Association of PARP inhibitor treatment on the prevalence and progression of clonal hematopoiesis in patients with advanced prostate cancer.

BACKGROUND: Poly ADP-ribose polymerase (PARP) inhibitors are approved for the treatment of some men with advanced prostate cancer. Rare but serious side effects include myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). The impact of PARP inhibitors on clonal hematopoiesis (CH), a potential precursor lesion associated with MDS and AML, is incompletely understood in prostate cancer. We hypothesized that PARP inhibitors would increase CH prevalence and abundance. METHODS: We prospectively enrolled participants with advanced prostate cancer treated with PARP inhibitors. The presence of CH was assessed from leukocytes using an ultra-deep error-corrected dual unique molecular identifiers sequencing method targeting 49 genes most commonly mutated in CH and myeloid malignancies. Variant allele frequencies (VAF) of ≥0.5% were considered clinically significant. Blood samples were collected before and after PARP inhibitor treatment. RESULTS: Ten men were enrolled; mean age of 67 years. Six patients had Gleason 7 disease, and four had Gleason ≥8 disease at diagnosis. Nine had localized disease at diagnosis, and eight had prior treatment with radiation. The mean time between pre- and post-treatment blood samples was 11 months (range 2.6-31 months). Six patients (60%) had CH identified prior to PARP inhibitor treatment, three with multiple clones. Of 11 CH clones identified in follow-up, 5 (45%) appeared or increased after treatment. DNMT3A, TET2, and PPM1D were the most common CH alterations observed. The largest post-treatment increase involved the PPM1D gene. CONCLUSION: CH alterations are frequently found after treatment with PARP inhibitors in patients with prostate cancer and this may be one mechanism by which PARP inhibitors lead to increased risk of MDS/AML.

PROMISE Registry: A prostate cancer registry of outcomes and germline mutations for improved survival and treatment effectiveness.

BACKGROUND: Recently approved treatments and updates to genetic testing recommendations for prostate cancer have created a need for correlated analyses of patient outcomes data via germline genetic mutation status. Genetic registries address these gaps by identifying candidates for recently approved targeted treatments, expanding clinical trial data examining specific gene mutations, and understanding effects of targeted treatments in the real-world setting. METHODS: The PROMISE Registry is a 20-year (5-year recruitment, 15-year follow-up), US-wide, prospective genetic registry for prostate cancer patients. Five thousand patients will be screened through an online at-home germline testing to identify and enroll 500 patients with germline mutations, including: pathogenic or likely pathogenic variants and variants of uncertain significance in genes of interest. Patients will be followed for 15 years and clinical data with real time patient reported outcomes will be collected. Eligible patients will enter long-term follow-up (6-month PRO surveys and medical record retrieval). As a virtual study with patient self-enrollment, the PROMISE Registry may fill gaps in genetics services in underserved areas and for patients within sufficient insurance coverage. RESULTS: The PROMISE Registry opened in May 2021. 2114 patients have enrolled to date across 48 US states and 23 recruiting sites. 202 patients have met criteria for long-term follow-up. PROMISE is on target with the study's goal of 5000 patients screened and 500 patients eligible for long-term follow-up by 2026. CONCLUSIONS: The PROMISE Registry is a novel, prospective, germline registry that will collect long-term patient outcomes data to address current gaps in understanding resulting from recently FDA-approved treatments and updates to genetic testing recommendations for prostate cancer. Through inclusion of a broad nationwide sample, including underserved patients and those unaffiliated with major academic centers, the PROMISE Registry aims to provide access to germline genetic testing and to collect data to understand disease characteristics and treatment responses across the disease spectrum for prostate cancer with rare germline genetic variants.

Cost-Effectiveness of Systemic Treatments for Metastatic Castration-Sensitive Prostate Cancer: An Economic Evaluation Based on Network Meta-Analysis.

