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Context Cabergoline (CAB) is an off-label medical therapy for acromegaly, overshadowed by first-generation somatostatin receptor ligands, eg, octreotide (OCT). Objective This was a head-to-head comparison between OCT and CAB in inhibiting growth hormone (GH) secretion in primary cultures of GH- and GH/prolactin (PRL)-secreting tumors; we also investigated the role of somatostatin (SST) and dopamine type 2 (D2R) receptor expression. Methods We evaluated the antisecretory effect of OCT and CAB, together with receptor mRNA expression, in 23 tumor cultures obtained from acromegaly patients referred to the Erasmus Medical Center (Rotterdam, The Netherlands). GH concentrations in cell culture media were determined after 72-hour OCT and CAB treatment (10 nM). Results OCT showed a slightly higher efficacy compared with CAB (GH decrease −39.5% vs −32.5%, P = 0.079). The effect of the 2 drugs was superimposable in GH/PRL co-secreting tumors (−42.1% vs −44.8%), where SST1 and D2R had a higher expression compared with the pure GH-secreting tumors (P = 0.020 and P = 0.026). OCT was more effective than CAB in 8/23 cultures, while CAB was more effective than OCT in 3/23 (CAB+ group). In CAB+ tumors, SST1 expression was higher compared with the other groups (P = 0.034). At receiver operating characteristic (ROC) curve analysis, SST1 and D2R discriminated between GH and GH/PRL co-secretion (AUC 0.856, P = 0.013; AUC 0.822, P = 0.024). SST1 was the best predictor of CAB response (≥50% GH reduction, AUC 0.913, P = 0.006; 80% sensitivity, 94% specificity). Conclusion OCT is 5% to 10% more effective than CAB in vitro. SST1 mRNA expression can represent a reliable marker of GH/PRL co-secreting tumors showing a preferential response to CAB treatment.

Cushing syndrome results from supraphysiological exposure to glucocorticoids and is associated with significant morbidity and mortality. The pathogenesis includes administration of corticosteroids (exogenous Cushing syndrome) or autonomous cortisol overproduction, whether or not ACTH-dependent (endogenous Cushing syndrome). An early diagnosis of Cushing syndrome is warranted; however, in clinical practice, it is very challenging partly because of resemblance with other common conditions (ie, pseudo-Cushing syndrome). Initial workup should start with excluding local and systemic corticosteroid use. First-line screening tests including the 1-mg dexamethasone suppression test, 24-hour urinary free cortisol excretion, and late-night salivary cortisol measurement should be performed to screen for endogenous Cushing syndrome. Scalp-hair cortisol/cortisone analysis helps in the assessment of long-term glucocorticoid exposure as well as in detection of transient periods of hypercortisolism as observed in cyclical Cushing syndrome. Interpretation of results can be difficult because of individual patient characteristics and hence requires awareness of test limitations. Once endogenous Cushing syndrome is established, measurement of plasma ACTH concentrations differentiates between ACTH-dependent (80%-85%) or ACTH-independent (15%-20%) causes. Further assessment with different imaging modalities and dynamic biochemical testing including bilateral inferior petrosal sinus sampling helps further pinpoint the cause of Cushing’s syndrome. In this issue of “Approach to the patient,” the diagnostic workup of Cushing syndrome is discussed with answering the questions when to screen, how to screen, and how to differentiate the different causes. In this respect, the latest developments in biochemical and imaging techniques are discussed as well.

Objective The aim of this study was to develop an open-source and reproducible digital quantitative analysis (DIA) of somatostatin receptor subtype 2a (SST2) staining in formalin-fixed paraffin-embedded tissues of pancreatic neuroendocrine tumors (panNETs) and growth hormone (GH)-secreting pituitary adenomas (GHomas). Design SST2 immunostaining of 18 panNETs and 39 GHomas was assessed using a novel DIA protocol and compared with a widely used semi-quantitative immunoreactivity score (IRS). Methods The DIA software calculates the staining intensity/area and the percentage of positive cells (%PC). Four representative images were selected for each sample by two independent selectors (S1 and S2), with the analysis performed by two independent analyzers (A1 and A2). Agreement between observers was calculated using the concordance correlation coefficient (CCC). Results In panNETs, the CCC ranged 0.935–0.977 for intensity/area and 0.942–0.983 for %PC. In GHomas, the CCC ranged 0.963–0.997 for intensity/area and 0.979–0.990 for %PC. In both panNETs and GHomas, the DIA staining intensity was strongly correlated with the IRS (Spearman rho: 0.916–0.969, P P 2 expression, evaluated both as DIA intensity/area (Spearman rho: −0.448 to −0.527, P = 0.007–0.004) and DIA %PC (Spearman rho: −0.558 to −0.644, P ≤ 0.001). Conclusions The DIA has an excellent inter-observer agreement and showed a strong correlation with the widely used semi-quantitative IRS. The DIA protocol is an open-source, highly reproducible tool and provides a reliable quantitative evaluation of SST2 immunohistochemistry.

Objective Hyponatremia and hypernatremia are common electrolyte abnormalities in patients with malignancy and have been independently associated with worse survival outcomes. To date, there are no data on the impact of dysnatremia on survival outcomes in patients with neuroendocrine neoplasms (NENs). Design This study involves retrospective cohort analysis from a tertiary care center of NEN patients treated with peptide receptor radionuclide therapy (PRRT) with a cumulative activity of at least 3.7 GBq 177Lu-DOTATATE between the years 2000 and 2015. Methods Comparison of overall survival of patients with the occurrence of hyponatremia (serum sodium < 135 mmol/L) or hypernatremia (serum sodium > 145 mmol/L) before starting or during PRRT was perfomed. Results A total of 649 patients were included. Hyponatremia occurred in 57 patients during the observation period and was associated with a shorter median overall survival (95% CI) of 25 months (14–36) compared to 55 months (48–61) of the 512 normonatremic patients (P Conclusions The occurrence of hypo- or hypernatremia in PRRT-treated NET patients is associated with opposing outcomes with regard to overall survival. Sodium levels might have a prognostic role in these patients.

Neuroendocrine neoplasms (NENs) are rare, usually slow-growing tumors, often presenting with extensive liver metastases. Hyperammonemia due to insufficient hepatic clearance has been described in NEN cases; however, no systematic evaluation of risk factors and outcomes of NEN-associated hyperammonemia exists so far. This case report and retrospective review of NEN patients developing hyperammonemia from the years 2000 to 2020 at the Erasmus Medical Center in Rotterdam, the Netherlands, aimed to describe these patients and determine prognostic factors to improve evaluation and treatment. Forty-four NEN patients with documented hyperammonemia were identified. All patients had liver metastases with 30% (n = 13) showing signs of portal hypertension. Patients who developed encephalopathy had higher median ammonia levels, but there was no association between the severity of hyperammonemia and liver tumor burden or presence of liver insufficiency. Eighty-four percent (n = 37) of patients died during follow-up. The median (IQR) time from diagnosis of hyperammonemia to death was 1.7 months (0.1–22.7). Hyperbilirubinemia, hypoalbuminemia, elevated international normalized ratio, presence of liver insufficiency, encephalopathy and ascites were associated with worse outcomes. Their role as independent risk factors for mortality was confirmed using the Child–Pugh score as a summary factor (P < 0.001). No difference was seen concerning overall survival between our hyperammonemia patients and a propensity score-matched control stage IV NEN cohort. In conclusion, hyperammonemia comprises a relevant and potentially underdiagnosed complication of NEN liver metastases and is associated with worse outcomes. Assessment of signs of encephalopathy, risk factors and the Child–Pugh score could be helpful in selecting patients in whom ammonia levels should be measured.

