Background: Few measurements of fatigue and quality of life have been performed during neoadjuvant chemotherapy of early breast cancer. This study evaluates fatigue and quality of life experienced by early breast cancer patients during neoadjuvant chemotherapy and their association with different clinical parameters.

Methods: Fifty-four stage I-III patients' responses to the Multidimensional Fatigue Inventory (MFI) and to the Functional Assessment of Cancer Therapy-Breast (FACT-B) were analyzed by a linear covariance pattern model. Chemotherapy regimen, age, baseline fatigue level, body-mass-index and cancer stage were added to the model to estimate their impact on both outcomes.

Results: All fatigue dimensions worsened in clinically relevant levels. Physical fatigue worsened the most, mental fatigue the least. For quality of life, physical and functional well-being worsened the most. Only emotional well-being improved during chemotherapy. Physical well-being worsened more during standard than during dose-dense chemotherapy, and more during anthracycline than during taxane cycles. Age, body-mass-index and cancer stage had no impact. The higher the fatigue levels at baseline, the less they worsened during chemotherapy.

Conclusions: Further actions to reduce fatigue and improve quality of life during neoadjuvant chemotherapy of early breast cancer are needed. Focus should be laid on the physical dimension. Future research should also investigate the impact of different chemotherapy sequences and densities on fatigue and quality of life.

Study registration: The study was registered in the German Clinical Trials Register in May 2019 (DRKS00016761).