Investigating a biopsychosocial model of fatigue in patients with neuroendocrine neoplasms.

e23196 Background: Neuroendocrine neoplasms (NEN) are rare malignancies most commonly originating in the gastrointestinal tract, pancreas, or lungs, which can cause a variety of symptoms depending on tumor location, size, spread, and hormone secretion. Fatigue is one of the most common symptoms in patients with NEN, but factors associated with fatigue have not been well-characterized. The cause of cancer-related fatigue is likely multifactorial, with biologic, sociodemographic, and psychosocial factors contributing. In this study, we investigated factors related to fatigue in patients with NEN using a biopsychosocial framework. Methods: Participants were enrolled on a rare tumor natural history study (NCT03739827). They completed annual patient-reported outcome (PRO) evaluations to assess fatigue and other quality of life domains with the PRO Measurement Information System (PROMIS). Participants were included if they had a NEN diagnosis, were ≥18 years old, and completed at least one set of PROMIS measures. PROMIS generates standardized T-scores (mean = 50; standard deviation (SD) = 10). Results: A total of 64 of 94 (68%) patients with NEN completed PROMIS measures. Mean age was 59 years, and majority were female (61%), not newly diagnosed (median 3.2 years from diagnosis), and had metastatic disease (81%). Over half (53%) had PROMIS Fatigue T-scores > 55 indicating fatigue, including 31% with moderate to severe fatigue (T-scores > 60). Fatigue was stable over time, with no significant change in PROMIS Fatigue T-scores between baseline (mean = 54.9, SD = 8.7) and one-year follow-up (55.5, 7.6) (n = 32, p = 0.64). Pain was highly correlated with fatigue (ρ = 0.56, p < 0.01), as were psychosocial factors including depression (ρ = 0.57, p < 0.01), anxiety (ρ = 0.47, p < 0.01), and emotional support (ρ = -0.37, p = 0.02). There were no significant differences in fatigue based on sociodemographic factors including age (p = 0.43), sex (p = 0.76), or marital status (p = 0.17). Similarly, there were no significant differences in fatigue based on disease factors including time since diagnosis (p = 0.99), metastatic disease (p = 0.48), or chemotherapy/radiation treatment (p = 0.96), though tumor location approached significance (p = 0.08) with higher PROMIS Fatigue T-scores in patients with lung NENs (median 68.1, interquartile range 21.3) compared to those with gastrointestinal (55.4, 13.1), pancreatic (48.5, 13.5), and other tumor locations (55.4, 18.1). Conclusions: This study confirms fatigue is common in patients with NEN, and pain and psychosocial factors are highly associated with fatigue in these patients. Biologic and sociodemographic factors appear to have less impact on fatigue in this sample; however, further investigation is warranted, particularly of disease-specific factors. Gaining a better understanding of fatigue in patients with NEN will help inform interventions to alleviate fatigue and improve quality of life. Clinical trial information: NCT03739827 .