Treatment and long term safety outcomes of Peptide Receptor Radionuclide Therapy for metastatic neuroendocrine tumours: an Asian experience

Peptide-receptor radionuclide therapy (PRRT) is a targeted molecular therapy used to treat neuroendocrine tumours (NET). It has been shown to be effective and well-tolerated in patients with metastatic neuroendocrine tumours in several centres in United States (US), Europe and Australia. Tolerability and efficacy data emerging from Asian centres remain few. Epidemiological evidence suggests that there are differences in neuroendocrine neoplasms between the population groups. We aim to describe the treatment and safety outcomes of PRRT in the Asian population. Methods One hundred and seven (107) patients with metastatic neuroendocrine tumour who had undergone PRRT treatment from January 2012 to March 2019 were included in this retrospective study. The response rates using RECIST1.1 and qualitative analysis were examined. The overall and progression free survival curves were also evaluated. Results The median progression free survival was 49 months. Response assessment after completion of treatment showed that 33(37.9%) of 87 patients had partial or complete response. Subgroup analysis comparing high- and low-grade NET showed that there was a significant difference in the time to progression curves. Comparison of the number of cycles and progression free and overall survival also showed a significant difference. Ten patients (9%) had grade 3 or more haematological toxicities. Four patients (4%) had grade 3/4 hepatobiliary toxicities, although the presence of extensive liver metastases was a confounding factor. None of the patients had grade 3/4 acute kidney injury. Conclusion Our results show that PRRT is safe and effective in the treatment of metastatic neuroendocrine tumour in the Asian population. There was a significant difference in the progression free survival curves between low-grade and high-grade NET, and in the progression free and overall survival comparing the number of cycles received.

Prolonged Hypokalemia and Delayed Diagnosis of Primary Aldosteronism: Clinical Course and Risk Factors

INTRODUCTION

Primary Aldosteronism (PA) is a common cause of hypertension. However, diagnosis is often delayed, leading to poorer clinical outcomes. Hypokalemia with hypertension is characteristic of PA, and is an indication for screening. We evaluated if patients with PA had prolonged hypokalemia before diagnosis, the subsequent biochemical/clinical control, and factors associated with delayed diagnosis.

METHODS

Our study included all PA patients with hypokalemia diagnosed between 2001 to 2022. Delayed diagnosis was defined as duration of hypokalemia of >1 year from first occurrence, to first evaluation by a PA specialist. Patients were reassessed post-adrenalectomy using the Primary Aldosteronism Surgery Outcomes criteria. We performed multivariable analysis to assess for factors associated with delayed diagnosis.

RESULTS

Among 240 patients with PA who presented with hypokalemia, 122 (51%) patients had delayed diagnosis, with prolonged hypokalemia of median duration 4.5 (2.4-7.5) years. Patients with delayed diagnosis were older, had longer duration of hypertension, higher pill burden, lower renal function and more prevalent cardiovascular disease. Factors associated with delayed diagnosis included older age, presence of hyperlipidaemia, and less severe hypokalemia (serum potassium >3.0mmol/L). Compared to patients with early diagnosis, a lower proportion of those with delayed diagnosis underwent adrenal vein sampling (73% vs 58%), P<0.05. Sixty of 118 (50.8%) non-delayed, and 39 of 122 (32.0%) patients with delayed diagnosis underwent surgery.

CONCLUSION

Despite manifestation of hypokalemia, many patients with PA fail to be promptly screened. Greater emphasis in hypertension guidelines, and efforts to improve awareness of PA amongst primary care physicians are urgently needed.

Expanding the use of salivary cortisol as a non-invasive outpatient test in the dynamic evaluation of suspected adrenal insufficiency

Background

Adrenal insufficiency (AI) is potentially life-threatening, and accurate diagnosis is crucial. The first-line diagnostic test, the adrenocorticotrophic hormone (ACTH) stimulation test, measures serum total cortisol. However, this is affected in states of altered albumin or cortisol-binding globulin levels, limiting reliability. Salivary cortisol reflects free bioactive cortisol levels and is a promising alternative. However, few studies are available, and heterogenous methodologies limit applicability.

Methods

This study prospectively recruited 42 outpatients undergoing evaluation for AI, excluding participants with altered cortisol-binding states. Serum (immunoassay) and salivary (liquid chromatography tandem mass spectrometry) cortisol levels were sampled at baseline, 30 min, and 60 min following 250 µg synacthen administration. AI was defined as a peak serum cortisol level <500 nmol/L in accordance with guidelines.

