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Whyte E, Nezu M, Chik C, Tateno T. Update on Current Evidence for the Diagnosis and Management of Nonfunctioning Pituitary Neuroendocrine Tumors. Endocrinol Metab (Seoul) 2023; 38:631-654. [PMID: 37964483 PMCID: PMC10764990 DOI: 10.3803/enm.2023.1838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/29/2023] [Accepted: 11/01/2023] [Indexed: 11/16/2023] Open
Abstract
Pituitary neuroendocrine tumors (PitNETs) are the third most frequently diagnosed intracranial tumors, with nonfunctioning PitNETs (nfPitNETs) accounting for 30% of all pituitary tumors and representing the most common type of macroPitNETs. NfPitNETs are usually benign tumors with no evidence of hormone oversecretion except for hyperprolactinemia secondary to pituitary stalk compression. Due to this, they do not typically present with clinical syndromes like acromegaly, Cushing's disease or hyperthyroidism and instead are identified incidentally on imaging or from symptoms of mass effects (headache, vision changes, apoplexy). With the lack of effective medical interventions, first-line treatment is transsphenoidal surgical resection, however, nfPitNETs often have supra- or parasellar extension, and total resection of the tumor is often not possible, resulting in residual tumor regrowth or reoccurrence. While functional PitNETs can be easily followed for recurrence using hormonal biomarkers, there is no similar parameter to predict recurrence in nfPitNETs, hence delaying early recognition and timely management. Therefore, there is a need to identify prognostic biomarkers that can be used for patient surveillance and as therapeutic targets. This review focuses on summarizing the current evidence on nfPitNETs, with a special focus on potential new biomarkers and therapeutics.
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Affiliation(s)
- Elizabeth Whyte
- Division of Endocrinology and Metabolism, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Masahiro Nezu
- Division of Endocrinology and Metabolism, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Constance Chik
- Division of Endocrinology and Metabolism, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Toru Tateno
- Division of Endocrinology and Metabolism, Department of Medicine, University of Alberta, Edmonton, AB, Canada
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2
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Nf L, Ai M. Refractory Pit1 plurihormonal tumours and thyrotroph adenomas. Pituitary 2023:10.1007/s11102-023-01312-9. [PMID: 37117845 DOI: 10.1007/s11102-023-01312-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/29/2023] [Indexed: 04/30/2023]
Abstract
Pit-1 tumours are derived from neoplastic cells of either somatotroph, lactotroph or thyrotroph cell lineages, but there are also distinct mixed tumours and plurihormonal tumours within this category as described within the 2022 edition of the WHO classification of pituitary tumours. Plurihormonal tumours and thyrotroph adenomas are transcriptionally similar and grouped together to discuss in this review, although it is clear an immature type of plurihormonal tumour exists which are more commonly associated with refractory disease. Management of residual or recurrent disease should follow that of other aggressive pituitary tumours, although a trial of somatostatin analogue therapy is certainly warranted before considering temozolomide therapy.
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Affiliation(s)
- Lenders Nf
- Department of Endocrinology, St Vincent's Hospital, Sydney, NSW, Australia
- Garvan Institute of Medical Research, Sydney, NSW, Australia
- St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - McCormack Ai
- Department of Endocrinology, St Vincent's Hospital, Sydney, NSW, Australia.
- Garvan Institute of Medical Research, Sydney, NSW, Australia.
- St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia.
