HSD3B1 (1245A>C) germline variant and clinical outcomes in metastatic castration-resistant prostate cancer patients treated with abiraterone and enzalutamide: results from two prospective studies

Therapeutic biomarkers in metastatic castration-resistant prostate cancer: does the state matter?

The treatment of metastatic castration-resistant prostate cancer (mCRPC) has been fundamentally transformed by our greater understanding of its complex biological mechanisms and its entrance into the era of precision oncology. A broad aim is to use the extreme heterogeneity of mCRPC by matching already approved or new targeted therapies to the correct tumor genotype. To achieve this, tumor DNA must be obtained, sequenced, and correctly interpreted, with individual aberrations explored for their druggability, taking into account the hierarchy of driving molecular pathways. Although tumor tissue sequencing is the gold standard, tumor tissue can be challenging to obtain, and a biopsy from one metastatic site or primary tumor may not provide an accurate representation of the current genetic underpinning. Sequencing of circulating tumor DNA (ctDNA) might catalyze precision oncology in mCRPC, as it enables real-time observation of genomic changes in tumors and allows for monitoring of treatment response and identification of resistance mechanisms. Moreover, ctDNA can be used to identify mutations that may not be detected in solitary metastatic lesions and can provide a more in-depth understanding of inter- and intra-tumor heterogeneity. Finally, ctDNA abundance can serve as a prognostic biomarker in patients with mCRPC.The androgen receptor (AR)-axis is a well-established therapeutical target for prostate cancer, and through ctDNA sequencing, insights have been obtained in (temporal) resistance mechanisms that develop through castration resistance. New third-generation AR-axis inhibitors are being developed to overcome some of these resistance mechanisms. The druggability of defects in the DNA damage repair machinery has impacted the treatment landscape of mCRPC in recent years. For patients with deleterious gene aberrations in genes linked to homologous recombination, particularly BRCA1 or BRCA2, PARP inhibitors have shown efficacy compared to the standard of care armamentarium, but platinum-based chemotherapy may be equally effective. A hierarchy exists in genes associated with homologous recombination, where, besides the canonical genes in this pathway, not every other gene aberration predicts the same likelihood of response. Moreover, evidence is emerging on cross-resistance between therapies such as PARP inhibitors, platinum-based chemotherapy and even radioligand therapy that target this genotype. Mismatch repair-deficient patients can experience a beneficial response to immune checkpoint inhibitors. Activation of other cellular signaling pathways such as PI3K, cell cycle, and MAPK have shown limited success with monotherapy, but there is potential in co-targeting these pathways with combination therapy, either already witnessed or anticipated. This review outlines precision medicine in mCRPC, zooming in on the role of ctDNA, to identify genomic biomarkers that may be used to tailor molecularly targeted therapies. The most common druggable pathways and outcomes of therapies matched to these pathways are discussed.

Treatment patterns and outcomes in metastatic castration-resistant prostate cancer patients with and without somatic or germline alterations in homologous recombination repair genes

BACKGROUND

Although germline BRCA mutations have been associated with adverse outcomes in prostate cancer (PC), understanding of the association between somatic/germline alterations in homologous recombination repair (HRR) genes and treatment outcomes in metastatic castration-resistant PC (mCRPC) is limited. The aim of this study was to investigate the prevalence and outcomes associated with somatic/germline HRR alterations, particularly BRCA1/2, in patients initiating first-line (1L) mCRPC treatment with androgen receptor signalling inhibitors (ARSi) or taxanes.

PATIENTS AND METHODS

Data from 729 mCRPC patients were pooled for CAPTURE from four multicentre observational studies. Eligibility required 1L treatment with ARSi or taxanes, adequate tumour samples and biomarker panel results. Patients underwent paired normal and tumour DNA analyses by next-generation sequencing using a custom gene panel including ATM, BRCA1, BRCA2, BRIP1, CDK12, CHEK2, FANCA, HDAC2, PALB2, RAD51B and RAD54L. Patients were divided into subgroups based on somatic/germline alteration(s): with BRCA1/2 mutations (BRCA); with HRR mutations except BRCA1/2 (HRR non-BRCA); and without HRR alterations (non-HRR). Patients without BRCA1/2 mutations were classified as non-BRCA. Radiographic progression-free survival (rPFS), progression-free survival 2 (PFS2) and overall survival (OS) were assessed.