Results

The study recruited 21 (50%) participants with AI and 21 without AI. There were no significant differences in baseline characteristics, blood pressure, or sodium levels between groups. Following synacthen stimulation, serum and salivary cortisol levels showed good correlation at all timepoints (R2 = 0.74, P < 0.001), at peak levels (R2 = 0.72, P < 0.001), and at 60 min (R2 = 0.72, P < 0.001). A salivary cortisol cut-off of 16.0 nmol/L had a sensitivity of 90.5% and a specificity of 76.2% for the diagnosis of AI.

Conclusion

This study demonstrates a good correlation between serum and salivary cortisol levels during the 250 µg synacthen test. A peak salivary cortisol cut-off of 16.0 nmol/L can be used for the diagnosis of AI. It is a less invasive alternative to evaluate patients with suspected AI. Its potential utility in the diagnosis of AI in patients with altered cortisol-binding states should be further studied.

Bariatric Surgery in Kidney Transplant Candidates and Recipients: Experience at an Asian Center

Background

Kidney transplant (KT) candidates and recipients with obesity experience more frequent complications such as infection, poorer allograft outcomes, diabetes, and mortality, limiting their eligibility for transplantation. Bariatric surgery (BS) is not commonly performed among KT patients given concerns about immunosuppression absorption, wound healing, infections, and graft outcomes. Its role has not been described before in an Asian KT patient setting.

Methods

A retrospective review of patients who underwent BS at the largest KT center in Singapore from 2008 to 2020 was conducted. Metabolic outcomes, immunosuppression doses, graft outcomes, and mortality were studied.

Results

Seven patients underwent BS and KT (4 underwent BS before KT, 3 underwent BS after KT; 4 underwent sleeve gastrectomy, 3 underwent gastric bypass). Mean total weight losses of 23.8% at 1 year and 18.6% at 5 years post-BS were achieved. Among the five patients with diabetes, glycemic control improved after BS. There were no deaths in the first 90 days or graft loss in the first year after KT and BS. Patients who underwent BS after KT had no significant changes in immunosuppression dose.

Conclusion

BS can be safely performed in KT recipients and candidates and results in sustainable weight losses and improvements in metabolic comorbidities. Although no major complications were observed in our study, close monitoring of this complex group of patients is imperative.

Cardiovascular outcomes and all-cause mortality in primary aldosteronism after adrenalectomy or mineralocorticoid receptor antagonist treatment: a meta-analysis

BACKGROUND

In patients with primary aldosteronism (PA), long-term cardiovascular and mortality outcomes after adrenalectomy vs mineralocorticoid receptor antagonist (MRA) have not been compared yet. We aim to compare the clinical outcomes of these patients after treatment.

DESIGN AND METHODS

A systematic review and meta-analysis was conducted by searching PubMed, Cochrane library, and Embase from no start date restriction to 18 December 2021. Our composite primary outcomes were long-term all-cause mortality and/or major adverse cardiovascular events (MACE), including coronary artery disease (CAD), stroke, arrhythmia, and congestive heart failure. We adopted the random-effects model and performed subgroup analyses, meta-regression, and trial sequential analysis (TSA).

RESULTS

A total of 9 studies with 8473 adult patients with PA (≥18 years) were enrolled. A lower incidence of composite primary outcomes was observed in the adrenalectomy group (odds ratio (OR): 0.46 (95% CI: 0.38-0.56), P < 0.001). We found a lower incidence of all-cause mortality (OR: 0.33 (95% CI: 0.15-0.73), P = 0.006) and MACE (OR: 0.55, (95% CI: 0.40-0.74), P = 0.0001) in the adrenalectomy group. The incidence of CAD (OR: 0.33 (95% CI: 0.15-0.75), P = 0.008), arrhythmias (OR: 0.46 (95% CI: 0.27-0.81), P = 0.007), and congestive heart failure (OR: 0.52 (95% CI: 0.33-0.81), P = 0.004) was also lower in adrenalectomy group. The metaregression showed patient's age may attenuate the benefits of adrenalectomy on composite primary outcomes (coefficient: 1.084 (95% CI: 1.005-1.169), P = 0.036). TSA demonstrated that the accrued sample size and effect size were sufficiently large to draw a solid conclusion, and the advantage of adrenalectomy over MRA was constant with the chronological sequence.

