title: Octreotide LAR Dosage and Survival Among Elderly Patients With Distant-Stage Neuroendocrine Tumors.
abstract: BACKGROUND
  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.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Chan
authors.initials: C
authors.lastname: Shen
authors.affiliation: Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Arvind
authors.initials: A
authors.lastname: Dasari
authors.affiliation: Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Ya-Chen Tina
authors.initials: YC
authors.lastname: Shih
authors.affiliation: Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA jyao@mdanderson.org.
authors.forename: James C
authors.initials: JC
authors.lastname: Yao
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; 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 / Q000188:drug therapy*; D015282:Octreotide / Q000627:therapeutic use*; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D018931:Antineoplastic Agents, Hormonal; D015282:Octreotide
keywords: Malignant carcinoid syndrome; Neuroendocrine tumors; SEER-Medicare; Somatostatin analogue