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3
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Kontogeorgos G, Thodou E, Osamura RY, Lloyd RV. High-risk pituitary adenomas and strategies for predicting response to treatment. Hormones (Athens) 2022; 21:1-14. [PMID: 35061210 DOI: 10.1007/s42000-021-00333-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 10/18/2021] [Indexed: 12/30/2022]
Abstract
High-risk pituitary adenomas are aggressive. They show clinical and imaging features similar to those of carcinomas, including infiltration of the surrounding brain structures, but lack cerebrospinal or systemic metastases. In addition, they display distinct behavior, including tendency for fast growth and frequent recurrences, which are difficult to control. The term "high-risk" adenoma was first introduced in the 4th edition of the World Health Organization Classification of Endocrine Tumors in 2017. Five defined adenoma types belong to this category, including sparsely granulated somatotroph, lactotroph in men, Crooke cell, silent corticotroph, and plurihormonal PIT-1 positive adenomas. The morphological and immunohistochemical characteristics of high-risk adenomas are herein described in detail. In addition, the clinical features and the treatment options are presented. This review focuses on predictive markers assessed by immunohistochemistry, which help clinicians to design the appropriate treatment strategies for high-risk adenomas. Somatostatin receptor status predicts effectiveness of postsurgical treatment with somatostatin analogs, and MGMT expression predicts response to treatment with temozolomide. This comprehensive review presents the clinical and pathological features of high-risk pituitary adenomas, underlines the contribution of immunohistochemistry, and emphasizes the leading role of pathology in the design of optimal clinical management.
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Affiliation(s)
- George Kontogeorgos
- Division of Endocrinology, First Propaedeutic Department of Internal Medicine, Laikon Hospital, National and Kapodistrian University of Athens, Athens, Greece.
- Department of Pathology and Pituitary Tumor Reference Center, G. Gennimatas General Hospital of Athens, Athens, Greece.
| | - Eleni Thodou
- Department of Pathology, University of Thessaly, Larissa, Greece
| | - Robert Y Osamura
- Department of Pathology, Nippon Koukan Hospital, Kawasaki, Kanagawa, Japan
| | - Ricardo V Lloyd
- Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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4
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Postma MR, Kuijlen JMA, Korsten AGW, Westerlaan HE, van den Bergh ACM, Nuver J, den Dunnen WFA, van den Berg G. An aggressive poorly differentiated plurihormonal Pit-1-positive adenoma. Endocrinol Diabetes Metab Case Rep 2021; 2021:EDM200166. [PMID: 34673544 PMCID: PMC8558894 DOI: 10.1530/edm-20-0166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 09/28/2021] [Indexed: 11/14/2022] Open
Abstract
SUMMARY In July 2017, a 35-year-old woman was referred to our care for treatment of a large pituitary mass with an unusually high growth rate. She presented with right-sided ptosis and diplopia (n. III palsy), increasing retrobulbar pain and vertigo. Although laboratory investigations were consistent with acromegaly, she exhibited no clear phenotypic traits. During transsphenoidal surgery aimed at biopsy, typical adenomatous tissue was encountered, upon which it was decided to proceed to debulking. Histopathological analysis demonstrated a poorly differentiated plurihormonal Pit-1-positive adenoma with focal growth hormone (GH) and prolactin positivity, positive SSTR2 staining and a Ki-67 of 20-30%. Postoperative magnetic resonance imaging (MRI) examination revealed a large tumour remnant within the sella invading the right cavernous sinus with total encasement of the internal carotid artery and displacement of the right temporal lobe. As a consequence, she was treated additionally with radiotherapy, and a long-acting first-generation somatostatin analogue was prescribed. Subsequently, the patient developed secondary hypocortisolism and diabetes mellitus despite adequate suppression of GH levels. In September 2019, her symptoms recurred. Laboratory evaluations indicated a notable loss of biochemical control, and MRI revealed tumour progression. Lanreotide was switched to pasireotide, and successful removal of the tumour remnant and decompression of the right optic nerve was performed. She received adjuvant treatment with temozolomide resulting in excellent biochemical and radiological response after three and six courses. Symptoms of right-sided ptosis and diplopia remained. Evidence for systemic therapy in case of tumour progression after temozolomide is currently limited, although various potential targets can be identified in tumour tissue. LEARNING POINTS Poorly differentiated plurihormonal Pit-1-positive adenoma is a potentially aggressive subtype of pituitary tumours. This subtype can express somatostatin receptors, allowing treatment with somatostatin analogues. A multidisciplinary approach involving an endocrinologist, neurosurgeon, pituitary pathologist, neuroradiologist, radiation oncologist and medical oncologist is key for the management of patients with aggressive pituitary tumours, allowing the successful application of multimodality treatment. Temozolomide is first-line chemotherapy for aggressive pituitary tumours and carcinomas. Further development of novel targeted therapies, such as peptide receptor radionuclide therapy (PRRT), vascular endothelial growth factor (VEGF) receptor-targeted therapy, tyrosine kinase inhibitors, mammalian target of rapamycin (mTOR) inhibitors and immune checkpoint inhibitors, is needed.
