Glucose intolerance during hormonal therapy for prostate cancer

Leuprolide-Induced Hyperosmolar Hyperglycemic State in an Elderly Patient: A Case Report and Literature Review

We present a novel case of severe hyperosmolar hyperglycemic derangement in an elderly patient - without a known history of diabetes mellitus - after the first injection of leuprolide for the treatment of metastatic prostate adenocarcinoma. Whilst the available literature provided accumulative evidence of an association between insulin resistance and the use of gonadotropin-releasing hormone (GnRH) agonists, the initial presentation of leuprolide-induced impaired glycemic tolerance with a hyperosmolar hyperglycemic state (HHS) represents a clinical rarity that was seldom reported. A literature review was conducted to explore the underlying mechanisms of leuprolide-associated glucose intolerance. Screening for diabetes is recommended for patients receiving leuprolide therapy to identify at-risk patients and close glycemic monitoring is warranted in diabetic patients to minimize serious complications from poor glycemic control induced by leuprolide.

Endothelial dysfunction after androgen deprivation therapy and the possible underlying mechanisms

INTRODUCTION

Androgen deprivation therapy (ADT) is a key treatment modality in the management of prostate cancer (PCa), especially for patients with metastatic disease. Increasing evidences suggest that patients who received ADT have increased incidence of diabetes, myocardial infarction, stroke, and even mortality. It is important to understand the pathophysiological mechanisms on how ADT increases cardiovascular risk and induces cardiovascular events, which would provide important information for potential implementation of preventive measures.

METHODS

Twenty-six 12-week-old male SD rats were divided into four groups for different types of ADTs including: the bilateral orchidectomy group (Orx), LHRH agonist group (leuprolide), LHRH antagonist group (degarelix), and control group. After treated with drug or adjuvant injection every 3 weeks for 24 weeks, all rats were sacrificed and total blood were collected. Aorta, renal arteries, and kidney were preserved for functional assay, immunohistochemistry, western blot, and quantitative reverse-transcription polymerase chain reaction.

RESULTS

In vascular reactivity assays, aorta, intrarenal, and coronary arteries of all three ADT groups showed endothelial dysfunction. AT1R and related molecules at protein and messenger RNA (mRNA) level were tested, and AT1R pathway was shown to be activated and played a role in endothelial dysfunction. Both ACE and AT1R mRNA levels were doubled in the aorta in the leuprolide group while Orx and degarelix groups showed upregulation of AT1R in the kidney tissues. By immunohistochemistry, our result showed higher expression of AT1R in the intrarenal arteries of leuprolide and degarelix groups. The role of reactive oxygen species in endothelial dysfunction was confirmed by DHE fluorescence, nitrotyrosine overexpression, and upregulation of NOX2 in the different ADT treatment groups.

CONCLUSION

ADT causes endothelial dysfunction in male rats. GnRH receptor agonist compared to GnRH receptor antagonist, showed more impairment of endothelial function in the aorta and intrarenal arteries. Such change might be associated with upregulation and activation of AngII-AT1R-NOX2 induced oxidative stress in the vasculature. These results help to explain the different cardiovascular risks and outcomes related to different modalities of ADT treatment.

Cardiovascular outcomes in patients with locally advanced and metastatic prostate cancer treated with luteinising-hormone-releasing-hormone agonists or transdermal oestrogen: the randomised, phase 2 MRC PATCH trial (PR09)

BACKGROUND

Luteinising-hormone-releasing-hormone agonists (LHRHa) to treat prostate cancer are associated with long-term toxic effects, including osteoporosis. Use of parenteral oestrogen could avoid the long-term complications associated with LHRHa and the thromboembolic complications associated with oral oestrogen.

