The Prognostic-Based Approach in Growth Hormone-Secreting Pituitary Neuroendocrine Tumors (PitNET): Tertiary Reference Center, Single Senior Surgeon, and Long-Term Follow-Up

Grading and staging for pituitary neuroendocrine tumors

Pituitary adenoma/pituitary neuroendocrine tumors (PitNETs) are the second most common primary intracranial tumor and the most frequent neuroendocrine tumors/neoplasms of the human body. Thus, they are one of the most frequent diagnoses in neuropathologist's practise. 2022 5th edition WHO Classification of Endocrine and Neuroendocrine Tumors does not support a grading and/or staging system for PitNETs and argues that histological typing and subtyping are more robust than proliferation rate and invasiveness to stratify tumors. Numerous studies suggest the existence of clinically relevant molecular subgroups encouraging an integrated histo-molecular approach to the diagnosis of PitNETs to deepen the understanding of their biology and overcome the unresolved problem of grading system. The present review illustrates the main issues involved in establishing a grading and a staging system, as well as alternative systems validated by independent series to date. The state of art of the current histological and molecular markers is detailed, demonstrating that a standardized and reproducible clinico-pathological approach, combined with the integration of molecular data may help build a workflow to refine the definition of PitNETs with 'malignant potential' and most importantly, avoid delay in patient treatment. Next molecular studied are needed to validate an integrated histo-molecular grading for PitNETs.

Predictors of growth hormone level on postoperative day one in patients with acromegaly

PURPOSE

The growth hormone (GH) level on postoperative day one (POD1), i.e., POD1GH, holds significant value in assessing surgical efficacy and predicting long-term remission in patients with acromegaly. This study aims to explore the factors that influence the GH level of POD1 after microscopic transsphenoidal surgery (mTSS) in patients with acromegaly, providing insights for preoperative clinical decisions.

METHODS

A total of 85 acromegaly patients undergoing mTSS were included in this study. Sex; age; body mass index (BMI); preoperative serum hormone levels and tumor characteristics were assessed for their correlation with POD1GH levels. POD1GH level non-remission, defined as POD1GH > 2.5 ng/mL, was considered an outcome.

RESULTS

The patients with acromegaly were divided into two groups: adult males (43 cases) and adult females (42 cases), with mean ages of 43.33 ± 11.92 years and 47.02 ± 14.18 years, respectively. Correlation and multivariate linear regression analyses revealed positive correlations of preoperative GH and prolactin (PRL) levels in females with POD1GH levels, while preoperative FT3 and TT levels in males were negatively correlated with POD1GH levels. Binary logistic regression and receiver operating characteristic (ROC) analyses identified preoperative GH levels ≥30.25 ng/mL (OR = 2.236, 95%CI = 1.402-3.567, p < 0.001), FT3 levels ≤4.415 pmol/L (OR = 0.329, 95%CI = 0.167-0.648, p < 0.001), and age ≤51 years (OR = 0.566, 95%CI = 0.352-0.911, p = 0.019) as independent risk factors for POD1GH level non-remission.

CONCLUSIONS

Preoperative GH, FT3, TT, and PRL levels are correlated with POD1GH levels, with variations observed between sex. Age, preoperative GH, and FT3 levels can predict POD1GH level non-remission. Therefore, the comprehensive consideration of multiple hormone axes is necessary for predicting postoperative efficacy.

How to standardize the diagnostic approach to pituitary neuroendocrine tumors

Pituitary tumors present heterogeneous biochemical, clinico-radiological, and histological features. Although histologically benign, a non-negligible number of cases present an unpredictable aggressive behavior with local invasiveness, partial/complete resistance to treatment and/or recurrence after surgery, and, rarely, metastasize, overall leading to a significant increase of morbidity, and, thus, requiring skilled multidisciplinary management in referral Centers. Histopathological diagnosis is essential to stratify cancer patient risk and uniform follow-up among Centers. Classification of pituitary neoplasia is continuously evolving in relation to the increased knowledge of mechanisms underlying adenohypophyseal cell tumorigenesis, and the attempts of combining clinico-radiological, biochemical, intraoperative, histological, and molecular elements, with the aim of identifying aggressive forms through. An integrated standardized histopathological report has been proposed in 2019 by the European Pituitary Pathology Group, based on the indications of the 2017 WHO classification of pituitary tumors. The last edition of the WHO Classification of Central Nervous System Tumors and of Endocrine and Neuroendocrine Tumors brought substantial novelties: 1) the replacement of the term "adenoma" with "Pituitary Neuroendocrine Tumor" (PitNET), and of "carcinoma" with "metastatic PitNET," and the consequent ICD-11 recoding from benign to malignant disease; and 2) the pivotal role of lineage restricted pituitary transcription factors for histological typing and subtyping. However, this approach does not reflect the spectrum of tumor phenotypes based on hormone secretion, nor include molecular features. Efforts of interdisciplinary groups of pituitary experts should be strongly encouraged to better understand factors involved in PitNETs evolution and, consequently, standardize diagnosis and reporting based on the most recent knowledges, essential to stratify cancer patient risk and uniform follow-up among centers.