Context Small-intestinal neuroendocrine tumors (SI-NETs) have a modest but significantly higher prevalence and worse prognosis in male patients. Objective This work aims to increase understanding of this sexual dimorphism in SI-NETs. Patients and Methods Retrospectively, SI-NET patients treated in a single tertiary center were included and analyzed for disease characteristics. Estrogen receptor 1 (ESR1) and 2 (ESR2), progesterone receptor (PGR), and androgen receptor (AR) messenger RNA (mRNA) expression was assessed in primary tumors and healthy intestine. Estrogen receptor alpha (ERα) and AR protein expression were analyzed by immunohistochemistry in primary tumors and mesenteric metastases. Results Of the 559 patients, 47% were female. Mesenteric metastasis/fibrosis was more prevalent in men (71% / 46%) than women (58% / 37%; P = 0.001 and P = 0.027, respectively). In women, prevalence of mesenteric metastases increased gradually with age from 41.1% in women 70 years. Increased expression of ESR1 and AR mRNA was observed in primary tumors compared to healthy intestine (both P < 0.001). ERα staining was observed in tumor cells and stroma with a strong correlation between tumor cells of primary tumors and mesenteric metastases (rho = 0.831, P = 0.02), but not in stroma (rho = −0.037, P = 0.91). AR expression was only found in stroma. Conclusion Sexual dimorphism in SI-NETs was most pronounced in mesenteric disease, and the risk of mesenteric metastasis in women increased around menopause. The combination of increased ERα and AR expression in the SI-NET microenvironment suggests a modulating role of sex steroids in the development of the characteristic SI-NET mesenteric metastasis and associated fibrosis.

Context Cushing disease, a chronic hypercortisolism disorder, is associated with considerable morbidity and mortality. Normalizing cortisol production is the primary treatment goal. Objective We aimed to evaluate the safety and efficacy of osilodrostat, a potent, orally available 11βhydroxylase inhibitor, compared with placebo in patients with Cushing disease. Methods LINC 4 was a phase III, multicenter trial comprising an initial 12-week, randomized, double-blind, placebo-controlled (osilodrostat:placebo, 2:1) period followed by a 36-week, open-label treatment period (NCT02697734). Adult patients (aged 18-75 years) with confirmed Cushing disease and mean urinary free cortisol (mUFC) excretion ≥ 1.3 times the upper limit of normal (ULN) were eligible. The primary endpoint was the proportion of randomized patients with mUFC ≤ ULN at week 12. The key secondary endpoint was the proportion achieving mUFC ≤ ULN at week 36 (after 24 weeks’ open-label osilodrostat). Results Seventy-three patients (median age, 39 years [range, 19-67]; mean/median mUFC, 3.1 × ULN/2.5 × ULN) received randomized treatment with osilodrostat (n = 48) or placebo (n = 25). At week 12, significantly more osilodrostat (77%) than placebo (8%) patients achieved mUFC ≤ ULN (odds ratio 43.4; 95% CI 7.1, 343.2; P Conclusion Osilodrostat rapidly normalized mUFC excretion in most patients with Cushing disease and maintained this effect throughout the study. The safety profile was favorable.

Purpose: Bronchial and gastroenteropancreatic neuroendocrine tumors (NET) are slow-growing tumors, which frequently express somatostatin receptors on their cell membranes. These receptors are targets for therapy with Lutetium-177–labeled somatostatin analogues. We have treated over 1,200 patients with peptide receptor radionuclide therapy (PRRT) with [177Lu-DOTA0,Tyr3]octreotate (177Lu-DOTATATE) since the year 2000 and present the results on efficacy, survival, and toxicity of this therapy.Experimental Design: For safety analysis, 610 patients treated with a cumulative dose of at least 100 mCi (3.7 GBq) 177Lu-DOTATATE were included. A subgroup of 443 Dutch patients who were treated with a cumulative dose of at least 600 mCi (22.2 GBq) 177Lu-DOTATATE before 2013 was further analyzed for efficacy and survival.Results: The objective response rate of the total group of patients was 39%. Stable disease was reached in 43% of patients. Progression-free survival (PFS) and overall survival (OS) for all NET patients were 29 months [95% confidence interval (CI), 26–33 months] and 63 months (95% CI, 55–72 months). Long-term toxicity included acute leukemia in four patients (0.7%) and myelodysplastic syndrome in nine patients (1.5%). No therapy-related long-term renal or hepatic failure occurred.Conclusions: PRRT with 177Lu-DOTATATE is a favorable therapeutic option in patients with metastatic bronchial and gastroenteropancreatic NETs that express somatostatin receptors. PRRT with 177Lu-DOTATATE is safe with few side-effects and shows good response rates with PFS of 29 months and OS of 63 months. Clin Cancer Res; 23(16); 4617–24. ©2017 AACR.

Supplement Table 1. A. Characteristics of the 4 patients with acute leukemia in follow-up

Supplement Figure 1. Median overall survival for patients receiving a cumulative dose of {greater than or equal to}100 mCi 177Lu-DOTATATE with a primary NET located in the midgut with and without progression at baseline.

Objective: Prolactin-secreting tumors respond well to medical management, with a few patients requiring surgery. We conducted a systematic review and meta-analysis to study the determinants of surgical remission in these tumors. Methods: We searched PubMed to identify eligible studies reporting postoperative remission in patients treated with transsphenoidal surgery for prolactinoma. Primary outcomes included postoperative remission, follow-up remission, and recurrence. Postoperative and follow-up remission were defined as normoprolactinemia at 1 year after operation, respectively. Recurrence was defined as hyperprolactinemia after initial normalization of prolactin levels. Odds ratios (ORs) were calculated, stratified by radiologic size, tumor extension, and tumor invasion, and analyzed using a random-effects model meta-analysis. Results: Thirty-five studies were included. Macroadenomas were associated with lower rates of postoperative remission (OR, 0.20; 95% confidence interval [CI], 0.16–0.24) and lower rates of remission at follow-up (OR, 0.11; 95% CI, 0.053–0.22). Postoperative remission was less likely in tumors with extrasellar or suprasellar extension (OR, 0.16; 95% CI, 0.06–0.43) and tumors with cavernous sinus invasion (OR, 0.03; 95% CI, 0.01–0.13). Female gender and absence of preoperative dopamine agonist treatment were also associated with higher remission rates. Across the included studies, there was considerable heterogeneity in each primary outcome (postoperative remission, I2 = 94%; follow-up remission, I2 = 86%; recurrence, I2 = 68%). Conclusions: Transsphenoidal surgery for prolactinomas may be particularly effective in small, noninvasive, treatment-naive tumors and may provide a viable first-line alternative to dopamine agonist therapy in such patients.

