Place of surgery in prolactinomas treatment (clinical study)
Authors: Matsueva I. A. , Vasukova E. A. , Paltsev A. A. , Tsoi U. A. , Grineva E. N. 
Published: November 2024

Relevance. Prolactinoma is one of the most common neuroendocrine tumors of the pituitary. Its prevalence 77,6 per 100,000 patients with pituitary masses. The first line of treatment for prolactinomas is drug therapy with dopamine agonists (DA). Cabergoline is the medicine of choice because it is more effective and has a better safety profile. In approximately 15 % of patients who fail to achieve remission of the disease even on the maximum tolerated dose of cabergoline, they are recommended to undergo transsphenoidal adenomectomy (TSA). However, in real clinical practice, when surgical treatment is performed despite achieving or nor achieving maximum tolerated dose of DA including being considered as first line of treatment. Knowing that risk of complications of TSA at the centers of excellence is practically zero and the development of remission is expected immediately after surgery, the choose of using TSA in the treatment of prolactinomas is being discussed.

Purpose and objectives of the study. Using the example of a specialized neurosurgical hospital, study the population of patients operated prolactinomas, determine the reasons for performing TSA, compare the contribution of known factors influencing remission of the disease after surgical treatment, and identify among them the most significant for the study population.

Materials and methods. The study included patients with prolactinoma who performed TSA at the V.A. Almazov National Medical Research Center in the period from 01.2018 to 03.2023, and the diagnosis of prolactinoma was confirmed by data from a morphological study of the surgical material (excatly, cells adenoma expressed prolactin). Based on the results of TSA, patients were divided into 2 groups depending on the outcome of the operation: a group of patients with succesful surgery and a group where there was no effect from the TSA (unsuccessful operation). The outcome of the operation was considered succesful when: 1) the fact of normoprolactinemia for 1 year after TSA, 2) to a significant (more than 50 %) reduction in the need for DA.

Results. The study included 60 patients with prolactinoma who performed TSA. Among the included patients, there were 36 men (60 %) and 24 women (40 %). The median age at diagnosis was 43 (Q1–Q3: 38–47) years for men and, 52 (Q1–Q3: 41–60) years for women. In 26 (43 %) patients, the indications for surgery corresponded to clinical recommendations: meanwhile 34 patients (56 %) were operated on at the request of the patient/doctor’s choice. Patients didn’t differ in age in the two groups (p = 0.447). Patients in the unsuccessful surgery group received DA therapy for a longer period of time (48 against 9 months, p < 0.001) and their weekly dosage was higher compared to patients with a positive effect from surgery (4 vs. 2 mg/week, p < 0.001). There was a statistically significant difference in such indicators as visual field impairment, deficiency of hormones of the anterior pituitary gland before/after surgery (p > 0.05).

Conclusion. In the study population, TSA was successful in 38 of them (63 %). The factors determining TSA success were the value of preoperative prolactin — 2476.5 ng/ml, the degree of invasion into the cavernous sinus according to the Knosp classification, the weekly dosage and duration of DA therapy.