Screening of Patients with Multiple Endocrine Neoplasia Type 1 (MEN-1): A Critical Analysis of Its Value

Screening of multiple endocrine neoplasia type 1 (MEN-1) patients is widely recommended because one-fifth succumb to malignant neoplasms. However, recommendations for screening modalities and intervals are based mostly on nonprospective data. Thirty-five of 48 MEN-1 patients were evaluated at least twice by an annual screening program in a single-center, prospective, nonrandomized study between 1997 and 2006. The screening program comprised anamnesis, clinical examination, imaging procedures, and extensive biochemical evaluations. Prospectively diagnosed lesions were evaluated separately from nonprospectively diagnosed lesions at first evaluation. The median age of the patients was 45 years (range = 15-70) at initial assessment. They were followed for a median of 72 months (range = 24-108) by a median of 6 (range = 2-10) evaluations. The vast majority of lesions were nonprospectively diagnosed at initial evaluation: 13 of 17 patients had primary hyperparathyroidism (pHPT), 24 of 29 had pancreatic endocrine tumors (PETs), and 4 of 4 had carcinoids. Vice versa adrenal lesions were mostly prospectively detected (18/23). Malignancy was observed in 10 patients (28%) in the initial assessment and without symptoms in 5 patients (9 PETs, 3 carcinoids). Endoscopic ultrasound (EUS) of 29 patients detected 88 PETs which were followed for 157 patient years. The mean annual growing rate was 13.28 +/- A 28.23 mm with respect to the baseline tumor diameter of 9 mm. In 35 patients the mean incidence of newly diagnosed PETs was 0.52/year. Adrenal lesions were invariably nonfunctional. A mean change in diameter of 6.7 +/- A 23.44% was monitored and malignant transformation was absent. Most lesions are detected at initial screening, particularly malignant tumors. Computed tomography of the abdomen and chest did not identify additional lesions. The interval between screenings could be extended to 3 years based on annually calculated growth rates and the incidence of MEN-1-associated lesions. The assessment of calcium, gastrin, and prolactin is sufficient for biochemical screening in MEN-1.