Endocrine Abstracts

Objective: Primary hyperparathyroidism (PHPT) is one of the most frequently diagnosed endocrine disorders. The Russian Registry of PHPT is an on-line web-based database with the aim to estimate the prevalence and main features of disease. PHPT in Multiple Endocrine Neoplasia type 1 (MEN-1) is associated with polyglandular and early involvement of parathyroid glands.

Material and Methods: The database from The Russian Registry of PHPT was used for retrospective analysis. We compared MEN-1 and sporadic PHPT cohorts regarding clinical and biochemical parameters, differences in preoperative features, operative strategies and outcome. Statistical analysis was performed with the STATISTICA 7 (DELL, USA), the significance levels in the range from critical to 0.05 were considered.

Results: Of a total 3010 patients from Registry, 128 patients meet the clinical and genetic criteria of MEN-1 and MEN-2A syndromes. Summary genetic testing was performed in 89 patients, mutations in MEN1 gene were verified in 60 patients (2%, 6/3010), inRET gene - in 2 (0.07%), in CDC73 gene - in 6 (0,2%). As expected, the PHPT manifestation in MEN-1 group was observed earlier 39,5 [26; 51] compared to sporadic disease 59 [53; 67] years (P < 0,001), average duration of disease before diagnosis was 13.2 [9;13] vs 6 [3; 11] years respectively (P < 0.001). The presence of 2 or more MEN-1-associated neoplasia’s was determined in 42%. The most frequent components were pituitary adenoma (71.9%), pancreatic tumors (40.4%) and adrenal adenoma (38.6%), while isolated PHPT was diagnosed in 3% (2/60). We did not find any differences in the PTH, phosphorus and creatinine levels, but suddenly more severe hypercalcemia was observed in MEN-1 group (2.85 ± 0.26 mmol/l vs 2.74 ± 0.28, P = 0.011), possibly due to delayed diagnosis. 68% of MEN-1 patients had symptomatic PHPT more often with bone manifestation (38.6%). Multiple parathyroid involvement on the time of primary diagnosis was found in 15 patients with MEN-1. Primary surgical treatment was performed in 42/57 patients with MEN-1, but only 55% of them underwent initially subtotal or total parathyroidectomy. We found a greater frequency of relapses compared to sporadic form (P <0.0001), reoperations for recurrent PHPT occurred in 35/57.

Conclusion: PHPT is the most common and earliest endocrinopathy in patients with MEN-1. According to the Russian registry, the average age of MEN-1 associated PHPT diagnosis is shifted by 10 years, and the symptomatic course with severe hypercalcemia is dominant. Thus indicates a late diagnosis and insufficient awareness on the PHPT diagnosis in the context of MEN-1.