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Affiliation(s)
| | | | - Astrid G W Korsten
- Department of Otorhinolaryngology-Head and Neck Surgery, Medical Imaging Center
| | | | - Alfons C M van den Bergh
- Department of Radiation Oncology, University Medical Center Groningen, Groningen, the Netherlands
| | - Janine Nuver
- Department of Medical Oncology, University Medical Center Groningen, Groningen, the Netherlands
| | - Wilfred F A den Dunnen
- Department of Pathology and Medical Biology, University Medical Center Groningen, Groningen, the Netherlands
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Drummond J, Roncaroli F, Grossman AB, Korbonits M. Clinical and Pathological Aspects of Silent Pituitary Adenomas. J Clin Endocrinol Metab 2019; 104:2473-2489. [PMID: 30020466 PMCID: PMC6517166 DOI: 10.1210/jc.2018-00688] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 07/12/2018] [Indexed: 12/22/2022]
Abstract
CONTEXT Silent pituitary adenomas are anterior pituitary tumors with hormone synthesis but without signs or symptoms of hormone hypersecretion. They have been increasingly recognized and represent challenging diagnostic issues. EVIDENCE ACQUISITION A comprehensive literature search was performed using MEDLINE and EMBASE databases from January 2000 to March 2018 with the following key words: (i) pituitary adenoma/tumor and nonfunctioning; or (ii) pituitary adenoma/tumor and silent. All titles and abstracts of the retrieved articles were reviewed, and recent advances in the field of silent pituitary adenomas were summarized. EVIDENCE SYNTHESIS The clinical and biochemical picture of pituitary adenomas reflects a continuum between functional and silent adenomas. Although some adenomas are truly silent, others will show some evidence of biochemical hypersecretion or could have subtle clinical signs and, therefore, can be referred to as clinically silent or "whispering" adenomas. Silent tumors seem to be more aggressive than their secreting counterparts, with a greater recurrence rate. Transcription factors for pituitary cell lineages have been introduced into the 2017 World Health Organization guidelines: steroidogenic factor 1 staining for gonadotroph lineage; PIT1 (pituitary-specific positive transcription factor 1) for growth hormone, prolactin, and TSH lineage, and TPIT for the corticotroph lineage. Prospective studies applying these criteria will establish the value of the new classification. CONCLUSIONS A concise review of the clinical and pathological aspects of silent pituitary adenomas was conducted in view of the new World Health Organization classification of pituitary adenomas. New classifications, novel prognostics markers, and emerging imaging and therapeutic approaches need to be evaluated to better serve this unique group of patients.