Context Peptide receptor radionuclide therapy (PRRT) with [Lutetium-177-DOTA0-Tyr3]octreotate (177Lu-DOTATATE) results in an increase of progression-free survival and quality of life in patients with progressive, well-differentiated neuroendocrine neoplasms (NENs). Objective To study the effect of 177Lu-DOTATATE in patients with carcinoid syndrome and radiologically stable or newly diagnosed disease treated solely for the purpose of symptom reduction. Design Retrospective cohort study. Setting Tertiary care hospital. Patients Twenty-two patients with a metastatic midgut NEN, elevated urinary 5-hydroxyindolacetic acid excretion, and flushing and/or diarrhea despite treatment with a somatostatin analog, without documented disease progression. Intervention PRRT with 177Lu-DOTATATE (intended cumulative dose: 29.6 GBq) with a primary aim to reduce symptoms. Results After PRRT, mean bowel movement frequency (BMF) decreased from 6.1 ± 3.4 to 4.6 ± 3.6 per day (P = 0.009). Flushes decreased from 4.3 ± 2.9 to 2.4 ± 2.7 flushes per day (P = 0.002). A decrease of BMF of more than 30% occurred in 47% of patients with baseline BMF of 4 or more (n = 17). In patients with ≥2 episodes of flushing a day (n = 15), 67% of patients had more than 50% decrease of daily flushing. A decrease in urinary 5-hydroxyindolacetic acid excretion of more than 30% was seen in 56% of patients. The European Organization for Research and Treatment of Cancer–Core Module diarrhea subscale score showed a trend toward improvement by an average of 16.7 ± 33.3 points (P = 0.11). Conclusion PRRT with 177Lu-DOTATATE effectively reduced diarrhea and flushing in patients with carcinoid syndrome and can be considered for symptomatic treatment of carcinoid syndrome insufficiently controlled with somatostatin analogs.

Cushing's syndrome (CS) is associated with a hypercoagulable state resulting in an increased risk on venous thromboembolism (VTE). In patients with untreated active CS VTE incidence is up to 18-fold higher compared to the general population, whereas after pituitary and adrenal surgery a postoperative VTE risk between 2.6 and 5.6% has been reported. Interestingly, after surgery the VTE risk is not only increased in the first week but also during several months postoperatively. The hypercoagulable state in CS is thought to be caused, at least in part, by an imbalance between activity of pro- and anticoagulant pathways. However, changes in activated partial thromboplastin time and plasma concentrations of pro-and anticoagulant factors are not observed in every CS patient. Only retrospective studies have shown that thromboprophylaxis lowers VTE risk in CS. Future prospective studies should asses the optimal timing, duration and type of thromboprophylaxis in CS to improve VTE-related morbidity and mortality.

Objective To investigate the long-term efficacy and tolerability of osilodrostat, a potent oral 11β-hydroxylase inhibitor, for treating Cushing's disease (CD). Design/methods A total of 137 adults with CD and mean 24-h urinary free cortisol (mUFC) > 1.5 × upper limit of normal (ULN) received osilodrostat (starting dose 2 mg bid; maximum 30 mg bid) during the prospective, Phase III, 48-week LINC 3 (NCT02180217) core study. Patients benefiting from osilodrostat at week 48 could enter the optional extension (ending when all patients had received ≥ 72 weeks of treatment or discontinued). Efficacy and safety were assessed for all enrolled patients from the core study baseline. Results Median osilodrostat exposure from the core study baseline to study end was 130 weeks (range 1–245) and median average dose was 7.4 mg/day (range 0.8–46.6). The reduction in mean mUFC achieved during the core was maintained during the extension and remained ≤ ULN. Of 106 patients, 86 (81%) patients who entered the extension had mUFC ≤ ULN at week 72. Improvements in cardiovascular/metabolic-related parameters, physical manifestations of hypercortisolism (fat pads, central obesity, rubor, striae, and hirsutism in females), and quality of life in the core study were also maintained or improved further during the extension. No new safety signals were reported; 15/137 (10.9%) and 12/106 (11.3%) patients discontinued for adverse events during the core and extension, respectively. Mean testosterone in females decreased towards baseline levels during the extension. Conclusions Data from this large, multicentre trial show that long-term treatment with osilodrostat sustains cortisol normalisation alongside clinical benefits in most patients with CD and is well tolerated.

Metastatic mesenteric masses of small intestinal neuroendocrine tumors (SI-NETs) are known to often cause intestinal complications. The aim of this study was to identify patients at risk to develop these complications based on routinely acquired CT scans using a standardized set of clinical criteria and radiomics. Retrospectively, CT scans of SI-NET patients with a mesenteric mass were included and systematically evaluated by five clinicians. For the radiomics approach, 1128 features were extracted from segmentations of the mesenteric mass and mesentery, after which radiomics models were created using a combination of machine learning approaches. The performances were compared to a multidisciplinary tumor board (MTB). The dataset included 68 patients (32 asymptomatic, 36 symptomatic). The clinicians had AUCs between 0.62 and 0.85 and showed poor agreement. The best radiomics model had a mean AUC of 0.77. The MTB had a sensitivity of 0.64 and specificity of 0.68. We conclude that systematic clinical evaluation of SI-NETs to predict intestinal complications had a similar performance than an expert MTB, but poor inter-observer agreement. Radiomics showed a similar performance and is objective, and thus is a promising tool to correctly identify these patients. However, further validation is needed before the transition to clinical practice.

Medical therapy of clinically nonfunctioning (nonsecreting) low grade (grade 1–2) neuroendocrine neoplasms consists of first-line first generation somatostatin analogs and second-line or third-line peptide receptor radiotherapy with radiolabeled beta-emitting somatostatin analogs, Everolimus, Sunitinib, and interferon-α. Second-generation somatostatin analogs like Pasireotide have no proven superiority over first-generation somatostatin analogs. Chemotherapy is usually reserved as second-line therapy in pancreatic neuroendocrine neoplasms and neuroendocrine carcinomas.

The concept of using a targeting molecule labeled with a diagnostic radionuclide for using positron emission tomography or single photon emission computed tomography imaging with the potential to demonstrate that tumoricidal radiation can be delivered to tumoral sites by administration of the same or a similar targeting molecule labeled with a therapeutic radionuclide termed “theranostics.” Peptide receptor radionuclide therapy (PRRT) with radiolabeled somatostatin analogs (SSAs) is a well-established second/third-line theranostic treatment for somatostatin receptor-positive well-differentiated (neuro-)endocrine neoplasms (NENs). PRRT with 177Lu-DOTATATE was approved by the regulatory authorities in 2017 and 2018 for selected patients with low-grade well-differentiated gastroenteropancreatic (GEP) NENs. It improves progression-free survival as well as quality of life of GEP NEN patients. Favorable symptomatic and biochemical responses using PRRT with 177Lu-DOTATATE have also been reported in patients with functioning metastatic GEP NENs like metastatic insulinomas, Verner Morrison syndromes (VIPomas), glucagonomas, and gastrinomas and patients with carcinoid syndrome. This therapy might also become a valuable therapeutic option for inoperable low-grade bronchopulmonary NENs, inoperable or progressive pheochromocytomas and paragangliomas, and medullary thyroid carcinomas. First-line PRRT with 177Lu-DOTATATE and combinations of this therapy with cytotoxic drugs are currently under investigation. New radiolabeled somatostatin receptor ligands include SSAs coupled with alpha radiation emitting radionuclides and somatostatin receptor antagonists coupled with radionuclides.