METHODS

In this multicentre, open-label, randomised, phase 2 trial, we enrolled men with locally advanced or metastatic prostate cancer scheduled to start indefinite hormone therapy. Randomisation was by minimisation, in a 2:1 ratio, to four self-administered oestrogen patches (100 μg per 24 h) changed twice weekly or LHRHa given according to local practice. After castrate testosterone concentrations were reached (1·7 nmol/L or lower) men received three oestrogen patches changed twice weekly. The primary outcome, cardiovascular morbidity and mortality, was analysed by modified intention to treat and by therapy at the time of the event to account for treatment crossover in cases of disease progression. This study is registered with ClinicalTrials.gov, number NCT00303784.

FINDINGS

85 patients were randomly assigned to receive LHRHa and 169 to receive oestrogen patches. All 85 patients started LHRHa, and 168 started oestrogen patches. At 3 months, 70 (93%) of 75 receiving LHRHa and 111 (92%) of 121 receiving oestrogen had achieved castrate testosterone concentrations. After a median follow-up of 19 months (IQR 12-31), 24 cardiovascular events were reported, six events in six (7·1%) men in the LHRHa group (95% CI 2·7-14·9) and 18 events in 17 (10·1%) men in the oestrogen-patch group (6·0-15·6). Nine (50%) of 18 events in the oestrogen group occurred after crossover to LHRHa. Mean 12-month changes in fasting glucose concentrations were 0·33 mmol/L (5·5%) in the LHRHa group and -0·16 mmol/L (-2·4%) in the oestrogen-patch group (p=0·004), and for fasting cholesterol were 0·20 mmol/L (4·1%) and -0·23 mmol/L (-3·3%), respectively (p<0·0001). Other adverse events reported by 6 months included gynaecomastia (15 [19%] of 78 patients in the LHRHa group vs 104 [75%] of 138 in the oestrogen-patch group), hot flushes (44 [56%] vs 35 [25%]), and dermatological problems (10 [13%] vs 58 [42%]).

INTERPRETATION

Parenteral oestrogen could be a potential alternative to LHRHa in management of prostate cancer if efficacy is confirmed. On the basis of our findings, enrolment in the PATCH trial has been extended, with a primary outcome of progression-free survival.

FUNDING

Cancer Research UK, MRC Clinical Trials Unit.

High glucose promotes pancreatic cancer cell proliferation via the induction of EGF expression and transactivation of EGFR

Multiple lines of evidence suggest that a large portion of pancreatic cancer patients suffer from either hyperglycemia or diabetes, both of which are characterized by high blood glucose level. However, the underlying biological mechanism of this phenomenon is largely unknown. In the present study, we demonstrated that the proliferative ability of two human pancreatic cancer cell lines, BxPC-3 and Panc-1, was upregulated by high glucose in a concentration-dependent manner. Furthermore, the promoting effect of high glucose levels on EGF transcription and secretion but not its receptors in these PC cell lines was detected by using an EGF-neutralizing antibody and RT-PCR. In addition, the EGFR transactivation is induced by high glucose levels in concentration- and time-dependent manners in PC cells in the presence of the EGF-neutralizing antibody. These results suggest that high glucose promotes pancreatic cancer cell proliferation via the induction of EGF expression and transactivation of EGFR. Our findings may provide new insight on the links between high glucose level and PC in terms of the molecular mechanism and reveal a novel therapeutic strategy for PC patients who simultaneously suffer from either diabetes or hyperglycemia.

Cardiovascular and metabolic complications during androgen deprivation: exercise as a potential countermeasure

Apart from the well-established adverse musculoskeletal and sexual health effects of androgen deprivation therapy (ADT), evidence is accumulating of substantial ADT-related cardiovascular and metabolic complications, which may impact quality of life and overall survival. In this brief review we discuss (1) the incidence of cardiovascular and metabolic complications during/following ADT from large cohort studies, (2) the increased risk factors for cardiovascular and metabolic disease from cross-sectional and prospective studies and (3) the use of physical exercise as a countermeasure in this new era of ADT-related toxicity. It is clear that exercise has the potential to provide a myriad of benefits to men undergoing ADT that may result in reduced morbidity and mortality, and subsequently improve quality of life.