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MESH Headings
- Biomarkers, Tumor/blood
- Chemotherapy, Adjuvant/methods
- Humans
- Magnetic Resonance Angiography
- Neoplasm Recurrence, Local/epidemiology
- Neoplasm Recurrence, Local/pathology
- Neoplasm Recurrence, Local/prevention & control
- Pituitary Gland, Anterior/diagnostic imaging
- Pituitary Gland, Anterior/pathology
- Pituitary Gland, Anterior/surgery
- Pituitary Hormones, Anterior/blood
- Pituitary Hormones, Anterior/metabolism
- Pituitary Neoplasms/blood
- Pituitary Neoplasms/diagnosis
- Pituitary Neoplasms/pathology
- Pituitary Neoplasms/therapy
- Prognosis
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Affiliation(s)
- Juliana Drummond
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Federico Roncaroli
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Ashley B Grossman
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Márta Korbonits
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
- Correspondenceand Reprint Requests: Márta Korbonits, MD, PhD, Department of Endocrinology, Barts and the London School of Medicine and Dentistry, Charterhouse Square, London EC1M 6BQ, United Kingdom. E-mail:
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Micko ASG, Höftberger R, Wöhrer A, Millesi M, Knosp E, Wolfsberger S. MGMT assessment in pituitary adenomas: comparison of different immunohistochemistry fixation chemicals. Pituitary 2018; 21:266-273. [PMID: 29344904 PMCID: PMC5942339 DOI: 10.1007/s11102-018-0862-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Despite the established role of O6-methyl-guanine-DNA methyltransferase (MGMT) as a marker for temozolomide response, consensus of the most reliable method to assess MGMT expression in pituitary adenomas is still missing. Currently, immunohistochemistry (IHC) assessment of formaldehyde fixed tissue samples is most widely used in a semiquantitative description. As formaldehyde fails to completely preserve nucleic acids, RCL2, an alcohol-based formaldehyde-free fixative, has been proposed as a more reliable alternative in terms of cell stability. Furthermore, as the current method of IHC is semiquantitative and observer-dependent, pyrosequencing, an objective tool to evaluate the methylation status of the MGMT promoter, has emerged as a reliable and accurate alternative. The aim of this study was to validate the current IHC method for assessment of MGMT protein expression in pituitary adenomas. METHODS The tissue samples of 8 macroadenomas with positive IHC MGMT expression (> 50%) were investigated: first, we compared the time dependent stability of MGMT protein expression after pituitary adenoma removal between formaldehyde vs. RCL2. Then, we compared positive IHC MGMT expression with methylated promoter status using pyrosequencing. RESULTS In the first 12 h after adenoma removal, tissue samples remained MGMT positive in significantly more samples when fixated with formaldehyde than with RCL2, respectively (96 vs. 81%, p = 0.025). CONCLUSION Our data confirm that the current method using formaldehyde tissue fixation and IHC reveals stable and reliable results of MGMT assessment in pituitary adenomas.
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Affiliation(s)
- Alexander S G Micko
- Department of Neurosurgery, Medical University Vienna, Waehringer Guertel 18-20, 1097, Vienna, Austria
- Institute of Neurology, Medical University of Vienna, Vienna, Austria
| | - Romana Höftberger
- Institute of Neurology, Medical University of Vienna, Vienna, Austria
| | - Adelheid Wöhrer
- Institute of Neurology, Medical University of Vienna, Vienna, Austria
| | - Matthias Millesi
- Department of Neurosurgery, Medical University Vienna, Waehringer Guertel 18-20, 1097, Vienna, Austria
| | - Engelbert Knosp
- Department of Neurosurgery, Medical University Vienna, Waehringer Guertel 18-20, 1097, Vienna, Austria.
| | - Stefan Wolfsberger
- Department of Neurosurgery, Medical University Vienna, Waehringer Guertel 18-20, 1097, Vienna, Austria
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Micko ASG, Wöhrer A, Höftberger R, Vila G, Marosi C, Knosp E, Wolfsberger S. MGMT and MSH6 immunoexpression for functioning pituitary macroadenomas. Pituitary 2017; 20:643-653. [PMID: 28900805 PMCID: PMC5655586 DOI: 10.1007/s11102-017-0829-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE Knowledge of biological behavior is crucial for clinical management of functioning pituitary macroadenomas. For recurrent cases unresponsive to standard treatment, temozolomide (TMZ) has been used as a therapeutic alternative. MGMT (O6-methyl-guanine-DNA methyltransferase) and MSH6 (mutS homolog 6) immunoexpression have been linked to the response to TMZ treatment and MGMT immunoexpression has been additionally linked to early recurrence of non-functioning pituitary adenomas. The aim of this study was to assess the prognostic value of MGMT and MSH6 immunoexpression for aggressive functioning pituitary adenomas. METHODS The study cohort comprised a single center series of 76 patients who underwent an operation for functioning pituitary macroadenoma. We retrospectively compared 38 patients with postoperative persistent or recurrent disease with another set of 38 patients who were in endocrine remission. RESULTS Low-to-moderate MGMT immunoexpression (<50%) was significantly more frequent in the group with persistent/recurrent disease than in cases of endocrine remission (66 vs. 21%, p < 0.001). Furthermore, adenomas with low-to-moderate MGMT immunoexpression were significantly more often recurrent (76 vs. 30%, p < 0.001) and invasive (64 vs. 28%, p = 0.002). CONCLUSION In our series, low-to-moderate MGMT immunoexpression was the only marker that significantly correlated with surgical invasiveness and recurrence in functioning pituitary macroadenomas. Therefore, in the future, MGMT status may be considered an additional marker for understanding the biological behavior of pituitary adenomas.