CONCLUSIONS

In conclusion, adrenalectomy could be preferred over MRA for patients with PA in reducing the risk of all-cause mortality and/or MACE and should be considered as the treatment of choice. That patients with PA could get less benefit from adrenalectomy as they age warrants further investigation.

11C-Metomidate PET-CT versus adrenal vein sampling to subtype primary aldosteronism: a prospective clinical trial

OBJECTIVE

Adrenal vein sampling (AVS) is recommended to subtype primary aldosteronism, but it is technically challenging. We compared 11C-Metomidate-PET-computed tomography (PET-CT) and AVS for subtyping of primary aldosteronism.

METHODS

Patients with confirmed primary aldosteronism underwent both AVS and 11C-Metomidate PET-CT (post-dexamethasone). All results were reviewed at a multidisciplinary meeting to decide on final subtype diagnosis. Primary outcome was accuracy of PET versus AVS to diagnosis of unilateral primary aldosteronism based on post-surgical biochemical cure. Secondary outcome was accuracy of both tests to final subtype diagnosis.

RESULTS

All 25 patients recruited underwent PET and successful AVS (100%). Final diagnosis was unilateral in 22 patients, bilateral in two and indeterminate in one due to discordant lateralization. Twenty patients with unilateral primary aldosteronism underwent surgery, with 100% complete biochemical success, and 75% complete/partial clinical success. For the primary outcome, sensitivity of PET was 80% [95% confidence interval (95% CI): 56.3-94.3] and AVS was 75% (95% CI: 50.9-91.3). For the secondary outcome, sensitivity and specificity of PET was 81.9% (95% CI: 59.7-94.8) and 100% (95% CI: 15.8-100), and AVS was 68.2% (95% CI: 45.1-86.1) and 100% (95% CI: 15.8-100), respectively. Twelve out of 20 (60%) patients had both PET and AVS lateralization, four (20%) PET-only, three (15%) AVS-only, while one patient did not lateralize on PET or AVS. Post-surgery outcomes did not differ between patients identified by either test.

CONCLUSION

In our pilot study, 11C-Metomidate PET-CT performed comparably to AVS, and this should be validated in larger studies. PET identified patients with unilateral primary aldosteronism missed on AVS, and these tests could be used together to identify more patients with unilateral primary aldosteronism.

VIDEO ABSTRACT

http://links.lww.com/HJH/B918.

Bone mineral density following liver transplantation: a 10-year trend analysis

We evaluated the prevalence of osteoporosis and annual changes in bone mineral density (BMD) over 10 years post-liver transplantation. BMD in the lumbar spine improved significantly post-transplantation, reaching a 12% increase at year 10. In contrast, BMD in the femoral neck and hip deteriorated and did not return to baseline levels.

INTRODUCTION

This study (1) evaluated the prevalence of osteoporosis, and the annual changes in bone mineral density (BMD) over 10 years, and (2) identified the risk factors for worsened BMD in stable liver transplant recipients (LTRs).

METHODS

LTRs who underwent liver transplantation (LT) at Singapore General Hospital between February 2006 and Mar 2019 were included. Demographic, clinical data, and BMD in the lumbar spine (LS), femoral neck (FN), and total hip (TH) were collected retrospectively from the medical records.

RESULTS

Eighty-three patients (mean age: 55 ± 8 years) with a median follow-up of 80 months were included. The prevalence of osteoporosis increased significantly from 18.1% pre-LT to 34.3% post-LT (p = 0.021), and the incidence of osteoporosis was 18.2%. Worsened BMD (normal to osteopenia/osteopenia to osteoporosis) was found in 27.2% of LTRs. No significant risk factors were associated with worsened BMD, but females had a trend towards a higher odd (adjusted odds ratio: 3.54, 95%CI (0.61-20.5), p = 0.159). The LS BMD increased within 6-month post-LT and continued to improve throughout the entire follow-up period. In contrast, BMD in the FN and TH deteriorated and did not return to baseline levels post-LT.

CONCLUSION

Prevalence of osteoporosis increased significantly post-LT. Over a 10-year follow-up, 27.2% of LTRs had worsened BMD status, and a possible risk factor may be female gender. While the LS BMD improved with time, the BMD in the FN and TH persisted below baseline throughout the follow-up period. Future studies should explore long-term therapies to improve BMD in the FN and TH post-LT.