RESULTS

Of 729 patients, 96 (13.2%), 127 (17.4%) and 506 (69.4%) were in the BRCA, HRR non-BRCA and non-HRR subgroups, respectively. BRCA patients performed significantly worse for all outcomes than non-HRR or non-BRCA patients (P < 0.05), while PFS2 and OS were significantly shorter for BRCA than HRR non-BRCA patients (P < 0.05). HRR non-BRCA patients also had significantly worse rPFS, PFS2 and OS than non-HRR patients. Exploratory analyses suggested that for BRCA patients, there were no significant differences in outcomes associated with 1L treatment choice (ARSi or taxanes) or with the somatic/germline origin of the alterations.

CONCLUSIONS

Worse outcomes were observed for mCRPC patients in the BRCA subgroup compared with non-BRCA subgroups, either HRR non-BRCA or non-HRR. Despite its heterogeneity, the HRR non-BRCA subgroup presented worse outcomes than the non-HRR subgroup. Screening early for HRR mutations, especially BRCA1/2, is crucial in improving mCRPC patient prognosis.

Adrenal-Permissive Germline HSD3B1 Allele and Prostate Cancer Outcomes

Importance

The adrenal androgen-metabolizing 3β-hydroxysteroid dehydrogenase-1 enzyme, encoded by the HSD3B1 gene, catalyzes the rate-limiting step necessary for synthesizing nontesticular testosterone and dihydrotestosterone production. The common adrenal-permissive HSD3B1(1245C) allele is responsible for encoding the 3β-HSD1 protein with decreased susceptibility to degradation resulting in higher extragonadal androgen synthesis. Retrospective studies have suggested an association of the HSD3B1 adrenal-permissive homozygous genotype with androgen deprivation therapy resistance in prostate cancer.

Objective

To evaluate differences in mortality outcomes by HSD3B1 genetic status among men with prostate cancer.

Design, Setting, and Participants

This cohort study of patients with prostate cancer who were enrolled in the Million Veteran Program within the Veterans Health Administration (VHA) system between 2011 and 2023 collected genotyping and phenotyping information.

Exposure

HSD3B1 genotype status was categorized as AA (homozygous adrenal-restrictive), AC (heterozygous adrenal-restrictive), or CC (homozygous adrenal-permissive).

Main Outcomes and Measures

The primary outcome of this study was prostate cancer-specific mortality (PCSM), defined as the time from diagnosis to death from prostate cancer, censored at the date of last VHA follow-up. Secondary outcomes included incidence of metastases and PCSM in predefined subgroups.

Results

Of the 5287 participants (median [IQR] age, 69 [64-74] years), 402 (7.6%) had the CC genotype, 1970 (37.3%) had the AC genotype, and 2915 (55.1%) had the AA genotype. Overall, the primary cause of death for 91 patients (1.7%) was prostate cancer. Cumulative incidence of PCSM at 5 years after prostate cancer diagnosis was higher among men with the CC genotype (4.0%; 95% CI, 1.7%-6.2%) compared with the AC genotype (2.1%; 95% CI, 1.3%-2.8%) and AA genotype (1.9%; 95% CI, 1.3%-2.4%) (P = .02). In the 619 patients who developed metastatic disease at any time, the cumulative incidence of PCSM at 5 years was higher among patients with the CC genotype (36.0%; 95% CI, 16.7%-50.8%) compared with the AC genotype (17.9%; 95% CI, 10.5%-24.7%) and AA genotype (18.5%; 95% CI, 12.0%-24.6%) (P = .01).

Conclusions and Relevance

In this cohort study of US veterans undergoing treatment for prostate cancer at the VHA, the HSD3B1 CC genotype was associated with inferior outcomes. The HSD3B1 biomarker may help identify patients who may benefit from therapeutic targeting of 3β-hydroxysteroid dehydrogenase-1 and the androgen-signaling axis.

