Hypocalcaemia following denosumab in prostate cancer: A clinical review

Bone health and body composition in prostate cancer: Meet-URO and AIOM consensus about prevention and management strategies

BACKGROUND

Prostate cancer (PCa) treatments are associated with a detrimental impact on bone health (BH) and body composition. However, the evidence on these issues is limited and contradictory. This consensus, based on the Delphi method, provides further guidance on BH management in PCa.

MATERIALS AND METHODS

In May 2023, a survey made up of 37 questions and 74 statements was developed by a group of oncologists and endocrinologists with expertise in PCa and BH. In June 2023, 67 selected Italian experts, belonging to the Italian scientific societies Italian Association of Medical Oncology and Italian Network for Research in Urologic-Oncology (Meet-URO), were invited by e-mail to complete it, rating their strength of agreement with each statement on a 5-point scale. An agreement ≥75% defined the statement as accepted.

RESULTS

In non-metastatic hormone-sensitive PCa, the panel agreed that androgen deprivation therapy (ADT) alone implies sufficient fracture risk to warrant antifracture therapy with bone-targeting agents (BTAs) for cancer treatment-induced bone loss (CTIBL) prevention (79%). Therefore, no consensus was reached (48%) for the treatment with BTAs of patients receiving short-term ADT (<6 months). All patients receiving active treatment for metastatic hormone-sensitive PCa (75%), non-metastatic castration-resistant PCa (89%) and metastatic castration-resistant PCa (mCRPC) without bone metastases (84%) should be treated with BTAs at the doses and schedule for CTIBL prevention. All mCRPC patients with bone metastasis should be treated with BTAs to reduce skeletal-related events (94%). In all settings, the panel analyzed the type and timing of treatments and examinations to carry out for BH monitoring. The panel agreed on the higher risk of sarcopenic obesity of these patients and its correlation with bone fragility.

CONCLUSIONS

This consensus highlights areas lacking major agreement, like non-metastatic hormone-sensitive prostate cancer patients undergoing short-term ADT. Evaluation of these issues in prospective clinical trials and identification of early biomarkers of bone loss are particularly urgent.

Co-expression network analysis for the identification of potential prostate cancer genes and in vitro confirmation of their expression in cell model in the presence of Staphylococcal tsst-1 gene

Prostate cancer has arisen as an important life-threatening malignancy in males worldwide. Therefore, it is important to study underlying molecular pathways to be able to proposed appropriate a novel pathway of apoptosis in prostate cancer. This study aimed to explore the molecular effects of Staphylococcal tsst-1 gene on PC3 cell line apoptosis by in silico and in vitro studies. In this work, the differential expression of genes in prostate cancer was predicted by analyzing the public dataset GSE132063. Then, the pcDNA3.1 (+) vector was used to transfer tsst-1 gene to the PC3 cells and its effects was investigated using flow cytometry and qPCR. Co-expression network analysis indicated that lncRNAs had strong relationship with apoptosis genes in prostate cancer. Results of protein-protein docking indicated that BCL2L11, GRAMD3 and EGR1 interacted with tsst-1. Finally, the flow cytometry results showed that transfection by pcDNA3.1 (+)- tsst-1 could increase cellular death rates (48.15%) compared with the pcDNA3.1 (+) groups (6.35%); and the expression levels of GRAMD3, EGR1, BCL2L11 and PLAC4 were dysregulated in tsst-1 -transfected PC3 compared with empty-transfected PC3 (p < .05). In conclusion, our data will provide a novel landscape to understanding the mechanism of Staphylococcal tsst-1 gene on the PC3 cells apoptosis pathways.

Current use of Molecular Mechanisms and Signaling Pathways in Targeted Therapy of Prostate Cancer

Prostate cancer (PC) is identified as a heterogeneous disease. About 20 to 30% of PC patients experience cancer recurrence, characterized by an increase in the antigen termed serum prostate-specific antigen (PSA). Clinical recurrence of PC commonly occurs after five years. Metastatic castration-resistant prostate cancer (mCRPC) has an intricate genomic background. Therapies that target genomic changes in DNA repair signaling pathways have been progressively approved in the clinic. Innovative therapies like targeting signaling pathways, bone niche, immune checkpoint, and epigenetic marks have been gaining promising results for better management of PC cases with bone metastasis. This review article summarizes the recent consideration of the molecular mechanisms and signaling pathways involved in local and metastatic prostate cancer, highlighting the clinical insinuations of the novel understanding.