Re-evaluating absent clinical success after adrenalectomy in unilateral primary aldosteronism

BACKGROUND

Adrenalectomy cures unilateral primary aldosteronism, and it improves or cures hypertension. However, a significant proportion of patients are classified with absent clinical success postsurgery, suggesting that surgery was ineffective.

METHODS

We assessed all patients 6 to 12 months post-surgery for clinical outcomes using Primary Aldosteronism Surgical Outcomes (PASO), AVIS-2, and CONNsortium criteria. We estimated blood pressure changes after adjustment for changes in defined daily dosages of antihypertensive medications. We also reassessed all patients using PASO at their recent clinical visit.

RESULTS

A total of 104 patients with unilateral primary aldosteronism underwent adrenalectomy at 2 tertiary centers from 2000 to 2019; 24 (23%), 31 (30%), and 54 (52%) patients were classified with absent clinical success using PASO, AVIS-2, and CONNsortium criteria, respectively. Among 24 patients with absent clinical success using PASO criteria, 10 had complete biochemical cure, 3 partial, 2 absent, and 9 had resolution of hypokalemia. On multivariable analysis, absent clinical success was associated with presence of hyperlipidemia, diabetes mellitus, and lower defined daily dosages at baseline. After adjustment for changes in defined daily dosages, 7 of 24 patients showed blood pressure improvement ≥20/10 mm Hg post-surgery. After a follow-up of mean 5.6 years, 12 of 24 patients showed partial or complete clinical success when reassessed using PASO criteria. Only 6 of 104 (5.8%) patients failed to show clinical improvement post-surgery using any of the 3 mentioned criteria or using PASO criteria at their recent clinical visit.

CONCLUSION

Although some patients may be classified with absent clinical success post-surgery, the assessment of clinical outcomes remains subject to many variables. In patients with unilateral primary aldosteronism, evidenced by lateralization on AVS, unilateral adrenalectomy should remain the recommended treatment.

Tolerability and Efficacy of Long-Term Medical Therapy in Primary Aldosteronism

Introduction: Patients with primary aldosteronism (PA) have increased cardiovascular risk and studies have found that medical therapy fails to ameliorate this. This may be due to side effects and limited efficacy of medications at tolerable doses. Methods: We conducted a retrospective study on 201 patients with PA treated with medical therapy (spironolactone, eplerenone or amiloride) for PA from 2000–2020 at two tertiary centres. Patients were assessed for efficacy to achieve clinical and biochemical control, and for side effects. Results: 53.7% of patients achieved blood pressure &lt;140/90mmHg, 44.6% achieved serum potassium ≥4.3mmol/L, and 63.2% achieved renin levels &gt;1ng/ml/hr. Concordance between biochemical control as assessed by potassium and renin levels was 49%. 45.3% of patients experienced side effects, with 8.5% switching to another medication, 18.9% decreasing dose, and 10.0% stopping medications altogether. Risk factors for side effects were spironolactone use, dose ≥50mg, duration of treatment ≥1 year, male gender and unilateral PA. Patients with unilateral PA, compared to bilateral PA, used higher median doses of spironolactone, 75mg vs 50mg, P&lt;0.001, but more had persistent hypokalemia, 20.5% versus 6.4%, P=0.007. 44 patients with unilateral PA underwent surgery after initial medical therapy, which further improved systolic and diastolic BP, from 142 to 134mmHg, P&lt;0.001, and from 85 to 79mmHg, P&lt;0.001, respectively. Conclusion: Dose-dependent side effects limit the efficacy of medical therapy in PA. Future prospective studies should assess the best monitoring strategy for biochemical control during long-term medical therapy. In patients with unilateral PA, surgery remains a better option compared to life-long medications.

Re-Evaluating Absent Clinical Success After Adrenalectomy in Unilateral Primary Aldosteronism

