Cytokeratin 5.2 expression as a predictive marker of outcome in patients with acromegaly following endoscopic transsphenoidal surgery.

backgroundThe study aimed to characterize clinico-radiological differences and their impact on post-surgical outcomes in histological subtypes of somatotroph adenomas (SA): densely granulated (DGSA) and sparsely granulated (SGSA).

methodsA single-centre study in individuals with SA from 2015 to 2024, where preoperative clinical, hormonal, and magnetic resonance imaging parameters were collected, and biochemical and radiological disease control were assessed postoperatively.

resultsOf 116 SA, 45(38.8%) and 71(61.2%) were DGSA and SGSA, respectively. The median (IQR) age at presentation was 35.0 (29.0–44.0) years, 56.9% were females, 92.2% had macroadenoma, and the mean tumour diameter was 24.9 ± 10.3 mm. The pre-operative nadir GH on OGTT [median (IQR)] was 31.1 (16.7–50.0) ng/mL, and IGF-1 was 3.7 ± 1.5 times the upper limit of normal. As compared to DGSA, SGSA presented earlier [40.0 vs. 33.5 years; p = 0.009], had larger tumor size [ 2239.4 mm3 vs. 5221.6 mm3; p = 0.005], were more invasive [ 33.3% vs. 54.1%; p = 0.038], proliferative [ki-67 Index 1.0% vs. 3.0%; p < 0.001], and had higher SSTR5 expression [H score 30.0 vs. 80.0; p = 0.006]. The post-surgical radiological [19.4% vs. 22.8%; p = 0.707 (NS)] and biochemical [17.2% vs. 32.2%; p = 0.727(NS)] disease control rates were similar in both groups.

conclusionIn comparison to DGSA, SGSA presents a decade earlier, are larger in size, more invasive, exhibits higher proliferation, and SSTR5 expression. However, this does not impact post-surgical biochemical and radiological disease control.