Octreotide LAR Dosage and Survival Among Elderly Patients With Distant-Stage Neuroendocrine Tumors.
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.
['Shen|Chan|C|', 'Xu|Ying|Y|', 'Dasari|Arvind|A|', 'Shih|Ya-Chen Tina|YC|', 'Yao|James C|JC|']
D000368:Aged D000369:Aged, 80 and over D018931:Antineoplastic Agents, Hormonal D018572:Disease-Free Survival D004305:Dose-Response Relationship, Drug D005260:Female D006801:Humans D053208:Kaplan-Meier Estimate D008297:Male D015999:Multivariate Analysis D018358:Neuroendocrine Tumors D015282:Octreotide D016016:Proportional Hazards Models D012189:Retrospective Studies D016896:Treatment Outcome
Neuroendocrine tumors Malignant carcinoid syndrome SEER-Medicare Somatostatin analogue