A common germline variant in CYP11B1 is associated with adverse clinical outcome of treatment with abiraterone or enzalutamide

Extragonadal androgens play a pivotal role in prostate cancer disease progression on androgen receptor signaling inhibitors (ARSi), including abiraterone and enzalutamide. We aimed to investigate if germline variants in genes involved in extragonadal androgen synthesis contribute to resistance to ARSi and may predict clinical outcomes on ARSi. We included ARSi naive metastatic prostate cancer patients treated with abiraterone or enzalutamide and determined 18 germline variants in six genes involved in extragonadal androgen synthesis. Variants were tested in univariate and multivariable analysis for the relation with overall survival (OS) and time to progression (TTP) by Cox regression, and PSA response by logistic regression. A total of 275 patients were included. From the investigated genes CYP17A1, HSD3B1, CYP11B1, AKR1C3, SRD5A1 and SRD5A2, only rs4736349 in CYP11B1 in homozygous form (TT), present in 54 patients (20%), was related with a significantly worse OS (HR = 1.71, 95% CI 1.09 - 2.68, p = 0.019) and TTP (HR = 1.50, 95% CI 1.08 - 2.09, p = 0.016), and was related with a significantly less frequent PSA response (OR = 0.48, 95% CI 0.24 - 0.96, p = 0.038) on abiraterone or enzalutamide in a multivariable analysis. The frequent germline variant rs4736349 in CYP11B1 is, as homozygote, an independent negative prognostic factor for treatment with abiraterone or enzalutamide in ARSi naive metastatic prostate cancer patients. Our findings warrant prospective investigation of this potentially important predictive biomarker.

Active DHEA uptake in the prostate gland correlates with aggressive prostate cancer

Strategies for patient stratification and early intervention are required to improve clinical benefits for patients with prostate cancer. Here, we found that active DHEA utilization in the prostate gland correlated with tumor aggressiveness at early disease stages, and 3βHSD1 inhibitors were promising for early intervention. [3H]-labeled DHEA consumption was traced in fresh prostatic biopsies ex vivo. Active DHEA utilization was more frequently found in patients with metastatic disease or therapy-resistant disease. Genetic and transcriptomic features associated with the potency of prostatic DHEA utilization were analyzed to generate clinically accessible approaches for patient stratification. UBE3D, by regulating 3βHSD1 homeostasis, was discovered to be a regulator of patient metabolic heterogeneity. Equilin suppressed DHEA utilization and inhibited tumor growth as a potent 3βHSD1 antagonist, providing a promising strategy for the early treatment of aggressive prostate cancer. Overall, our findings indicate that patients with active prostatic DHEA utilization might benefit from 3βHSD1 inhibitors as early intervention.

Analysis of genetic biomarkers, polymorphisms in ADME-related genes and their impact on pharmacotherapy for prostate cancer

Prostate cancer (PCa) is a non-cutaneous malignancy in males with wide variation in incidence rates across the globe. It is the second most reported cause of cancer death. Its etiology may have been linked to genetic polymorphisms, which are not only dominating cause of malignancy casualties but also exerts significant effects on pharmacotherapy outcomes. Although many therapeutic options are available, but suitable candidates identified by useful biomarkers can exhibit maximum therapeutic efficacy. The single-nucleotide polymorphisms (SNPs) reported in androgen receptor signaling genes influence the effectiveness of androgen receptor pathway inhibitors and androgen deprivation therapy. Furthermore, SNPs located in genes involved in transport, drug metabolism, and efflux pumps also influence the efficacy of pharmacotherapy. Hence, SNPs biomarkers provide the basis for individualized pharmacotherapy. The pharmacotherapeutic options for PCa include hormonal therapy, chemotherapy (Docetaxel, Mitoxantrone, Cabazitaxel, and Estramustine, etc.), and radiotherapy. Here, we overview the impact of SNPs reported in various genes on the pharmacotherapy for PCa and evaluate current genetic biomarkers with an emphasis on early diagnosis and individualized treatment strategy in PCa.

Targeting the Androgen Signaling Axis in Prostate Cancer

Activation of the androgen receptor (AR) and AR-driven transcriptional programs is central to the pathophysiology of prostate cancer. Despite successful translational efforts in targeting AR, therapeutic resistance often occurs as a result of molecular alterations in the androgen signaling axis. The efficacy of next-generation AR-directed therapies for castration-resistant prostate cancer has provided crucial clinical validation for the continued dependence on AR signaling and introduced a range of new treatment options for men with both castration-resistant and castration-sensitive disease. Despite this, however, metastatic prostate cancer largely remains an incurable disease, highlighting the need to better understand the diverse mechanisms by which tumors thwart AR-directed therapies, which may inform new therapeutic avenues. In this review, we revisit concepts in AR signaling and current understandings of AR signaling-dependent resistance mechanisms as well as the next frontier of AR targeting in prostate cancer.

