Endocrine Abstracts

Context: Prolactinomas are the most common functioning pituitary adenomas & it is recognised that gender has an influence on presentation and management of this condition.

Objective: To examine the effects of gender on presentation and response to treatment in a large cohort of adults with confirmed prolactinoma (MRI performed and macroprolactin excluded).

Design & patients: This retrospective cohort study design used an electronic database (Diabeta3^®) to identify adult patients with prolactinoma attending the endocrinology department of a University Teaching Hospital from October 2007-February 2008. Data including tumour size, prolactin levels, age at diagnosis, current management and gender were recorded.

Results: Three hundred and sixty-nine patients (326 females, 43 males; 7.3:1 females to males) with prolactinoma were included in the study. In the total cohort the ratio of microprolactinoma-to-macroprolactinoma was 8.2:1. Males presented significantly later in life than females (43.7±16.5 vs 31.4±8.5 years (mean±SD), P=<0.0001), with higher prolactin levels (53 339±10 4240 vs 3799±11 020 mU/l, P=<0.0001) and a larger tumour size at diagnosis (16.4±15.3 vs 7.7±4.23 mm, P=<0.0001). The majority of patients were receiving cabergoline therapy (51.5%). A higher proportion of males than females achieved normoprolactinemia (62.8 vs 44.2%, P=0.03) with men receiving a higher dose of cabergoline per week (1000 μg (250–6000) versus 500 μg (250–3000) (median (range)), P=0.0003).

Conclusions: Prolactinomas occur more frequently in females but males present at a later age with higher PRL levels and larger tumour size at diagnosis. In this study the overall rates of biochemical normalisation were low, although males had higher rates of normoprolactinemia during treatment. This may reflect more aggressive treatment of the relatively larger prolactin secreting adenomas seen in males and a ‘tolerance’ of modest hyperprolactinaemia in females without clinical symptoms from prolactin excess.