INTRODUCTION: Immune checkpoint inhibitor (ICI) associated diabetes is a harmful adverse event (AE) in patients with cancer following anti-programmed (cell) death protein-1 (PD-1) treatment. There are no available biomarkers able to predict this AE. The primary aim of this study was to investigate C-peptide levels as potential predictor for the occurrence of ICI-related diabetes. The secondary aim was to describe the presence of islet autoantibodies and course of pancreatic enzymes in patients with and without ICI-related diabetes.METHODS: From a total of 1318 patients with cancer who started anti-PD-1 treatment 8 cases and 16 controls were studied in this nested case-control study. C-peptide levels, islet autoantibodies, and pancreatic enzymes were measured in prospectively collected blood serum.RESULTS: In cases versus controls, median C-peptide levels were comparable at baseline and before toxicity or at the corresponding time point in controls. No patient had C-peptide levels below reference range before toxicity onset. Two out of eight patients in the ICI-related diabetes group had positive islet autoantibodies, whereas one out of 16 patients in the control group had positive islet autoantibodies. Pancreatic enzymes were elevated before diabetes onset in one patient (13%) and in one control (6%) at the corresponding time point.CONCLUSIONS: In patients developing ICI-related diabetes, changes in C-peptide levels, islet autoantibody positivity, and pancreatic enzymes before ICI-related diabetes onset seem comparable to patients without ICI-related diabetes. (NTR: NL6828).

Purpose Peptide receptor radionuclide therapy (PRRT) can cause dose-limiting toxicities (DLTs) of the bone marrow, liver, and kidneys. It is yet unknown whether women and men are equally at risk of these DLTs.Methods Neuroendocrine tumor patients treated with 177Lu-DOTATATE between 2000 and 2015 in our phase II trial with available laboratory data were included. For all DLTs, the highest Common Terminology Criteria for Adverse Events (version 4.03) grades that occurred from the start of PRRT until 3 months after the last cycle were scored.Results At baseline, women (n = 439) had a significantly lower body mass index, Karnofsky Performance Score, hemoglobin level, and creatinine clearance and a significantly higher platelet level than men (n = 534). Both groups received a median activity of 29.6 GBq (800 mCi). After the start of PRRT, women more frequently developed grade ≥2 thrombocytopenia compared with men (25% vs 18%, P = 0.004) due to a significant increase in grade ≥3 thrombocytopenia (11% vs 6%, P = 0.008). Furthermore, the incidence of grade ≥3 anemia was higher in women (7% vs 3%, P = 0.002). In the multivariable regression model, female sex (odds ratio, 2.50; 95% confidence interval, 1.67–3.74) was confirmed to be an independent risk factor for grade ≥2 thrombocytopenia, among baseline platelet count, bone metastases, uptake on 111In-DTPA-octreotide scan, Karnofsky Performance Score, alkaline phosphatase, lymphocytes, albumin, and renal function.Conclusions Female neuroendocrine tumor patients more often experienced PRRT-induced toxicities of platelets and hemoglobin than males, but this did not lead to a lower cumulative activity.

Purpose Peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTATATE induces objective response in up to 57% of pancreatic neuroendocrine neoplasms (panNENs). Therefore, PRRT may comprise a downstaging option for panNEN patients who are not eligible for upfront curative surgery or are at high risk for recurrence. The aim of this study was to assess the potency of induction PRRT for locally advanced panNENs and to evaluate the effect of surgery after PRRT on overall survival (OS). Methods Retrospective cohort study of panNEN patients treated with induction 177Lu-DOTATATE. Results After PRRT, 26 out of 49 patients underwent pancreatic surgery with curative intent (PRRT + surgery). Partial objective response was obtained in 62% of the PRRT + surgery group versus 26% of the patients not undergoing panNEN surgery (PRRT-only group, p = 0.02). Downstaging in tumour-vessel interface was observed in 38% of all patients with at least one involved vessel. Median OS was 14.7 years (95% CI 5.9–23.6) for the PRRT + surgery group compared to 5.5 years (95% CI 4.5–6.5) for the PRRT-only group (p = 0.003). In the Cox proportional hazards analysis, surgery was not significantly associated with OS after propensity score adjustment with cumulative activity, performance status, tumour size after PRRT, and tumour grade. Median progression-free survival was 5.3 years (95% CI 2.4–8.1) for the PRRT + surgery group and 3.0 years (95% CI 1.6–4.4) for the PRRT-only group (p = 0.02). Conclusion Early administration of PRRT followed by surgery is associated with favourable long-term outcomes in patients with locally advanced or oligometastatic panNEN and can be considered for selected patients with vascular involvement and/or increased risk of recurrence.

Background: A metastatic mesenteric mass is a hallmark of small intestinal neuroendocrine tumours (SI-NETs). However, little is known on its development over time. Therefore, we conducted a study to assess the evolution of a SI-NET-associated mesenteric mass over time. Methods: Retrospectively, 530 patients with proven SI-NET were included. The presence and growth of a mesenteric mass was assessed using RECIST 1.1 criteria on every consecutive CT-scan until the end of follow-up or resection. Results: At baseline, a mesenteric mass was present in 64% of the patients, of whom 13.5% showed growth of the mesenteric mass with a median time to growth of 40 months. Male gender was the only independent predictor of growth (OR 2.67). Of the patients without a mesenteric mass at the first evaluation, 2.6% developed a pathological mesenteric mass. Treatment with peptide receptor radionuclide therapy (PRRT, N = 132) resulted in an objective size reduction of the mesenteric mass in 3.8%. Conclusion: The metastatic mesenteric mass in SI-NETs has a static behavior over time. Therefore, site-specific growth behavior should be taken into account when selecting target lesions and assessing disease progression and therapeutic response. PRRT appears not to be effective for size reduction of the mesenteric mass.