Prospective role of 3βHSD1 in prostate cancer precision medicine

BACKGROUND

Prostate cancer is addicted to androgens. The steroidogenic enzyme 3β-hydroxysteroid dehydrogenase 1 (3βHSD1) recognizes pregnenolone, dehydroepiandrosterone (DHEA), and steroidal medicine abiraterone as substrates to accelerate disease progression.

METHODS

References for this review were identified through searches of PubMed with the search terms "prostate cancer", "HSD3B1", and "3bHSD1" from 1990 until June, 2022.

RESULTS

Genotype of 3βHSD1 has been reported to correlate with tumor aggressiveness of advanced prostate cancer in multiple clinical scenarios. The ethnic differences and limitations of using 3βHSD1 genotype as a prognostic biomarker have been discussed here. The activity of 3βHSD1 increases in patients treated with abiraterone and enzalutamide, giving rise to treatment resistance. Further elucidation of 3βHSD1 regulatory mechanisms will shed light on more approaches for disease intervention. We also review the recent advance on 3βHSD1 inhibitors and targeting 3βHSD1 for prostate cancer management. Novel 3βHSD1 inhibitors will be needed to provide additional options for prostate cancer management.

CONCLUSION

3βHSD1 is both a predictive biomarker and a promising therapeutic target for prostate cancer.

BMX controls 3βHSD1 and sex steroid biosynthesis in cancer

Prostate cancer is highly dependent on androgens and the androgen receptor (AR). Hormonal therapies inhibit gonadal testosterone production, block extragonadal androgen biosynthesis, or directly antagonize AR. Resistance to medical castration occurs as castration-resistant prostate cancer (CRPC) and is driven by reactivation of the androgen-AR axis. 3β-hydroxysteroid dehydrogenase-1 (3βHSD1) serves as the rate-limiting step for potent androgen synthesis from extragonadal precursors, thereby stimulating CRPC. Genetic evidence in men demonstrates the role of 3βHSD1 in driving CRPC. In postmenopausal women, 3βHSD1 is required for synthesis of aromatase substrates and plays an essential role in breast cancer. Therefore, 3βHSD1 lies at a critical junction for the synthesis of androgens and estrogens, and this metabolic flux is regulated through germline-inherited mechanisms. We show that phosphorylation of tyrosine 344 (Y344) occurs and is required for 3βHSD1 cellular activity and generation of Δ4, 3-keto-substrates of 5α-reductase and aromatase, including in patient tissues. BMX directly interacts with 3βHSD1 and is necessary for enzyme phosphorylation and androgen biosynthesis. In vivo blockade of 3βHSD1 Y344 phosphorylation inhibits CRPC. These findings identify what we believe to be new hormonal therapy pharmacologic vulnerabilities for sex-steroid dependent cancers.

A phosphorylation switch controls androgen biosynthesis in prostate cancer

Androgen biosynthesis enzyme 3β-hydroxysteroid dehydrogenase type 1 (3βHSD1) encoded by HSD3B1 has emerged as a potential driver for therapeutic resistance in prostate cancer. Patients with homozygous HSD3B1(1245C) inheritance are intrinsically more resistant to currently available androgen/androgen receptor-targeting (AR-targeting) drugs. In this issue of the JCI, Li et al. present data on the regulation of 3βHSD1 phosphorylation and activity by tyrosine kinase BMX. Inhibition of BMX activity by genetic or pharmacologic approaches blocked androgen biosynthesis in prostate cancer cells and inhibited tumor growth in preclinical xenograft models. The findings provide insights into mechanisms underlying castration resistance in prostate cancer and reveal a potential strategy to circumvent therapeutic resistance in patients with homozygous HSD3B1(1245C) inheritance.

Androgen Receptor Signaling Inhibition in Advanced Castration Resistance Prostate Cancer: What Is Expected for the Near Future?

