Advanced prostate cancer as a cause of oncogenic osteomalacia: an underdiagnosed condition.

PURPOSE: Tumor-induced osteomalacia (TIO) is a paraneoplastic bone mineral disturbance related to fibroblast growth factor 23 (FGF23) overproduction by the tumor, usually from mesenchymal origin. Such condition leads to high phosphate renal wasting and, consequently, to cumbersome symptoms as weakness, bone pain, and fractures. METHOD: Case report. RESULT: We report a case of an advanced castration-refractory prostate cancer patient, which developed severe hypophosphatemia with elevated phosphate excretion fraction. TIO was suspected, and increased levels of FGF23 reinforced such diagnosis. The patient died 4 months after being diagnosed with TIO. CONCLUSION: This case suggests that TIO has a dismal prognosis in prostate cancer patients. The clinical oncology community must be aware about such disturbance that can be present in those patients with weakness, bone pain, and hypophosphatemia.

Cisplatin based chemoradiation late toxicities in head and neck squamous cell carcinoma patients.

BACKGROUND: Cisplatin-based chemoradiation (CRT) offers head and neck squamous cell carcinoma (HNSCC) patients better overall survival when compared to radiation alone. However, it also increases acute and late toxicity (LT). Here we aimed to review the main aspects of diagnosis and treatment of long-term toxicities in HNSCC patients after CRT. METHODS: We crossed-searched PubMed MeshTerms: Survivors, Deglutition Disorders, Xerostomia, Hypothyroidism, Cisplatin, Kidney, Hearing, and Osteoradionecrosis, with keywords: "Head and Neck Neoplasms" and "Chemoradiotherapy." A total of 5,541 publications were retrieved and 48 were selected for this systematic review. RESULTS: Dysphagia (25%), xerostomia (40-80%, depending on the technique used), hypothyroidism (42%), ototoxicity (27%), and osteoradionecrosis (4%) were the most commonly reported LT and were related to compromised quality of life aspects in HNSCC patients. Concurrent cisplatin and higher radiation doses, especially to normal tissue, increased the rates of LT. CONCLUSIONS: Late CRT toxicities were reported mostly in retrospective studies. Addressing these adverse effects as endpoints in future clinical trials is necessary to provide tools to prevent and treat them adequately, allowing better quality of life and survival results.