Strontium-89 for prostate cancer with bone metastases: the potential of cancer control and improvement of overall survival

Strontium-89 plus zoledronic acid versus zoledronic acid for patients with painful bone metastatic breast cancer

INTRODUCTION

β-ray strontium-89 (Sr-89) intra-irradiation therapy has been approved and clinically used to reduce bone metastasis pain not alleviated by bone-modifying agents, external radiation, and analgesic agents. We examined the efficacy of zoledronic acid (ZOL) and Sr-89 combination therapy compared with ZOL alone in breast cancer patients with bone metastases.

MATERIALS AND METHODS

A randomized controlled trial was conducted on breast cancer patients with bone metastasis to compare the efficacy between ZOL monotherapy and ZOL plus Sr-89 combination therapy. The primary endpoints were changes in urinary NTX levels at 13 weeks and brief pain inventory scores. The secondary endpoints were analgesic drug usages, response rates, changes in bone metabolism markers, quality of life, and adverse event rates.

RESULTS

Thirty of the planned 60 cases were randomly assigned to ZOL alone or ZOL + Sr-89. There were no significant differences in the changes in urinary NTX levels between the 2 groups (P = 0.365). There was no consistent difference in the pain score changes between the 2 groups. Sr-89 addition to ZOL slightly reduced the white blood cell and platelet counts. However, all adverse events were Grade 1. Safety and analgesic drug dose reduction were more evident in ZOL + Sr-89.

CONCLUSION

This trial showed the lack of benefits from Sr-89 addition to ZOL for breast cancer patients with painful bone metastases. However, safety and analgesic drug dose reduction were more evident in ZOL + Sr-89, indicating its potential for pain control. Sr-89 therapy is safe, thus more effective radiopharmaceuticals are anticipated.

Association of Urinary Strontium Levels with Pregnancy-induced Hypertension

Pregnancy-induced hypertension (PIH), including gestational hypertension and preeclampsia, accounts for the majority of maternal and perinatal morbidity and mortality. Strontium (Sr) has been recently associated with preeclampsia in a small group of women; however, the role of Sr in PIH is not fully understood and warrants further investigation. In this study, we examined the association between urinary Sr levels and PIH, and assessed the effect of maternal age on the association. Urinary Sr concentrations were measured in 5423 pregnant women before delivery by inductively coupled plasma mass spectrometry (ICP-MS). Logistic regression analysis adjusting for potential confounders was applied to explore the association between Sr and PIH, and to evaluate the Sr-PIH relationship stratified by maternal age. Among the participants, 200 (3.83%) women were diagnosed with PIH. Compared with non-PIH women, women who developed PIH had lower urinary Sr concentrations (131.26 vs. 174.98 μg/L creatinine, P<0.01). With the natural log-transformed urinary creatinine-standardized Sr concentrations increasing, the risk of PIH decreased significantly [adjusted OR=0.60 (95%CI: 0.51, 0.72)]. Furthermore, the significant association of Sr with PIH was found among women under 35 years (P<0.01). Our finding suggested that Sr may play a potential protective role in the pathogenesis of PIH, especially among young pregnant women under 35 years old.

Analysis of Clinical Trials on Therapies for Prostate Cancer in Mainland China and Globally from 2010 to 2020

The overall aging of the world population has contributed to the continuous upward trend in the incidence of prostate cancer (PC). Trials on PC therapy have been extensively performed, but no study has analyzed the overall trends and characteristics of these trials, especially for those carried out in China. This study aimed to provide insights on the future direction of drug development in PC, thus supplying essential supportive data for stakeholders, including researchers, patients, investors, clinicians, and pharmaceutical industry. The details of the clinical trials of drug therapies for PC during January 1, 2010, to January 1, 2020, were collected from Pharmaprojects. A total of 463 clinical trials on different therapies with 132 different drugs were completed. The long-acting endocrine therapy with few side effects, radiotherapy combined with immune checkpoint inhibitors, gene-targeted chemotherapeutics, and novel immunotherapeutic products changed the concept of PC treatment. In mainland China, 31 trials with 19 drugs have been completed in the 10 assessment years. China has initiated a few trials investigating a limited number of drug targets, centered in a markedly uneven geographical distribution of leading clinical trial units; hence, the development of PC drugs has a long way to go. Given the large patient pool, China deserves widespread attention for PC drug research and development. These findings might have a significant impact on scientific research and industrial investment.

The efficacy and safety of zoledronic acid and strontium-89 in treating non-small cell lung cancer: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Zoledronic acid (ZA) and strontium-89 have been widely used to treat lung cancer with bone metastases. The authors perform this meta-analysis to better evaluate the clinical outcome of ZA and strontium-89 for non-small cell lung cancer (NSCLC) patients.