The androgen signaling pathway is the cornerstone in the treatment of high risk or advanced prostate cancer patients. However, in recent years, different mechanisms of resistance have been defined in this field, limiting the efficacy of the currently approved antiandrogen drugs. Different therapeutic approaches are under research to assess the role of combination therapies against escape signaling pathways or the development of novel antiandrogen drugs to try to solve the primary or acquired resistance against androgen dependent or independent pathways. The present review aims to summarize the current state of androgen inhibition in the therapeutic algorithm of patients with advanced prostate cancer and the mechanisms of resistance to those available drugs. In addition, this review conducted a comprehensive overview of the main present and future research approaches in the field of androgen receptor inhibition to overcome these resistances and the potential new drugs under research coming into this setting.

Serum prolactin level as a predictive factor for abiraterone response in patients with metastatic castration-resistant prostate cancer

BACKGROUND

To investigate the prognostic value and potential therapeutic target of the baseline serum hormones in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone.

METHODS

This retrospective study was performed in patients with mCRPC receiving abiraterone acetate (AA) from July 2016 to September 2020. Patients who had serum hormone tests within 2 weeks before AA treatment were included. Univariate analysis and Cox regression were performed to evaluate the correlation of sex hormones with progression-free survival (PFS) and overall survival (OS). Prolactin (PRL) expression in the clinical specimens was evaluated by immunohistochemistry. Bone metastases were quantified by automated Bone Scan Index (aBSI).

RESULTS

The study included 61 patients with a median follow-up of 19.0 months. Patients with lower baseline PRL levels (median) responded better to AA than those with higher baseline PRL levels as indicated by prostate-specific antigen (PSA) reduction (PSA90, 66.7% vs. 25.8%, p = 0.001), PFS (19.6 vs. 7.9 months), and OS (52.8 vs. 19.2 months). Cox regression adjusted for clinical factors also confirmed that baseline PRL level was an independent predictive factor for PFS (hazard ratio = 1.096, p = 0.007). Prostatic PRL expression increased as the disease progressed. PRL expression was also detected in biopsy samples from bone metastasis but not in normal bone tissue, and the serum PRL levels were positively correlated with aBSIs (r = 0.28, p = 0.037).

CONCLUSIONS

Serum PRL levels are predictive of response to AA in patients with mCRPC. Serum PRL levels are positively correlated with the volume of metastatic bone disease.

Association Between Adrenal-Restrictive HSD3B1 Inheritance and Hormone-Independent Subtypes of Endometrial and Breast Cancer

BACKGROUND

The germline variant rs1047303 (HSD3B1[1245A/C]), restricting or enabling production of potent androgens and estrogens from adrenal precursors, affects outcomes of castration-resistant prostate cancer and is associated with estrogen receptor positivity in postmenopausal breast cancer. Like breast cancer, endometrial cancer is another malignancy with hormone-dependent and hormone-independent subtypes. We hypothesized that adrenal-restrictive HSD3B1 genotype would associate with hormone-independent cancer subtypes.

METHODS

We employed a previously described classification of tumors in The Cancer Genome Atlas into genomic clusters. We determined HSD3B1 genotype frequencies by endometrial cancer genomic cluster and calculated the odds per adrenal-restrictive A allele for the largely hormone-independent copy-number (CN) high subtype vs other subtypes. An equivalent analysis was performed for the genomically similar, hormone-independent basal breast cancer subtype. Last, we performed survival analyses for UK Biobank participants with endometrial cancer by HSD3B1 genotype. All statistical tests were 2-sided.

RESULTS

The adrenal-restrictive HSD3B1(1245A) allele was associated with the CN-high endometrial cancer subtype (odds ratio [OR] = 1.63, 95% confidence interval [CI] = 1.14 to 2.32; P = .007). Similarly, HSD3B1(1245A) was associated with the basal breast cancer subtype (OR = 1.54, 95% CI = 1.13 to 2.08; P = .006). In the UK Biobank, endometrial cancer patients homozygous for HSD3B1(1245A) had worse overall (hazard ratio [HR] = 1.39, 95% CI = 1.16 to 1.68; P < .001) and cancer-specific (HR = 1.39, 95% CI = 1.14 to 1.70; P = .001) survival, consistent with the A allele being enriched in the more aggressive CN-high subtype.

