Gender-related differences in MEN1 lesion occurrence and diagnosis: a cohort study of 734 cases from the Groupe d'etude des Tumeurs Endocrines

Context: Multiple endocrine neoplasia type 1 (MEN1) disease is an autosomal dominant syndrome that is believed to equally affect men and women. This assumption has never been confirmed. Objective: The aims of this study were to evaluate the impact of gender on the prevalence of MEN1 lesions, on their lifetime probability of occurrence, and on the diagnosis of MEN1. Design: Data regarding a study of 734 cases of MEN1 from the multicenter 'Groupe d'etude des Tumeurs Endocrines' were analyzed. Results: There were 57.8% females. The prevalence and probability of pancreatic tumors were higher in males than in females (P=0.06, P=0.0004). This difference was due to gastrinomas. The prevalence and probability of developing pituitary tumors were significantly greater in females (P<0.001, P<0.0001). Thymic tumors were exclusively found in men. There were no significant gender differences in the prevalence and the probability of developing hyperparathyroidism, or adrenal and bronchial tumors, or in the proportion of positive genetic tests. A family history of MEN1 was more frequently found in men than in women at the time of diagnosis (P=0.02). In the case of pituitary tumor, the proportion of patients diagnosed with MEN1 at the time of the first lesion was lower in women (44.2%) than in men (67.3%). Conclusion: The phenotype expression of the MEN1 disease gene was different in males and females. In female patients, the possibility of MEN1 is not sufficiently taken into account. Any patient presenting a lesion that belongs to the MEN1 spectrum, such as a pituitary tumor, should be closely questioned about their family history and should be tested for hypercalcemia.