Severe and refractory hypocalcaemia secondary to osteoblastic bone metastases in bladder signet ring carcinoma: A case report and literature review

RATIONALE

Symptomatic hypocalcaemia is uncommon, occurring in <2% of patients with malignancy. Osteoblastic bone metastasis as a cause of hypocalcaemia is rare and not reported in bladder cancer.

PATIENT CONCERNS

We report a case of refractory hypocalcaemia in a patient with bladder cancer with extensive osteoblastic bone metastases. A 64-year-old male with a history of signet ring bladder carcinoma with osteoblastic bone metastases presented with severe hypocalcaemia with corrected calcium of 1.64 (2.09-2.46) mmol/L as well as hypomagnesemia and hypophosphatemia. He was previously treated with chemotherapy and immunotherapy. Denosumab was also initiated for the prevention of skeletal-related events.

DIAGNOSES

Additional investigations showed significantly elevated bone formation markers N-terminal propeptide of type I procollagen and alkaline phosphatase. Chest radiography and computed tomography scan also demonstrated extensive areas of sclerotic bone lesions suggestive of osteoblastic bone metastases. He was diagnosed with severe hypocalcaemia secondary to osteoblastic bone metastases and partly to denosumab, vitamin D deficiency, and hypomagnesemia.

INTERVENTIONS

He was treated aggressively with calcium and vitamin D replacement.

OUTCOMES

Despite prolonged intravenous calcium replacement and high doses of oral calcium, cholecalciferol, and calcitriol replacement, he had persistent hypocalcaemia with calcium levels ranging from 1.8 to 1.9 mmol/L. He died 4 months after his admission.

LESSONS

Osteoblastic bone metastases lead to an increased influx of calcium and phosphate into the bone leading to hypocalcaemia and should be considered as a differential in severe and refractory hypocalcaemia. It is rare and has not been described in bladder cancer. Precaution should be taken upon the initiation of antiresorptive in patients with osteoblastic bone metastases.

Targeting signaling pathways in prostate cancer: mechanisms and clinical trials

Prostate cancer (PCa) affects millions of men globally. Due to advances in understanding genomic landscapes and biological functions, the treatment of PCa continues to improve. Recently, various new classes of agents, which include next-generation androgen receptor (AR) signaling inhibitors (abiraterone, enzalutamide, apalutamide, and darolutamide), bone-targeting agents (radium-223 chloride, zoledronic acid), and poly(ADP-ribose) polymerase (PARP) inhibitors (olaparib, rucaparib, and talazoparib) have been developed to treat PCa. Agents targeting other signaling pathways, including cyclin-dependent kinase (CDK)4/6, Ak strain transforming (AKT), wingless-type protein (WNT), and epigenetic marks, have successively entered clinical trials. Furthermore, prostate-specific membrane antigen (PSMA) targeting agents such as ¹⁷⁷Lu-PSMA-617 are promising theranostics that could improve both diagnostic accuracy and therapeutic efficacy. Advanced clinical studies with immune checkpoint inhibitors (ICIs) have shown limited benefits in PCa, whereas subgroups of PCa with mismatch repair (MMR) or CDK12 inactivation may benefit from ICIs treatment. In this review, we summarized the targeted agents of PCa in clinical trials and their underlying mechanisms, and further discussed their limitations and future directions.

Life-threatening sustained hypocalcemia following Denosumab use in metastatic prostate cancer

INTRODUCTION

Prostate cancer is the second most frequently diagnosed cancer among men worldwide in 2020. Skeletal-related events (SRE) like pathologic fracture or spinal cord compression are commonly seen in metastatic prostate cancer. Denosumab, a monoclonal antibody, acts by inhibiting osteoclast-mediated bone resorption in bone metastasis from solid tumors and reduces bone turnover and destruction. However, there is an increased risk of life-threatening denosumab-induced hypocalcemia with an incidence of 0.1 to 12.8%.

