Burden of Disease in Patients With Tumor-Induced Osteomalacia

Tumor-induced osteomalacia (TIO) is a chronic condition associated with muscle weakness and long-term disability. We conducted a cross-sectional study of patients diagnosed with TIO who had been referred to our institution between May 2018 and December 2019. Our aim was to assess health-related quality of life (HRQoL), fatigue, pain, and muscle mass and strength in these patients. Detailed information was obtained regarding general characteristics, initial symptoms and biochemical parameters measured at diagnosis and on the first visit to our institution. Fatigue was assessed using the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue) scale, pain using the Brief Pain Inventory-Short Form (BPI-sf) scale and HRQoL by the 36-item Short Form survey (SF-36) questionnaire. Eight patients were included in the study: three without tumor localization, four with nonremission after surgery, and one with clinical recurrence 2 years after surgery. Fatigue experienced by patients with TIO was significantly higher compared to the general population ( ˂ .0001). The physical summary measure of the SF-36 showed significantly lower values than those of the Argentinean population with chronic conditions (mean 20.4 versus 45.9, < .0001). According to the BPI-sf, patients with TIO have moderate average pain and the pain interferes severely with walking, general activities, work, and mood. Seven patients had a diagnosis of sarcopenia, four of which had severe sarcopenia. To our best knowledge, this is the first study aimed to quantify fatigue, pain, HRQoL, and muscle mass and strength in a group of patients with TIO. We hope our results contribute to a better understanding of the burden of disease and to establish a basis for future studies-with larger samples-which will make it possible to assess the efficacy of therapeutic interventions for these conditions. © 2020 American Society for Bone and Mineral Research © 2020 The Authors. published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.