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Affiliation(s)
- Alexander S G Micko
- Department of Neurosurgery, Medical University Vienna, Waehringer Guertel 18-20, 1097, Vienna, Austria
| | - Adelheid Wöhrer
- Institute of Neurology, Medical University Vienna, Vienna, Austria
| | | | - Greisa Vila
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University Vienna, Vienna, Austria
| | - Christine Marosi
- Division of Oncology, Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria
| | - Engelbert Knosp
- Department of Neurosurgery, Medical University Vienna, Waehringer Guertel 18-20, 1097, Vienna, Austria.
| | - Stefan Wolfsberger
- Department of Neurosurgery, Medical University Vienna, Waehringer Guertel 18-20, 1097, Vienna, Austria
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O-6-Methylguanine-DNA methyltransferase expression is associated with pituitary adenoma tumor recurrence: a systematic meta-analysis. Oncotarget 2017; 8:19674-19683. [PMID: 28152515 PMCID: PMC5386713 DOI: 10.18632/oncotarget.14936] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 12/01/2016] [Indexed: 11/25/2022] Open
Abstract
O-6-methylguanine-DNA methyltransferase (MGMT) reportedly counteracts the cytotoxic effects of the alkylating agent temozolomide. MGMT expression is often low in aggressive pituitary adenomas (PAs) and recurrent PAs. However, because these associations are controversial, we performed this meta-analysis to clarify the involvement of MGMT in the prognosis and clinicopathology of PA. We searched for relevant studies in electronic databases (MEDLINE, the Cochrane Library Database, EMBASE, CINAHL, Web of Science and the Chinese Biomedical Database (CBD)) and calculated/pooled the odds ratios (ORs) or standard mean differences (SMDs) with 95% confidence intervals (95% CIs). Eleven case-control studies with a total of 454 PA patients were included. Our meta-analysis revealed that lower expression of MGMT was associated with PA recurrence (OR=2.09, 95% CI=1.09-4.02; p=0.026). On the other hand, MGMT expression was not associated with PA invasiveness (OR=1.112, 95% CI=0.706-1.753; p=0.646), Unexpectedly, MGMT expression could not be used to distinguish functional from non-functional PA patients (OR=1.766, 95% CI=0.938-3.324; p=0.078). The MGMT expression was not found to be related to other clinicopathological indicators of PA including age, gender or tumor size. No publication bias was detected in this meta-analysis (p>0.05). This meta-analysis suggests that MGMT expression may be associated with PA tumor recurrence, but not be related to invasiveness or other clinicopathological indicators. Thus, detection of MGMT expression may facilitate outcome prediction and guide clinical therapy for PA patients.
