Octreotide LAR Dosage and Survival Among Elderly Patients With Distant-Stage Neuroendocrine Tumors

Abstract

INTRODUCTION: Octreotide long-acting repeatable (LAR) is approved for the management of carcinoid syndromes and may improve progression-free survival of patients with well-differentiated neuroendocrine tumors (NETs). It is unknown whether the dosage of octreotide LAR affects survival. This paper evaluates the association between initial octreotide LAR dosage and overall survival of elderly patients with NETs. PATIENTS AND METHODS: Patients with distant-stage NET diagnosed between January 1999 and December 2009 who received octreotide LAR treatment within 12 months of diagnosis were identified from the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. Those under age 65 years, enrolled in health maintenance organizations, or without continuous enrollment in Medicare Parts A and B were excluded. We compared the 5-year survival of patients with NET based on dose per 28 days averaged over the initial 3 months: low (≤20 mg); medium (21-30 mg); high (>30 mg). Kaplan-Meier estimations and Cox proportional hazard modeling were used to examine the association between octreotide LAR dose and survival. RESULTS: Among 222 patients with distant-stage NET who received octreotide LAR treatment, 81 (36%) received a low dosage, 82 (37%) received a medium dosage, and only 59 (27%) received a high dosage. Multivariate analysis showed that compared with a medium octreotide LAR dose, a low dosage was associated with significantly worse survival (hazard ratio [HR]: 2.00; p = .001), whereas a high initial dosage (HR: 1.09; p = .719) did not show additional survival benefits over that observed with a medium dosage. CONCLUSION: This population-based study suggests potential survival benefits for octreotide LAR provided within 12 months of diagnosis at a dosage of 21-30 mg among elderly patients with distant-stage NET.