OBJECTIVES: To assess the cost-effectiveness of systemic treatments for metastatic castration-sensitive prostate cancer from the US healthcare sector perspective with a lifetime horizon. METHODS: We built a partitioned survival model based on a network meta-analysis of 7 clinical trials with 7287 patients aged 36 to 94 years between 2004 and 2018 to predict patient health trajectories by treatment. We tested parameter uncertainties with probabilistic sensitivity analyses. We estimated drug acquisition costs using the Federal Supply Schedule and adopted generic drug prices when available. We measured cost-effectiveness by an incremental cost-effectiveness ratio (ICER). RESULTS: The mean costs were approximately $392 000 with androgen deprivation therapy (ADT) alone and approximately $415 000, $464 000, $597 000, and $959 000 with docetaxel, abiraterone acetate, enzalutamide, and apalutamide, added to ADT, respectively. The mean quality-adjusted life-years (QALYs) were 3.38 with ADT alone and 3.92, 4.76, 3.92, and 5.01 with docetaxel, abiraterone acetate, enzalutamide, and apalutamide, added to ADT, respectively. As add-on therapy to ADT, docetaxel had an ICER of $42 069 per QALY over ADT alone; abiraterone acetate had an ICER of $58 814 per QALY over docetaxel; apalutamide had an ICER of $1 979 676 per QALY over abiraterone acetate; enzalutamide was dominated. At a willingness to pay below $50 000 per QALY, docetaxel plus ADT is likely the most cost-effective treatment; at any willingness to pay between $50 000 and $200 000 per QALY, abiraterone acetate plus ADT is likely the most cost-effective treatment. CONCLUSIONS: These findings underscore the value of abiraterone acetate plus ADT given its relative cost-effectiveness to other systemic treatments for metastatic castration-sensitive prostate cancer.

Efficacy of systemic therapies in men with metastatic castration resistant prostate cancer harboring germline ATM versus BRCA2 mutations.

BACKGROUND: Among men with metastatic prostate cancer, about 10% have germline alterations in DNA damage response genes. Most studies have examined BRCA2 alone or an aggregate of BRCA1/2 and ATM. Emerging data suggest that ATM mutations may have distinct biology and warrant individual evaluation. The objective of this study is to determine whether response to prostate cancer systemic therapies differs between men with germline mutations in ATM (gATM) and BRCA2 (gBRCA2). METHODS: This is an international multicenter retrospective matched cohort study of men with prostate cancer harboring gATM or gBRCA2. PSA50 response (≥50% decline in prostate-specific antigen) was compared using Fisher's exact test. RESULTS AND LIMITATIONS: The study included 45 gATM and 45 gBRCA2 patients, matched on stage and year of germline testing. Patients with gATM and gBRCA2 had similar age, Gleason grade, and PSA at diagnosis. We did not observe differences in PSA50 responses to abiraterone, enzalutamide, or docetaxel in metastatic castration resistant prostate cancer between the two groups; however, 0/7 with gATM and 12/14 with gBRCA2 achieved PSA50 response to PARPi (p < .001). Median (95% confidence interval) overall survival from diagnosis to death was 10.9 years (9.5-not reached) versus 9.9 years (7.1-not reached, p = .07) for the gATM and gBRCA2 cohorts, respectively. Limitations include the retrospective design and lack of mutation zygosity data. CONCLUSIONS: Conventional therapies can be effective in gATM carriers and should be considered before PARPi, which shows limited efficacy in this group. Men with gATM mutations warrant prioritization for novel treatment strategies.

The Society for Integrative Oncology Practice Recommendations for online consultation and treatment during the COVID-19 pandemic.

OBJECTIVE: The Society for Integrative Oncology (SIO) Online Task Force was created in response to the challenges facing continuity of integrative oncology care resulting from the COVID-19 pandemic. The Task Force set out to guide integrative oncology practitioners in providing effective and safe online consultations and treatments for quality-of-life-concerns and symptom management. Online treatments include manual, acupuncture, movement, mind-body, herbal, and expressive art therapies. METHODS: The SIO Online Practice Recommendations employed a four-phase consensus process: (1) literature review and discussion among an international panel of SIO members, identifying key elements essential in an integrative oncology visit; (2) development, testing, and refinement of a questionnaire defining challenges and strategies; (3) refinement input from integrative oncology experts from 19 countries; and (4) SIO Executive Committee review identifying the most high-priority challenges and strategies. RESULTS: The SIO Online Practice Recommendations address ten challenges, providing practical suggestions for online treatment/consultation. These include overcoming unfamiliarity, addressing resistance among patients and healthcare practitioners to online consultation/treatment, exploring ethical and medical-legal aspects, solving technological issues, preparing the online treatment setting, starting the online treatment session, maintaining effective communication, promoting specific treatment effects, involving the caregiver, concluding the session, and ensuring continuity of care. CONCLUSIONS: The SIO Online Practice Recommendations are relevant for ensuring continuity of care beyond the present pandemic. They can be implemented for patients with limited accessibility to integrative oncology treatments due to geographic constraints, financial difficulties, physical disability, or an unsupportive caregiver. These recommendations require further study in practice settings.

