Human body composition is important in numerous cancer research domains. Our objective was to evaluate clinically accessible methods to achieve practical and precise measures of body composition in cancer patients. Dual-energy X-ray absorptiometry (DXA)-based analysis of fat and fat-free mass was performed in 50 cancer patients and compared with bioelectrical impedance analysis (BIA) and with regional computed tomography (CT) images available in the patients' medical records. BIA overestimated or underestimated fat-free mass substantially compared with DXA as the method of reference (up to 9.3 kg difference). Significant changes in fat-free mass over time detected with DXA in a subset of 21 patients (+2.2 +/- 3.2%/100 days, p = 0.003), was beyond the limits of detection of BIA. Regional analysis of fat and fat-free tissue at the 3rd lumbar vertebra with either DXA or CT strongly predicted whole-body fat and fat-free mass (r = 0.86-0.94; p < 0.001). CT images provided detail on specific muscles, adipose tissues and organs, not provided by DXA or BIA. CT presents great practical significance due to the prevalence of these images in patient diagnosis and follow-up, thus marrying clinical accessibility with high precision to quantify specific tissues and to predict whole-body composition.

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Purpose: Evidence suggests that lean body mass (LBM) may be useful to normalize doses of chemotherapy. Data from a prospective study were used to determine if the highest doses of 5-fluorouracil (5-FU) per kilogram LBM would be associated with dose-limiting toxicity in stage II/III colon cancer patients treated with 5-FU and leucovorin. Experimental Design: Toxicity after cycle 1was graded according to National Cancer Institute CommonToxicity Criteria, version 2.0. Muscle tissue was measured by computerized tomography. An extrapolation to the LBM compartment of the whole body was employed. Results: Mean values of 5-FU/LBM of the entire population were different in terms of presence or absence of toxicity (P = 0.036). A cut point of 20 mg 5-FU/kg LBM seemed to be a threshold for developing toxicity (P = 0.005). This observation was pertinent to women (odds ratio, 16.73; P = 0.021). Women in this study had a relatively low proportion of LBM relative to their body surface area. Conclusion: Our study shows that low LBM is a significant predictor of toxicity in female patients administered 5-FU using the convention of dosing per unit of body surface area. We conclude that variation in toxicity between females and males may be partially explained by this feature of body composition. 5-Fluorouracil (5-FU) is a potent anti-metabolite used to treata variety of solid tumors, and it is a well-established form of chemotherapy for colorectal cancer (1). The Mayo regimen of bolus 5-FU and leucovorin is associated with significant myelosuppression, mucositis, and diarrhea. In one study, 35% of patients had significant toxicity with patients experiencing dose reductions, therapy discontinuations, hospitalization, and even death (2). Attempts have been made to identify clinical variables to predict patients at risk for severe toxicity (3), but an approach for individualizing 5-FU dosing remains unclear.Interpatient variation in toxicities can arise from differences in target protein(s) expression, drug metabolism, and excretion. Disparate metabolism and excretion of anticancer drugs in turn can be due to environmental, physiologic, and genetic factors.Our hypothesis is that a physiologic factor, heterogeneous body composition of cancer patients, and, specifically, relative amounts of lean and adipose tissue compartments contribute to interpatient variation in toxicities. We propose that the size of lean and fat compartments relate to the pharmacokinetic properties of a drug, as hydrophilic drugs distribute into the lean compartment, whereas lipophilic drugs distribute into the fat compartment.Currently, for most chemotherapy, dose is determined using body surface area (BSA). The practice originated from observations that basal metabolic rates scaled between species according to weight. Early investigators used BSA to estimate an appropriate starting dose for an anticancer drug for phase I studies based on preclinical animal studies (4). BSA dosing became established in clinical settings in part by dogma and not due to s...

The term sarcopenia was introduced in 1988. The original definition was a “muscle loss” of the appendicular muscle mass in the older people as measured by dual energy x‐ray absorptiometry (DXA). In 2010, the definition was altered to be low muscle mass together with low muscle function and this was agreed upon as reported in a number of consensus papers. The Society of Sarcopenia, Cachexia and Wasting Disorders supports the recommendations of more recent consensus conferences, i.e. that rapid screening, such as with the SARC‐F questionnaire, should be utilized with a formal diagnosis being made by measuring grip strength or chair stand together with DXA estimation of appendicular muscle mass (indexed for height2). Assessments of the utility of ultrasound and creatine dilution techniques are ongoing. Use of ultrasound may not be easily reproducible. Primary sarcopenia is aging associated (mediated) loss of muscle mass. Secondary sarcopenia (or disease‐related sarcopenia) has predominantly focused on loss of muscle mass without the emphasis on muscle function. Diseases that can cause muscle wasting (i.e. secondary sarcopenia) include malignant cancer, COPD, heart failure, and renal failure and others. Management of sarcopenia should consist of resistance exercise in combination with a protein intake of 1 to 1.5 g/kg/day. There is insufficient evidence that vitamin D and anabolic steroids are beneficial. These recommendations apply to both primary (age‐related) sarcopenia and secondary (disease related) sarcopenia. Secondary sarcopenia also needs appropriate treatment of the underlying disease. It is important that primary care health professionals become aware of and make the diagnosis of age‐related and disease‐related sarcopenia. It is important to address the risk factors for sarcopenia, particularly low physical activity and sedentary behavior in the general population, using a life‐long approach. There is a need for more clinical research into the appropriate measurement for muscle mass and the management of sarcopenia. Accordingly, this position statement provides recommendations on the management of sarcopenia and how to progress the knowledge and recognition of sarcopenia.

Sarcopenia is underrecognized in nonmetastatic breast cancer and occurs in over one-third of newly diagnosed patients. Measures of both sarcopenia and adiposity from clinically acquired CT scans in nonmetastatic patients provide significant prognostic information that outperform BMI and will help to guide interventions to optimize survival outcomes.