Clinical implications of the 2022 WHO classification on the multidisciplinary management of PitNETS patients

The review explores the 2022 update to the World Health Organization (WHO) classification of pituitary adenomas, now referred to as pituitary neuroendocrine tumors (PitNETs), and his possible impact on the clinical management of PitNET patients. The review highlights the differences and the evolution from the 2017 to 2022 version, with the current classification considering the lineage of the tumor cells, cell type, hormones produced, and other auxiliary characteristics for a comprehensive histological classification. The revision in terminology reflects a broader perspective on neuroendocrine neoplasia. The new approach based on transcription factors, hormone expression and other biomarkers has allowed a major revision of the nomenclature and a more accurate classification of pituitary adenomas. Furthermore, in some cases this approach is also assuming a prognostic value, useful in clinical practice. However, despite this elaborate classification and stratification, the review points out the lack of a robust grading or staging system and suggests the need for further research and validation of diagnostic methods. Despite these limitations, the revised classification presents a significant step towards understanding and managing PitNETs patients.

Clinicopathological Analysis of Densely and Sparsely Granulated Somatotroph Tumors of Pituitary

OBJECTIVE

Somatotroph tumors are the second most common type of pituitary neuroendocrine tumors, which can be further classified into 2 subtypes-densely granulated somatotroph tumors (DGSTs) and sparsely granulated somatotroph tumors (SGSTs). The aim of this study was to investigate the clinical significance of the 2 subtypes in a retrospective analysis.

METHODS

From the database of the Ningbo Clinical Pathology Diagnosis Center, we collected patients diagnosed with pituitary somatotroph tumors. We then compiled pertinent clinical and radiological data and proceeded with histopathological examination involving hematoxylin-eosin staining and immunohistochemical staining. Subsequent analysis compared the 2 subtypes using either χ2 test or Fisher exact test.

RESULTS

We analyzed 40 cases of somatotroph tumors, 18 cases DGSTs and 22 SGSTs. Male-to-female ratio was 5:4 for DGSTs and 4:7 for SGSTs. Mean age was 52.83 years for DGSTs and 47.18 years for SGSTs. Statistically significant differences were observed between the DGST and SGST groups in invasiveness (P = 0.0267) and postoperative remission (P = 0.007). Cells of both DGSTs and SGSTs exhibited coexpression of PIT1, growth hormone, and CAM5.2, although the patterns of CAM5.2 expression differed between the 2 subtypes.

CONCLUSIONS

The efficacy of CAM5.2 staining in distinguishing between DGSTs and SGSTs was demonstrated. SGSTs, with their increased invasiveness and lower remission rate, are a high-risk subtype. The histological subtype of somatotroph tumors plays a crucial role in guiding treatment decisions and prognostic evaluation in affected patients.

[Unification of pathomorphological examination of patients with neuroendocrine tumors of the pituitary gland. Controversial issues of the new classification]

The progressive improvement of the classification using modern analytical methods is an essential tool for the development of precise and personalized approaches to the treatment of pituitary adenomas. In recent years, endocrinologists have witnessed evolutionary changes that have occurred in the histopathological identification of pituitary neoplasms, revealing new possibilities for studying tumorigenesis and predicting biological behavior.The paper considers the historical aspects of the gradual improvement of the classification of pituitary adenomas, as well as the new international 2022 WHO classification, according to which pituitary adenomas are included in the list of neuroendocrine tumors (PitNETs) to reflect the biological aggressiveness of some non-metastatic pituitary adenomas. The characteristics of pituitary adenoma are presented, as well as a list of histological subtypes of aggressive neuroendocrine tumors of the pituitary gland, marked by the main potentials for invasive growth, an increased risk of recurrence and a negative clinical prognosis.The expediency of changing the definition of «pituitary adenoma» to «neuroendocrine tumor» is discussed. It is emphasized that the introduction of a unified clinical, laboratory and morphological protocol into national clinical practice will help provide comparable comparative studies on the prognosis of the disease and the effectiveness of secondary therapy and also contribute to adequate management of potentially aggressive PitNETs.