Context Pretreatment with α-adrenergic receptor blockers is recommended to prevent hemodynamic instability during resection of a pheochromocytoma or sympathetic paraganglioma (PPGL). Objective To determine which type of α-adrenergic receptor blocker provides the best efficacy. Design Randomized controlled open-label trial (PRESCRIPT; ClinicalTrials.gov NCT01379898) Setting Multicenter study including 9 centers in The Netherlands. Patients 134 patients with nonmetastatic PPGL. Intervention Phenoxybenzamine or doxazosin starting 2 to 3 weeks before surgery using a blood pressure targeted titration schedule. Intraoperative hemodynamic management was standardized. Main Outcome Measures Primary efficacy endpoint was the cumulative intraoperative time outside the blood pressure target range (ie, SBP >160 mmHg or MAP Results Median cumulative time outside blood pressure targets was 11.1% (interquartile range [IQR]: 4.3–20.6] in the phenoxybenzamine group compared to 12.2% (5.3–20.2)] in the doxazosin group (P = .75, r = 0.03). The hemodynamic instability score was 38.0 (28.8–58.0) and 50.0 (35.3–63.8) in the phenoxybenzamine and doxazosin group, respectively (P = .02, r = 0.20). The 30-day cardiovascular complication rate was 8.8% and 6.9% in the phenoxybenzamine and doxazosin group, respectively (P = .68). There was no mortality after 30 days. Conclusions The duration of blood pressure outside the target range during resection of a PPGL was not different after preoperative treatment with either phenoxybenzamine or doxazosin. Phenoxybenzamine was more effective in preventing intraoperative hemodynamic instability, but it could not be established whether this was associated with a better clinical outcome.

Background Osilodrostat, a potent oral 11β-hydroxylase inhibitor, provided rapid and sustained normalization of mean urinary free cortisol (mUFC) in patients with Cushing's disease (CD) during the 48-week (W) core period of LINC 4 (NCT02697734), and was well tolerated. We report long-term efficacy and safety results from the LINC 4 core and extension phases combined. Methods 73 adults with CD and mUFC >1.3× the upper limit of normal (ULN) were enrolled. LINC 4 comprised a 12W, randomized, double-blind, placebo-controlled period followed by 36W of open-label osilodrostat. At W48, patients could enter an optional extension. Dose adjustments were permitted based on efficacy/tolerability (range during open-label treatment 1–30 mg bid). LINC 4 ended when all patients transitioned to a separate long-term safety study (not reported) or discontinued treatment. Efficacy/safety are reported for all patients unless otherwise stated, and excludes data collected during W1–12 for placebo recipients. Results Of the 65 patients who completed the core phase, 60 entered the extension. Median (range) osilodrostat exposure from core baseline to study end was 87.1 (2–127) W; median average (IQR) dose was 4.6 (3.7–9.2) mg/day. 15 patients discontinued osilodrostat; 7 after W48 (6 because of adverse events [AEs]). The proportion of patients with normal mUFC (≤138 nmol/24h [50 µg/24h]) was 68.5% (n=50/73) at W48, 61.5% (n=40/65) at W72 and 72.4% (n=42/58) at the end-of-treatment extension (EOT) visit. Median mUFC decreased from 2.5×ULN (core baseline) to 0.5×ULN (W48 and W72), to 0.4×ULN (EOT). Median late-night salivary cortisol decreased from 2.8×ULN (core baseline) to 1.2×ULN (W48 and W72), to 1.1×ULN (EOT).The most common AEs during the entire study were decreased appetite (46.6%), arthralgia (45.2%), fatigue (39.7%), nausea (37.0%), headache (34.2%) and dizziness (30.1%). Hypocortisolism- and adrenal-hormone-precursor-accumulation-related AEs occurred in 28.8% (21/73) and 61.6% (45/73) of patients during the entire study, less frequently in the extension than the core. Most were grade 1/2 and resolved with dose reduction/interruption and/or concomitant medication. During the extension, hirsutism and acne were reported as AEs by 1 and 0 patients, respectively.Median ACTH increased from 1.1×ULN (core baseline) to 3.0×ULN (W48), to 3.6×ULN (W72), to 3.5×ULN (EOT). Median change (95% CI) in pituitary tumor volume (assessed by MRI) from core baseline to last available assessment was 4.0 mm3 (−24.1–169.8); pituitary-tumor-enlargement-related AEs led to drug discontinuation in 2 and 0 patients during the core and extension, respectively. No trend was observed between tumor volume change and osilodrostat dose. Conclusion Osilodrostat provided long-term control of cortisol production during LINC 4. Fewer AEs related to hypocortisolism and accumulation of adrenal-hormone-precursors occurred during the extension than during the core. Osilodrostat is an effective and well-tolerated long-term treatment option for CD patients. Presentation: Tuesday, June 14, 2022 10:15 a.m. - 10:30 a.m.

In the literature, up to 45% of neuroendocrine tumor (NET) patients who are treated with

Corticotroph tumor progression after bilateral adrenalectomy/Nelson’s syndrome (CTP-BADX/NS) is a severe complication of bilateral adrenalectomy (BADX). The aim of our study was to investigate the prevalence, presentation and outcome of CTP-BADX/NS in patients with Cushing’s disease (CD) included in the European Registry on Cushing’s Syndrome (ERCUSYN). We examined data on 1045 CD patients and identified 85 (8%) who underwent BADX. Of these, 73 (86%) had follow-up data available. The median duration of follow-up since BADX to the last visit/death was 7 years (IQR 2–9 years). Thirty-three patients (45%) experienced CTP-BADX/NS after 3 years (1.5–6) since BADX. Cumulative progression-free survival was 73% at 3 years, 66% at 5 years and 46% at 10 years. CTP-BADX/NS patients more frequently had a visible tumor at diagnosis of CD than patients without CTP-BADX/NS (P P = 0.033). Diagnosis of CTP-BADX/NS, older age, greater UFC levels at diagnosis of CD and initial treatment predicted mortality. In conclusion, CTP-BADX/NS was reported in 45% of the ERCUSYN patients who underwent BADX, and control of tumor growth was reached in half of them. Future studies are needed to establish effective strategies for prevention and treatment.

Simple Summary: Patients with the rare cancer adrenocortical carcinoma are exposed to many symptoms and treatment side-effects. Research on how this can affect their health-related quality of life (HRQoL) is limited, however. This article includes the first assessment of HRQoL in a population-based cohort of patients with adrenocortical carcinoma with the European Organization for Research and Treatment of Cancer QLQ-C30 questionnaire and the newly developed disease-specific additional questionnaire ACC-QOL. The ACC-QOL has good psychometric properties in terms of validity, reliability, and responsiveness. Patients diagnosed more than 5 years ago reported a relatively good HRQoL compared with the Dutch reference population, but experienced residual fatigue and emotional problems. Patients after additional surgery reported a slightly lower HRQoL due to physical limitations. Patients who had recently received mitotane or chemotherapy reported a worse HRQoL and problems in many domains. This knowledge and the new disease-specific questionnaire can aid future research, side-effect monitoring, treatment guidance, and shared decision making. We aimed to develop a disease-specific adrenocortical carcinoma (ACC) health-related quality of life (HRQoL) questionnaire (ACC-QOL) and assess HRQoL in a population-based cohort of patients with ACC. Development was in line with European Organization for Research and Treatment of Cancer (EORTC) guidelines, though not an EORTC product. In phase I and II, we identified 90 potential HRQoL issues using literature and focus groups, which were reduced to 39 by healthcare professionals. Pilot testing resulted in 28 questions, to be used alongside the EORTC QLQ-C30. In Phase III, 100 patients with ACC were asked to complete the questionnaires twice in the PROFILES registry (3-month interval, respondents: first 67, second 51). Confirmatory factor analysis demonstrated the structural validity of 26 questions with their scale structure (mitotane side-effects, hypercortisolism/hydrocortisone effects, emotional effects). Internal consistency and reliability were good (Cronbach's alpha 0.897, Interclass correlation coefficient 0.860). Responsiveness analysis showed good discriminative ability (AUC 0.788). Patients diagnosed more than 5 years ago reported a good HRQoL compared with the Dutch reference population, but experienced residual fatigue and emotional problems. Patients who underwent recent treatment reported a lower HRQoL and problems in several domains. In conclusion, we developed an ACC-specific HRQoL questionnaire with good psychometric properties.