CONCLUSIONS

These findings suggest roles for adrenal-restrictive vs adrenal-permissive steroidogenesis, by way of rs1047303 genotype, in the development of and/or outcomes from at least 3 commonly hormone-associated types of cancer: prostate, breast, and endometrial.

P1245 Polymorphic Variants of HSD3B1 Gene Confer Different Outcome in Specific Subgroups of Patients Infected With SARS-CoV-2

Introduction: Severe respiratory syndrome coronavirus 2 (SARS-CoV-2) uses the androgen receptor (AR), through ACE2 receptor and TMPRSS2, to enter nasal and upper airways epithelial cells. Genetic analyses revealed that HSD3B1 P1245C polymorphic variant increases dihydrotestosterone production and upregulation of TMPRSS2 with respect to P1245A variant, thus possibly influencing SARS-CoV-2 infection. Our aim was to characterize the HSD3B1 polymorphism status and its potential association with clinical outcomes in hospitalized patients with COVID-19 in Southern Switzerland.

Materials and Methods: The cohort included 400 patients hospitalized for COVID-19 during the first wave between February and May 2020 in two different hospitals of Canton Ticino. Genomic DNA was extracted from formalin-fixed paraffin-embedded tissue blocks, and HSD3B1 gene polymorphism was evaluated by Sanger sequencing. Statistical associations were verified using different test.

Results:HSD3B1 polymorphic variants were not associated with a single classical factor related to worse clinical prognosis in hospitalized patients with SARS-CoV-2. However, in specific subgroups, HSD3B1 variants played a clinical role: intensive care unit admission was more probable in patients with P1245C diabetes compared with P1245A individuals without this comorbidity and death was more associated with hypertensive P1245A>C cases than patients with P1245A diabetes without hypertension.

Discussion: This is the first study showing that HSD3B1 gene status may influence the severity of SARS-CoV-2 infection. If confirmed, our results could lead to the introduction of HSD3B1 gene status analysis in patients infected with SARS-CoV-2 to predict clinical outcome.

Management of prostate cancer by targeting 3βHSD1 after enzalutamide and abiraterone treatment

Novel strategies for prostate cancer therapy are required to overcome resistance to abiraterone and enzalutamide. Here, we show that increasing 3βHSD1 after abiraterone and enzalutamide treatment is essential for drug resistance, and biochanin A (BCA), as an inhibitor of 3βHSD1, overcomes drug resistance. 3βHSD1 activity increases in cell lines, biopsy samples, and patients after long-term treatment with enzalutamide or abiraterone. Enhanced steroidogenesis, mediated by 3βHSD1, is sufficient to impair enzalutamide function. In patients, accelerated abiraterone metabolism results in a decline of plasma abiraterone as disease progresses. BCA inhibits 3βHSD1 and suppresses prostate cancer development alone or together with abiraterone and enzalutamide. Daidzein, a BCA analog of dietary origin, is associated with higher plasma abiraterone concentrations and prevented prostate-specific antigen (PSA) increases in abiraterone-resistant patients. Overall, our results show that 3βHSD1 is a promising target to overcome drug resistance, and BCA suppresses disease progression as a 3βHSD1 inhibitor even after abiraterone and enzalutamide resistance.

Inhibiting 3βHSD1 to eliminate the oncogenic effects of progesterone in prostate cancer

Prostate cancer continuously progresses following deprivation of circulating androgens originating from the testis and adrenal glands, indicating the existence of oncometabolites beyond androgens. In this study, mass-spectrometry-based screening of clinical specimens and a retrospective analysis on the clinical data of prostate cancer patients indicate the potential oncogenic effects of progesterone in patients. High doses of progesterone activate canonical and non-canonical androgen receptor (AR) target genes. Physiological levels of progesterone facilitate cell proliferation via GATA2. Inhibitors of 3β-hydroxysteroid dehydrogenase 1 (3βHSD1) has been discovered and shown to suppress the generation of progesterone, eliminating its transient and accumulating oncogenic effects. An increase in progesterone is associated with poor clinical outcomes in patients and may be used as a predictive biomarker. Overall, we demonstrate that progesterone acts as an oncogenic hormone in prostate cancer, and strategies to eliminate its oncogenic effects may benefit prostate cancer patients.

