Body Composition Changes Induced by Perioperative Chemotherapy in Patients With Breast Cancer

Fluid retention is a well-recognized adverse effect of docetaxel; however, its impact on body composition has rarely been characterized longitudinally. Herein, we describe serial changes in body composition, including body water compartments, throughout the different phases of perioperative chemotherapy for breast cancer.

Patients receiving neoadjuvant or adjuvant chemotherapy containing docetaxel, either doxorubicin plus cyclophosphamide (AC) followed by sequential docetaxel or docetaxel plus cyclophosphamide (TC), underwent bioelectrical impedance analysis before every cycle. The AC, sequential docetaxel, and TC phases were analyzed by comparison with their respective baselines using paired t-tests. Hydration indices, including extracellular water (ECW)/total body water (TBW), TBW/fat-free mass, and extracellular mass/body cell mass, were used to differentiate fluid-related changes from tissue-related changes, with measurements obtained before the docetaxel phase considered the pre-chemotherapy baseline.

Sixty-one patients were enrolled, and 367 measurements were analyzed. During AC, TBW, intracellular water (ICW), and lean-mass indices decreased, whereas fat mass increased and body weight remained unchanged. During sequential docetaxel, increases in water compartments and lean indices were accompanied by increases in hydration indices (all p < 0.001 before cycle 4), indicating extracellular fluid expansion. Relative to the pre-chemotherapy baseline, rather than the post-AC nadir, lean indices and ICW returned to approximately pretreatment values but did not exceed them, whereas ECW rose above it (+0.34 L, p = 0.013). No parameter changed significantly during TC.

Perioperative chemotherapy resulted in regimen-specific changes in body composition. During AC, body water and lean mass decreased, and fat mass increased, despite a stable body weight. The apparent increase in lean mass during sequential docetaxel treatment was better explained by recovery from the post-AC nadir accompanied by extracellular fluid accumulation than by true muscle gain. Therefore, body weight alone may be insufficient for monitoring these changes.