The effect of somatostatin analogues on Ki-67 levels in GH-secreting adenomas

Recurrent Cushing's Disease in Adults: Predictors and Long-Term Follow-Up

Cushing's disease (CD) is characterized by endogenous hypercortisolism that is associated with increased mortality and morbidity. Due to high recurrence rates in CD, the determination of high-risk patients is of paramount importance. In this study, we aimed to determine recurrence rates and clinical, laboratory, and histological predictors of recurrence in a high volume single-center. This retrospective study included 273 CD patients operated in a single pituitary center between 1997 and 2020. The patients with early postoperative remission were further grouped according to recurrence status (recurrent and sustained remission groups). Demographic, radiologic, laboratory, pathologic, and follow-up clinical data of the patients were analyzed and compared between groups. The recurrence rate was 9.6% in the first 5 years; however, the overall recurrence rate was 14.2% in this study. Higher preoperative basal ACTH levels were significantly correlated with CD recurrence even with ACTH levels adjusted for tumor size, Ki-67 levels, and tumoral invasion. Recurrence rates were significantly higher in patients with ACTH levels higher than 55 pg/ml, tumor diameter>9.5 mm, and if adrenal axis recovery was before 6 months. The severity of hypercortisolism, morbidities, and demographic factors except age were not predictive factors of recurrence. Based on our study data, younger age at diagnosis, a diagnosis of osteoporosis, higher preoperative ACTH levels, larger tumor size, invasive behavior, higher Ki 67 index, and early recovery of the adrenal axis during the postoperative period attracted attention as potential predictors of recurrent disease.

Real-life clinical impact of a five-tiered classification of pituitary tumors

INTRODUCTION

Usually benign, pituitary tumors (PT) can be invasive and aggressive with a propensity to progress and/or recur. Trouillas's clinicopathological classification attempts to predict the evolutionary risk of a PT. In this study, we assessed the prognostic value of this classification in an independent patient cohort and analyzed its impact on treatment strategies.

PATIENTS AND METHODS

In this study, 607 patients operated on between 2008 and 2018 for a PT were included. Grading was established based on invasion, proliferative activity (Ki-67, mitotic index) and p53 positivity. The therapeutic management following surgery was analyzed. Progression-free survival (PFS) of the graded tumors was estimated (Kaplan-Meier method and log-rank test) and a multivariate analysis was performed (Cox regression model).

RESULTS

Grading identified non-invasive PT without (grade 1a: 303 cases) or with proliferative activity (grade 1b: 53 cases) and invasive PT without (grade 2a: 202 cases) or with proliferative activity (grade 2b: 49 cases). The mean follow-up was 47 ± 30 months (median: 38 months). Progression/recurrence occurred in 127 cases. Grades were significant and independent predictors of PFS (P < 0.001) with a 4.8-fold higher risk of progression/recurrence in grade 2b as compared to grade 1a. As second-line therapy, gamma knife or conventional radiotherapy controlled tumor growth in 91.6 and 100% of cases, respectively, irrespective of the grade. Proliferative tumors exposed the patient to a 9.5-fold higher risk of having ≥3 adjuvant therapeutic lines as compared to non-proliferative tumors.

DISCUSSION

Grading of a PT according to Trouillas's classification predicts its risk of progression and should advocate for a personalized therapeutic approach in invasive and proliferative tumors.

SIGNIFICANCE STATEMENT

This is the first study to assess, on a cohort of 607 well-characterized patients, the real-life therapeutic impact of the five-tiered clinicopathological classification of pituitary tumors. First, we validate that pituitary tumor grades predict the evolutionary risk of the tumor, with a significant higher risk of progression/recurrence in invasive and/or proliferative tumors (mean follow-up: 47 ± 30 months, median: 38 months). Moreover, our study provides evidence that patients with proliferative tumors have a higher risk to be retreated after primary surgery and point toward the fact that radiotherapy can successfully control tumor growth in case of progression or recurrence. Our findings advocate for a personalized therapeutic approach in clinically aggressive pituitary tumors.

Preoperative Medical Treatment for Patient with Acromegaly: yes or no?

