A Systematic Review of Economic and Quality-of-Life Research in Carcinoid Syndrome

Background: To date, the economic burden and patient-reported outcomes associated with carcinoid syndrome (CS) in patients with neuroendocrine tumor (NET) remain largely unknown.

Objectives: The objective of this study was to perform a systematic review of economic and quality-of-life (QOL) studies related to the treatment of CS.

Methods: Articles included in the review were extracted from PubMed, Embase, and the Cochrane Library. Studies had to be in English and published between 1 January 2000 and 2 July 2020. Other study eligibility criteria included patients with NET with CS receiving treatment for CS, study outcomes of cost or QOL, and clinical trials or population-based studies using claims or other secondary databases. The interventions included somatostatin analogs, telotristat ethyl, or other treatment for CS. To evaluate the quality and bias of the included studies, the 24-item CHEERS and 10-item Gill and Feinstein checklists were used. We report a narrative synthesis of the findings from the selected studies.

Results: A total of 12 economic and 12 QOL studies met the inclusion criteria and were included for review. Patients with uncontrolled CS symptoms had 23-92% higher costs than those with controlled CS; mostly, ambulatory/outpatient services were the primary drivers of the costs. The use of telotristat ethyl may be cost effective if the societal willingness to pay is as high as $US150,000 per quality-adjusted life-year in the USA. Of the 12 QOL papers, only three case-control studies assessed QOL at baseline and more than two follow-up time points. Seven studies evaluated QOL at two or more time points but lacked a control group, obscuring direct intervention effects on patients' well-being.

Conclusions: We observed wide variations in the reviewed studies evaluating the economic burden and patient-reported outcomes, in terms of cost and QOL, of patients with CS. Although QOL is consistently impaired and costs are consistently increased by CS, the numbers of both cost and QOL studies among this patient population remain sparse, and many of the existing studies indicated an important need for quality improvement.