Body composition and outcome in gastrointestinal cancer patients

Abstract

In recent years it has been hypothesized that body composition alterations may influence the disease course of patients with gastrointestinal cancer. Several methodologies have been used in the past such as anthropometric measures and bioelectrical impedance to assess body composition. However, recently more sophisticated methodologies for body composition assessment have been explored such as ultrasound, Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) image analysis. CT imaging is known to be highly specific and precise, since it has been shown to correlate closely with dual energy X-ray absorptiometry which is considered the gold standard for body composition evaluation. This technique further allows determination of cross-sectional areas of skeletal muscle tissue, subcutaneous and visceral adipose tissue and muscle attenuation (a marker of skeletal muscle fat infiltration).

Cachexia is a prevalent condition in cancer patients and is defined as the ongoing loss of skeletal muscle mass, with or without the loss of fat mass [1]. Therefore nutritional screening (NS) has been considered mandatory, but recent research has shown that abnormal body composition phenotypes detected by CT analysis were misclassified by most NS tools, which clearly demonstrates the need for progress in nutritional screening of cancer patients [2].

CT scan imaging has demonstrated to be a breakthrough technique, mostly in cancer patients, since it has led to a better understanding of body composition phenotypes and their association with outcome. Recent studies suggest that differences in body composition may be involved in the variability of toxicity to ChT, and that information regarding body composition may be relevant for antineoplastic treatment planning. As compared to conventional prognostic factors, body composition seems to predict with the same or even better accuracy, long term survival and post-operative complications, among others. In fact, there is growing evidence that body composition phenotypes such as sarcopenia (decreased skeletal muscle tissue) is associated with postoperative complications [3], chemotherapy toxicity and response [4] and decreased survival [5]. Also, excess visceral adipose tissue and sarcopenic obesity have been associated with worse outcome [4]. Nonetheless, knowledge is lacking in regard to the effect of potential modifiable protective factors, such as dietary intake and exercise, on body composition alterations thereby improving final outcome. Bearing in mind that CT scan imaging is part of the clinical work up of gastrointestinal cancer patients, the opportunistic use of CT scan images for body composition assessment is feasible.