Long-term experience with octreotide and lanreotide for the treatment of gastroenteropancreatic neuroendocrine tumors

Introduction: The somatostatin analogs (SSA) octreotide and lanreotide are a mainstay in the treatment of neuroendocrine tumors (NET). The two pivotal trials differed considerably in terms of patient characteristics and are not directly comparable. Further comparative data are lacking.

Methods: This retrospective chart review study included patients with gastroenteropancreatic NET grade 1 or 2 who were treated with octreotide LAR or lanreotide autogel. The main aim was to compare the two SSA based on progression-free survival (PFS) and overall survival (OS) from treatment start.

Results: In total, 129 patients were analyzed, 60% (n = 77) had a small intestinal NET and 31% (n = 40) a pancreatic NET. Histologically, 34% (n = 44) had NET G1, 55% (n = 71) a NET G2, and 11% (n = 14) a NET G1/G2 unclassified. Lanreotide was used in 90 patients (70%) and octreotide in 39 patients (30%). Overall, the median PFS was 32.2 months (95% CI 23.0-42.9 months). No PFS difference (p = 0.8) was observed between lanreotide (29.8 months, 95% CI 18.7-48.5 months) and octreotide (36.0 months, 95% CI 23.2-68.2 months). Median OS from treatment start was calculated at 93.5 months (95% CI 71.1-132.9 months). Again, the median OS following lanreotide (113.4 months, 95% CI 62.3-NA months) or after octreotide (90.3 months, 95% CI 71.1-NA months) did not differ significantly (p > 0.9).

Conclusions: Our long-term experience with octreotide and lanreotide in NET did not reveal differences in antitumor effectiveness. This is consistent with previous reports and might suggest that both SSA can be used interchangeably if needed.