P-234 Incidence of Sarcopenia and its relationship with Body Mass Index in colorectal cancer patients

Abstract

Introduction: Depletion of skeletal muscle (sarcopenia) and, hence, of overall Lean Body Mass (LBM) has been associated with poor performance status, chemotherapy toxicity, and shortened survival in cancer patients, whereas it may be present in patients with normal body weight as well as in overweight and obese. Current evidence suggests that LBM may be a better measure for normalizing doses of drugs that are distributed and metabolized in lean tissues, compared with Body Surface Area (BSA) or Body Mass Index (BMI) alone. As it has been reported that patients with colorectal cancer may have low LBM relative to their BSA, the aim of this study was to determine the incidence of sarcopenia and its relationship with BMI in colorectal cancer patients planned to undergo surgery and / or chemotherapy. Methods: Nineteen consecutive patients with colorectal malignant neoplasms having digitally stored recent abdominal CT images for initial routine diagnostics and staging were prospectively studied. Their BMI was calculated (weight kg / height m2), and their CT images were analyzed using SliceOmatic software V4.3 (Tomovision). A transverse CT image from the 3rd lumbar vertebrae was assessed for each scan and skeletal muscle tissue area was estimated. Cross-sectional area was normalized for stature (cm2/m2). Sarcopenia was defined using the cut-off point for lumbar Skeletal Muscle Index (SMI) of 52.4 cm2 of muscle mass / height m2 for men, and of 38.5 cm2 of muscle mass / height m2for women. Descriptive values are expressed as mean +- SD. The Correlation Coefficient (R) was used to evaluate if BMI was correlated with SMI. Results: Out of the 19 patients, 11 were men and 8 women, of mean age 71.2 +- 12.4 years. The mean value of BMI was 22.9 +- 3.5, and of SMI was 35.2 +- 8.4. Incidence of sarcopenia (low SMI) was 89.4% (17 patients), having a positive correlation with BMI (R = 0.734, p < 0.05). Subdividing patients in two groups according to their BMI (group-A those with BMI within normal limits, and group-B those overweight), 13 out of the 14 patients of group-A had SMI below normal values (R = 0.645, p < 0.05); however, there was not found any significant correlation between BMI and SMI of the overweight patients (3 out of the 5 overweight patients of group-B had SMI below normal values; R = - 0.072, p = 0.9). Conclusion: The results of this study suggest that the incidence of any degree of sarcopenia in colorectal cancer patients is high, representing an occult condition that can be present with any body weight and BMI. Although further research is needed to investigate the clinical significance of these findings, according to the current evidence sarcopenia should, however, be considered when planned chemotherapy in order to minimize toxicity risk and to individualize drug dosing.References:Prado CM, Baracos VE, McCargar LJ et al. Body composition as an independent determinant of 5-fluorouracil-based chemotherapy toxicity.