9281 Menopause Has a Beneficial Influence on the Evolution of Prolactinomas: a Study in 95 Patients

Abstract Disclosure: S. Constantinescu: None. C. Nava: None. F. Chasseloup: None. P. Chanson: Consulting Fee; Self; Eli Lilly & Company, Recordati, Ipsen, Novo Nordisk. O. Alexopoulou: None. D.M. Maiter: Consulting Fee; Self; Ipsen, Recordati, Pfizer, Inc. The natural occurrence of menopause is considered to have beneficial effects in women with a prolactinoma and represents a window of opportunity for successful dopamine agonist (DA) withdrawal. Strong evidence for these effects remains however scarce. We retrospectively analyzed data from 95 women undergoing menopause (Mp) (FSH>35 U/L) while still treated with DA (cabergoline (CAB) in 82) for a prolactinoma diagnosed at a mean age of 38.0 ± 8.0 years. The pituitary tumor was a microadenoma in 66 and a macroadenoma in 29 (invasive in 12). Our objectives were to identify the influence of menopause on the evolution of treated prolactinomas and on the risk of recurrence after DA withdrawal. In post-menopausal women still treated with DA (median dose of 0.50 mg CAB/week or equivalent), a significant decrease in median prolactin (PRL) was observed from a premenopausal value of 15.1 µg/L to 10.7 µg/L 3-6 months after Mp (n=64, P=0.05) and to 7.7 µg/L 24 months after Mp (n=43, P < 0.001). There was also a significant reduction in median coronal tumor surface at 24 months, from 12.6 to 7.1 mm² (p < 0. 01). DA treatment was withdrawn in 53 women (56%) after a median interval of 26 months after menopause (range: 3-262). Strict criteria for discontinuation were fulfilled in 52 of them: a normal PRL for at least 24 months under a cabergoline dose ≤ 0.50 mg/week and a more than 50%-reduction in tumor surface area for macroadenomas. Among them, 37 women (71%) remained in remission during a median follow-up period of 26 months (range: 6-176), while 15 (29%) had an asymptomatic biological recurrence after a median duration of 6 months (range: 2-47). Only one woman showed minimal tumor regrowth. 12/15 of the biological recurrences of hyperprolactinemia occurred within the first year after withdrawal and the estimated probability of remission at 5 years was 66%. Multivariate analysis showed that the only independent predictor of recurrence was the PRL value observed 3 to 6 months after DA discontinuation (p = 0.028). Estrogen-progestin replacement therapy, given in 21 women, did not influence these outcomes. In conclusion, we confirm that menopause has a beneficial effect on the evolution of treated and untreated prolactinomas. When using strict criteria for DA withdrawal in the post-menopausal period, a sustained clinical and biological remission can be expected in two-thirds of women, and when recurrence occurs, it is usually mild and asymptomatic. Presentation: 6/2/2024