Octreotide LAR use among elderly patients with carcinoid syndrome and survival outcomes: A population-based analysis.

Abstract

322 Background: Octreotide LAR is indicated for the treatment of carcinoid syndrome, diarrhea related to VIPoma, and may delay tumor growth in neuroendocrine tumors (NETs). The pattern of octreotide LAR use in clinical practice and its impact on survival outcomes has not been well-documented. Methods: Using the SEER-Medicare database, we identified NET patients diagnosed between 7/1999 and 12/2007. We excluded those under age 65, enrolled in HMOs, and without continuous Part A and B enrollment within 12 months of diagnosis. Potential indication for octreotide use was defined as ≥ 2 claims for carcinoid syndrome, flushing, diarrhea, or malignant islet cell neoplasm within first year of diagnosis, with the first claim occurring within 6 months of diagnosis. HCPCS codes, J2352 and J2353, were used to identify octreotide LAR treatment. Multivariate logistic regression and Cox proportional hazard survival analyses were performed to ascertain factors associated with octreotide use and evaluate impact of octreotide use on survival; covariates included age, race, region, comorbidity score, urban/rural status, tumor characteristics, neighborhood socioeconomic status and year of diagnosis. Results: Among those with potential indication for octreotide use (carcinoid syndrome and islet cell), 264 (49%) out of 539 distant stage patients, and 83 (10%) out of 850 patients with local regional disease were started on octreotide LAR within 6 months of diagnosis. Multivariate logistic regression showed that patients living in the southern region were less likely to use octreotide. Multivariate proportional hazard model showed that octreotide LAR provided a significant 5-year survival benefit for distant stage patients (HR=.80, p-value=.047); while this survival benefit was not shown for the local/regional stage patients (HR=.97, p-value=.89). Conclusions: This retrospective study suggests a possible survival benefit for use of octreotide LAR in distant stage elderly patients with carcinoid syndrome. Data also suggest that many elderly patients with claims for carcinoid syndrome did not receive octreotide LAR therapy within 6 months of diagnosis. Further studies and improved education are warranted.