Clinically relevant determinants of body composition, function and nutritional status as mortality predictors in lung cancer patients

Abstract

Lung cancer belongs to the type of tumors with a relatively high frequency of malnutrition, sarcopenia and cachexia, severe metabolic syndromes related to impairment of physical function and quality of life, resistance to therapy and short survival. Inexpensive and accessible methods of evaluating changes in body composition, physical function and nutrition status are for this reason of great importance for clinical practice to enable the early identification, monitoring, preventing and treatment of these nutritional deficiencies. This could lead to improved outcomes in the quality of life, physical performance and survival of patients with lung cancer. The aim of this article is to summarize the recent knowledge for the use of such methods, their predictability for patient outcomes and an association with other clinically relevant parameters, specifically with lung cancer patients, because such an article collectively describing their practical application in clinical practice is lacking. The interest of this article is in the use of anthropometry, handgrip dynamometry, bioelectrical impedance analysis derived phase angle and nutritional screening questionnaires in lung cancer patients.

Introduction

Many serious illnesses (e.g. cancer, sepsis or AIDS) are associated with a severe metabolic syndrome called cachexia. The important clinical symptoms include involuntary weight loss accompanied by sarcopenia (skeletal muscle wasting and weakness), fatigue, anorexia, metabolic imbalance and signs of systemic inflammation. Cachexia cannot be fully reversed by conventional nutrition support [1].

In recent years, the staging of cachexia has occurred. An international panel of experts have created a three-stage classification specific for cancer cachexia: precachexia, cachexia and refractory cachexia. Precachexia is a state characterized by early clinical signs and metabolic disturbances preceding substantial weight loss. The criteria for cachexia are considerable body weight loss (more than 5% over the past 6 months) or a body mass index (BMI) of less than 20 in combination with weight loss (more than 2% over the past 6 months) or sarcopenia (appendicular skeletal muscle index determined by dual energy X-ray absorptiometry of lower than 7.26 and 5.45 kg m⁻² in men and women, respectively) in combination with body weight loss (more than 2% over the past 6 months), but have not entered the refractory stage. Refractory cachexia is a stage characterized by low performance status and low life expectancy (less than 3 months) due to very advanced or rapidly progressive cancer that is unresponsive to therapy [2], [3].

Lung cancer belongs to the type of tumors with a relatively high frequency of malnutrition, sarcopenia and cachexia, as demonstrated by the result of recent works. According to the Mini Nutrition Assessment (MNA), 26% of patients with advanced non-small cell lung carcinoma (NSCLC) were malnourished and another 46% of patients were at risk of malnutrition [4]; according to Subjective Global Assessment (SGA), 60% of patients were malnourished [5]. Prado et al. demonstrated that the majority of overweight NSCLC patients (more than 53%) were sarcopenic [6]. According to cancer-specific cachexia classifications (as mentioned above), 18% of NSCLC patients were diagnosed as cachectic, 23% of patients were diagnosed as in a state of precachexia [7].

Cachexia and muscle wasting are related to the impairment of physical function [8], quality of life [5], resistance to therapy [9] and shorter survival rate [10]. Early identification, monitoring, prevention and treatment of these nutritional deficiencies could lead to improved outcomes in the quality of life, physical performance and survival of patients with NSCLC. There are several inexpensive and accessible methods of evaluating changes in body composition, physical function and nutritional status including anthropometry, handgrip dynamometry, bioelectrical impedance analysis derived phase angle and nutritional screening questionnaires. The aim of this article is to summarize the recent knowledge of the use of these methods, their predictability of patient outcomes and the association of other clinically relevant parameters, specifically with lung cancer patients. Such an article collectively describing their practical application in clinical practice is lacking.