Sarcopenia as a determinant of chemotherapy toxicity and time to tumor progression in metastatic breast cancer patients receiving capecitabine treatment.
OBJECTIVE
Body composition has emerged as an important prognostic factor in cancer patients. Severe depletion of skeletal muscle (sarcopenia) and, hence, of overall lean body mass may represent an occult condition in individuals with normal or even high body weight. Sarcopenia has been associated with poor performance status, 5-fluorouracil toxicity, and shortened survival in cancer patients. Here, we prospectively studied patients with metastatic breast cancer receiving capecitabine treatment in order to determine if sarcopenia was associated with a higher incidence of toxicity and a shorter time to tumor progression (TTP).


METHODS
Fifty-five women with metastatic breast cancer resistant to anthracycline and/or taxane treatment were included. Skeletal muscle cross-sectional area at the third lumbar vertebra was measured by computerized tomography, and sarcopenia was defined using a previously published cutoff point. Toxicity was assessed after cycle 1 of treatment, and TTP was determined prospectively.


RESULTS
Approximately 25% of patients were classified as sarcopenic, and this feature was seen in normal weight, overweight, and obese individuals. Toxicity was present in 50% of sarcopenic patients, compared with only 20% of nonsarcopenic patients (P = 0.03), and TTP was shorter in sarcopenic patients (101.4 days; confidence interval, 59.8-142.9) versus nonsarcopenic patients (173.3 days; confidence interval, 126.1-220.5; P = 0.05).


CONCLUSIONS
Sarcopenia is a significant predictor of toxicity and TTP in metastatic breast cancer patients treated with capecitabine. Our results raise the potential use of body composition assessment to predict toxicity and individualize chemotherapy dosing.
Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
Carla M M
CM
Prado
Vickie E
VE
Baracos
Linda J
LJ
McCargar
Tony
T
Reiman
Marina
M
Mourtzakis
Katia
K
Tonkin
John R
JR
Mackey
Sheryl
S
Koski
Edith
E
Pituskin
Michael B
MB
Sawyer
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000009:adverse effects* / Q000627:therapeutic use; D001823:Body Composition / Q000187:drug effects / Q000502:physiology; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D000069287:Capecitabine; D003841:Deoxycytidine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D005472:Fluorouracil / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006801:Humans; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000187:drug effects*; D009135:Muscular Diseases / Q000139:chemically induced*; D009362:Neoplasm Metastasis; D011446:Prospective Studies
D000964:Antimetabolites, Antineoplastic; D003841:Deoxycytidine; D000069287:Capecitabine; D005472:Fluorouracil