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High doses of progesterone activate canonical and non-canonical AR signaling

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Progesterone of physiological levels exerts its chronic oncogenic effect via GATA2

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Targeting 3βHSD1 to suppress progesterone synthesis blocks its oncogenic effects

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Serum progesterone might be a predictive biomarker for abiraterone response

Clinical impact of HSD3B1 polymorphism by metastatic volume and somatic HSD3B1 alterations in advanced prostate cancer

This study aimed to investigate the significance of HSD3B1 gene status including germline polymorphism and somatic alterations in prostate cancer. Patients with prostate cancer treated with androgen-deprivation therapy, as well as tissues from metastatic prostate cancer, were included. Genomic DNA was extracted from cancer tissues and whole blood samples, and HSD3B1 (rs1047303, 1245C) was genotyped by Sanger sequencing. The association of HSD3B1 genotype with progression-free survival according to metastatic volume was examined. Copy number alteration and gene expression of HSD3B1 were examined in prostate cancer cells and public datasets. Among 194 patients, 121 and 73 patients were categorized into low- and high-volume diseases respectively. In multivariate analysis, the adrenal-permissive genotype (AC/CC) was significantly associated with increased risk of progression compared with the adrenal-restrictive genotype (AA) in low volume, but not high-volume diseases. Somatic mutation in HSD3B1 was detected at least in two cases of castration-resistant prostate cancer tissues. HSD3B1 amplification and overexpression were detected in castration-resistant prostate cancer cells and tissues. The current findings suggest that both germline and somatic alterations of HSD3B1 may cooperatively promote castration resistance in prostate cancer and HSD3B1 as a promising biomarker for precision medicine, warranting further investigations.

Circulating and Intratumoral Adrenal Androgens Correlate with Response to Abiraterone in Men with Castration-Resistant Prostate Cancer

PURPOSE

In metastatic castration-resistant prostate cancer (mCRPC) low serum androgens prior to starting abiraterone acetate (AA) is associated with more rapid progression. We evaluated the effect of AA on androgens in castration-resistant prostate cancer (CRPC) metastases and associations of intratumoral androgens with response.

EXPERIMENTAL DESIGN

We performed a phase II study of AA plus prednisone in mCRPC. The primary outcome was tissue testosterone at 4 weeks. Exploratory outcomes were association of steroid levels and genomic alterations with response, and escalating AA to 2,000 mg at progression.

RESULTS

Twenty-nine of 30 men were evaluable. Testosterone in metastatic biopsies became undetectable at 4 weeks (P < 0.001). Serum and tissue dehydroepiandrosterone sulfate (DHEAS) remained detectable in many patients and was not increased at progression. Serum and tissue DHEAS in the lowest quartile (pretreatment), serum DHEAS in the lowest quartile (4 weeks), and undetectable tissue DHEAS (on-therapy) associated with rapid progression (20 vs. 48 weeks, P = 0.0018; 20 vs. 52 weeks, P = 0.0003; 14 vs. 40 weeks, P = 0.0001; 20 vs. 56 weeks, P = 0.02, respectively). One of 16 men escalating to 2,000 mg had a 30% PSA decline; 13 developed radiographic progression by 12 weeks. Among patients with high serum DHEAS at baseline, wild-type (WT) PTEN status associated with longer response (61 vs. 33 weeks, P = 0.02).

CONCLUSIONS

Low-circulating adrenal androgen levels are strongly associated with an androgen-poor tumor microenvironment and with poor response to AA. Patients with CRPC with higher serum DHEAS levels may benefit from dual androgen receptor (AR)-pathway inhibition, while those in the lowest quartile may require combinations with non-AR-directed therapy.