CASE REPORT

Our patient is a 69-year-old man with widespread skeletal metastatic disease from primary prostate cancer who presented to the hospital complaining of generalized fatigue and joint pain. Due to severe debilitating low back pain secondary to osteochondral lesions, the patient was started on Denosumab 120 mg. On presentation, serum calcium was found to be severely low at 5.9 mg/dl (serum calcium level prior to Denosumab was 9.1 mg/dl).

MANAGEMENT AND OUTCOME

Denosumab was discontinued immediately, and the patient was started on IV calcium gluconate. Repeat serum calcium level continued to be low at 6.7 likely due to the long elimination half-life of Denosumab (25-30 days). He was transferred to a long-term acute care facility for long-term IV calcium replacement, where he succumbed to illness six weeks later.

DISCUSSION

Denosumab, an anti-resorptive treatment for skeletal metastasis from solid tumors, is shown to cause severe life-threatening hypocalcemia. The maximum serum drug level of Denosumab reaches 7-21 days after administration. Sustained hypocalcemia is rare and life-threatening. Clinicians should use this medication with caution due to its unpredictable side effect profile.

Hypocalcemia in a Patient With Metastatic Prostate Cancer From Denosumab Treatment

Denosumab is a humanized monoclonal antibody that binds RANKL to inhibit osteoclast activity. It is indicated for the prevention of skeletal-related events (SRE) in patients with solid tumors who have bone metastasis and in patients with multiple myeloma. Hypocalcemia is one of the known side effects of denosumab, which can be prevented with calcium supplementation.

We present a case of a 72-year-old male with diagnosed metastatic prostate cancer who had received one dose of denosumab 10 days prior to presentation with fatigue, insomnia, and somnolence. His labs showed severe (Grade 4) hypocalcemia, which improved with intravenous calcium supplementation. This case highlights a known but life-threatening side effect of denosumab and the potential need for prolonged calcium monitoring in patients placed on the drug.

Predictors for development of denosumab-induced hypocalcaemia in cancer patients with bone metastases determined by ordered logistic regression analysis

This retrospective study was undertaken to identify predictors for the development of hypocalcaemia even with prophylactic administration of calcium and vitamin D, and to help guide future strategies to improve the safety, efficacy, and QOL of patients receiving denosumab. Between January 2016 and February 2020, a total of 327 advanced cancer patients at our hospital who were receiving denosumab were enrolled. Variables associated with the development of hypocalcaemia were extracted from the clinical records. The level of hypocalcaemia was evaluated using CTCAE version 5. Multivariate ordered logistic regression analysis was performed to identify predictors for the development of hypocalcaemia. Optimal cut off thresholds were determined using ROC analysis. Values of P < 0.05 (2-tailed) were considered significant. 54 patients have developed hypocalcemia (≥ Grade 1). Significant factors identified included concomitant use of vonoprazan [odds ratio (OR) = 3.74, 95% confidence interval (CI) 1.14–12.26; P = 0.030], dexamethasone (OR = 2.45, 95%CI 1.14–5.42; P = 0.022), pre-treatment levels of serum calcium (OR = 0.27, 95%CI 0.13–0.54; P < 0.001), ALP/100 (OR = 1.04, 95%CI 1.01–1.07; P = 0.003), and haemoglobin (OR = 0.79, 95%CI 0.68–0.93; P = 0.004). ROC curve analysis revealed that the threshold for pre-treatment levels of serum calcium was ≤ 9.3 mg/dL, ALP was ≥ 457 U/L, and haemoglobin was ≤ 10.4 g/dL. In conclusion, concomitant use of vonoprazan or dexamethasone, and pre-treatment levels of serum calcium (low), ALP (high) and haemoglobin (low) were identified as significant predictors for the development of denosumab-induced hypocalcaemia.