc is reduced one-year post-chemotherapy. Early interventions should be directed toward the prevention of the decline of cognitive functioning and body image, and to alleviate fatigue, pain, and arm symptoms.