Retrospective analysis of serum testosterone levels by LC-MS/MS in chemically castrated prostate cancer patients: Biological variation and analytical performance specifications

Conducting Human Biology Research Using Invasive Clinical Samples: Methods, Strengths, and Limitations

Invasive biological samples collected during clinical care represent a valuable yet underutilized source of information about human biology. However, the challenges of working with clinical personnel and the invasive nature of sample collection in biomedical studies can hinder the acquisition of sufficiently large sample sizes for robust statistical analyses. In addition, the incorporation of demographic data from participants is crucial for ensuring the inclusiveness of representative populations, identifying at-risk groups, and addressing healthcare disparities. Drawing on both research experiences and the existing literature, this article provides recommendations for researchers aiming to undertake efficient and impactful projects involving invasive human samples. The suggested strategies include: (1) establishing productive collaborations with clinicians; (2) optimizing sample quality through meticulous collection and handling procedures; and (3) strategically implementing a retrospective model to capitalize on existing invasive sample repositories. When established, cooperative work between clinical health care workers and biological anthropologists can yield insights into human biology that have the potential to improve human health and wellbeing.

Assessment of Cardiovascular Events Caused by New-Generation Androgen Receptor Pathway Inhibitors Used for Prostate Cancer: A Real-World Study in Japan

INTRODUCTION

Androgen receptor pathway inhibitors (ARPIs) that significantly improve the prognosis of patients with prostate cancer include abiraterone acetate (androgen synthesis inhibitor) and enzalutamide (androgen receptor inhibitor). A recent analysis of ARPI and cardiovascular events using the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) has been reported; however, the evidence on cardiovascular events for abiraterone acetate and enzalutamide in real-world clinical practice is insufficient. Using a large Japanese database of medical institutions, the Japanese Medical Data Center (JMDC) medical institution database (JMDC Inc., Tokyo, Japan), this study tested the hypothesis that the risk of cardiovascular events with enzalutamide is lower than that with abiraterone acetate.

METHOD

Using the JMDC medical institution database, patients with new use of abiraterone acetate or enzalutamide who had not experienced a major cardiovascular event between October 2014 and February 2022 were included. After adjusting for age, comorbidities, and concomitant medications using propensity score matching, cumulative incidence rates were compared for cardiovascular death and all cardiovascular events as the primary endpoints, and major cardiovascular events, myocardial infarction, heart failure, and stroke as secondary endpoints.

RESULT

A total of 3,033 patients in the enzalutamide group and 2,021 in the abiraterone group met the eligibility criteria. After propensity score matching, the cohort included 1,940 patients in the enzalutamide group and 1,940 patients in the abiraterone group. Enzalutamide was associated with significantly lower cumulative rates of cardiovascular death (hazard ratio [HR]: 0.30, 95% confidence interval [CI]: 0.10-0.93), all cardiovascular events (HR: 0.79, 95% CI: 0.64-0.98), major cardiovascular events (HR: 0.79, 95% CI: 0.64-0.97), and myocardial infarction (HR: 0.62, 95% CI: 0.46-0.84) compared to abiraterone.

CONCLUSION

In a national sample of males with prostate cancer, those newly treated with enzalutamide had a lower risk of adverse cardiovascular events than those treated with abiraterone acetate.

An LC-MS/MS-based method for the simultaneous quantification of melatonin, cortisol and cortisone in saliva

Disturbances in the diurnal pattern are associated with several clinical and psychological conditions, including depression and fatigue. Salivary sampling for melatonin, cortisol and cortisone provides a non-invasive method for frequent sampling and obtaining biochemical insight into the diurnal pattern of individuals. Therefore, a new liquid chromatography-tandem mass spectrometry-based method for the measurement of salivary melatonin, cortisol and cortisone was developed and validated. The method required 250 μl saliva, used isotope dilution methodology and was based on a liquid-liquid extraction for sample preparation, reversed-phase chromatography and multiple reaction monitoring on a mass spectrometer for quantitation. The lower limits of quantification obtained were 0.010 nmol/L for melatonin, 0.5 nmol/L for cortisol and 1.00 nmol/L for cortisone and the limits of detection were 0.003 nmol/L, 0.15 nmol/L and 0.1 nmol/L respectively. The method imprecision was ≤14% for all measurands, and the method comparison showed highly comparable results with high correlation coefficients (all ≥0.964). Potential interference of cortisol and cortisone by prednisolone was observed and could be detected by chromatogram review. Typical diurnal patterns for melatonin, cortisol and cortisone were observed in the saliva of 20 cancer survivors who collected saliva throughout the day.

