The effect of carcinoid syndrome diarrhea (CSD) interventions on patient experience outcomes: A systematic literature review (SLR)

Introduction: CSD is related to serotonin secretion by neuroendocrine tumors. Aim(s): A SLR was conducted to investigate symptomatic treatments (antidiarrheals, opioids, 5-HT3 antagonists), somatostatin analogs (SSAs) and telotristat ethyl (TE) as CSD interventions; we focus on patient (pt) experience outcomes. Materials and methods: MEDLINE/Embase/the Cochrane Library were searched in March/April 2018 with terms for carcinoid syndrome/symptomatic treatments/SSAs/TE. Congress abstract books/SLR bibliographies/ClinicalTrials.gov were hand-searched. Two independent reviewers screened articles at title/abstract and full text stage. Eligible publications reported interventional/observational studies of CSD interventions. Results: 79 publications on 43 studies were included. 32 studies of SSAs were identified (11-392 pts; 6 phase 2/3 trials); only 4 studies, all in lanreotide, assessed pt experience outcomes. 3/4 reported improved diarrhea and/or pt satisfaction using EORTC QLQ-C30, with 1 study also reporting improvements on the PGIC scale. 1/4 reported improved composite symptom severity scores. 4 studies of TE were identified (15-135 pts; 2 phase 3 trials); all assessed pt experience using EORTC QLQ-C30, reporting improved symptom relief and diarrhea. 7 studies of symptomatic treatments were identified; only 1 study (odansetron, prospective cohort) assessed pt experience outcomes. In this study, 3/6 pts with diarrhea on study entry reported improvements on a VAS scale. Conclusion: A limited number of studies assessed pt experience and sample sizes were small. Evidence from phase 2/3 trials showed improvements with TE and SSAs. However, more evidence is needed to better meet the needs of pts with CSD.