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Abstract
This review focuses on discussing the main changes on the upcoming fourth edition of the WHO Classification of Tumors of the Pituitary Gland emphasizing histopathological and molecular genetics aspects of pituitary neuroendocrine (i.e., pituitary adenomas) and some of the non-neuroendocrine tumors involving the pituitary gland. Instead of a formal review, we introduced the highlights of the new WHO classification by answering select questions relevant to practising pathologists. The revised classification of pituitary adenomas, in addition to hormone immunohistochemistry, recognizes the role of other immunohistochemical markers including but not limited to pituitary transcription factors. Recognizing this novel approach, the fourth edition of the WHO classification has abandoned the concept of "a hormone-producing pituitary adenoma" and adopted a pituitary adenohypophyseal cell lineage designation of the adenomas with subsequent categorization of histological variants according to hormone content and specific histological and immunohistochemical features. This new classification does not require a routine ultrastructural examination of these tumors. The new definition of the Null cell adenoma requires the demonstration of immunonegativity for pituitary transcription factors and adenohypophyseal hormones Moreover, the term of atypical pituitary adenoma is no longer recommended. In addition to the accurate tumor subtyping, assessment of the tumor proliferative potential by mitotic count and Ki-67 index, and other clinical parameters such as tumor invasion, is strongly recommended in individual cases for consideration of clinically aggressive adenomas. This classification also recognizes some subtypes of pituitary neuroendocrine tumors as "high-risk pituitary adenomas" due to the clinical aggressive behavior; these include the sparsely granulated somatotroph adenoma, the lactotroph adenoma in men, the Crooke's cell adenoma, the silent corticotroph adenoma, and the newly introduced plurihormonal Pit-1-positive adenoma (previously known as silent subtype III pituitary adenoma). An additional novel aspect of the new WHO classification was also the definition of the spectrum of thyroid transcription factor-1 expressing pituitary tumors of the posterior lobe as representing a morphological spectrum of a single nosological entity. These tumors include the pituicytoma, the spindle cell oncocytoma, the granular cell tumor of the neurohypophysis, and the sellar ependymoma.
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Affiliation(s)
- Ozgur Mete
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
- Department of Pathology, University Health Network, 200 Elizabeth Street, 11th Floor, Toronto, ON, M5G 2C4, Canada.
- Endocrine Oncology Site Group, Princess Margaret Cancer Centre, Toronto, ON, Canada.
| | - M Beatriz Lopes
- Department of Pathology and Neurological Surgery, University of Virginia Health System, Charlottesville, VA, USA
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Jiang XB, Hu B, He DS, Mao ZG, Wang X, Song BB, Zhu YH, Wang HJ. Expression profiling of O(6) methylguanine-DNA-methyl transferase in prolactinomas: a correlative study of promoter methylation and pathological features in 136 cases. BMC Cancer 2015; 15:644. [PMID: 26400193 PMCID: PMC4581044 DOI: 10.1186/s12885-015-1595-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 08/07/2015] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Low-level expression of O(6) methylguanine-DNA-methyl transferase (MGMT) prolactinomas has been noted previously in case reports, although what modulates MGMT expression remains unclear. This study therefore aimed to delineate the factors regulating MGMT expression in prolactinomas. METHODS We retrospectively reviewed 136 prolactinoma patients who were treated in our center between January 2000 and September 2013. Expression of MGMT, Ki-67, and p53 protein were examined by immunohistochemical staining, and MGMT promoter methylation evaluated with methylation-specific PCR. RESULTS MGMT immunopositivity was <25 % in 106/136 tumor specimens (77.94 %). MGMT immunoexpression was positively correlated with age (r = 0.251, p = 0.003), but inversely correlated with p53 staining (r = -0.153, p = 0.021). Moreover, reduced MGMT expression was more frequent in atypical prolactinomas (p = 0.044). Methylated MGMT promoter was confirmed in 10/46 specimens (21.7 %), all of which had low level or absent MGMT staining. Both p53 protein (r = -0.33, p = 0.025) and promoter methylation (r = -0.331, p = 0.025) were negatively associated with MGMT expression. Multivariate logistic analysis indicated that age (odds ratio [OR] = 1.127. 95 % confidence interval [CI] 1.027-1.236, p = 0.012) and p53 (OR = 0.116. 95 % CI 0.018-0.761, p = 0.025) staining were independent determents of MGMT expression. CONCLUSIONS The majority of prolactinomas, especially atypical prolactinomas, showed low-level or no MGMT immunoexpression, providing a rationale for the utility of temozolomide as an alternative to managing prolactinomas. In summary, epigenetic and transcriptional regulation are involved in silencing MGMT expression.