Introduction: Adrenalectomy cures unilateral primary aldosteronism (PA), and improves or cures hypertension. However, a significant proportion of patients are classified with absent clinical success post-surgery, suggesting that surgery was ineffective. Methods: We assessed all patients 6–12 months after unilateral adrenalectomy for clinical outcomes using Primary Aldosteronism Surgical Outcomes (PASO), AVIS-2 and CONNsortium criteria. We estimated blood pressure (BP) changes after adjustment for changes in defined daily dosages (DDD) of antihypertensive medications. Finally, patients were reassessed using PASO at their most recent clinical visit. Results: 104 patients with unilateral PA underwent adrenalectomy at two tertiary centres from 2000–2019. 24 (23%), 31(30%) and 54 (52%) patients were classified with absent clinical success using PASO, AVIS-2 and CONNsortium criteria respectively. Amongst 24 patients with absent clinical success using PASO criteria, 10 had complete biochemical cure, 3 partial, 2 absent, and 9 had resolution of hypokalemia. On multivariate analysis, absent clinical success was associated with presence of hyperlipidemia, diabetes mellitus and lower DDD at baseline. After adjustment for changes in DDD, 7 of 24 patients showed BP improvement ≥20/10mmHg. After follow-up of mean 5.6 years, 12 of 24 patients showed partial or complete clinical success when reassessed using PASO criteria. Only 6 of 104 (5.8%) patients failed to show any clinical improvement after surgery. Conclusions: Although some patients may be classified with absent clinical success post-surgery, majority demonstrate evidence of clinical benefit. Unilateral adrenalectomy remains the recommended treatment option for patients with unilateral PA.

SAT-547 Aldosterone-Potassium Ratio Predicts Primary Aldosteronism Subtype

Objective Prediction models have been developed to predict either unilateral or bilateral primary aldosteronism, and these have not been validated externally. We aimed to develop a simplified score to predict both subtypes and validate this externally.

Methods Our development cohort was taken from 165 patients who underwent adrenal vein sampling (AVS) in two Asian tertiary centres. Unilateral disease was determined using both AVS and post-operative outcome. Multivariable analysis was used to construct prediction models. We validated our tool in a European cohort of 97 patients enrolled in a clinical trial. Previously published prediction models were also tested in our cohorts.

Results Backward stepwise logistic regression analysis yielded a final tool using baseline-aldosterone-to-lowest-potassium ratio (APR, ng/dL/mmol/L), with an area under receiver operating characteristic curve of 0.80 (95% CI: 0.70 - 0.89). In the Asian development cohort, probability of bilateral disease was 90.0% (with APR <5) and probability of unilateral disease was 91.4% (with APR >15). Similar results were seen in the European validation cohort. Combining both cohorts, probability of bilateral disease was 76.7% (with APR <5), and probability for unilateral was 91.7% (with APR >15). Other models had similar predictive ability but required more variables, and were less sensitive for identifying bilateral PA.

Conclusion The novel aldosterone-potassium ratio (APR) is a convenient score to guide clinicians and patients of various ethnicities on the probability of PA subtype. Using APR to identify patients more likely to benefit from AVS may be a cost-effective strategy to manage this common condition.

OR34-01 11C Metomidate PET-CT Identifies More Unilateral Primary Aldosteronism Than Adrenal Vein Sampling

Introduction. Adrenal vein sampling (AVS) is the current reference test to identify unilateral, surgically-curable primary aldosteronism (PA). However, AVS is invasive and technically difficult. Even in AVS-proven unilateral PA, up to 6% of patients with fail to have biochemical cure after surgery using the PASO criteria. 11C-Metomidate PET-CT offers a non-invasive alternative. We compared the accuracy of both PET-CT and AVS using post-surgery cure (PASO criteria) as the reference.

Methods. This multi-centre prospective trial recruited 25 patients with confirmed PA, and all underwent CT, AVS, and PET-CT tests. Sequential AVS under ACTH-stimulation was done by an experienced interventionalist, and cortisol gradient of >5 was taken to be successful cannulation. Lateralization ratio >4 was consistent with unilateral PA. All results were reviewed at a multidisciplinary meeting to decide on the diagnosis (unilateral or bilateral PA) and management (secondary outcome). Primary outcome was biochemical cure using PASO criteria at 6 months post-surgery (ClinicalTrials.gov: NCTxxxxxxxx).

Results. Recruitment for the study has been complete with 25 patients, 49.2 ± 9.5 yr, 14 females (56.0%). All 25 patients had successful AVS. 22 of 25 patients (88.0%) had unilateral PA, and 3 patients (12.0%) had bilateral PA. PET-CT identified unilateral PA in 18 of 22 patients (sensitivity 81.8%), while AVS identified unilateral PA in 15 of 22 patients (sensitivity 68.2%). In one patient, repeat AVS done simultaneously without ACTH-stimulation aided to identify unilateral PA, when initial AVS failed to do so. Other cases where AVS failed to identify unilateral PA were due to venous anomalies, and limitation of the lateralization cut-off of 4. 18 of 22 patients have undergone surgery, with 3 patients awaiting surgery, and 1 opting for medical treatment. Post-surgery, all patients had complete normalization of aldosterone-renin ratio, and hypokalemia (if present). 2 patients had bilateral PA on both PET-CT and AVS. 1 patient had discordant AVS and PET-CT results, with AVS lateralizing to right, and PET-CT to left. This patient was classified as bilateral PA and treated medically.

