Use of routinely available clinical, nutritional, and functional criteria to classify cachexia in advanced cancer patients.

BACKGROUND: Cachexia is a highly prevalent syndrome in cancer and chronic diseases. However, due to the heterogeneous features of cancer cachexia, its identification and classification challenge clinical practitioners. OBJECTIVE: To determine the clinical relevance of a cancer cachexia classification system in advanced cancer patients. DESIGN: Beginning with the four-stage classification system proposed for cachexia [non-cachexia (NCa), pre-cachexia (PCa), cachexia (Ca) and refractory cachexia (RCa)], we assigned patients to these cachexia stages according to five classification criteria available in clinical practice: 1) biochemistry (high C-reactive protein or leukocytes, or hypoalbuminemia, or anemia), 2) food intake (normal/decreased), weight loss: 3) moderate (≤5%) or 4) significant (>5%/past six months) and 5) performance status (Eastern Cooperative Oncology Group Performance Status ≥ 3). We then determined if symptom severity, body composition changes, functional levels, hospitalizations and survival rates varied significantly across cachexia stages. RESULTS: Two-hundred and ninety-seven advanced cancer patients with primary gastrointestinal and lung tumors were included. Patients were classified into Ca (36%), PCa and RCa (21%, respectively) and NCa (15%). Significant (p < 0.05) differences were observed among cachexia stages for most of the outcome measures (symptoms, body composition, handgrip strength, emergency room visits and length of hospital stays) according to cachexia severity. Survival also differed between cachexia stages (except between PCa and Ca). CONCLUSION: Five clinical criteria can be used to stage cancer cachexia patients and predict important clinical, nutritional and functional outcomes. The lack of statistical difference between PCa and Ca in almost all clinical outcomes examined suggests either that the PCa group includes patients already affected by early cachexia or that more precise criteria are needed to differentiate PCa from Ca patients. More studies are required to validate these findings.

Use of prediction equations to determine the accuracy of whole-body fat and fat-free mass and appendicular skeletal muscle mass measurements from a single abdominal image using computed tomography in advanced cancer patients.

Measurements of body composition using dual-energy X-ray absorptiometry (DXA) and single abdominal images from computed tomography (CT) in advanced cancer patients (ACP) have important diagnostic and prognostic value. The question arises as to whether CT scans can serve as surrogates for DXA in terms of whole-body fat-free mass (FFM), whole-body fat mass (FM), and appendicular skeletal muscle (ASM) mass. Predictive equations to estimate body composition for ACP from CT images have been proposed (Mourtzakis et al. 2008; Appl. Physiol. Nutr. Metabol. 33(5): 997-1006); however, these equations have yet to be validated in an independent cohort of ACP. Thus, this study evaluated the accuracy of these equations in estimating FFM, FM, and ASM mass using CT images at the level of the third lumbar vertebrae and compared these values with DXA measurements. FFM, FM, and ASM mass were estimated from the prediction equations proposed by Mourtzakis and colleagues (2008) using single abdominal CT images from 43 ACP and were compared with whole-body DXA scans using Spearman correlations and Bland-Altman analyses. Despite a moderate to high correlation between the actual (DXA) and predicted (CT) values for FM (rho = 0.93; p ≤ 0.001), FFM (rho = 0.78; p ≤ 0.001), and ASM mass (rho = 0.70; p ≤ 0.001), Bland-Altman analyses revealed large range-of-agreement differences between the 2 methods (29.39 kg for FFM, 15.47 kg for FM, and 3.99 kg for ASM mass). Based on the magnitude of these differences, we concluded that prediction equations using single abdominal CT images have poor accuracy, cannot be considered as surrogates for DXA, and may have limited clinical utility.

Determining the precision of dual energy x-ray absorptiometry and bioelectric impedance spectroscopy in the assessment of breast cancer-related lymphedema.