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Affiliation(s)
- Xiao-Bing Jiang
- Department of Neurosurgery, First Affiliated Hospital of Sun Yat-sen University, Haizhu, Yixian Rd, Guangdong, Guangzhou, China. .,Key Laboratory of Pituitary Adenoma in Guangdong Province, Guangzhou, 510080, China. .,Department of Neurosurgery, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China.
| | - Bin Hu
- Department of Neurosurgery, First Affiliated Hospital of Sun Yat-sen University, Haizhu, Yixian Rd, Guangdong, Guangzhou, China. .,Key Laboratory of Pituitary Adenoma in Guangdong Province, Guangzhou, 510080, China.
| | - Dong-Sheng He
- Department of Neurosurgery, First Affiliated Hospital of Sun Yat-sen University, Haizhu, Yixian Rd, Guangdong, Guangzhou, China. .,Key Laboratory of Pituitary Adenoma in Guangdong Province, Guangzhou, 510080, China.
| | - Zhi-Gang Mao
- Department of Neurosurgery, First Affiliated Hospital of Sun Yat-sen University, Haizhu, Yixian Rd, Guangdong, Guangzhou, China. .,Key Laboratory of Pituitary Adenoma in Guangdong Province, Guangzhou, 510080, China.
| | - Xin Wang
- Key Laboratory of Pituitary Adenoma in Guangdong Province, Guangzhou, 510080, China. .,Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
| | - Bing-Bing Song
- Key Laboratory of Pituitary Adenoma in Guangdong Province, Guangzhou, 510080, China. .,Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
| | - Yong-Hong Zhu
- Key Laboratory of Pituitary Adenoma in Guangdong Province, Guangzhou, 510080, China. .,Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
| | - Hai-Jun Wang
- Department of Neurosurgery, First Affiliated Hospital of Sun Yat-sen University, Haizhu, Yixian Rd, Guangdong, Guangzhou, China. .,Key Laboratory of Pituitary Adenoma in Guangdong Province, Guangzhou, 510080, China.
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11
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Zhou Y, Zhang X, Klibanski A. Genetic and epigenetic mutations of tumor suppressive genes in sporadic pituitary adenoma. Mol Cell Endocrinol 2014; 386:16-33. [PMID: 24035864 PMCID: PMC3943596 DOI: 10.1016/j.mce.2013.09.006] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 09/03/2013] [Indexed: 12/28/2022]
Abstract
Human pituitary adenomas are the most common intracranial neoplasms. Approximately 5% of them are familial adenomas. Patients with familial tumors carry germline mutations in predisposition genes, including AIP, MEN1 and PRKAR1A. These mutations are extremely rare in sporadic pituitary adenomas, which therefore are caused by different mechanisms. Multiple tumor suppressive genes linked to sporadic tumors have been identified. Their inactivation is caused by epigenetic mechanisms, mainly promoter hypermethylation, and can be placed into two groups based on their functional interaction with tumor suppressors RB or p53. The RB group includes CDKN2A, CDKN2B, CDKN2C, RB1, BMP4, CDH1, CDH13, GADD45B and GADD45G; AIP and MEN1 genes also belong to this group. The p53 group includes MEG3, MGMT, PLAGL1, RASSF1, RASSF3 and SOCS1. We propose that the tumor suppression function of these genes is mainly mediated by the RB and p53 pathways. We also discuss possible tumor suppression mechanisms for individual genes.
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Affiliation(s)
- Yunli Zhou
- Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States
| | - Xun Zhang
- Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States
| | - Anne Klibanski
- Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States.
