Association between duration of somatostatin analogs (SSAs) use and quality of life in patients with carcinoid syndrome in the United States based on the FACT-G instrument.
e15693 Background: Carcinoid syndrome (CS) results from the secretion of bioactive amines by functional neuroendocrine tumors. The only FDA-approved agents to treat carcinoid syndrome symptoms (CSS) are SSAs. This study assessed the association of duration of SSA use and quality of life (QoL) among patients with CSS usingthe validated Functional Assessment of Cancer Therapy-General (FACT-G) instrument. Methods: Patients with CSS in the US were recruited by NCAN for a two-part online, anonymous survey (~6 months apart). The first survey was fielded between July-October 2016 and results are reported here. Eligible patients were ≥18 years old with CSS and received either SSA or non-SSA treatment for CSS control. The survey consisted of demographic, clinical and QoL questions, including FACT-G. Descriptive and multivariable regression analyses, adjusting for demographic and clinical characteristics, were performed to assess predictors of FACT-G QoL scores. Duration of SSA use was categorized into quartiles ( < 2.7, 2.7-4.42, 4.43-8.0, and > 8.0 years). Results: Among 117 patients who completed the first survey, 76.9% were female and 87.2% Caucasian with a mean age of 58.0 years. A predominant number of patients (98.3%) received SSAs in the past month. The mean ± SD FACT-G total score was 67.6 ± 20.0 (possible range: 0-108), lower than that of the general US population (80.1 ± 18.1). The mean ± SD duration of SSA use was 6.1 ± 4.7 years. Descriptive analysis suggested that patients receiving SSA treatment for > 8 years had higher (better) FACT-G subscale and total scores than reference group < 2.7 years. Multivariable models showed that FACT-G total score was 11.3 points ( P= 0.033) higher for patients treated with SSA > 8 years compared to those treated for < 2.7 years. Similar patterns were observed for two FACT-G subscales - Physical Well Being and Functional Well Being. Conclusions: The duration of SSA use was positively associated with QoL benefit among CS patients. This may be explained by long-term effectiveness of SSAs or selection bias favoring patients with more indolent disease. Future studies will be needed to distinguish between these possibilities.