THU089 Natural Course Of Non-Functioning Pituitary Adenoma According To Age And Sex: A Longitudinal Observational Study

Disclosure: S. Park: None. H. Kang: None. C. Ahn: None. S. Kim: None. Y. Kim: None. J. Kim: None. Backgrounds: Non-functional pituitary tumors (NFPTs) are the most common tumor among pituitary adenomas. Surgical treatment is recommended when patients present a mass effect such as a headache, visual field defect, or hormonal dysfunction. However, there is a lack of data regarding the natural course of NFPTs according to sex and age. Herein, we aimed to characterize age and sex-dependent tumor growth in patients with NFPTs. Methods: We enrolled 435 patients (males, n= 162) who were diagnosed with NFPTs and followed up at least one time and more than 12 months from 1997 to 2021 at a tertiary center. Study subjects were divided into three groups according to their age (ages≤50, 51≤age<65, age≥65 years). The characteristics and tumor growth of NFPTs were compared according to sex and age groups. Results: Male patients were older than female patients (median [range], 58.0 [47.0;65.0] vs. 50.0 [39.0;60.0], P<0.001). Annual tumor volume and percent change were higher in male patients compared to female patients (P<0.001, P=0.009, respectively). Despite the shorter follow-up duration in males (61 months in males vs. 71 months in females), male patients underwent surgery more often than female patients (25.9% vs. 11.4%, P<0.001). In male patients, there was no significant difference in the rate of tumor growth between different age groups. However, in female patients, a more rapid increase in annual tumor volume percent change was observed in the older age group compared to the younger age group (2.2 [-3.5;15.2] in females ≤50 years, 6.7 [-2.1;23.7] in 51≤ female <65 years, 10.1 [2.9;25.7] in female≥65 years, P=0.018). The relative risk of tumor growth of more than 20 percent, as compared with the reference group in females younger than 51 years, was 1.81 in the female group aged between 51 to 64 years (95% CI 1.06-3.08, P=0.029), and 2.45 in the female group older than 65 years (95% CI 1.16-5.18, P=0.019) compared to reference group of females younger than 51 years. Conclusion: The NFPT grows more rapidly in males than in females. The growth of NFPT was not significantly different according to age in males, however, in females, the growth of NFPT was more rapid in the older age group. Therefore, males and old females among patients with NFPTs should be more closely followed-up. Presentation: Thursday, June 15, 2023