The Role of the Small Bowel in Unintentional Weight Loss after Treatment of Upper Gastrointestinal Cancers

Abstract

Upper gastrointestinal (GI) cancers are responsible for significant mortality and morbidity worldwide. To date, most of the studies focused on the treatments’ efficacy and post-treatment survival rate. As treatments improve, more patients survive long term, and thus the accompanying complications including unintentional weight loss are becoming more important. Unintentional weight loss is defined as >5% of body weight loss within 6–12 months. Malignancies, particularly GI cancers, are diagnosed in approximately 25% of patients who present with unintentional weight loss. Whereas some recent studies discuss pathophysiological mechanisms and new promising therapies of cancer cachexia, there is a lack of studies regarding the underlying mechanism of unintentional weight loss in patients who are tumor free and where cancer cachexia has been excluded. The small bowel is a central hub in metabolic regulation, energy homeostasis, and body weight control throughout the microbiota-gut-brain axis. In this narrative review article, the authors discussed the impacts of upper GI cancers’ treatment modalities on the small bowel which may lead to unintentional weight loss and some new promising therapeutic agents to treat unintentional weight loss in long term survivors after upper GI operations with curative intent.

Cachectic Body Composition and Inflammatory Markers Portend a Poor Prognosis in Patients with Locally Advanced Pancreatic Cancer Treated with Chemoradiation

“…Furthermore, weight loss was described in several studies of pancreatic cancer patients receiving mostly chemotherapy [21,29,30,31]. Moreover, the contribution of the small bowel to weight loss via the “microbiota-gut-brain axis” that might be disturbed by systemic treatments was also recently discussed [32].…”

The Problem of Appetite Loss After Major Abdominal Surgery

“…A change in gut microbiota may also lead to faster satiation. 15 Preserving the duodenal passage may also result in more normal (rather than increased) levels of the appetite suppressing hormone cholecystokinin. 54 Reduced bowel motility may be another source of appetite loss.…”

“…14 Also, significant weight loss as a consequence of appetite loss has been well documented and is especially common after upper gastrointestinal surgery. 15 If postoperative appetite loss leads to malnutrition, this adversely impacts survival, complications, and quality of life. 16 After nonabdominal surgery such as primary joint replacement, it takes up to 4 weeks for patients to recover their preoperative appetite.…”