Male sex, the levels of prolactin, presence of hypopituitarism and suprasellar extension are predictors of prolactinomas resistance to medical therapy

• Autor(a) principal: Mariana Pires Garcia
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: https://hdl.handle.net/10216/150323
• topic: Ciências médicas e da saúde; Medical and Health sciences

Introduction - International guidelines recommend dopamine agonists as first-line treatment strategy for prolactinomas. Dopaminergic agonists allow the normalization of prolactin levels and the reduction of the tumor dimension. Despite its high efficacy, some prolactinomas are resistant to this therapy. Therefore, this retrospective study aims to identify differences between resistant and responder prolactinomas, to better identify them in clinical practice. Methods - Clinical, laboratory, and imaging characteristics of a cohort of 122 prolactinomas, followed at Centro Hospitalar Universitário de São João, were analyzed. Resistance was defined as the use of cabergoline in doses superior to 3 mg/week without lowering prolactin levels or tumor size. Results are presented as mean ± standard deviation and compared as appropriated, namely using a univariate and multivariate analysis. Results - We considered 114 patients as responders (23.7% male; age 21.5 ± 11.0 years; mean prolactin levels 147.0 ng/mL; 2.8% without visible lesion, 52.8% micro and 44.4% macroprolactinomas; suprasellar extension in 28.2%; infrasellar extension in 28.0% and parasellar extension in 30.1%) and 8 resistant (62.5% male; age 16.8 ± 12.9 years; mean prolactin levels 2430.0 ng/mL; all of them were macroprolactinomas and 87.5% presented extension in at least one of the 3 considered dimensions). Responders used medium doses of 6.6 ± 6.3 mg/day of bromocriptine and 1.1 ± 0.6 mg/week of cabergoline, while resistants used 16.3 ± 11.1 mg/day of bromocriptine and 5.4 ± 4.3 mg/week of cabergoline. One resistant patient was treated with temozolomide. All resistant had hypogonadism and presented more pituitary hypofunctions than responders. Conclusion - Male sex, higher prolactin levels, hypopituitarism and suprasellar extension are predictors of prolactinomas resistance to dopaminergic agents.