BACKGROUND: The composition of breast cancer-related lymphedema (BCRL) has been shown to evolve from the initial accumulation of fluid to the development of fibrotic lesions and abnormal fat deposition. Therefore, precise and reliable assessments of BCRL are required to develop accurate staging and management. Although dual energy x-ray absorptiometry (DXA) and bioelectric impedance spectroscopy (BIS) have been used to assess BCRL, no study has evaluated the precision of these two modalities in the same cohort. METHODS AND RESULTS: We determined the precision of DXA and BIS in lymphedematous (LE) and nonaffected (NA) arms of 24 women with Stage II unilateral BCRL. Precision was calculated from the results of paired bilateral arm measurements obtained from DXA scans measuring fat, lean, and bone mineral masses, BIS measuring extracellular fluid (ECF) and total fluid volume, and circumferential tape measurements (CM) of the arms to calculate the anatomic volume. Precision error was expressed as the root mean square (RMS) of the coefficients of variation (%CV) and standard deviations (SD). RESULTS: The precisions of DXA and BIS varied from 1.16% (DXA measurements of LE arm total volume) to 1.86% (BIS LE arm total fluid volume) and from 0.95% (DXA lean mass of NA arm) to 1.72% (DXA BMC of NA arm). Precision of CM measures of arm volume were 1.71% CV for LE arm and 2.51% CV for NA arm. The fat and lean masses of the LE arm exceeded the NA arm by about 15% (p<0.0001). ECF and total fluid volume of LE arm was 22.6% and 19% greater than the NA arm (p<0.0001), respectively. CONCLUSION: For BCRL, these findings suggest that DXA and BIS are two measurement instruments that provide acceptable levels of precision for the measurement of arm lean mass, fat mass and ECF volume, respectively.

Estimation of total-body and regional soft tissue composition from DXA bone densitometry of the lumbar spine and hip.

The percent fat in soft tissues adjacent to the lumbar spine and proximal femur, which are required parameters in the calculation of bone mineral by conventional dual-energy X-ray absorptiometry (DXA) of the spine and hip, were analyzed for their relationship with the total-body soft tissue-scanning derivatives. The cohort (N=149), consisting of stable actively treated male human immunodeficiency virus HIV-positive patients, was split in half to obtain prediction equations with one half to be validated by the other half. Prediction equations for the dependent variables total-body fat, total-body lean mass, trunk fat, total arm + leg fat, and leg fat were derived by step-down multiple regression. A Bland-Altman comparison of the predicted and observed values showed that the limits of agreement were too large to be clinically helpful. The correlations of the ratio of adjacent spine/hip fat with ratios of trunk/arm + leg fat and trunk/leg fat, markers of peripheral lipoatrophy in HIV, were 0.725 and 0.780, respectively. The 3 ratios were compared with the clinical diagnosis of the presence or absence of peripheral lipoatrophy by receiver operating characteristic analysis. The area under the curve was 0.720 for adjacent spine/hip fat ratio and 0.655 and 0.699 for trunk/arm + leg fat and trunk/leg fat, respectively; they were not significantly different. In conclusion, for male HIV-positive patients, the difference between predicted values and actual values rendered limits of agreement that were too wide to be clinically acceptable. The ratio of percent fat in the lumbar spine region to percent fat in the proximal femur region reflected the presence of peripheral lipoatrophy as effectively as the trunk/peripheral fat ratio that was derived from the total-body scan.

[A fractured kidney, an unexpected sequela of a remote lumbar trauma]. / Un rein fracturé, séquelle inattendue d'un ancien traumatisme lombaire.

A 40-year old man is evaluated for arterial hypertension of one's year duration, which responded well to salt restriction and mild antihypertensive medication. The standard investigation for possible secondary hypertension is negative. In view of a remote history of left renal trauma, it is decided to do an angiogram, which reveals the presence of a fractured left kidney. This unusual image is considered to be secondary to the combination of an arterial supply provided by two polar arteries and of scarring in the mid-portion of the renal parenchyma secondary to the remote trauma.

Precision and reliability of strength (Jamar vs. Biodex handgrip) and body composition (dual-energy X-ray absorptiometry vs. bioimpedance analysis) measurements in advanced cancer patients.