A phase II randomized trial of RAdium-223 dichloride and SABR Versus SABR for oligomEtastatic prostate caNcerS (RAVENS).

BACKGROUND: Metastasis directed therapy (MDT) for patients with oligometastatic disease is associated with improvements in progression free survival (PFS) and overall survival (OS) compared to systemic therapy alone. Additionally, within a prostate-cancer-specific cohort, MDT is able to forestall initiation of androgen deprivation therapy (ADT) in men with hormone-sensitive, oligometastatic prostate cancer (HSOPCa) compared to observation. While MDT appears to be safe and effective in HSOPCa, a large percentage of men will eventually have disease recurrence. Patterns of failure in HSOPCa demonstrate patients tend to have recurrence in the bone following MDT, raising the question of sub-clinically-apparent osseous disease. Radium-223 dichloride is a radiopharmaceutical with structural similarity to calcium, allowing it to be taken up by bone where it emits alpha particles, and therefore might have utility in the treatment of micrometastatic osseous disease. Therefore, the primary goal of the phase II RAVENS trial is to evaluate the efficacy of MDT + radium-223 dichloride in prolonging progression free survival in men with HSOPCa. METHODS: Patients with HSOPCa and 3 or less metastases with at least 1 bone metastasis will be randomized 1:1 to stereotactic ablative radiation (SABR, also known as stereotactic body radiation therapy (SBRT)) alone vs SABR + radium-223 dichloride with a minimization algorithm to balance assignment by institution, primary intervention, prior hormonal therapy, and PSA doubling time. SABR is delivered in one to five fractions and patients in the SABR + radium-223 dichloride arm will receive six infusions of radium-223 dichloride at four-week intervals. The primary end point is progression free survival. The secondary clinical endpoints include toxicity and quality of life assessments, local control at 12 months, locoregional progression, time to distant progression, time to new metastasis, and duration of response. DISCUSSION: The RAVENS trial will be the first described phase II, non-blinded, randomized study to compare SABR +/- radium-223 dichloride in patients with HSOPCa and 3 or less metastases with at least one bone metastasis. The primary hypothesis is that SABR + radium-223 dichloride will increase median progression-free survival from 10 months in the SABR arm to 20 months in the SABR + radium-223 dichloride arm. TRIAL REGISTRATIONS: Clinicaltrials.gov. Identifier: NCT04037358. Date of Registration: July 30, 2019. Date of First Participant Enrolled: August 9, 2019. Date of Last Approved Amendment: October 16, 2019. Protocol Version: Version 5.

A pilot study of prostate-specific membrane antigen (PSMA) dynamics in men undergoing treatment for advanced prostate cancer.