Conclusion. This is the first study to demonstrate that 11C-Metomidate PET-CT may identify cases of unilateral PA not detected with AVS, using the stringent PASO criteria for post-operative biochemical cure.

SUN-901 A Case of Coexisting Insulinoma and Islet Cell Hyperplasia

Introduction

Insulinoma is the most common neuroendocrine tumour of the pancreas and cause of endogenous hyperinsulinemia hypoglycaemia. Islet cell hyperplasia is a rare cause of hypoglycaemia in adults.

Clinical Case

A 42-year-old lady presented with hyperphagia, giddiness, decreased concentration and weight gain of 10 kg over one year. Her symptoms occurred both during fasting and postprandial. She did not have any medical conditions and did not take alcohol.

A 72-hour fast confirmed the presence of endogenous hyperinsulinemia; serum glucose of 2.4 mmol/L paired with insulin 8.14 mU/L and C -peptide 0.71 nmol/L occurring after 16 hours of fasting. Screening for sulphonylureas and meglitinides was negative. Serum beta-hydroxybutyrate was 0.1 mmol/L with a 1.6 mmol/L rise in serum glucose post 1 mg glucagon administration. Computed tomography (CT) of the abdomen showed a 13 X 11 X 15 mm exophytic lesion at the superior aspect of the pancreatic body and another exophytic projection measuring 9 X 8 X 6 mm arising from the tail. In view of possible multifocal insulinoma, a ⁶⁸Ga-DOTATATE scan was performed and it showed an intensely DOTATATE-avid exophytic nodule arising from the pancreatic body and a second indeterminate DOTATATE-avid nodule close to the pancreatic tail. In addition, there was diffuse DOTATATE uptake in the tail of pancreas.

She underwent enucleation of pancreatic body nodule and spleen-saving distal pancreatectomy as the pancreatic tail nodule was not seen intra-operatively. Histology showed an insulinoma; a well-differentiated neuroendocrine tumour (Grade 1, pT1 N0 Mx) that was positively stained for synaptophysin, CD56, insulin, SSTR2 and SSTR5. The pancreatic tail nodule and distal pancreatectomy specimen showed islet cell hyperplasia; the pancreatic parenchyma showed multiple foci of well-circumscribed nests of bland islet cells with similar morphology to those seen in the insulinoma. She did not have further hypoglycaemia episodes post-operatively.

Concomitant presence of fasting and postprandial hypoglycaemia may suggest underlying dual pathology. Clinical and biochemical differentiation between insulinoma and islet cell hyperplasia is difficult. Therefore, imaging for diagnosis and precise preoperative localisation is important for successful resection of suspected lesions. ⁶⁸Ga-DOTATATE scan can be as useful as ⁶⁸Ga-DOTANOC and ⁶⁸Ga-DOTATOC scan and is better than CT scan in localising not only insulinoma but also islet cell hyperplasia. In this case, islet cell hyperplasia-induced hyperinsulinemic hypoglycaemia may have persisted if distal pancreatectomy was not performed.

Conclusion

Adult-onset endogenous hyperinsulinemia hypoglycaemia can be caused by concurrent insulinoma and islet cell hyperplasia. ⁶⁸Ga-DOTATATE scan may be a useful, non-invasive investigation, especially in cases where CT imaging suggests multifocal disease.

Clinicopathologic Characteristics and Survival of Patients with Gastroenteropancreatic Neuroendocrine Neoplasm in a Multi-Ethnic Asian Institution

BACKGROUND

Epidemiological evidence suggests there are differences in gastroenteropancreatic neuroendocrine neoplasm (GEPNEN) among population groups. We aimed to contribute to the current evidence by evaluating the clinicopathological characteristics of GEPNEN in a multi-ethnic Asian group.

MATERIALS AND METHODS

This was a retrospective chart review of patients diagnosed with GEPNEN at a tertiary medical institution at Singhealth Outram Campus, Singapore, between 1995 and 2015.

