[Expression of estrogen and progesterone receptors in vestibular schwannomas]. / Analiz ekspressii retseptorov estrogena i progesterona v vestibulyarnykh shvannomakh.

INTRODUCTION: Stereotactic radiosurgery is one of the main treatments for vestibular schwannomas (VS). Their feature is frequent post-radiation pseudoprogression. This may be due to hormonal status of patients. OBJECTIVE: To analyze expression of progesterone and estrogen receptors in women and men with VS. MATERIAL AND METHODS: Immunohistochemical analysis of expression of progesterone (PR) and estrogen receptors (ER) after biopsy was performed in 240 patients with VS between 2018 and 2021. ER/PR expression was assessed in men (n=120) and women (n=120) in 3 age subgroups: young age (18-44 years), middle age (45-59 years) and old age (60-79 years). Each subgroup included 40 patients. Statistical analysis was performed using the Mann-Whitney test and MedCalc software. RESULTS: ER expression is not typical for VS (men - 1 (0.01%), women - 3 (2.5%)). At the same time, PR expression was found in 29 (24.2%) men and 21 (17.5%) women. We found no significant difference in expression of ER and PR between men and women. However, variability in PR expression was revealed, i.e. predominance of this indicator in young women (p=0.0463) and middle-aged men (p=0.0110). Expression of PR was similar in elderly patients (p=0.2382). CONCLUSION: The established incidence of PR expression may be one of the probable causes affecting development and duration of VS pseudoprogression after radiosurgery without clear relationship between sex and age. Further prospective research is needed to predict the risks of pseudoprogression.

[Stereotactic radiosurgery for vestibular schwannoma: early and long-term radiation-induced changes and tumor growth control]. / Radiokhirurgiya vestibulyarnykh shvannom: dinamika blizhaishikh i otdalennykh postluchevykh izmenenii i kontrol' opukholevogo rosta.

Stereotactic radiosurgery of vestibular schwannoma is an effective and safe method of treatment. The phenomenon of schwannoma pseudo-progression (transient post-radiation enlargement) complicates assessment of the outcomes after radiosurgery. OBJECTIVE: To investigate the changes of vestibular schwannoma in different periods after radiosurgery. MATERIAL AND METHODS: We analyzed early and long-term radiation-induced changes in 333 patients who received Gamma Knife treatment at the Burdenko Neurosurgery Center between April 2005 and December 2015. Mean follow-up period was 60 months (range 15-167). There were 89 men (26.7%) and 244 (73.4%) women. Mean age of patients was 48.2 years. Mean baseline tumor volume was 4.1 cm3 (range 0.1-14.5). Dynamics of changes was assessed using volumetric comparison. RESULTS: Tumor shrinkage without pseudo-progression was observed in 149 (44.7%) patients. Typical pseudo-progression in different variants was found in 131 (39.3%) patients, i.e. short-term (1 year) and long-term (≥2 years) course, complete and incomplete process. Eleven patients had atypical pseudo-progression after initial tumor shrinkage. Progression-free 5- and 10-year survival in the entire group was 87 and 81%, respectively. Progression-free 5-year survival rate was 95 and 92% in patients with and without pseudo-progression, respectively. Ten-year survival rate was 89 and 89%, respectively. CONCLUSION: Knowledge of pseudo-progression features is essential for the most reasonable and reliable assessment of treatment results and justification of timing and frequency of subsequent MR control. Atypical course of pseudo-progression can simulate tumor recurrence. In case of tumor enlargement at any follow-up stage after radiosurgery, advisability of surgery should be determined considering clinical data and likelihood of tumor shrinkage following natural regression of post-radiation tumor enlargement.