BACKGROUND: Prostate-specific membrane antigen (PSMA) is a rational target for noninvasive detection of recurrent prostate cancer (PCa) and for therapy of metastatic castration-resistant prostate cancer (mCRPC) with PSMA-targeted agents. Here we conducted serial measurements of PSMA expression on circulating tumor cells (CTCs) to evaluate patterns of longitudinal PSMA dynamics over the course of multiple sequential therapies. METHODS: A retrospective investigation of men with mCRPC undergoing evaluation at medical oncology clinics at our institution assessed the dynamics of PSMA expression in the context of different systemic treatments administered sequentially. Eligibility included patients who began systemic therapies with androgen receptor (AR)-directed agents or taxane agents for whom peripheral blood samples were tested for CTC mRNA of AR splice variant-7 (AR-V7), prostate-specific antigen (PSA), and PSMA (with >2 CTC + results) in a CLIA-accredited laboratory. RESULTS: From August 2015 to November 2017, we identified 96 eligible men. Fifteen had greater than or equal to 2 sequential therapies and evaluable CTC samples, greater than or equal to 1 expressing PSMA (PSMA+). Among the 15 patients included in this analysis, a total of 54 PSMA status evaluations were performed in the context of 48 therapies during a median follow-up of 18 months. At baseline, PSMA signal was detected ("positive") in 11 of 15 (73.3%) patients, while for 4 of 15 (26.7%) patients PSMA signal was undetectable ("negative"). In all but two patients, the baseline collection corresponded with a change in treatment. On the second assessment, PSMA increases were detected in all 4/4 (100%) PSMA-negative patients and 8 of 11 (72.7%) PSMA-positive patients. PSMA significantly decreased in a patient treated with 177 Lu-PSMA-617. Serum PSA declines were seen in 7 of 8 (88%) of the treatment periods where PSMA decreased. CONCLUSIONS: PSMA expression in CTCs is a dynamic marker. PSMA transcript declines appear to be associated with concurrent decreases in serum PSA. Sequential CTC sampling could provide a noninvasive response assessment to systemic treatment for mCRPC.

Bipolar androgen therapy in men with metastatic castration-resistant prostate cancer after progression on enzalutamide: an open-label, phase 2, multicohort study.

BACKGROUND: Prostate cancer that progresses after enzalutamide treatment is poorly responsive to further antiandrogen therapy, and paradoxically, rapid cycling between high and low serum testosterone concentrations (bipolar androgen therapy [BAT]) in this setting might induce tumour responses. We aimed to evaluate BAT in patients with metastatic castration-resistant prostate cancer that progressed after enzalutamide. METHODS: We did this single-centre, open-label, phase 2, multicohort study in the USA. We included patients aged 18 years or older who had histologically confirmed and radiographically documented metastatic castration-resistant prostate cancer, with no more than two previous second-line hormonal therapies, and a castrate concentration of testosterone. Patients were asymptomatic, with Eastern Cooperative Oncology Group performance status of 0-2, and did not have high-risk lesions for tumour flare (eg, >5 sites of visceral disease or bone lesions with impending fracture). For the cohort reported here, we required patients to have had progression on enzalutamide with a continued prostate-specific antigen (PSA) rise after enzalutamide treatment discontinuation. Patients received BAT, which consisted of intramuscular testosterone cipionate 400 mg every 28 days until progression and continued luteinising hormone-releasing hormone agonist therapy. Upon progression after BAT, men were rechallenged with oral enzalutamide 160 mg daily. The co-primary endpoints were investigator-assessed 50% decline in PSA concentration from baseline (PSA50) for BAT (for all patients who received at least one dose) and for enzalutamide rechallenge (based on intention-to-treat analysis). These data represent the final analysis for the post-enzalutamide cohort, while two additional cohorts (post-abiraterone and newly castration-resistant prostate cancer) are ongoing. The trial is registered with ClinicalTrials.gov, number NCT02090114. FINDINGS: Between Aug 28, 2014, and May 18, 2016, we accrued 30 eligible patients and treated them with BAT. Nine (30%; 95% CI 15-49; p<0·0001) of 30 patients achieved a PSA50 to BAT. 29 patients completed BAT and 21 proceeded to enzalutamide rechallenge, of whom 15 (52%; 95% CI 33-71; p<0·0001) achieved a PSA50 response. During BAT, the only grade 3-4 adverse event occurring in more than one patient was hypertension (three [10%] patients). Other grade 3 or worse adverse events occurring during BAT in one [3%] patient each were pulmonary embolism, myocardial infarction, urinary obstruction, gallstone, and sepsis. During enzalutamide retreatment, no grade 3-4 toxicities occurred in more than one patient. No treatment-related deaths were reported during either BAT or enzalutamide retreatment. INTERPRETATION: BAT is a safe therapy that resulted in responses in asymptomatic men with metastatic castration-resistant prostate cancer and also resensitisation to enzalutamide in most patients undergoing rechallenge. Further studies with BAT are needed to define the potential clinical role for BAT in the management of metastatic castration-resistant prostate cancer and the optimal strategy for sequencing between androgen and antiandrogen therapies in metastatic castration-resistant prostate cancer to maximise therapeutic benefit to patients. FUNDING: National Institutes of Health and National Cancer Institute.

