REDUCED RATES OF METABOLISM AND DECREASED PHYSICAL-ACTIVITY IN BREAST-CANCER PATIENTS RECEIVING ADJUVANT CHEMOTHERAPY

Weight gain, a common side effect among breast cancer patients receivi ng adjuvant chemotherapy, may decrease quality of life and impair surv ival. Weight gain during treatment is a well-known problem and has bee n studied by many investigators. However, few controlled studies have been conducted to determine reasons to explain this apparent energy im balance. An exploratory study was undertaken to quantitate potential c hanges in energy intake and specific components of energy expenditure in breast cancer patients receiving adjuvant chemotherapy. The researc h hypothesis was that a reduction in resting metabolic rate (RMR) woul d be observed during the period in which women received adjuvant chemo therapy. Twenty premenopausal patients with stage I or II breast cance r and receiving cyclophosphamide + doxorubicin + 5-fluorouracil; cyclo phosphamide + methotrexate + 5-fluorouracil +/- doxorubicin; doxorubic in + cyclophosphamide +/- leucovorin; or methotrexate + 5-fluorouracil + leucovorin chemotherapy were recruited. RMR, diet-induced thermogen esis, energy intake, physical activity, and body composition were asse ssed before the initiation and throughout the course of therapy, Compl ete data on 18 subjects suggest that RMR decreased significantly from baseline to midtreatment (P = 0.02) and rebounded to levels similar to those at baseline on completion of chemotherapy. Overall, levels of p hysical activity and energy intake also decreased significantly during treatment compared with baseline levels (P = 0.04 and P = 0.03, respe ctively). These findings suggest that chemotherapy provokes many signi ficant changes in body composition and metabolic requirements. Additio nal research in this area will provide valuable insight into creating optimal interventions to curb weight gain in women with breast cancer.