The Association Between Somatostatin Receptor Ligand and Vitamin B12 Levels in Patients With Acromegaly

Purpose: Vitamin B12 causes hematologic and neuropsychiatric disorders, so it is important to evaluate it in risky situations. In this study, we aimed to evaluate the association between somatostatin receptor ligands and vitamin B12 levels in patients with acromegaly.Methods: Patients who were followed up with the diagnosis of acromegaly in the Endocrinology and Metabolism outpatient clinic of Istanbul University-Cerrahpaşa Medical Faculty were evaluated. Patients were divided into groups according to their somatostatin receptor ligand use status. The groups were evaluated according to their vitamin B12 levels, demographic data, and biochemical parameters.Results: One hundred fifty-two patients were evaluated. Thirteen patients had vitamin B12 deficiency. The majority (11/13) of patients with vitamin B12 deficiency were patients using somatostatin receptor ligand. In addition, the number of patients with vitamin B12 deficiency who received lanreotide autogel treatment was significantly higher compared with patients who did not use somatostatin receptor ligand (p = 0.011). Vitamin B12 levels were higher in patients who received lanreotide autogel treatment than in patients who did not use somatostatin receptor ligand treatment (p = 0.040). There was a negative correlation between vitamin B12 levels and lanreotide autogel use time, cumulative lanreotide autogel dose.Conclusion: It is important to evaluate the level of vitamin B 12 in the follow-up of patients with acromegaly using somatostatin receptor ligand treatment.

Multicenter, Observational Study of Lanreotide Autogel for the Treatment of Patients with Neuroendocrine Tumors in Routine Clinical Practice in Germany and Austria

Background The long-acting somatostatin analog lanreotide autogel is effective in the treatment of patients with neuroendocrine tumors. Objective To evaluate the long-term treatment response in patients with neuroendocrine tumors receiving lanreotide autogel in routine clinical practice. Methods Non-interventional, 24-month study in patients with neuroendocrine tumors treated with lanreotide autogel (NCT01840449). Results Patients (n=80) from 26 centers in Germany and Austria were enrolled. Neuroendocrine tumors were mainly grade 1/2, metastasized, intestinal, and associated with carcinoid syndrome; 88.9% had received previous neuroendocrine tumor treatment. Of those, 84.4% had previous surgery, 18.7% had received octreotide. The primary endpoint, defined by a <50% chromogranin A increase at month 12 compared with the lowest value between baseline and month 3 was achieved by 89.5% patients. Stable disease according to Response Evaluation Criteria in Solid Tumors 1.1 was observed in 76.9 and 75.0% patients at months 12 and 24 of lanreotide treatment, respectively. Mean change of chromogranin A levels from baseline to month 24 was −0.12 × upper limit of normal (95% CI, −0.22; −0.45). In a post hoc analysis, 38.5% of the subgroup of patients with carcinoid syndrome had daily diarrhea at baseline vs. 21.4% at month 24. At baseline, 27.8% of patients received lanreotide 120 mg every 4 weeks vs. 56.7% at month 24. Quality of life data were heterogeneous. No new safety issues arose and/or required further investigation. Conclusions Our study reflects routine lanreotide autogel use in patients with advanced/metastatic neuroendocrine tumors. This analysis shows effectiveness with stabilization of disease-related symptoms and good tolerability of lanreotide autogel in clinical practice.

External validity of somatostatin analogues trials in advanced neuroendocrine neoplasms: the GETNE-TRASGU study

Introduction: Somatostatin analogues (SSA) prolong progression-free survival (PFS) in patients with well-differentiated gastroenteropancreatic neuroendocrine tumors (GEP-NETs). However, the eligibility criteria in randomized clinical trials (RCTs) have been restricted, which contrasts with the vast heterogeneity found in NETs. Methods: We identified patients with well-differentiated (Ki67% ≤20%), metastatic GEP-NETs treated in first-line with SSA monotherapy from the Spanish R-GETNE registry. The therapeutic effect was evaluated using a Bayesian Cox model. The objective was to compare survival-based outcomes from real world clinical practice versus RCTs. Results: The dataset contained 535 patients with a median age of 62 years (range: 26-89). The median Ki67% was 4 (range: 0-20). The most common primary tumor sites were: midgut, 46%; pancreas, 34%; unknown primary, 10%; and colorectal, 10%. Half of the patients received octreotide LAR (n=266) and half, lanreotide autogel (n=269). The median PFS was 28.0 months (95% CI, 22.1-32.0) for octreotide vs 30.1 months (95% CI, 23.1-38.0) for lanreotide. The overall hazard ratio for lanreotide vs octreotide was 0.90 (95% credible interval, 0.71-1.12). The probability of effect sizes >30% with lanreotide vs octreotide was 2% and 6% for midgut and foregut NENs, respectively. Conclusion: Our study evaluated the external validity of RCTs examining SSAs in the real world, as well as the main effect-modifying factors (progression status, symptoms, tumor site, specific metastases, and analytical data).. Our results indicate that both octreotide LAR and lanreotide autogel had a similar effect on PFS. Consequently, both represent valid alternatives in patients with well-differentiated, metastatic GEP-NENs.