Peptide receptor radionuclide therapy (PRRT) withRetrospective cohort study of panNEN patients treated with inductionAfter PRRT, 26 out of 49 patients underwent pancreatic surgery with curative intent (PRRT + surgery). Partial objective response was obtained in 62% of the PRRT + surgery group versus 26% of the patients not undergoing panNEN surgery (PRRT-only group, p = 0.02). Downstaging in tumour-vessel interface was observed in 38% of all patients with at least one involved vessel. Median OS was 14.7 years (95% CI 5.9-23.6) for the PRRT + surgery group compared to 5.5 years (95% CI 4.5-6.5) for the PRRT-only group (p = 0.003). In the Cox proportional hazards analysis, surgery was not significantly associated with OS after propensity score adjustment with cumulative activity, performance status, tumour size after PRRT, and tumour grade. Median progression-free survival was 5.3 years (95% CI 2.4-8.1) for the PRRT + surgery group and 3.0 years (95% CI 1.6-4.4) for the PRRT-only group (p = 0.02).Early administration of PRRT followed by surgery is associated with favourable long-term outcomes in patients with locally advanced or oligometastatic panNEN and can be considered for selected patients with vascular involvement and/or increased risk of recurrence.

Simple Summary Adrenal glands are common dissemination sites for metastases of various solid tumors. The rapid development of new treatment strategies, such as targeted therapy and immunotherapy for different cancer types, has led to increased metastatic adrenalectomies. Therefore, clear communication between oncologists and adrenal gland specialists has become increasingly important to outweigh surgical risks versus oncological advantages of adrenalectomies in these patients. This study assesses trends in diagnosis, type of surgery, and short-term and long-term surgical outcomes of patients who underwent metastatic adrenalectomy. We included a total of 95 patients with an adrenal metastasis of non-adrenal primary tumors, most often colorectal or lung cancer, who underwent (minimal invasive) adrenalectomy. 37.9% of the patients experienced one or more complications after adrenalectomy. Within our patient cohort, an increased demand for metastatic adrenalectomy was observed over the past years, which might be associated with the rise of targeted- and immunotherapy. Our data aims to assist multidisciplinary teams with weighing the pros and cons of resection of the metastasized adrenal gland of cancer patients. Abstract The adrenal glands are common dissemination sites for metastasis of various solid tumors. Surgical treatment is often recommended because targeted therapies and immunotherapy are frequently ineffective for adrenal metastasis. We report the experience with short-term and long-term surgical outcomes of patients undergoing surgery for adrenal metastasis in two hospitals. A retrospective, multicenter study was performed to analyze patient characteristics, tumor-related data, perioperative outcomes, and oncological outcomes. Postoperative complications that occurred within 30 days were scored according to the Clavien Dindo classification. Metastatic adrenalectomy was performed in 95 patients. We observed an increase from an average of 3 metastatic adrenalectomies per year between 2001–2005 to 10 between 2015–2019. The most frequent underlying malignancies were colorectal and lung cancer. In 55.8%, minimal invasive adrenalectomy was performed, including six conversions to open surgery. A total of 37.9% of patients had postoperative complications, of which ileus or gastroparesis, wound problems, pneumonia, and heart arrhythmias were the most occurring complications. Improved cancer care has led to an increased demand for metastatic adrenalectomy over the past years. Complication rates of 37.9% are significant and cannot be neglected. Therefore, multidisciplinary teams should weigh the decision to perform metastatic adrenalectomy for each patient individually, taking into account the drawbacks of the described morbidity versus the potential benefits.

Background: Cross-sectional imaging regularly results in incidental discovery of adrenal tumours, requiring exclusion of adrenocortical carcinoma (ACC). However, differentiation is hampered by poor specificity of imaging characteristics. We aimed to validate a urine steroid metabolomics approach, using steroid profiling as the diagnostic basis for ACC. Methods: We did a prospective multicentre study in adult participants (age ≥18 years) with newly diagnosed adrenal masses. We assessed the accuracy of diagnostic imaging strategies based on maximum tumour diameter (≥4 cm vs

We performed genome-wide association study meta-analysis to identify genetic determinants of skeletal age (SA) deviating in multiple growth disorders. The joint meta-analysis (N = 4557) in two multiethnic cohorts of school-aged children identified one locus, CYP11B1 (expression confined to the adrenal gland), robustly associated with SA (rs6471570-A; β = 0.14; P = 6.2 × 10−12). rs6410 (a synonymous variant in the first exon of CYP11B1 in high LD with rs6471570), was prioritized for functional follow-up being second most significant and the one closest to the first intron-exon boundary. In 208 adrenal RNA-seq samples from GTEx, C-allele of rs6410 was associated with intron 3 retention (P = 8.11 × 10−40), exon 4 inclusion (P = 4.29 × 10−34), and decreased exon 3 and 5 splicing (P = 7.85 × 10−43), replicated using RT-PCR in 15 adrenal samples. As CYP11B1 encodes 11-β-hydroxylase, involved in adrenal glucocorticoid and mineralocorticoid biosynthesis, our findings highlight the role of adrenal steroidogenesis in SA in healthy children, suggesting alternative splicing as a likely underlying mechanism., Olja Grgic, Matthew Gazzara, and Alessandra Chesi et al. perform a genome-wide association study meta-analysis for skeletal age in two pediatric cohorts. They observe that variation in the adrenal gene, CYP11B1, impacts its alternative splicing, suggesting that adrenal steroidogenesis may contribute toward variation in skeletal age in otherwise healthy children.

Background Despite adequate presurgical management, blood pressure fluctuations are common during resection of pheochromocytoma or sympathetic paraganglioma (PPGL). To a large extent, the variability in blood pressure control during PPGL resection remains unexplained. Adrenomedullin and B-type natriuretic peptide, measured as MR-proADM and NT-proBNP, respectively, are circulating biomarkers of cardiovascular dysfunction. We investigated whether plasma levels of MR-proADM and NT-proBNP are associated with blood pressure fluctuations during PPGL resection. Methods Study subjects participated in PRESCRIPT, a randomized controlled trial in patients undergoing PPGL resection. MR-proADM and NT-proBNP were determined in a single plasma sample drawn before surgery. Multivariable linear and logistic regression analyses were used to explore associations between these biomarkers and blood pressure fluctuations, use of vasoconstrictive agents during surgery as well as the occurrence of perioperative cardiovascular events. Results A total of 126 PPGL patients were included. Median plasma concentrations of MR-proADM and NT-proBNP were 0.51 (0.41–0.63) nmol/L and 68.7 (27.9–150.4) ng/L, respectively. Neither MR-proADM nor NT-proBNP were associated with blood pressure fluctuations. There was a positive correlation between MR-proADM concentration and the cumulative dose of vasoconstrictive agents (03B2 0.44, P =0.001). Both MR-proADM and NT-proBNP were significantly associated with perioperative cardiovascular events (OR: 5.46, P =0.013 and OR: 1.54, P =0.017, respectively). Conclusions plasma MR-proADM or NT-proBNP should not be considered as biomarkers for the presurgical risk assessment of blood pressure fluctuations during PPGL resection. Future studies are needed to explore the potential influence of these biomarkers on the intraoperative requirement of vasoconstrictive agents and the perioperative cardiovascular risk.