Advances in mass spectrometry imaging for spatial cancer metabolomics

Mass spectrometry (MS) has become a central technique in cancer research. The ability to analyze various types of biomolecules in complex biological matrices makes it well suited for understanding biochemical alterations associated with disease progression. Different biological samples, including serum, urine, saliva, and tissues have been successfully analyzed using mass spectrometry. In particular, spatial metabolomics using MS imaging (MSI) allows the direct visualization of metabolite distributions in tissues, thus enabling in-depth understanding of cancer-associated biochemical changes within specific structures. In recent years, MSI studies have been increasingly used to uncover metabolic reprogramming associated with cancer development, enabling the discovery of key biomarkers with potential for cancer diagnostics. In this review, we aim to cover the basic principles of MSI experiments for the nonspecialists, including fundamentals, the sample preparation process, the evolution of the mass spectrometry techniques used, and data analysis strategies. We also review MSI advances associated with cancer research in the last 5 years, including spatial lipidomics and glycomics, the adoption of three-dimensional and multimodal imaging MSI approaches, and the implementation of artificial intelligence/machine learning in MSI-based cancer studies. The adoption of MSI in clinical research and for single-cell metabolomics is also discussed. Spatially resolved studies on other small molecule metabolites such as amino acids, polyamines, and nucleotides/nucleosides will not be discussed in the context.

The European biological variation study (EuBIVAS): Biological variation data for testosterone, follicle stimulating hormone, prolactin, luteinizing hormone and dehydroepiandrosterone sulfate in men

BACKGROUND

Knowledge of biological variation (BV) of hormones is essential for interpretation of laboratory tests and for diagnostics of endocrinological and reproductive diseases. There is a lack of robust BV data for many hormones in men.

METHODS

We used serum samples collected weekly over 10 weeks from the European Biological Variation Study (EuBIVAS) to determine BV of testosterone, follicle-stimulating hormone (FSH), prolactin, luteinizing hormone (LH) and dehydroepiandrosterone sulfate (DHEA-S) in 38 men. We derived within-subject (CVI) and between-subject (CVG) BV estimates by CV-ANOVA after trend, outlier, and homogeneity analysis and calculated reference change values, index of individuality (II), and analytical performance specifications.

RESULTS

The CVI estimates were 10 % for testosterone, 8 % for FSH, 13 % for prolactin, 22 % for LH, and 9 % for DHEA-S, respectively. The IIs ranged between 0.14 for FSH to 0.66 for LH, indicating high individuality.

CONCLUSIONS

In this study, we have used samples from the highly powered EuBIVAS study to derive BV estimates for testosterone, FSH, prolactin, LH and DHEA-S in men. Our data confirm previously published BV estimates of testosterone, FSH and LH. For prolactin and DHEA-S BV data for men are reported for the first time.

Predictive value of low testosterone concentrations during and prior to enzalutamide treatment in metastatic castration-resistant prostate cancer

BACKGROUND

Enzalutamide is an effective treatment for metastatic castration-resistant prostate cancer (mCRPC) patients. However, variances in responses are observed and there is a need for biomarkers predicting treatment outcome and selection. In this study, we aimed to explore the predictive value of testosterone for first-line enzalutamide treatment of mCRPC.

METHODS

A retrospective analysis of 72 mCRPC patients with no prior abiraterone or docetaxel treatment was performed. Serum testosterone was measured using a liquid chromatography tandem-mass spectrometry method. Association of pre- and during-enzalutimide treatment testosterone levels with progression-free survival (PFS) and failure-free survival (FFS) was investigated using univariate and multivariate Cox models. Testosterone levels were dichotomized into a low (Q1) and high (interquartile range-Q4) group.

RESULTS

Median PFS (7.4 v. 20.8 months, P<0.0001) and FFS (6.6 v. 17.7 months, P<0.0001) were shorter for patients with low testosterone levels (<0.217 nmol/L) during enzalutamide treatment. Furthermore, univariate Cox proportional hazards models revealed that low testosterone levels were associated with shorter PFS (HR 3.5, 95%CI 1.9-6.3; P<0.001) and FFS (HR 3.1, 95%CI 1.7-5.5; P<0.001). Pre-treatment testosterone levels were lower than during-treatment levels (P<0.0001) and low pre-treatment testosterone levels (<0.143 nmol/L) were associated with shorter median PFS (12.6 v. 20.5 months, P<0.01) and FFS (12.6 v. 22.5 months, P<0.01).

CONCLUSION

The results of this study suggest that low serum testosterone levels during and prior to enzalutamide treatment can predict progression in mCRPC patients and identifies tumors resistant to next-in-line enzalutamide treatment. Validation in a prospective cohort is warranted.

Serum testosterone measured by liquid chromatography-tandem mass spectrometry is an independent predictor of response to castration in metastatic hormone-sensitive prostate cancer

BACKGROUND

Although testosterone levels have been associated with progression-free survival (PFS) in metastatic hormone-sensitive prostate cancer (mHSPC) patients, this has primarily been investigated using inaccurate immunoassays (IA). Here, we investigated whether castrate testosterone levels determined by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay is an independent risk factor for treatment response in mHSPC.

