Radiation techniques in aggressive pituitary tumours and carcinomas

A Rare Prolactin-secreting Pituitary Carcinoma With Epidural and Thecal Metastases

Pituitary carcinomas are rare but associated with significant morbidity and mortality. They remain challenging to diagnose and manage. In this case, we describe a 56-year-old man who presented with erectile dysfunction and binocular vertical diplopia. He had central hypogonadism, secondary adrenal insufficiency, and central hypothyroidism on biochemical testing. His serum prolactin was 1517 mcg/L (1517 ng/mL; reference range 4-15 mcg/L), and his sellar magnetic resonance imaging showed a 2.0 × 2.2 × 3.1 cm pituitary tumor. Pathology revealed a prolactin-secreting carcinoma. Despite treatment with a high-dose dopaminergic, 2 transsphenoidal resections, and 1 course of radiation, prolactin levels continued to rise. He developed metastases to the epidural space and thecal sac from the thoracic to sacral spine, for which he received 12 cycles of temozolomide chemotherapy with initial clinical and biochemical response. This was followed by disease escape and progression. We discuss the clinical and imaging features that warrant a high index of suspicion for pituitary carcinoma and review contemporary treatment.

Assessing Quality of Life among Radiation-Induced Hypopituitary Patients

Introduction  Radiation-induced hypopituitarism (RIH) has long been recognized as one of the deleterious side effects of skull base radiation. This study aims to assess the quality of life (QoL) among patients with RIH compared with radiated patients who did not develop hypopituitarism using the validated Anterior Skull Base Questionnaire (ASBQ). Methods  This was a single-institution retrospective cohort study. Included patients had a history of anterior skull base tumor, underwent at least one round of radiation to the skull base, and had filled out at least one ASBQ survey after their radiation treatment. Three statistical models were used to determine the effect of hypopituitarism and treatment on QoL scores. Results  A total of 145 patients met inclusion criteria, and 330 ASBQ surveys were analyzed. Thirty-five percent (51/145) had evidence of RIH at some point after their radiation treatment. Those with hypopituitarism had significantly lower overall ASBQ scores across all three models even after adjusting for potential confounders and intraperson correlation (average decrease of 0.24-0.45 on a 5-point Likert scale; p -values ranging from 0.0004 to 0.018). The increase in QoL with hormonal replacement was modulated by time out from radiation, with long-term survivors (5+ years out from radiation) gaining the most benefit from treatment (increase of 0.89 on a 5-point Likert scale, p 0.0412), especially in the vitality domain. Conclusion  This data demonstrates that hypopituitarism is an independent predictor of lower QoL. Early detection and appropriate treatment are essential to avoid the negative impact of hypopituitarism on QoL.

Sprouting Angiogenesis in Human Pituitary Adenomas

Introduction

Angiogenesis in pituitary tumors is not fully understood, and a better understanding could help inform new pharmacologic therapies, particularly for aggressive pituitary tumors.

Materials and Methods

219 human pituitary tumors and 12 normal pituitary glands were studied. Angiogenic genes were quantified by an angiogenesis qPCR array and a TaqMan probe-based absolute qPCR. Angiogenesis inhibition in pituitary tumors was evaluated in vitro with the endothelial tube formation assay and in vivo in RbΔ19 mice.

Results

71 angiogenic genes, 40 of which are known to be involved in sprouting angiogenesis, were differentially expressed in pituitary tumors. Expression of endothelial markers CD31, CD34, and ENG was significantly higher in pituitary tumors, by 5.6, 22.3, and 8.2-fold, respectively, compared to in normal pituitary tissue. There was no significant difference in levels of the lymphatic endothelial marker LYVE1 in pituitary tumors compared with normal pituitary gland tissue. Pituitary tumors also expressed significantly higher levels of angiogenesis growth factors, including VEGFA (4.2-fold), VEGFB (2.2), VEGFC (19.3), PGF (13.4), ANGPT2 (9.2), PDGFA (2.7), PDGFB (10.5) and TGFB1 (3.8) compared to normal pituitary tissue. Expression of VEGFC and PGF was highly correlated with the expression of endothelial markers in tumor samples, including CD31, CD34, and ENG (endoglin, a co-receptor for TGFβ). Furthermore, VEGFR inhibitors inhibited angiogenesis induced by human pituitary tumors and prolonged survival of RbΔ19 mice.

Conclusion

Human pituitary tumors are characterized by more active angiogenesis than normal pituitary gland tissue in a manner consistent with sprouting angiogenesis. Angiogenesis in pituitary tumors is regulated mainly by PGF and VEGFC, not VEGFA and VEGFB. Angiogenesis inhibitors, such as the VEGFR2 inhibitor cabozantinib, may merit further investigation as therapies for aggressive human pituitary tumors.