Sufficient expression of somatostatin receptor (SSTR) in well-differentiated neuroendocrine tumors (NETs) is crucial for treatment with somatostatin analogs (SSAs) and peptide receptor radionuclide therapy (PRRT) using radiolabeled SSAs. Impaired prognosis has been described for SSTR-negative NET patients; however, studies comparing matched SSTR-positive and -negative subjects who have not received PRRT are missing. This retrospective analysis of two prospectively maintained NET databases aimed to compare matched metastatic grade 1 or 2 SSTR-positive and –negative NET patients. SSTR-negativity was defined as having insufficient tumor uptake on diagnostic SSTR imaging. Patients that underwent PRRT were excluded. Seventy-seven SSTR-negative and 248 SSTR-positive grade 1–2 NET patients were included. Median overall survival rates were significantly lower for SSTR-negative compared to SSTR-positive NET patients (53 months vs 131 months; P < 0.001). To adjust for possible confounding by age, gender, grade and site of origin, 69 SSTR-negative NET patients were propensity score matched to 69 SSTR-positive NET patients. Group characteristics were similar, with the exception of SSTR-negative patients receiving more often chemotherapy and targeted treatment. The inferior survival outcome of SSTR-negative compared to SSTR-positive NET patients persisted with a median overall survival of 38 months vs 131 months (P = 0.012). This relationship upheld when correcting for the main influencing factors of having a higher grade tumor or receiving surgery in a multivariate Cox regression analysis. In conclusion, we showed that propensity score-matched SSTR-negative NET patients continue to have a worse prognosis compared to SSTR-positive NET patients despite receiving more aggressive treatment. Differences in tumor biology likely underlie this survival deficit.

Pituitary-directed medical treatment for Cushing’s disease (CD) is currently represented by membrane receptor targeting drugs (somatostatin analogs and dopamine agonists). Somatostatin and dopamine receptors are regulated by β-arrestins, which have been shown to be differentially regulated by glucocorticoids in non-neuroendocrine cells. In this study we investigated the effects of glucocorticoids on β-arrestin expression in corticotroph tumor cells. First, AtT20 cells, a mouse model of CD, were exposed to dexamethasone (Dex) at different time points and β-arrestin expression was evaluated at mRNA and protein levels. Futhermore, β-arrestin mRNA expression was evaluated in 17 human corticotroph adenoma samples and correlated to patients’ pre-operative cortisol levels. We observed that Dex treatment induced a time-dependent increase in β-arrestin 1 mRNA expression and a decrease in β-arrestin 2. The same modulation pattern was observed at protein level. Dex-mediated modulation of β-arrestins was abolished by co-treatment with mifepristone, and Dex withdrawal restored β-arrestin expression to basal levels after 72 h. The evaluation of β-arrestin mRNA in corticotroph adenomas from CD patients with variable disease activity showed a significant positive correlation between β-arrestin 1 mRNA and urinary cortisol levels. The effect of glucocorticoids on β-arrestin levels was confirmed by the analysis of two samples from a single patient, which underwent adenomectomy twice, with different pre-operative cortisol levels. In conclusion, glucocorticoids induce an inverse modulation of the two β-arrestin isofoms in corticotroph tumor cells. Since β-arrestins regulate membrane receptor functions, this finding may help to better understand the variable response to pituitary-targeting drugs in patients with Cushing’s disease.

Background Current perioperative patient care aims to maintain homeostasis by attenuation of the stress response to surgery, as a more vigorous stress response can have detrimental effects on postoperative recovery. This systematic review and meta-analysis aims to assess the effect of perioperative music on the physiological stress response to surgery. Methods The Embase, Medline Ovid, Cochrane Central, Web of Science, and Google Scholar databases were searched from inception date until February 5, 2019, using a systematic literature search following the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines for randomized controlled trials investigating the effect of music before, during, and/or after surgery in adult surgical patients on the stress response to surgery. Meta-analysis was performed using a random effects model and pooled standardized mean differences were calculated with 95% confidence intervals. This study was registered in the PROSPERO database (CRD42018097060). Results The literature search identified 1076 articles. Eighteen studies (1301 patients) were included in the systematic review, of which eight were included in the meta-analysis. Perioperative music attenuated the neuroendocrine cortisol stress response to surgery (pooled standardized mean difference −0.30, [95% confidence interval −0.53 to −0.07], P = 0.01, I2 = 0). Conclusions Perioperative music can attenuate the neuroendocrine stress response to surgery.

Introduction Adrenocortical carcinoma (ACC) is a rare cancer that commonly spreads to the liver, lungs and lymph nodes. Bone metastases are infrequent. Objective The aim of this report was to describe the clinical characteristics, survival perspective, prognostic factors and frequency of adverse skeletal-related events (SREs) in patients with ACC who developed bone metastasis. Methods This is a retrospective, observational, multicenter, multinational study of patients diagnosed with bone metastases from ACC who were treated and followed up in three European countries (France, Italy and The Netherlands) and one center in the United States. Results Data of 156 patients were captured. The median overall survival was 11 months. SREs occurred in 47% of patients: 17% bone fractures, 17% spinal cord compression, 1% hypercalcemia, 12% developed more than one SRE. In multivariate analysis, cortisol hypersecretion was the only prognostic factor significantly associated with a higher mortality risk (hazard ratio (HR) 2.24, 95% confidence interval (CI): 1.19–4.23, P = 0.013) and with the development of a SREs (of border line significance). The administration of antiresorptive therapies (bisphosphonates and denosumab) was associated with a lower risk of death, even if not significant, and their survival benefit appeared confined in patients attaining serum mitotane levels within the therapeutic range. Conclusion Bone metastases in ACC patients are associated with poor prognosis and high risk of SREs. Cortisol hypersecretion was the only prognostic factor suggesting a potential benefit from antisecretory medications. The therapeutic role of bisphosphonates and denosumab to improve patient outcome deserves to be tested in a prospective clinical trial.