METHODS

In total, 106 mHSPC patients treated with luteinizing-hormone releasing-hormone (LHRH) agonists were retrospectively analyzed between March 2018 and August 2021. Testosterone levels in serum samples were quantitated using an LC-MS/MS assay. In a subset of patients, IA (Roche Cobas Pro) values were compared with LC-MS/MS results. Survival analysis was performed using Kaplan-Meier curves and Cox proportional hazard models.

RESULTS

Median PFS was shorter for high testosterone levels (>0.231 nmol/L, 18.4 v. 42.6 months, HR 1.7, p = 0.018). Low testosterone levels and a PSA response below 4 ng/mL was associated with longer median PFS (46.2 months) than the remaining combinations (13.8-19.3 months, 3.4-5.8, overall p < 0.01). In 67 patients, testosterone levels below the median remained associated with longer PFS, whereas IA measurements did not show a similar difference.

CONCLUSION

Our results suggest that high castration testosterone levels measured by LC-MS/MS is an independent response predictor for mHSPC patients.

Testosterone analysis in castrated prostate cancer patients: suitability of the castration cut-off and analytical accuracy of the present-day clinical immunoassays

OBJECTIVES

Testosterone testing is relevant for evaluating castration adequacy and diagnosis of castration-resistant prostate cancer (PCa). However, the recommended testosterone cut-off of 1.7 nmol/L (50 ng/dL) to define adequate castration is based on consensus and not validated for the automated immunoassays (AIA) used in today's medical laboratories. Furthermore, appropriate population intervals have not been determined by a state-of-the-art assay. We investigated the analytical suitability of this cut-off and the accuracy of the present-day AIAs for testosterone analysis in castrated PCa patients.

METHODS

Leftover serum from 120 PCa patients castrated with luteinizing hormone-releasing hormone agonists was analysed for testosterone by five methods: Architect i2000 (Abbott), Access (Beckman), Cobas 6000 (Roche), Atellica (Siemens), LC-MS/MS. For all assays, the castration 95th, 97.5th and 99th percentile upper limits were determined. Furthermore, Passing-Bablok regression, mean bias and Spearman's correlation coefficients were compared to the LC-MS/MS method and total error based on biological variation.

RESULTS

All castration upper limits, ranging from 0.472 nmol/L (LC-MS/MS) to 1.25 nmol/L (Access) (95% percentile), were significantly lower than the current castration cut-off (1.7 nmol/L). Slopes of Passing-Bablok regressions comparing the AIA with the LC-MS/MS method ranged from 1.4 (Cobas and Atellica) to 3.8 (Access). The Architect showed the highest correlation with LC-MS/MS (ρ=0.58). All AIA failed to meet the desirable total error criterion.

CONCLUSIONS

These results suggest that a lower general testosterone castration cut-off may be more appropriate in evaluating the adequacy of castration in PCa and that present-day AIA lack analytical accuracy to quantify testosterone levels in castrated PCa.

Changes in Sex Steroids and relation with Menopausal Complaints in Women Undergoing Risk-Reducing Salpingo-Oophorectomy

Context

Risk-reducing salpingo-oophorectomy (RRSO) is performed in BRCA1 or 2 mutant carriers to minimize ovarian cancer risk. Although studies have been performed investigating sex steroid levels, menopausal complaints, and sexual functioning in relation to RRSO, their exact relationship remains unknown.

Objectives

To investigate the impact of RRSO on serum sex steroid levels and their association with menopausal complaints and sexual functioning.

Methods

This prospective observational cohort study included 57 premenopausal and 37 postmenopausal women at risk of ovarian cancer and opting for RRSO. Data collection involved validated questionnaires on sexual functioning and menopausal complaints. Testosterone, androstenedione, estradiol, and estrone levels in serum determined by liquid chromatography-tandem mass spectrometry were obtained 1 day before, 6 weeks, and 7 months after RRSO.

Results

In premenopausal women, all 4 steroids were decreased both 6 weeks (P < 0.01) and 7 months (P < 0.01) after RRSO. Furthermore, in these women, decreases in estrogens were associated with a decrease in sexual functioning 7 months after RRSO (P < 0.05). In postmenopausal women, only testosterone was decreased 6 weeks and 7 months (P < 0.05) after RRSO, which was associated with an increase in menopausal complaints at 7 months post-RRSO (P < 0.05).

Conclusion

Our results suggest that in premenopausal women, decreases in estrogens are related to a decrease in sexual functioning and that in postmenopausal women, testosterone is decreased after RRSO, which indicates that postmenopausal ovaries maintain some testosterone production. Furthermore, in postmenopausal women, a large decrease of testosterone was associated with more menopausal complaints, indicating that future studies investigating testosterone supplementation are warranted.