Early Satiety in Cancer: An Investigation into a Highly Impactful Orphan Symptom

Abstract

Patients with cancer experience multiple symptoms throughout the different stages of cancer care. One common symptom related to nutritional intake is known as early satiety. This symptom has no agreed definition but has been described as 'feeling full quickly'. This thesis explored this symptom in cancer with a focus on two patient populations: those undergoing active anticancer treatment and those with advanced cancer receiving specialist palliative care. A scoping review of the literature found early satiety is a chronically under-researched symptom in cancer. Where studies outlined how early satiety was identified, there were several different descriptions used and less than half used validated tools to identify it. This review also found it to be present in many different cancers and was unanimously the most common symptom post oesophagectomy in cancer. Early satiety was also associated with cachexia, poorer physical health, and shorter prognosis. Despite this impact, there was no clear pathophysiology identified and no studies investigated any potential treatment. Patients with cancer had a high symptom burden, regardless of disease stage. Early satiety was almost never self-reported by patients unless assessed using a closed question symptom checklist. Despite rarely self-reporting it, early satiety was one of the most common symptoms, more common than other well-known symptoms in cancer of anorexia or nausea. It was also one of the only symptoms to be associated with both screened risk of malnutrition and diagnosed malnutrition. To determine how patients with early satiety described it, a new questionnaire was developed and piloted on patients with advanced cancer. Once adjusted, it was then used on both cohorts. Most experiences regarding early satiety appeared to be individualised. There were mixed reports regarding when early satiety was first experienced and its severity. One commonality was that it reduced nutritional intake. Another was that none had ever been screened for early satiety prior to inclusion in this thesis. Patients with cancer had a lower quality of life compared to normative values for the general population. Early satiety significantly impaired this quality of life alongside several other symptoms. It appeared to have a specific reduction in the role functioning component of quality of life. There appeared to be no impact of early satiety on physical functioning in cancer. This thesis confirmed that early satiety is a highly impactful orphan symptom in cancer that impacts both physical and psychological health. It is under reported in both research and clinical care. This thesis also demonstrated the need for further research into this symptom to ensure improved patient care.