RESULTS

Two hundred ninety-five patients were included in the evaluation, comprising Chinese (74.6%), Malay (4.4%), Indian (9.5%) and other (11.5%) ethnic backgrounds. The median age at diagnosis was 59 years; 52.5% were males. Distribution of disease stage at diagnosis was: localised (42.4%), regional (15.3%) and distant (38.0%). The three most common primary tumour sites were located in the pancreas (38.6%), rectum (19.7%) and stomach (9.5%), which varied significantly with ethnic background and age at diagnosis. Malay patients were younger (median 42 years) at diagnosis than Chinese (60 years). Patients with an appendiceal neuroendocrine neoplasm (NEN) (48 years) were younger compared to oesophageal NEN (66 years). Disease stage correlated with primary tumour site and grade (p < 0.001). Median overall survival (OS) for all GEPNEN was 10.2 years. Age at diagnosis, disease stage and grading were prognostic factors of OS in multivariable analyses.

CONCLUSION

Our findings correspond with other studies that focus on GEPNEN incidences in Asian countries, with the pancreas, rectum and stomach being the most common primary tumour sites. Our findings suggest racial differences in primary tumour site and age at diagnosis. Further prospective population-based registries are required to understand these epidemiological differences.

Factors Associated with Resolution of Hypertension after Adrenalectomy in Patients with Primary Aldosteronism

BACKGROUND

The aim of this study was to investigate the factors associated with resolution of hypertension after adrenalectomy in patients with primary aldosteronism. A secondary aim was to describe our use of the contralateral ratio in adrenal venous sampling (AVS) in the setting of suboptimal successful cannulation rates.

METHODS

A retrospective review of patients who underwent AVS followed by unilateral adrenalectomy for primary aldosteronism was performed.

RESULTS

Complete resolution of hypertension and hypokalemia was seen in 17 of 40 patients (42.5%), while a clinical improvement in hypertension was seen in 38 of 40 (95%). Shorter duration of hypertension, mean aldosteronoma resolution score (ARS), and a high ARS of 3 to 5 were associated with resolution of hypertension after adrenalectomy (P=0.02, P=0.02, and P=0.004, respectively). Of the individual components of ARS, only a duration of hypertension of ≤6 years was associated with resolution of hypertension after adrenalectomy (P=0.03).

CONCLUSION

A shorter duration of hypertension was significantly associated with resolution of hypertension after adrenalectomy in patients with primary aldosteronism.

Phaeochromocytoma presenting with pseudo-intestinal obstruction and lactic acidosis

Phaeochromocytomas are rare neuroendocrine tumours with variable clinical signs and symptoms. Hypertension, tachycardia, sweating and headaches are cardinal manifestations. Although nausea and abdominal pain are the more common gastrointestinal features, rare gastrointestinal spectrums have been reported that can mimic abdominal emergencies. Metabolic effects of hypercatecholaminaemia are vast and one such rare presentation is lactic acidosis. We describe a case of phaeochromocytoma presenting with both intestinal pseudo-obstruction as well as lactic acidosis. This case report highlights the importance of having a high index of suspicion for and early recognition of the gastrointestinal and metabolic manifestations of phaeochromocytomas.

Day 1 post-operative fasting hyperglycemia may affect graft survival in kidney transplantation

BACKGROUND

Early post-operative hyperglycemia is commonly encountered in patients without pre-existing diabetes mellitus who are undergoing kidney transplantation. The aim of this study was to determine the effect of early post-operative hyperglycemia on graft and patient survival after kidney transplantation in our center.

MATERIAL AND METHODS

This was a single-center retrospective review of solitary kidney recipients transplanted in our center between January 1998 and December 2007. Of a total of 432 patients, 377 were eligible for the study. Fasting plasma glucose (FPG) levels at day 1 (D1) and day 5 (D5) after transplantation were recorded. Hyperglycemia was defined as FPG ≥ 7.0 mmol/l. Outcome events recorded included deaths and graft failures.

RESULTS

The mean age at transplantation was 43.2 ± 9.5 years and 50.4% were male. The mean FPG levels at D1 and D5 were 7.5 ± 1.3 mmol/L and 5.3 ± 1.3 mmol/L, respectively; 64.2% of recipients had FPG ≥ 7.0 mmol/L on D1 and this was reduced to 8.5% on D5. Recipients with D1 FPG ≥ 7.0 mmol/L had significantly poorer graft survival (39 events) compared to those without D1 hyperglycemia (6 events), with a hazard ratio of 3.708 (95% CI, 1.568-8.766, P=0.003). There was a trend towards better patients survival in recipients with D1 FPG <7.0 mmol/L (P=0.056).

