Estudo da massa e qualidade muscular por tomografia computadorizada em pacientes com câncer colorretal

• Autor(a) principal: Souza, Nilian Carla Silva
• Data de Publicação: 2018
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/7200
• topic: Colorectal cancer; Muscle mass; Myosteatosis; Computed tomography; Mioesteatose; Sarcopenia; Tomografia computadorizada; Nutrição; Câncer colorretal; Massa muscular; CNPQ::CIENCIAS DA SAUDE::NUTRICAO

Sarcopenia is a syndrome defined as the concomitant condition of low muscle mass and low muscle function that occurs with aging, as well as in chronic diseases, such as cancer. Low muscularity is often observed in patients with cancer and its prevalence varies from 20 to 70%. The present study aimed to evaluate the validity of methods to measure muscle mass in patients with colorectal cancer. The first study of this thesis aimed to explore the determinants of myosteatosis and to investigate whether myosteatosis is associated with frailty components in patients with colorectal cancer. This study showed that body fat and gait speed were the significant and independent determinants of myosteatosis and that myostetatosis was associated with frailty in obese patients. Considering computed tomography (CT) as a reference method, the aim of the second study was to evaluate the muscle mass in patients with colorectal cancer at the third lumbar vertebra region as well as by surrogate methods that are suitable for clinical practice. In addition, this study also sought to investigate: 1) the validity of methods used in clinical practice to evaluate muscle mass (mid-upper arm muscle area, calf circumference, skeletal muscle mass assessed by bioelectrical impedance analysis and muscle deficit by the physical examination from the patient-generated subjective global assessment) compared with CT; 2) the association between different muscle measurements with clinical parameters and nutritional status 3) to identify which substitute method shows the highest prognostic value of low muscularity. The main findings of the second study showed that physical exam was the method with higher agreement with CT to assess muscle mass. Low Muscularity groups had higher proportion of malnourished individuals and lower values of body mass index, body fat percentage and phase angle. The Cox regression models adjusted for age, sex and tumor stage showed that physical exam had the highest hazard ratio and C-statistic value among all methods investigated. In addition, the prevalence of low muscle mass varied from 9.6 to 54.3%, depending on the method applied to evaluate muscle mass. These studies corroborate the importance of assessing muscle mass and muscle quality in patients with cancer, considering the relevance for the diagnosis of sarcopenia, the prevention of nutritional disturbances and the possibility to apply early therapeutic interventions. In addition, methods accessible for use in clinical practice, such as physical exam, showed a good agreement with the gold standard method (CT) for the evaluation of muscle mass in colorectal cancer patients