Long-term bone mineral density changes after surgical cure of patients with tumor-induced osteomalacia

• Published in: Osteoporosis international Vol. 31; no. 7; pp. 1383 - 1387
• Main Authors: Colangelo, L., Pepe, J., Nieddu, L., Sonato, C., Scillitani, A., Diacinti, D., Angelozzi, M., Cipriani, C., Minisola, S.
• Format: Journal Article
• Language: English
• Published: London Springer London 01.07.2020; Springer Nature B.V
• Subjects: Absorptiometry, Photon; Adult; Bone Density; Bone mineral density; Calcium; Cancellous Bone; Dual energy X-ray absorptiometry; Endocrinology; Female; Femur; Femur Neck - diagnostic imaging; Humans; Long bone; Lumbar Vertebrae - diagnostic imaging; Lumbar Vertebrae - surgery; Male; Medicine; Medicine & Public Health; Middle Aged; Mineralization; Orthopedics; Osteoid; Osteomalacia; Osteoporosis; Paraneoplastic Syndromes; Patients; Rheumatology; Salts; Short Communication; Surgery; Tumor-induced osteomalacia; TmP/GFR; Fibroblast growth factor 23; Vitamin D
• ISSN: 0937-941X; 1433-2965
• DOI: 10.1007/s00198-020-05369-1

Summary This paper reports our personal experience filling the gap regarding changes of bone mineral density after surgical treatment in patient suffering from tumor-induced osteomalacia. Introduction No systematic data are available regarding long-term bone mineral density (BMD) changes after surgical cure of patients with tumor-induced osteomalacia. Methods From October 2001 through April 2018, we studied 10 consecutive patients (mean age ± SD, 45.5 ± 13.8 years; 5 males and 5 females) with tumor-induced osteomalacia. We evaluated BMD when initially presented at our Center and after surgical removal of the tumor. Results Basal BMD and corresponding Z-score values (mean values ± SD) measured by DXA were as follows: L 1 –L 4  = 0.692 ± 0.15 g/cm 2 , Z-score = − 2.80 ± 1.60; femur neck 0.447 ± 0.10 g/cm 2 , Z-score = − 2.66 ± 0.93; total femur = 0.450 ± 0.08 g/cm 2 , Z-score = −3.04 ± 0.85). Furthermore, Trabecular Bone Score (TBS) was evaluated in three patients (basal values, 0.990 ± 0.32). Seven patients were intermittently followed after surgical excision of the tumor while supplemented with cholecalciferol and calcium salts; the remaining three were lost to follow-up. There was a striking increase of BMD values that peaked at 26.7 ± 6.50 months: L 1 –L 4  = 1.289 ± 0.247 g/cm 2 , p  < 0.001, Z-score + 1.75 ± 1.42; femur neck = 0.890 ± 0.235 g/cm 2 , p  = 0.028, Z-score = + 0.50 ± 1.40; total femur = 0.834 ± 0.150 g/cm 2 , p  = 0.005, Z-score = − 0.74 ± 1.14. In patients with the greatest bone involvement at lumbar site, there was a striking increase of an average 1.5% ( p  < 0.01) in respect to baseline Z-score value for each additional month of observation during the first 2–3 years post-surgery. An improvement of trabecular microarchitecture was also documented (TBS, 1.255 ± 0.16). Conclusion This is the first case series documenting an impressive increase of BMD at both lumbar and femoral sites, together with an improvement of trabecular microarchitecture as documented by TBS. This is the consequence of huge mineralization of the large amount of osteoid tissue after resolution of the disease.