Prognostic Models in Growth-Hormone- and Prolactin-Secreting Pituitary Neuroendocrine Tumors: A Systematic Review

Growth-hormone (GH)- and prolactin (PRL)-secreting PitNETs (pituitary neuroendocrine tumors) are divided into multiple histological subtypes, which determine their clinical and biological variable behavior. Proliferation markers alone have a questionable degree of prediction, so we try to identify validated prognostic models as accurately as possible. (1) Background: The data available so far show that the use of staging and clinical-pathological classification of PitNETs, along with imaging, are useful in predicting the evolution of these tumors. So far, there is no consensus for certain markers that could predict tumor evolution. The application of the WHO (World Health Organisation) classification in practice needs to be further evaluated and validated. (2) Methods: We performed the CRD42023401959 protocol in Prospero with a systematic literature search in PubMed and Web of Science databases and included original full-text articles (randomized control trials and clinical trials) from the last 10 years, published in English, and the search used the following keywords: (i) pituitary adenoma AND (prognosis OR outcome OR prediction), (ii) growth hormone pituitary adenoma AND (prognosis OR outcome OR prediction), (iii) prolactin pituitary adenoma AND (prognosis OR outcome OR prediction); (iv) mammosomatotroph adenoma AND (prognosis OR outcome OR prediction). (3) Results: Two researchers extracted the articles of interest and if any disagreements occurred in the selection process, these were settled by a third reviewer. The articles were then assessed using the ROBIS bias assessment and 75 articles were included. (4) Conclusions: the clinical-pathological classification along with factors such as GH, IGF-1, prolactin levels both preoperatively and postoperatively offer valuable information.

Usefulness of a clinicopathological classification in predicting treatment-related outcomes and multimodal therapeutic approaches in pituitary adenoma patients: retrospective analysis on a Portuguese cohort of 129 patients from a tertiary pituitary center

PURPOSE

A clinicopathological classification has been designed to predict recurrence/progression in patients with pituitary adenomas (PAs). We aimed to study its usefulness in predicting PAs that will have a challenging disease course and may require more often complex multimodal and multiple therapeutic approaches.

METHODS

Retrospective analysis of 129 patients with PAs operated in our institution between 2001 and 2020 (84 non-clinically functioning PAs, 32 acromegaly, 9 Cushing's disease, 2 prolactinomas and 2 thyrotropinomas). Grading was based on invasion and proliferation: 1a (non-invasive, non-proliferative; n = 59), 1b (non-invasive, proliferative; n = 17), 2a (invasive, non-proliferative; n = 38), and 2b (invasive, proliferative; n = 15).

RESULTS

Of the 129 patients, 68 (52.7%) were females, and the mean age at diagnosis was 53.7 ± 15.4 years. The mean follow-up duration was 93.1 ± 61.8 months. Grade 2b PAs when compared to other grades (2b-2a-1b-1a) had significantly higher rates of persistent tumor remnant within 1-year after operation (93-78-18-30%; p < 0.001), active disease at last follow-up (40-27-12-10%; p = 0.004), re-operation (27-16-0-5%; p = 0.023), irradiation (53-38-12-7%; p < 0.001), multimodal treatment (67-49-18-25%; p = 0.003), multiple treatment (33-27-6-9%; p = 0.017). Patients with grade 2b PAs also required a higher mean number of treatments (2.6-2.1-1.2-1.4; p < 0.001).

CONCLUSIONS

This clinicopathological classification appears to be a useful grading system to identify PAs that may be more refractory and more often require complex multimodal and multiple therapeutic approaches. Invasive PAs, especially grade 2b tumors, may be more likely to need complex treatment approach, including radiotherapy, and may display higher rates of active disease at last follow-up, despite receiving higher number of treatments.

Multidisciplinary management of difficult/aggressive growth-hormone pituitary neuro-endocrine tumors

Growth Hormone-secreting adenomas exhibits variable biological behavior and heterogeneous natural history, ranging from small adenomas and mild disease, to invasive and aggressive neoplasms with more severe clinical picture. Patients not cured or controlled after neurosurgical and first-generation somatostatin receptor ligands (SRL) therapy could require multiple surgical, medical and/or radiation treatments to achieve disease control. To date, no clinical, laboratory, histopathological, or neuroradiological markers are able to define the aggressiveness or predict the disease prognosis in patients with acromegaly. Therefore, the management of these patients requires careful evaluation of laboratory assessments, diagnostic criteria, neuroradiology examinations, and neurosurgical approaches to choose an effective and patient-tailored medical therapy. A multidisciplinary approach is particularly useful in difficult/aggressive acromegaly to schedule multimodal treatment, which includes radiation therapy, chemotherapy with temozolomide and other, recent emerging treatments. Herein, we describe the role of the different members of the multidisciplinary team according to our personal experience; a flow-chart for the therapeutic approach of difficult/aggressive acromegaly patients is proposed.