Abstract
IntroductionThe long-acting somatostatin analogues (LA-SSAs) octreotide LAR (OCT) and lanreotide (LAN) improve progression-free survival (PFS) in gastrointestinal neuroendocrine tumors (NETs), however, no head-to-head comparison exists. We compared treatment patterns and efficacy in a small bowel and pancreatic NET population-based cohort from British Columbia, Canada.MethodsWe identified 321 patients receiving either LAN or OCT for retrospective chart review. These somatostatin analogs were evaluated for impact on progression-free and overall survival.ResultsAge, sex, ECOG, and primary site did not differ by treatment, however, LAN was more commonly used in higher grade tumors (P = 0.019). PFS was longer for patients receiving LAN than OCT (Hazard Ratio (HR) 0.60, 95% CI 0.40-0.89, P = 0.011). Similarly, overall survival (OS) was longer for patients receiving LAN than OCT (HR 0.45, 95% CI 0.28-0.73, P = 0.016). Sensitivity analysis among patients diagnosed after both agents were reimbursed showed similar results for PFS (HR 0.50, 95% CI 0.28-0.90, P = 0.018). There was similar dose escalation with LAN vs OCT (OR: 0.80, CI 0.38-1.77, P = 0.70), with 29.4% of patients in the LAN group requiring LA-SSA dose escalation compared to 34.3% in the OCT group. There was numerically less short acting octreotide use in the LAN group (P = 0.087), with none of these patients requiring short acting octreotide, compared to 8.7% of the OCT group.ConclusionLAN was associated with longer time to cancer progression, as well as less use of short acting rescue octreotide in our population-based cohort. However, given the retrospective design and reimbursement-era differences, these findings should be interpreted cautiously and warrant confirmation in prospective or head-to-head studies.