Implementation and Feasibility of a Multidisciplinary Endocrine-Led Outpatient Clinic for Cancer Cachexia and Other Forms of Unintentional Weight Loss: A Real-World Observational Study

<b>Purpose:</b> Cachexia, characterized by involuntary weight loss, muscle wasting, and metabolic dysfunction, is prevalent in advanced cancer and chronic illnesses. Despite its impact, outpatient treatment models in the U.S. remain limited and unstandardized. Here, we aim to describe the structure, implementation, patient characteristics, and real-world clinical trajectories of a multidisciplinary clinic for cancer cache as well as other forms of unintentional weight loss clinic within an academic endocrinology practice. <b>Methods:</b> We conducted a retrospective observational cohort study of 103 patients referred to a single-center unintentional weight loss clinic over five years. Patients received comprehensive assessments (weight trajectory, nutrition status, 5× sit-to-stand test, handgrip strength) and personalized interventions including nutrition counseling, resistance training, and pharmacologic therapies. <b>Results:</b> Among 103 patients (median age 69.7 years; 53% male), 64% had cancer, while 36% were referred for non-malignant causes of weight loss or cachexia. Reduced appetite or food intake was reported in 43%, and functional impairment was common, with low handgrip strength in 47% and impaired 5× sit-to-stand performance in 79% of assessed patients. Systemic abnormalities were frequent, including elevated hs-CRP (57%), elevated neutrophil-to-lymphocyte ratio (43%), and hypoalbuminemia (26%). Among patients with available paired follow-up data, the median rate of weight change shifted from -0.5 kg/month prior to enrollment to 0.0 kg/month three months after the initial visit (<i>p</i> < 0.0001). Five-times sit-to-stand performance improved modestly at three months (<i>p</i> = 0.042), while handgrip strength was unchanged. Half of patients that engaged with the clinic returned for at least follow-up, but there was no identifiable difference between the population of patients that returned versus those that did not. <b>Conclusions:</b> A structured, multidisciplinary unintentional weight loss clinic in an endocrinology setting was associated with stabilization of weight and modest changes in physical function in this single-center cohort among patients who engaged in follow-up. These findings highlight the successful implementation of integrated outpatient care models and provide practice-based context for future interventions and therapeutic evaluations.