CONCLUSIONS

D1 post-transplantation hyperglycemia may be associated with increased risk of graft failure. It is thus important to closely monitor glucose levels during the early post-transplantation period so that high risk patients can be identified and appropriate measures can be implemented to improve the long-term outcome.

Dopamine-secreting carotid body paragangliomas-biochemical control with radiotherapy

Head and neck paragangliomas that are exclusively or predominantly dopamine-secreting are rare. Surgery and/or radiotherapy are modalities for locoregional tumoral control. Little is known about the efficacy of radiotherapy for biochemical control in such tumors. We report a 62-year-old Chinese man with bilateral carotid body tumors which were exclusively dopamine secreting. The left-sided tumor invaded the skull base and encased the left carotid artery. Surgery was not performed due to high risk of morbidity and mortality. The patient received external beam radiotherapy to bilateral neck regions. Progressive decline and eventual normalization of urinary dopamine excretion was seen together with a slight reduction in tumor size. This is the first report demonstrating the efficacy of radiotherapy for both biochemical and locoregional control of functioning carotid body paragangliomas.

Incidence and Risk Factors for Development of New-onset Diabetes after Kidney Transplantation

Introduction: New-onset diabetes after transplantation (NODAT) is an increasingly recognised metabolic complication of kidney transplantation that is associated with increased morbidity and mortality. This study aimed to determine the incidence of NODAT and identify risk factors for development of NODAT among kidney allograft recipients in a single centre. Materials and Methods: We retrospectively reviewed all kidney allograft recipients in our centre between 1998 and 2007. NODAT were determined using criteria as per American Diabetes Association guidelines. Logistic regression analyses were performed to identify predictors of NODAT. Results: Among 388 patients included in the analysis, NODAT was reported in 94 patients (24.2%) after a median follow-up time of 52.1 months. The cumulative incidence of NODAT was 15.8%, 22.8% and 24.5% at 1, 3, and 5 years following transplantation. Seven clinical factors were independent predictors of NODAT: older age, HLA B13 and B15 phenotypes, use of sirolimus, acute rejections, higher pre-transplant and post-transplant (day 1) plasma glucose levels. Patients with NODAT had poorer outcomes in both graft and patient survival. Conclusion: Our study demonstrates a significant risk and burden of NODAT in an Asian transplant population. Risk stratification and aggressive monitoring of blood glucose early post-transplantation is necessary to identify high-risk patients so that appropriate tailoring of immunosuppression and early institution of lifestyle modifications can be implemented. Key words: Diabetes mellitus, Immunosuppression, Kidney transplantation, Metabolic complication, Sirolimus

Incidence and risk factors for development of new-onset diabetes after kidney transplantation

INTRODUCTION

New-onset diabetes after transplantation (NODAT) is an increasingly recognised metabolic complication of kidney transplantation that is associated with increased morbidity and mortality. This study aimed to determine the incidence of NODAT and identify risk factors for development of NODAT among kidney allograft recipients in a single centre.

MATERIALS AND METHODS

We retrospectively reviewed all kidney allograft recipients in our centre between 1998 and 2007. NODAT were determined using criteria as per American Diabetes Association guidelines. Logistic regression analyses were performed to identify predictors of NODAT.

RESULTS

Among 388 patients included in the analysis, NODAT was reported in 94 patients (24.2%) after a median follow-up time of 52.1 months. The cumulative incidence of NODAT was 15.8%, 22.8% and 24.5% at 1, 3, and 5 years following transplantation. Seven clinical factors were independent predictors of NODAT: older age, HLA B13 and B15 phenotypes, use of sirolimus, acute rejections, higher pre-transplant and post-transplant (day 1) plasma glucose levels. Patients with NODAT had poorer outcomes in both graft and patient survival.

CONCLUSION

Our study demonstrates a significant risk and burden of NODAT in an Asian transplant population. Risk stratification and aggressive monitoring of blood glucose early post-transplantation is necessary to identify high-risk patients so that appropriate tailoring of immunosuppression and early institution of lifestyle modifications can be implemented.