Transsphenoidal surgery is the first-line treatment for acromegaly. However, several factors can modify surgical remission rates, such as the initial hormone levels, the size and invasiveness of the tumor, and the degree of experience of the surgeon. Physicians treating patients with acromegaly should thus consider how to improve surgical remission rates. As stated in recent guidelines, the major point is to consider that any patient with acromegaly should be referred to an expert neurosurgeon to maximize the chances of surgical sure. The benefits of presurgical medical treatment, mainly using somatostatin receptor ligands (SRLs), given 3 to 6 months before surgery, remain controversial. By normalizing growth hormone and insulin-like growth factor 1 levels, SRLs may improve the overall condition of the patient, thus decreasing anesthetic and surgical complications. By decreasing the tumor size and modifying the consistency of the tumor, SRLs might also make surgical excision easier. This is however theoretical as published data are contradictory on both points, and only limited data support the use of a systematical presurgical medical treatment. The aim of this review is to analyze the potential benefits and pitfalls of using presurgical medical treatment in acromegaly in view of the contradictory literature data. We also attempt to determine the profile of patients who might most benefit from this presurgical medical treatment approach as an individualized therapeutic management of acromegaly.

A Nomogram for Preoperatively Predicting the Ki-67 Index of a Pituitary Tumor: A Retrospective Cohort Study

Background

The Ki-67 index is an indicator of proliferation and aggressive behavior in pituitary adenomas (PAs). This study aims to develop and validate a predictive nomogram for forecasting Ki-67 index levels preoperatively in PAs.

Methods

A total of 439 patients with PAs underwent PA resection at the Department of Neurosurgery in Jinling Hospital between January 2018 and October 2020; they were enrolled in this retrospective study and were classified randomly into a training cohort (n = 300) and a validation cohort (n = 139). A range of clinical, radiological, and laboratory characteristics were collected. The Ki-67 index was classified into the low Ki-67 index (<3%) and the high Ki-67 index (≥3%). Least absolute shrinkage and selection operator algorithm and uni- and multivariate logistic regression analyses were applied to identify independent risk factors associated with Ki-67. A nomogram was constructed to visualize these risk factors. The receiver operation characteristic curve and calibration curve were computed to evaluate the predictive performance of the nomogram model.

Results

Age, primary-recurrence subtype, maximum dimension, and prolactin were included in the nomogram model. The areas under the curve (AUCs) of the nomogram model were 0.694 in the training cohort and 0.658 in the validation cohort. A well-fitted calibration curve was also generated for the nomogram model. A subgroup analysis revealed stable predictive performance for the nomogram model. A correlation analysis revealed that age (R = −0.23; p < 0.01), maximum dimension (R = 0.17; p < 0.01), and prolactin (R = 0.16; p < 0.01) were all significantly correlated with the Ki-67 index level.

Conclusions

Age, primary-recurrence subtype, maximum dimension, and prolactin are independent predictors for the Ki-67 index level. The current study provides a novel and feasible nomogram, which can further assist neurosurgeons to develop better, more individualized treatment strategies for patients with PAs by predicting the Ki-67 index level preoperatively.

Medication for Acromegaly Reduces Expression of MUC16, MACC1 and GRHL2 in Pituitary Neuroendocrine Tumour Tissue

Acromegaly is a disease mainly caused by pituitary neuroendocrine tumor (PitNET) overproducing growth hormone. First-line medication for this condition is the use of somatostatin analogs (SSAs), that decrease tumor mass and induce antiproliferative effects on PitNET cells. Dopamine agonists (DAs) can also be used if SSA treatment is not effective. This study aimed to determine differences in transcriptome signatures induced by SSA/DA therapy in PitNET tissue. We selected tumor tissue from twelve patients with somatotropinomas, with half of the patients receiving SSA/DA treatment before surgery and the other half treatment naive. Transcriptome sequencing was then carried out to identify differentially expressed genes (DEGs) and their protein–protein interactions, using pathway analyses. We found 34 upregulated and six downregulated DEGs in patients with SSA/DA treatment. Three tumor development promoting factors MUC16, MACC1, and GRHL2, were significantly downregulated in therapy administered PitNET tissue; this finding was supported by functional studies in GH3 cells. Protein–protein interactions and pathway analyses revealed extracellular matrix involvement in the antiproliferative effects of this type of the drug treatment, with pronounced alterations in collagen regulation. Here, we have demonstrated that somatotropinomas can be distinguished based on their transcriptional profiles following SSA/DA therapy, and SSA/DA treatment does indeed cause changes in gene expression. Treatment with SSA/DA significantly downregulated several factors involved in tumorigenesis, including MUC16, MACC1, and GRHL2. Genes that were upregulated, however, did not have a direct influence on antiproliferative function in the PitNET cells. These findings suggested that SSA/DA treatment acted in a tumor suppressive manner and furthermore, collagen related interactions and pathways were enriched, implicating extracellular matrix involvement in this anti-tumor effect of drug treatment.

