title: Octreotide long-acting repeatable use among elderly patients with carcinoid syndrome and survival outcomes: a population-based analysis.
abstract: BACKGROUND
  Octreotide long-acting repeatable (LAR) is indicated for the treatment of carcinoid syndrome and diarrhea related to VIPoma, and may delay tumor growth in patients with neuroendocrine tumors (NETs). To the authors' knowledge, the pattern of octreotide LAR use in clinical practice and its impact on survival outcomes has not been well documented.
  
  
  METHODS
  Using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, the authors identified patients with NET aged ≥ 65 years who were diagnosed between July 1999 and December 2007. Patients with US Food and Drug Administration-approved indications for octreotide LAR were identified from Medicare claims. Multivariate logistic regression was performed to ascertain factors associated with octreotide LAR use, whereas the Cox proportional hazards model was used to evaluate the impact of octreotide LAR on survival.
  
  
  RESULTS
  Among those with Food and Drug Administration-approved indications, 245 of 4848 patients with distant-stage disease (51%) and 81 of 807 patients with local/regional disease (10%) initiated treatment with octreotide LAR within 6 months of diagnosis. Multivariate logistic regression indicated that among those with distant-stage disease, older age (≥ 80 years vs 65-69 years) (odds ratio [OR], 0.43; 95% confidence interval [95% CI], 0.23-0.81), female sex (OR, 0.62; 95% CI, 0.40-0.97), and living in the South (vs Northeast) (OR, 0.36; 95% CI, 0.18-0.72) were associated with a lower likelihood of using octreotide LAR. The multivariate proportional hazards model showed that octreotide LAR provided a significant 5-year survival benefit for patients with distant-stage disease (hazards ratio, 0.61; P ≤ .001), whereas this survival benefit was not shown for the patients with local/regional stage (hazards ratio, 0.88; P = .563).
  
  
  CONCLUSIONS
  The results of this retrospective study suggest a possible survival benefit for the use of octreotide LAR in elderly patients with distant-stage NET with carcinoid syndrome. The results of the current study also suggest that octreotide LAR is underused in this population despite recommended guidelines.
authors.affiliation: Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas; Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Chan
authors.initials: C
authors.lastname: Shen
authors.forename: Ya-Chen Tina
authors.initials: YC
authors.lastname: Shih
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.forename: James C
authors.initials: JC
authors.lastname: Yao
mesh_terms: D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D015897:Comorbidity; D015986:Confounding Factors, Epidemiologic; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008303:Malignant Carcinoid Syndrome / Q000188:drug therapy* / Q000208:ethnology / Q000401:mortality* / Q000473:pathology; D006278:Medicare; D060787:Neoplasm Grading; D018358:Neuroendocrine Tumors / Q000188:drug therapy / Q000401:mortality; D015282:Octreotide / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D010190:Pancreatic Neoplasms / Q000188:drug therapy / Q000401:mortality; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018426:SEER Program; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D003969:Vipoma / Q000188:drug therapy / Q000401:mortality
chemical_list: D018931:Antineoplastic Agents, Hormonal; D015282:Octreotide
keywords: Epidemiology; Surveillance; and End Results (SEER)-Medicare; health services for the aged; malignant carcinoid syndrome; neuroendocrine tumors; octreotide; somatostatin analog