Summary Cushing's syndrome is associated with multisystem morbidity and, when suboptimally treated, increased mortality. Medical therapy is an option for patients if surgery is not successful and can be classified into pituitary-directed drugs, steroid synthesis inhibitors, and glucocorticoid receptor antagonists. In the last decade there have been new developments in each drug category. Targeting dopamine and somatostatin receptors on corticotroph adenomas with cabergoline or pasireotide, or both, controls cortisol production in up to 40% of patients. Potential new targets in corticotroph adenomas include the epidermal growth factor receptor, cyclin-dependent kinases, and heat shock protein 90. Osilodrostat and levoketoconazole are new inhibitors of steroidogenesis and are currently being evaluated in multicentre trials. CORT125134 is a new selective glucocorticoid receptor antagonist under investigation. We summarise the drug therapies for various forms of Cushing's syndrome and focus on emerging drugs and drug targets that have the potential for new and effective tailor-made pharmacotherapy for patients with Cushing's syndrome.

Some biomarkers for functioning and non-functioning neuroendocrine neoplasms (NENs) are currently available. Despite their application in clinical practice, results should be interpreted cautiously. Considering the variable sensitivity and specificity of these parameters, there is an unmet need for novel biomarkers to improve diagnosis and predict patient outcome. Nowadays, several new biomarkers are being evaluated and may become future tools for the management of NENs. These biomarkers include (1) peptides and growth factors; (2) DNA and RNA markers based on genomics analysis, for example, the so-called NET test, which has been developed for analyzing gene transcripts in circulating blood; (3) circulating tumor/endothelial/progenitor cells or cell-free tumor DNA, which represent minimally invasive methods that would provide additional information for monitoring treatment response and (4) improved imaging techniques with novel radiolabeled somatostatin analogs or peptides. Below we summarize some future directions in the development of novel diagnostic and predictive/prognostic biomarkers in NENs. This review is focused on circulating and selected tissue markers.

Introduction Temozolomide (TMZ) treatment is an effective treatment for aggressive pituitary tumors, leading to tumor regression or stabilization of tumor progression in the majority of cases. In cases of disease recurrence, however, TMZ treatment does not control tumour regrowth. The expression of O6-methyl-guanine-DNA-methyltransferase (MGMT) protein and mismatch repair components (MMR) are implicated in the mechanism of TMZ resistance. In the present study, we aimed to develop an in vitro model of acquired TMZ resistance and to describe its mechanism. Methods The mouse AtT20 corticotrope pituitary tumor cell line was used. Two protocols were developed, one based on high dose of TMZ (high TMZ-challenge) and another one using lower TMZ concentrations (low TMZ-challenge) that are clinically achievable after a standard TMZ schedule. Both protocols consisted in pulse exposures to increasing concentrations of TMZ for 24rhs. TMZ concentrations in the high TMZ-challenge were 100, 200 and 300 µM while in the low TMZ-challenge were 20, 40, 60 and 80 µM. AtT20 cells treated with challenges of the vehicle dimethyl sulfoxide (vehicle-challenged cells) were used as control. Results The TMZ challenges induced a significant increase in EC50 (decreased sensitivity) of the growth inhibitory effect of TMZ in TMZ-challenged cells compared to vehicle-challenged cells in both protocols (high TMZ-challenge, EC50 = 123 µM vs 19 µM, p Conclusion The present study describes an acquired TMZ-resistant corticotrope pituitary tumor cell model. TMZ resistance was demonstrated in both protocols by a sustained increase in TMZ EC50, small TMZ-induced cell cycle changes, and lower increase in TMZ-induced apoptosis. Additionally, TMZ challenges affected AtT20 cell morphology. This was evident only in the high TMZ-challenge protocol. Acquired TMZ resistance was associated with a strong increase in MGMT expression. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Objective Cushing's disease (CD) is a debilitating disorder of chronic hypercortisolism. Assessment of 24h mean urinary free cortisol (mUFC) and late-night salivary cortisol (LNSC) is recommended for screening and monitoring treatment response. In the published core period of the Phase III, LINC 3 study (NCT02180217), osilodrostat therapy (a potent oral 11β-hydroxylase inhibitor) produced rapid, sustained reductions in both mUFC and LNSC alongside improvements in clinical signs of hypercortisolism and health-related quality of life (HRQoL) in patients with CD. Here we explored cardiovascular/metabolic-related parameters, physical features and HRQoL according to mUFC and/or LNSC control. Methods LINC 3 (core period) enrolled 137 adults with CD and mUFC >1.5x upper limit of normal (ULN), who received open-label osilodrostat up to 48-week (W) (starting dose: 2 mg twice daily [bid]; maximum: 30 mg bid); eligible patients were randomized in an 8W placebo-controlled, withdrawal period (W26–34). mUFC (three sample average; normal 11–138 nmol/24h [4–‍50 µg/24h]) and LNSC (single sample; normal ≤2.5 nmol/L) were assessed centrally by liquid chromatography-tandem mass spectrometry. Cardiovascular/metabolic-related parameters, physical features (rating: 0=absent;1=mild;2=moderate;3=severe), CushingQoL and Beck Depression Inventory-II (BDI-II) scores were also evaluated. Data were recorded at baseline, regularly throughout, and at W48. Analyses are presented for patients with both mUFC and LNSC assessments, defined as: both mUFC+LNSC controlled (mUFC≤ULN+LNSC≤ULN), only mUFC controlled (mUFC≤ULN+LNSC>ULN), only LNSC controlled (mUFC>ULN+LNSC≤ULN) and both mUFC+LNSC uncontrolled (mUFC>ULN+LNSC>ULN). Results Of evaluable patients at baseline (n=87), 74 (85.1%) had both mUFC+LNSC uncontrolled. At W48, 38 patients (54.3%) had both mUFC+LNSC controlled, 21 (30.0%) had only mUFC controlled, 3 (4.3%) had only LNSC controlled, and 8 (11.4%) had both mUFC+LNSC uncontrolled. Patients with both mUFC+LNSC controlled had generally greater mean improvements from baseline to W48 in cardiovascular/metabolic-related parameters than those with only mUFC or LNSC controlled or both mUFC+LNSC uncontrolled, respectively: weight, –5.9, –3.3, –2.2 and –‍3.8 kg; systolic blood pressure, –14.4, –8.0, –7.4, –3.0 mmHg; diastolic blood pressure, –‍8.6, –4.8, –8.2, –4.0 mmHg; fasting plasma glucose, –16.9, –4.8, –15.0, –11.0 mg/dL; and HbA1c, –0.4, –0.3, –0.9, –0.0%. CushingQoL/BDI-II scores improved from baseline to W48 irrespective of mUFC and/or LNSC control. The proportion of patients with improved physical manifestations of hypercortisolism (facial rubor, striae, fat pads, bruising, hirsutism [females], muscle atrophy) was greatest in patients with both mUFC+LNSC controlled or only mUFC controlled. Discussion At W48, over half the evaluable patients had both mUFC+LNSC controlled following osilodrostat treatment. Improvements in clinical signs of hypercortisolism and HRQoL occurred irrespective of mUFC and/or LNSC control; however, for some clinical outcomes, improvements were greater in patients with both mUFC+LNSC controlled. Findings are limited by small patient numbers in some groups. mUFC and LNSC are complementary parameters used to assess disease control and patients with both mUFC+LNSC controlled have better outcomes. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.