Prognostic Factors for Refractory Outcome in Localizing TIO: Experience in a Tertiary Center

Area of Science:

• Endocrinology
• Oncology
• Nephrology

Background:

• Tumor-induced osteomalacia (TIO) is a paraneoplastic disorder causing renal phosphate wasting.
• Surgical tumor removal typically cures TIO, but some cases are refractory, leading to complications.

Purpose of the Study:

• To identify risk factors associated with refractory outcomes in TIO patients.
• To determine predictors of successful TIO treatment post-intervention.

Main Methods:

• Retrospective cohort study of 44 TIO patients diagnosed between 1998 and 2023.
• Analysis of factors influencing cure, defined as sustained normophosphatemia post-intervention.

Main Results:

• Tumor-induced osteomalacia (TIO) patients diagnosed after 2013 had higher cure rates.
• Negative surgical margins and soft tissue origins were associated with better prognoses.
• Spine localization and bone origin correlated with refractory TIO outcomes.
• Post-procedural FGF23 levels were the strongest biochemical predictor of cure.

Conclusions:

• Recent diagnoses and clear surgical resection margins improve TIO prognoses.
• Tumor location (bone/spine) and origin influence treatment outcomes.
• Baseline biochemistry is not predictive of cure, but post-procedural FGF23 is a key indicator.