METHODS

We carried out standard meta-analysis and network meta-analysis based on a comprehensive data retrieval of EMBASE, PubMed, and Cochrane Library databases (up to March 2019). Random and fixed effects models were used where indicated and between-study heterogeneity was assessed. The primary endpoints were overall survival (OS) and skeletal-related events (SREs). The second endpoints were progression-free survival (PFS) and overall response rate (ORR).

RESULTS

Seven randomized clinical trials, including 1426 NSCLC patients with seven studies of zoledronic acid and two studies of strontium-89, met the inclusion criteria. Compared with the control group, ZA is associated with a OS benefit (1-year survival rate: RR = 1.76, 95% CI 1.36-2.27; and 24-month survival rate: RR = 2.38, 95% CI 1.35-4.19) and a reduction of SREs (RR = 0.57, 95% CI 0.40-0.84) for the patients with bone metastases. No statistical differences were found in PFS and ORR. Network meta-analysis for the patients with bone metastases showed that ZA + strontium-89 and ZA harbored significantly clinical benefits than strontium-89 and placebo in terms of 1-year survival rate and SREs. Both head-to-head study and network meta-analysis showed that strontium-89 had no statistical impact on OS and SREs compared with placebo.

CONCLUSION

Our analysis demonstrates that ZA +strontium-89 can be considered a priority for NSCLC patients with bone metastases, followed by ZA.

Diagnosis and treatment of bone metastasis: comprehensive guideline of the Japanese Society of Medical Oncology, Japanese Orthopedic Association, Japanese Urological Association, and Japanese Society for Radiation Oncology

Diagnosis and treatment of bone metastasis requires various types of measures, specialists and caregivers. To provide better diagnosis and treatment, a multidisciplinary team approach is required. The members of this multidisciplinary team include doctors of primary cancers, radiologists, pathologists, orthopaedists, radiotherapists, clinical oncologists, palliative caregivers, rehabilitation doctors, dentists, nurses, pharmacists, physical therapists, occupational therapists, medical social workers, etc. Medical evidence was extracted from published articles describing meta-analyses or randomised controlled trials concerning patients with bone metastases mainly from 2003 to 2013, and a guideline was developed according to the Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014. Multidisciplinary team meetings are helpful in diagnosis and treatment. Clinical benefits such as physical or psychological palliation obtained using the multidisciplinary team approaches are apparent. We established a guideline describing each specialty field, to improve understanding of the different fields among the specialists, who can further provide appropriate treatment, and to improve patients’ outcomes.

Essential Metals Zinc, Selenium, and Strontium Protect against Chromosome Damage Caused by Polycyclic Aromatic Hydrocarbons Exposure

Essential metals play important roles in maintaining cellular homeostasis, but the effects of their interaction with the environmental pollutants are still not very well-known in human subjects. The aim of this study was to evaluate the roles of essential metals and their interactions with polycyclic aromatic hydrocarbons (PAHs) on chromosome damage, an early carcinogenic event. A total of 1245 male workers were included in this study and the levels of 11 urinary essential metals, 12 urinary PAH metabolites, plasma concentrations of benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydotetrol-albumin (BPDE-Alb) adducts, and lymphocyte micronucleus (MN) frequencies were monitored. We found that zinc (Zn), selenium (Se), and strontium (Sr) have significant inverse dose-response relationships with MN frequencies (all P < 0.05). Furthermore, the protective roles of Zn, Se, and Sr were mainly shown among subjects with high levels of BPDE-Alb adducts. Significant effect modification of BPDE-Alb adducts on the associations of Zn, Se, and Sr with MN frequencies was observed (all Pinteraction < 0.05). Our study showed evidence that Zn, Se, and Sr play protective roles in reducing chromosome damage, and these effects can be modified by PAH exposure levels. These findings add potential evidence for the preventive effects of Zn, Se, and Sr against carcinogenesis in human subjects.

Radium-223-Dichloride in Castration Resistant Metastatic Prostate Cancer-Preliminary Results of the Response Evaluation Using F-18-Fluoride PET/CT

The purpose of this study was to evaluate the outcome after Radium-223-dichloride (²²³RaCl₂) treatment of patients with skeletal metastases of castration resistant prostate cancer using whole-body ¹⁸F-Fluoride PET/CT. Sodium ¹⁸F-fluoride [¹⁸F]-NaF PET/CT was performed prior the treatment of ²²³RaCl₂, after the first cycle and after the sixth cycle. The skeletal metastases were analyzed quantitatively using modified PET response evaluation PERCIST criteria. The patients were also analyzed for S-PSA. All ten patients responded in [¹⁸F]-NaF scans after 6 cycles, but interim analysis after the 1st cycle did not give additional information about the outcome. The S-PSA decrease correlated with [¹⁸F]-NaF response, only 1 patient demonstrated progressive disease, i.e., >25% increase in S-PSA values during ²²³RaCl₂. Our results (although preliminary) suggest that ¹⁸F-Fluoride PET/CT is useful in the follow-up of castration resistant prostate cancer with skeletal metastases.