A New Old Target: Androgen Receptor Signaling and Advanced Prostate Cancer

Owing to the development of multiple novel therapies, there has been major progress in the treatment of advanced prostate cancer over the last two decades; however, the disease remains invariably fatal. Androgens and the androgen receptor (AR) play a critical role in prostate carcinogenesis, and targeting the AR signaling axis with abiraterone, enzalutamide, darolutamide, and apalutamide has improved outcomes for men with this lethal disease. Targeting the AR and elucidating mechanisms of resistance to these agents remains central to drug development efforts. This review provides an overview of the evolution and current approaches for targeting the AR in advanced prostate cancer. It describes the biology of AR signaling, explores AR-targeting resistance mechanisms, and discusses future perspectives and promising novel therapeutic strategies. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 62 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Clinical implications of genomic alterations in metastatic prostate cancer

There has been a rapid expansion in treatment options for the management of metastatic prostate cancer, but individual patient outcomes can be variable due to inter-patient tumor heterogeneity. Fortunately, the disease can be stratified on the basis of common somatic features, providing potential for the development of clinically useful prognostic and predictive biomarkers. Tissue biopsy programs and studies leveraging circulating tumor DNA (ctDNA) have revealed specific genomic alterations that are associated with aggressive disease biology. In this review, we discuss the potential for genomic subtyping to improve prognostication and to help guide treatment selection. We summarize data on associations between AR pathway alterations and patient response to AR signaling inhibitors and other standards of care. We describe the links between detection of different types of DNA damage repair defects and clinical outcomes with targeted therapies such as poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors or immune checkpoint inhibitors. PI3K signaling pathway inhibitors are also in advanced clinical development and we report upon the potential for these and other novel targeted therapies to have impact in specific molecular subsets of metastatic prostate cancer. Finally, we discuss the growing use of blood-based analytes for prognostic and predictive biomarker development, and summarize ongoing prospective biomarker-driven clinical trials.

Androgens in prostate cancer: A tale that never ends

Androgens play an essential role in prostate cancer. Clinical treatments that target steroidogenesis and the androgen receptor (AR) successfully postpone disease progression. Abiraterone and enzalutamide, the next-generation androgen receptor pathway inhibitors (ARPI), emphasize the function of the androgen-AR axis even in castration-resistant prostate cancer (CRPC). However, with the increased incidence in neuroendocrine prostate cancer (NEPC) showing resistance to ARPI, the importance of androgen-AR axis in further disease management remains elusive. Herein we review the steroidogenic pathways associated with different disease stages and discuss the potential targets for disease management after manifesting resistance to abiraterone and enzalutamide.

Hormonal Therapy for Prostate Cancer

Huggins and Hodges demonstrated the therapeutic effect of gonadal testosterone deprivation in the 1940s and therefore firmly established the concept that prostate cancer is a highly androgen-dependent disease. Since that time, hormonal therapy has undergone iterative advancement, from the types of gonadal testosterone deprivation to modalities that block the generation of adrenal and other extragonadal androgens, to those that directly bind and inhibit the androgen receptor (AR). The clinical states of prostate cancer are the product of a superimposition of these therapies with nonmetastatic advanced prostate cancer, as well as frankly metastatic disease. Today's standard of care for advanced prostate cancer includes gonadotropin-releasing hormone agonists (e.g., leuprolide), second-generation nonsteroidal AR antagonists (enzalutamide, apalutamide, and darolutamide) and the androgen biosynthesis inhibitor abiraterone. The purpose of this review is to provide an assessment of hormonal therapies for the various clinical states of prostate cancer. The advancement of today's standard of care will require an accounting of an individual's androgen physiology that also has recently recognized germline determinants of peripheral androgen metabolism, which include HSD3B1 inheritance.

Genetic Polymorphisms and Pharmacotherapy for Prostate Cancer

The therapeutic landscape of pharmacotherapy for prostate cancer has dramatically evolved, and multiple therapeutic options have become available for prostate cancer patients. Therefore, useful biomarkers to identify suitable candidates for treatment are required to maximize the efficacy of pharmacotherapy. Genetic polymorphisms such as single-nucleotide polymorphisms (SNPs) and tandem repeats have been shown to influence the therapeutic effects of pharmacotherapy for prostate cancer patients. For example, genetic polymorphisms in the genes involved in androgen receptor signaling are reported to be associated with the therapeutic outcome of androgen-deprivation therapy as well as androgen receptor-pathway inhibitors. In addition, SNPs in genes involved in drug metabolism and efflux pumps are associated with therapeutic effects of taxane chemotherapy. Thus, genetic polymorphisms such as SNPs are promising biomarkers to realize personalized medicine. Here, we overview the current findings on the influence of genetic polymorphisms on the outcome of pharmacotherapy for prostate cancer and discuss current issues as well as future visions in this field.