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Annamalai AK, Dean AF, Kandasamy N, Kovacs K, Burton H, Halsall DJ, Shaw AS, Antoun NM, Cheow HK, Kirollos RW, Pickard JD, Simpson HL, Jefferies SJ, Burnet NG, Gurnell M. Temozolomide responsiveness in aggressive corticotroph tumours: a case report and review of the literature. Pituitary 2012; 15:276-87. [PMID: 22076588 DOI: 10.1007/s11102-011-0363-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
Pituitary carcinoma occurs in ~0.2% of resected pituitary tumours and carries a poor prognosis (mean survival <4 years), with standard chemotherapy regimens showing limited efficacy. Recent evidence suggests that temozolomide (TMZ), an orally-active alkylating agent used principally in the management of glioblastoma, may also be effective in controlling aggressive/invasive pituitary adenomas/carcinomas. A low level of expression of the DNA-repair enzyme O6-methylguanine-DNA methyltransferase (MGMT) predicts TMZ responsiveness in glioblastomas, and a similar correlation has been observed in the majority of aggressive pituitary adenomas/carcinomas reported to date. Here, we report a case of a silent pituitary corticotroph adenoma, which subsequently re-presented with Cushing's syndrome due to functioning hepatic metastases. The tumour exhibited low immunohistochemical MGMT expression in both primary (pituitary) and secondary (hepatic) lesions. Initial TMZ therapy (200 mg/m² for 5 days every 28 days-seven cycles) resulted in marked clinical, biochemical [>50% fall in adrenocorticotrophic hormone (ACTH)] and radiological [partial RECIST (response evaluation criteria in solid tumors) response] improvements. The patient then underwent bilateral adrenalectomy. However, despite reintroduction of TMZ therapy (further eight cycles) ACTH levels plateaued and no further radiological regression was observed. We review the existing literature reporting TMZ efficacy in pituitary corticotroph tumours, and highlight the pointers/lessons for treating aggressive pituitary neoplasia that can be drawn from experience of susceptibility and evolving resistance to TMZ therapy in glioblastoma. Possible strategies for mitigating resistance developing during TMZ treatment of pituitary adenomas/carcinomas are also considered.
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Affiliation(s)
- A K Annamalai
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge & Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
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McCormack AI, Wass JAH, Grossman AB. Aggressive pituitary tumours: the role of temozolomide and the assessment of MGMT status. Eur J Clin Invest 2011; 41:1133-48. [PMID: 21496012 DOI: 10.1111/j.1365-2362.2011.02520.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Aggressive pituitary tumours are associated with substantial morbidity and mortality. Treatment options are often limited, and chemotherapy has been reserved as salvage therapy although historically results have often been disappointing. However, temozolomide, an oral alkylating agent, has recently demonstrated significant activity against these tumours. A DNA repair protein, 06-methylguanine-DNA methyltransferase (MGMT) has been suggested as a biomarker to predict response to temozolomide in pituitary tumours. MATERIALS AND METHODS This paper will review the current literature on temozolomide and pituitary tumours and discuss the recent controversy surrounding the value of determining the MGMT status in this tumour group. A PubMed search was performed to retrieve articles, using the terms 'pituitary tumour' and 'temozolomide'. RESULTS Overall, 24/40 (60%) of the published cases demonstrated a response to temozolomide therapy. The highest response rates were seen amongst prolactinomas (73%) and ACTH-secreting tumours (60%), whilst nonfunctioning pituitary tumours exhibit lower response rates (40%). Responsivity is typically evident in the first 3 months of therapy and may be dramatic and sustained. Low MGMT expression, as determined by immunohistochemistry, is associated with a high response rate (76%), whilst high MGMT expression has not been associated with responses. MGMT promoter methylation does not correlate with temozolomide response. CONCLUSIONS Temozolomide is the first chemotherapeutic agent to show substantial response rates in aggressive pituitary tumours. MGMT immunohistochemistry, but not MGMT methylation analysis, shows promise as a predictive tool. Prospective clinical trials are now necessary to more accurately determine the efficacy of this agent in this patient group.
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Affiliation(s)
- Ann I McCormack
- Cancer Genetics Unit, Hormones and Cancer Group, Kolling Institute of Medical Research, Royal North Shore Hospital, Sydney, NSW, Australia
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Salehi F, Scheithauer BW, Kros JM, Lau Q, Fealey M, Erickson D, Kovacs K, Horvath E, Lloyd RV. MGMT promoter methylation and immunoexpression in aggressive pituitary adenomas and carcinomas. J Neurooncol 2011; 104:647-57. [DOI: 10.1007/s11060-011-0532-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 01/31/2011] [Indexed: 01/08/2023]
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