Guaraldi, Federica

AbstractObjectiveTo profile clinically non‐aggressive and aggressive pituitary adenomas (PAs)/pituitary neuroendocrine tumours (PitNETs) and pituitary carcinomas for somatic mutations and epigenetic alterations of genes involved in cell proliferation/differentiation, microRNAs (miRNA)/long noncoding RNA (LncRNA)‐post‐transcriptional regulators and therapy targets.DesignRetrospective observational study.Patients and MeasurementsA total of 64 non‐aggressive and 41 aggressive PAs/PitNETs and 6 pituitary carcinomas treated by endoscopic surgery with ≥1‐year follow‐up were included. Somatic mutations of 17 genes and DNA methylation of 22 genes were assessed. Ten normal pituitaries were used as control.ResultsWe found at least one mutation in 17 tumours, including 6/64 non‐aggressive, 10/41 aggressive PAs/PitNETs, and 1/6 pituitary carcinoma. AIP (N = 6) was the most frequently mutated gene, followed by NOTCH (4), and TP53 (3). Hypermethylation of PARP15, LINC00599, ZAP70 was more common in aggressive than non‐aggressive PAs/PITNETs (p < .05). Lower levels of methylation of AIP, GNAS and PDCD1 were detected in aggressive PAs/PITNETs than non‐aggressive ones (p < .05). For X‐linked genes, males presented higher level of methylation of FLNA, UXT and MAGE family (MAGEA11, MAGEA1, MAGEC2) genes in aggressive vs. non‐aggressive PAs/PITNETs (p < .05).In pituitary carcinomas, methylation of autosomal genes PARP15, LINC00599, MIR193 and ZAP70 was higher than in PAs/PITNETs, while X‐linked genes methylation level was lower.ConclusionsSomatic mutations and methylation levels of genes involved in cell proliferation/differentiation, miRNA/LncRNA‐post‐transcriptional regulators and targets of antineoplastic therapies are different in non‐aggressive and in aggressive PAs/PitNETs. Methylation profile also varies according to gender. Combined genetic‐epigenetic analysis, in association with clinico‐radiological‐pathological data, may be of help in predicting PA/PitNET behaviour.

Objective and design A clinicopathological score has been proposed by Trouillas et al. to predict the evolution of pituitary adenomas. Aim of our study was to perform an independent external validation of this score and identify other potential predictor of post-surgical outcome. Methods The study sample included 566 patients with pituitary adenomas, specifically 253 FSH/LH-secreting, 147 GH-secreting, 85 PRL-secreting, 72 ACTH-secreting and 9 TSH-secreting tumours with at least 3-year post-surgical follow-up. Results In 437 cases, pituitary adenomas were non-invasive, with low (grade 1a: 378 cases) or high (grade 1b: 59 cases) proliferative activity. In 129 cases, tumours were invasive, with low (grade 2a: 87 cases) or high (grade 2b: 42 cases) proliferative activity. During the follow-up (mean: 5.8 years), 60 patients developed disease recurrence or progression, with a total of 130 patients with pituitary disease at last follow-up. Univariate analysis demonstrated a significantly higher risk of disease persistence and recurrence/progression in patients with PRL-, ACTH- and FSH/LH-secreting tumours as compared to those with somatotroph tumours, and in those with high proliferative activity (grade 1b and 2b) or >1 cm diameter. Multivariate analysis confirmed tumour type and grade to be independent predictors of disease-free-survival. Tumour invasion, Ki-67 and tumour type were the only independent prognostic factors of disease-free survival. Conclusions Our data confirmed the validity of Trouillas’ score, being tumour type and grade independent predictors of disease evolution. Therefore, we recommend to always consider both features, together with tumour histological subtype, in the clinical setting to early identify patients at higher risk of recurrence.