Carcinoid syndrome: update on the pathophysiology and treatment

TELEPRO: Patient-Reported Carcinoid Syndrome Symptom Improvement Following Initiation of Telotristat Ethyl in the Real World

BACKGROUND

When carcinoid syndrome (CS) diarrhea (CSD) is inadequately controlled with long-acting somatostatin analogs (SSAs), clinical practice guidelines recommend addition of the tryptophan hydroxylase inhibitor telotristat ethyl (TE). In a 12-week multinational, randomized controlled trial, TE added to SSA reduced peripheral serotonin and the frequency of CSD. We evaluated real-world effectiveness of TE using patient-reported data from a nurse support program over 3 months.

MATERIALS AND METHODS

This study used a deidentified data set of patients initiating TE who opted into a nurse support program between March and November 2017 and reported CS symptom burden at baseline and at least one follow-up time point at months 1, 2, and 3. Patients reported demographic and medical history information as well as frequency of bowel movements (BMs) and flushing episodes, severity of nausea, urgency and abdominal pain (0 "no/not at all" to 100 "worst imaginable/very urgent"), and stool form (1 "very hard" to 10 "watery"). Mean changes from baseline in CS symptom burden were reported using paired-sample t tests and Wilcoxon signed-rank tests.

RESULTS

Most patients initiating TE enrolled in the nurse program (791/898, 88%), of whom 369 (47%) were included in the analysis. Patients treated with TE reported significant reductions in CSD and other CS symptoms (all p < .001). At least half of patients treated with TE experienced ≥30% improvement from baseline in BM frequency and an average reduction of at least two BMs per day within 3 months.

CONCLUSION

Patients taking SSA therapy showed substantial burden of disease before initiating TE and significant improvements with the addition of TE treatment in this real-world effectiveness study.

IMPLICATIONS FOR PRACTICE

Patients with carcinoid syndrome diarrhea uncontrolled by high doses of long-acting somatostatin analogs may be candidates for additional therapy with the tryptophan hydroxylase inhibitor telotristat ethyl. Understanding the real-world prevalence of uncontrolled symptoms and the effectiveness of telotristat ethyl in clinical practice may further support clinical and policy decisions for these patients. This study investigated self-reported carcinoid syndrome symptom burden and improvements among patients initiating telotristat ethyl and participating in a voluntary nurse support program. Disease burden and off-label somatostatin analog treatment before initiating telotristat ethyl were high, and symptoms improved markedly over 1, 2, and 3 months of treatment.

Management of Gastrointestinal Neuroendocrine Tumors

Neuroendocrine neoplasms (NENs) are derived from neuroendocrine cell system and can have benign or malignant characteristics. They are rare tumors, but have been increasing in incidence over the past 40 years. Patients with NENs may develop symptoms due to primary tumor invasion, metastasis, or from secretion of hormonally active tumor substances. Multiple imaging modalities are used for diagnosis and staging, including specialty scans such as ¹¹¹In pentetreotide (Octreoscan) and ⁶⁸Gallium-DOTATATE, along with endoscopy, endoscopic ultrasound, and biochemical marker testing. Treatment involves both surgical approach, for both primary and metastatic lesions, as well as medical management for symptom management and disease progression. This article will review the current clinical knowledge regarding the diagnosis, treatment, and prognosis of these fascinating neoplasms and the associated hormonal syndromes.

Evidence-Based Policy in Practice: Management of Carcinoid Syndrome Diarrhea

Carcinoid syndrome causes substantial morbidity and reduces quality of life and survival. In a recent clinical trial, 97% of patients reported bowel movement-related issues, abdominal pain, flushing, and low energy. Combining somatostatin analogs with elotristat ethyl provides a new option for managing refractory CS symptoms. Health care providers should consider strategies that take advantage of approved dosing for patients with CS-related diarrhea.

Carcinoid Heart Disease and Decreased Overall Survival among Patients with Neuroendocrine Tumors: A Retrospective Multicenter Latin American Cohort Study

The background to this study was that factors associated with carcinoid heart disease (CHD) and its impacts on overall survival (OS) are scantly investigated in patients (pts) with neuroendocrine tumors (NETs). In terms of materials and methods, a retrospective multicenter cohort study was conducted of factors associated with CHD in advanced NET pts with carcinoid syndrome (CS) and/or elevated urinary 5-hidroxyindole acetic acid (u5HIAA). CHD was defined as at least moderate right valve alterations. The results were the following: Among the 139 subjects included, the majority had a midgut NET (54.2%), 81.3% had CS, and 93% received somatostatin analogues. In a median follow-up of 39 months, 48 (34.5%) pts developed CHD, with a higher frequency in pts treated in public (77.2%) versus private settings (22.9%). In a multivariate logistic regression, unknown primary or colorectal NETs (Odds Ratio (OR) 4.35; p = 0.002), at least 50% liver involvement (OR 3.45; p = 0.005), and being treated in public settings (OR 4.76; p = 0.001) were associated with CHD. In a Cox multivariate regression, bone metastases (Hazard Ratio {HR} 2.8; p = 0.031), CHD (HR 2.63; p = 0.038), and a resection of the primary tumor (HR 0.33; p = 0.026) influenced the risk of death. The conclusions were the following: The incidence of CHD was higher in pts with a high hepatic tumor burden and in those treated in a public system. Delayed diagnosis and limited access to effective therapies negatively affected the lives of NET patients.