Aggressive prolactinoma (Review)

Aggressive prolactinoma (APRL) is a subgroup of aggressive pituitary tumors (accounting for 10% of all hypophyseal neoplasia) which are defined by: invasion based on radiological and/or histological features, a higher proliferation profile when compared to typical adenomas and rapidly developing resistance to standard medication/protocols in addition to an increased risk of early recurrence. This is a narrative review focusing on APRL in terms of both presentation and management. Upon admission, the suggestive features may include increased serum prolactin with a large tumor diameter (mainly >4 cm), male sex, early age at diagnosis (<20 years), and genetic predisposition [multiple endocrine neoplasia type 1 (MEN1), aryl hydrocarbon receptor interacting protein (AIP), succinate dehydrogenase (SDHx) gene mutations]. Potential prognostic factors are indicated by assessment of E-cadherin, matrix metalloproteinase (MMP)-9, and vascular endothelial growth factor (VEGF) status. Furthermore, during management, APRL may be associated with dopamine agonist (DA) resistance (described in 10-20% of all prolactinomas), post-hypophysectomy relapse, mitotic count >2, Ki-67 proliferation index ≥3%, the need for radiotherapy, lack of response in terms of controlling prolactin levels and tumor growth despite multimodal therapy. However, none of these as an isolated element serves as a surrogate of APRL diagnosis. A fourth-line therapy is necessary with temozolomide, an oral alkylating chemotherapeutic agent, that may induce tumor reduction and serum prolactin reduction in 75% of cases but only 8% have a normalization of prolactin levels. Controversies surrounding the duration of therapy still exist; also regarding the fifth-line therapy, post-temozolomide intervention. Recent data suggest alternatives such as somatostatin analogues (pasireotide), checkpoint inhibitors (ipilimumab, nivolumab), tyrosine kinase inhibitors (TKIs) (lapatinib), and mTOR inhibitors (everolimus). APRL represents a complex condition that is still challenging, and multimodal therapy is essential.

Aggressive pituitary tumours and pituitary carcinomas

Although usually benign, anterior pituitary tumours occasionally exhibit aggressive behaviour, with invasion of surrounding tissues, rapid growth, resistance to conventional treatments and multiple recurrences. In very rare cases, they metastasize and are termed pituitary carcinomas. The time between a 'classical' pituitary tumour and a pituitary carcinoma can be years, which means that monitoring should be performed regularly in patients with clinical (invasion and/or tumour growth) or pathological (Ki67 index, mitotic count and/or p53 detection) markers suggesting aggressiveness. However, although both invasion and proliferation have prognostic value, such parameters cannot predict outcome or malignancy without metastasis. Future research should focus on the biology of both tumour cells and their microenvironment, hopefully with improved therapeutic outcomes. Currently, the initial therapeutic approach for aggressive pituitary tumours is generally to repeat surgery or radiotherapy in expert centres. Standard medical treatments usually have no effect on tumour progression but they can be maintained on a long-term basis to, at least partly, control hypersecretion. In cases where standard treatments prove ineffective, temozolomide, the sole formally recommended treatment, is effective in only one-third of patients. Personalized use of emerging therapies, including peptide receptor radionuclide therapy, angiogenesis-targeted therapy and immunotherapy, will hopefully improve the outcomes of patients with this severe condition.

Synchronous pituitary and pineal gland lesions presenting with panhypopituitarism in a patient with widespread colorectal cancer: a case report

A 60-year-old man presented to our hospital because of febrile neutropenia due to chemotherapy for his metastasized colon cancer. During hospital stay, polyuria and polydipsia were noted. He reported that his thirst had become increasingly intolerable over the last weeks. Diabetes mellitus was diagnosed. Polyuria and polydipsia persisted despite euglycemia under insulin treatment. Because of thirst and high urine volumes during the night, diabetes insipidus was suspected. Endocrinological work up revealed complete panhypopituitarism with impairment of all anterior and posterior axes. After substitution with hydrocortisone, levothyroxine and desmopressin symptoms resolved. MRI of the brain revealed one round, contrast enhancing lesion in the pituitary stalk and one in the pineal gland. Because of extensive extracerebral metastasis and poor performance status, the patient opted for radiation therapy only. He died 2.5 months later due to non-cerebral manifestations of his cancer before cerebral radiotherapy could be initiated.

Diagnosis and treatment of refractory pituitary adenomas: a narrative review

Although aggressive pituitary adenomas (PAs) have been proposed and widely discussed for more than a decade, there is no general agreement regarding their definition, diagnosis or management. As one of the largest pituitary centers in China, we have diagnosed and treated more than fifty cases of aggressive PA and 3 pituitary carcinomas in the past 5 years and proposed a new term, i.e., refractory PAs, to define these adenomas. The definitions of aggressive and refractory PAs overlap with each other, though there are some differences between them. We interpret the definition for refractory PA in this review, emphasizing that more attention and early identification of these adenomas are needed. Although temozolomide (TMZ) has been used to treat pituitary carcinomas and refractory PA since 2006, which has significantly improved the prognosis of these patients, treatment of refractory PA is a tremendous challenge for endocrinologists and neurosurgeons. Overall, refractory PA is defined as PA with a Ki-67 labeling index ≥3%, a faster growth rate than that of normal PA, infiltration of surrounding tissues, recurrence or regrowth in the early postoperative period, and continued growth and/or secretion of excessive hormones despite attempts to control it. These criteria for refractory PA are stricter than for aggressive PA. The diagnosis and treatment of refractory PA requires the collaboration of a multidisciplinary team to achieve the best results.

UPDATES IN AGGRESSIVE PITUITARY TUMORS

Aggressive pituitary tumors lie between pituitary adenomas and carcinomas, displaying a particular behavior, with invasion, resistance to conventional therapy and early recurrence. The radiological grading, along with prognostic markers such as Ki-67 proliferation index, p53, MGMT and transcription factors are important factors in establishing the benign, aggressive, or malignant nature of pituitary tumors, with a more accurate treatment strategy. In this article, we report the novelties in defining, classifying, and managing aggressive pituitary tumors and their malignant potential, focusing on clinicopathological, histological, molecular and radiological data.