Important deteriorations in body composition and strength occur and need to be accurately measured in advanced cancer patients (ACPs). The aim of this study was to establish the relationship between a single-frequency bioimpedance analyzer (BIA) and the dual-energy X-ray absorptiometer (DXA), as well as the Jamar handgrip dynometer and the Biodex handgrip attachment, and to determine the precision of each of these instruments in ACPs. Eighty-one ACPs with non-small-cell lung cancer and gastrointestinal cancer were recruited from the McGill University Health Centre (Montreal, Que.). Consecutive paired measurements, with repositioning between measurements, were obtained for total-body DXA, BIA, Biodex handgrip, and BIA plus Jamar handgrip. The total-body percent coefficient of variation (%CV) for the BIA and DXA were 1.34 and 1.56 for fat mass (FM), respectively, and 0.42 and 0.72 for fat free mass (FFM), respectively. The %CV for the Jamar and Biodex handgrips were 6.3 and 16.7, respectively. Bland-Altman plots were used to characterize the limits of agreement between DXA and BIA for FM (4.60 +/- 7.80 (-3.19 to 12.39) kg) and FFM (-1.87 +/- 7.16 (-9.03 to 5.29) kg). Both DXA and BIA demonstrate good short-term precision in ACPs. However, given its poor accuracy, it remains to be determined if BIA can be used to monitor ACPs for changes in total-body tissue composition as a function of time, whether for observation or response to treatment. Furthermore, because of wide limits of agreement, the DXA and BIA cannot be used interchangeably in research or clinical settings. The Jamar handgrip dynamometer shows more consistency than the Biodex handgrip attachment in ACPs, and should therefore be the preferred measure of changes in strength over time.

Bone mineral and soft-tissue changes in AIDS-associated lipoatrophy.

It is well established that body weight influences bone mass, but there is considerable controversy in the literature as to whether the principal determinant is lean mass, fat mass, or combinations of both, with variable degrees of relative influence as a function of age and sex. Total body and regional tissue composition studies were performed with DXA in a cohort of 102 HIV+ males who were on highly active antiretroviral therapy. These medications may be associated with a unique peripheral lipoatrophy without commensurate loss of lean tissue mass, and thereby provide an opportunity to assess the relative influence of fat mass on BMC levels in the absence of lean mass change. A comparison of the first quartile of peripheral fat (the lowest fat mass) with the remainder of the cohort showed no significant difference in lean mass in the total body, trunk, lower limbs, and upper limbs. In contrast, a significantly lower BMC was registered in the first peripheral fat quartile for all regions, implying an association of fat mass with BMC. By quartile stratification of the regional BMC, a comparison of the first and fourth quartiles demonstrated that the percentage fat mass decrease exceeded the lean mass decrease by a factor of 1.8 to 4.5. Regional BMCs were also stratified into two groups, < or =50 percentile and >50 percentile, and analyzed by Spearman correlation and robust multiple regression. It was found that lean mass was a determinant of BMC in both groups, whereas fat mass was an independent predictor in the >50 percentile BMC group only. The BMD t-score for the total hip was significantly lower in the first quartile of lower limb fat mass than the t-score of the remaining cohort, but this difference was not significant for the BMD lumbar spine t-score. This is a reflection of the influence of preferential local peripheral lipoatrophy on the adjacent mineral content and provides further evidence of fat mass as a determinant of BMC in addition to lean mass.

Range of change of measured BMD in the femoral neck and total hip with rotation in women.

To obtain a quantitative assessment of the range of variation of bone mineral density (BMD) measurements in the femoral neck and total hip with rotation of the hip, 200 women, ages 21-86 years, were scanned by DXA in the neutral position and with 25% internal rotation of the leg. The difference in BMDs (neutral minus internal rotation) was > or =0 in about 65% of the patients, whereas the remaining 35% were <0. In terms of absolute change, the femoral neck median BMD of 0.025 g/cm2 was significantly greater than the total hip, 0.016 g/cm2. Percent absolute femoral neck change was 3.13% compared to 1.79% for the total hip. Absolute change of the total hip correlated positively with age, while the femoral neck showed a positive trend that was not statistically significant at the P = 0.05 level. Despite the total hip's lower precision error and smaller BMD change with rotation, the number of patients exceeding the 95% confidence limit for each site was virtually the same, 11% for the femoral neck and 13% for the total hip. This finding underlines the need to achieve confirmed repositioning accuracy in longitudinal studies, whether at zero femoral neck axis anteversion or otherwise, to appreciate the relative advantages of total hip measurement. The question that remains is what method can be employed to obtain this confirmation simply and economically in a busy clinical service facility with the usual turnover in personnel.