Comparative efficacy, tolerability, and survival outcomes of various radiopharmaceuticals in castration-resistant prostate cancer with bone metastasis: a meta-analysis of randomized controlled trials

Background

A meta-analysis was conducted to assess the impact of radiopharmaceuticals (RPs) in castration-resistant prostate cancer (CRPC) on pain control, symptomatic skeletal events (SSEs), toxicity profile, quality of life (QoL), and overall survival (OS).

Materials and methods

The PubMed/MEDLINE, CANCERLIT, EMBASE, Cochrane Library database, and other search engines were searched to identify randomized controlled trials (RCTs) comparing RPs with control (placebo or radiation therapy) in metastatic CRPC. Data were extracted and assessed for the risk of bias (Cochrane’s risk of bias tool). Pooled data were expressed as odds ratio (OR), with 95% confidence intervals (CIs; Mantel–Haenszel fixed-effects model).

Results

Eight RCTs with a total patient population of 1,877 patients were identified. The use of RP was associated with significant reduction in pain intensity and SSE (OR: 0.63, 95% CI: 0.51–0.78, I²=27%, P,0.0001), improved QoL (OR: 0.71, 95% CI: 0.55–0.91, I²=65%, three trials, 1,178 patients, P=0.006), and a minimal improved OS (OR: 0.84, 95% CI: 0.64–1.04, I²=47%, seven trials, 1,845 patients, P=0.11). A subgroup analysis suggested an improved OS with radium-223 (OR: 0.68, 95% CI: 0.51–0.90, one trial, 921 patients) and strontium-89 (OR: 0.21, 95% CI: 0.05–0.91, one trial, 49 patients). Strontium-89 (five trials) was associated with increased rates of grade 3 and 4 thrombocytopenia (OR: 4.26, 95% CI: 2.22–8.18, P=0.01), leucopenia (OR: 7.98, 95% CI: 1.82–34.95, P=0.02), pain flare (OR: 6.82, 95% CI: 3.42–13.55, P=0.04), and emesis (OR: 3.61, 95% CI: 1.76–7.40, P=0.02).

Conclusion

The use of RPs was associated with significant reduction in SSEs and improved QoL, while the radium-223-related OS benefit warrants further large, RCTs in docetaxel naive metastatic CRPC patients.

A patient with esophageal cancer with bone metastasis who achieved pain relief with repetitive administration of strontium-89 chloride

A 75-year-old woman was diagnosed with esophageal cancer with difficulty in swallowing. She had a past history of rheumatoid arthritis, scleroderma, interstitial pneumonia, angina pectoris (with coronary artery bypass surgery) and arrhythmia (with pacemaker implantation). She refused surgery, and chemotherapy and radiotherapy were not performed because of the high risk accompanied with multiple comorbidities. She received proton therapy at another hospital and the primary lesion shrank. Bone metastasis in the thoracic vertebrae was diagnosed 10 months after diagnosis of esophageal cancer. Non-steroidal anti-inflammatory drugs and zoledronic acid were administered for back pain. Oxycodone was also administered but discontinued due to nausea. After strontium-89 ((89)Sr) chloride administration, her back pain was relieved. (89)Sr was administered five times every 3 months, and the pain did not worsen until her death due to pneumonia 2 years after diagnosis of esophageal cancer. (89)Sr was effective for pain from bone metastasis of esophageal cancer, and its repeated administration was safe.

Effect of Strontium Chloride on Experimental Bladder Inflammation in Rat

Introduction. Strontium salts are anti-irritants for chemically induced sensory irritation. Interstitial cystitis is a painful disease without definitive therapy. The aim of the study was to determine the effect of strontium in bladder with experimental interstitial cystitis model. Material and Methods. Rats' bladders in control group were instilled with NaCl. Second group was instilled with E. coli LPS. Third group was instilled with strontium. Fourth group was initially instilled with strontium and then LPS. Fifth group was instilled with LPS initially and then strontium. Urine of rats was collected at the beginning and end of the study. Results. Histamine and TNF-α changes were statistically significant in the second group but were not significant in the third group. When we compared the histamine levels of second via fourth and fifth groups the changes were statistically not significant. When we compared the TNF-α levels of second via fourth and fifth groups the changes were statistically significant. Conclusions. In our model, strontium did not make any significant changes in histopathology or histamine levels; however, it significantly reduced the levels of TNF-α. Given the role of TNF-α in the physiopathology of interstitial cystitis, these results suggested that further studies are required to evaluate the potential use of strontium in the management of interstitial cystitis.