Ki67 in endocrine neoplasms: to count or not to count, this is the question! A systematic review from the English language literature

BACKGROUND

Endocrine neoplasms are generally slow-growing tumors that can show hormonal activity and give metastases. In most cases they are benign and clearly malignant forms are easy to diagnose. However, borderline forms may occur and be, for the pathologists, very difficult to classify. In these cases, there is a strong need to identify factors that may aid. Official classification systems for endocrine neoplasms are based on the evaluation of proliferation and, in most cases, they rely on mitotic count. In support, the study of Ki67 is carried out which, however, has not yet been included in any official classification system, except for neuroendocrine neoplasms of the gastro-entero-pancreatic tract.

PURPOSE

The aim of the present study was to investigate the proven or unproven role of Ki67 in endocrine neoplasms, in different districts, in order to bring to light the substantial differences, in terms of proliferation, existing between neoplasms so similar, but at the same time, so different.

METHODS

A thorough search of English language literature was performed, looking for articles concerning Ki67 in five endocrine neoplasms (pituitary adenomas, thyroid neoplasms, adrenocortical neoplasms, pheochromocytomas and paragangliomas).

RESULTS

From 2170, 236 articles were selected and it was seen that the endocrine neoplasm in which Ki67 was most studied was the pituitary, where it still shows a controversial role. In other neoplasms different roles were identified.

CONCLUSION

The pathologist should be aware of the contribution that this proliferative marker can give to the diagnosis and, sometimes, to the therapy selection, for the clinician.

SNPs of miR-23b, miR-107 and HMGA2 and their Relations with the Response to Medical Treatment in Acromegaly Patients

INTRODUCTION

Acromegaly is a chronic disease of increased growth hormone (GH) secretion and elevated insulin-like growth factor-I (IGF-I) levels induced by a pituitary adenoma. HMGA2 (high mobility group A2) and AIP (aryl hydrocarbon receptor-interacting protein) expression levels are related to GH-secreting adenomas, and also a response to Somatostatin Analogs (SSAs). We studied SNPs in miR-107 and miR-23b that related with AIP and HMGA2 genes respectively and control their expression, and also SNP in the 3'UTR of HMGA2 gene. Our aim was to investigate genotype distributions of the studied SNPs, as well as the possible relationship between disease and/or response to SSAs treatment in patients with acromegaly.

MATERIAL AND METHODS

Genotypes were determined by qRT-PCR method from DNA materials obtained blood samples of acromegaly patients (141) and healthy individuals (99). The genotype distributions of patients and healthy groups, as well as the relationship between the clinical data of the disease and genotypes were statistically compared.

RESULTS

In acromegaly patients with T-allele, p53 expression (p=0.049) was significantly higher. In patients with CT+TT genotype and T-allele who were responder to SSA-treatment Ki-67 index (respectively p=0.019, p=0.020 respectively) was higher. We did not observe the genotypes for miR-23b and miR-107 polymorphisms in the patients and control group of Turkish population.

CONCLUSION

The genetic variations of the miRNAs genes related with HMGA2 and AIP genes were not seen in our study. Although there is no relationship between HMGA2-rs1351394 polymorphism and acromegaly disease, T allele was associated with some clinical features related to adenoma in patients with acromegaly.

MGMT immunohistochemistry in pituitary tumors: controversies with clinical implications

INTRODUCTION

Temozolomide (TMZ) is currently considered as a rational therapeutic option for patients with progressively aggressive pituitary adenomas and carcinomas not responding to conventional therapies. Administration of TMZ results in clinical response and improvement in survival of many of these patients depending upon the expression of the DNA repair enzyme O-6 methylguanine DNA transferase (MGMT). Low or negative MGMT immunoreactivity predicts responsiveness to TMZ therapy. Therefore, MGMT serves as a criterion to select candidate patients anticipating response to treatment.

MATERIALS AND METHODS

The MGMT expression was investigated in 25 pituitary adenomas with Ki-67 labeling index more that 3% and p53 expression, using various antigen retrieval protocols. After direct application of the antibody, only one adenoma yielded positive for MGMT. However, after pretreatment of tissue sections with antigen retrieval protocols, another 3 adenomas, initially negative turned to positive.

CONCLUSIONS

These findings could explain lack of response to TMZ treatment in patients with false negative MGMT immunohistochemistry. Evaluation of tumor samples for MGMT expression should carefully be carried-out using the optimum immunohistochemical protocol to obtain consistent and reliable results that help to identify patients that could respond to TMZ therapy.