[Correlation analysis of anterior pituitary hormone and tumor size in patients with pituitary adenomas]

Objective: To summarize the correlation between anterior pituitary function and tumor size in patients with different hormone-secreting pituitary adenomas. Methods: This was a retrospective case series study. The clinical data of 1 946 patients with pituitary adenoma hospitalized in the First Medical Center of Chinese PLA General Hospital from January 1, 2005, to December 31, 2020, were collected. The correlation between tumor size and anterior pituitary hormone levels was analyzed using Spearman rank correlation analysis in different types of pituitary adenomas. Results: The median age of the 1 946 patients was 45.1 years, of which 857 (44.0%) were men. The maximum tumor diameter of the patients [M (Q₁, Q₃)] was 22 (14, 30) mm. Tumor size in nonfunctioning adenomas (n=1 191) was negatively correlated with adrenocorticotropic hormone (ACTH) (r=-0.11, P<0.001), growth hormone (r=-0.13, P<0.001), and luteinizing hormone (men: r=-0.26, P<0.001, women: r=-0.31, all P<0.001). The tumor size of somatotropic adenomas (n=297) was positively correlated with growth hormone (r=0.46, P<0.001), but negatively correlated with male testosterone (r=-0.41, P<0.001). The tumor size of ACTH-secreting pituitary adenomas (n=155) was positively correlated with the ACTH level at 8∶00 AM (r=0.25, P<0.001); however, no correlation was found with cortisol at 8∶00 AM (P>0.05). The tumor size of prolactinomas (n=303) was positively correlated with the prolactin level (men: r=0.34, P=0.001; women: r=0.13, P=0.070). Conclusions: The correlation between the function of the anterior pituitary and size of the tumor depends on the cellular origin of the pituitary adenoma and specific type of hormone secretion. In somatotroph adenomas, ACTH-secreting pituitary adenomas, and prolactinomas, there is a positive correlation between tumor size and level of hormones secreted by the corresponding tumors. In patients with nonfunctioning adenomas, the tumor size was negatively correlated with the hormone levels of the pituitary-adrenal and pituitary-growth hormone axes.