Risk factors for metastatic prostate cancer: A sentinel event case series.

BACKGROUND: Root cause analysis is a technique used to assess systems factors related to "sentinel events"-serious adverse events within healthcare systems. This technique is commonly used to identify factors, which allowed these adverse events to occur, to target areas for improvement and to improve health care delivery systems. We sought to apply this technique to men presenting with metastatic prostate cancer (PCa). METHODS: We performed an in-depth case series analysis of 15 patients, who presented with metastatic disease at Johns Hopkins Sidney Kimmel Comprehensive Cancer Center using root cause analysis to refine a list of health system factors that lead to late stage presentation in the current era. RESULTS: Key factors in late diagnosis of PCa included lack of insurance, lack of routine PSA testing, comorbidities, reticence of patients to follow up actionable PSA, and aggressive disease. Three patients had aggressive disease that would not have been discovered at an early stage in the disease process, despite routine screening. However, analysis of the remaining 12 patients illuminated health system factors led to missing important diagnostic information, which might have led to diagnosis of PCa at a curable stage. CONCLUSIONS: The cases help highlight the need for systems based approaches to early diagnosis of PCa. A heterogeneous group of barriers to early diagnosis were identified in our series of patients including economic, health systems, and cultural factors. These findings underscore the need for individualized approaches to preventing delayed diagnosis of PCa. While limited by our single-institution scope, this approach provides a model for research and quality improvement initiatives to identify modifiable systems factors impeding appropriate diagnoses of PCa.

AR-V7 and resistance to enzalutamide and abiraterone in prostate cancer.

BACKGROUND: The androgen-receptor isoform encoded by splice variant 7 lacks the ligand-binding domain, which is the target of enzalutamide and abiraterone, but remains constitutively active as a transcription factor. We hypothesized that detection of androgen-receptor splice variant 7 messenger RNA (AR-V7) in circulating tumor cells from men with advanced prostate cancer would be associated with resistance to enzalutamide and abiraterone. METHODS: We used a quantitative reverse-transcriptase-polymerase-chain-reaction assay to evaluate AR-V7 in circulating tumor cells from prospectively enrolled patients with metastatic castration-resistant prostate cancer who were initiating treatment with either enzalutamide or abiraterone. We examined associations between AR-V7 status (positive vs. negative) and prostate-specific antigen (PSA) response rates (the primary end point), freedom from PSA progression (PSA progression-free survival), clinical or radiographic progression-free survival, and overall survival. RESULTS: A total of 31 enzalutamide-treated patients and 31 abiraterone-treated patients were enrolled, of whom 39% and 19%, respectively, had detectable AR-V7 in circulating tumor cells. Among men receiving enzalutamide, AR-V7-positive patients had lower PSA response rates than AR-V7-negative patients (0% vs. 53%, P=0.004) and shorter PSA progression-free survival (median, 1.4 months vs. 6.0 months; P<0.001), clinical or radiographic progression-free survival (median, 2.1 months vs. 6.1 months; P<0.001), and overall survival (median, 5.5 months vs. not reached; P=0.002). Similarly, among men receiving abiraterone, AR-V7-positive patients had lower PSA response rates than AR-V7-negative patients (0% vs. 68%, P=0.004) and shorter PSA progression-free survival (median, 1.3 months vs. not reached; P<0.001), clinical or radiographic progression-free survival (median, 2.3 months vs. not reached; P<0.001), and overall survival (median, 10.6 months vs. not reached, P=0.006). The association between AR-V7 detection and therapeutic resistance was maintained after adjustment for expression of full-length androgen receptor messenger RNA. CONCLUSIONS: Detection of AR-V7 in circulating tumor cells from patients with castration-resistant prostate cancer may be associated with resistance to enzalutamide and abiraterone. These findings require large-scale prospective validation. (Funded by the Prostate Cancer Foundation and others.).

Prognostic factors for clinical outcomes in patients with metastatic castration resistant prostate cancer treated with sequential novel androgen receptor-directed therapies.

BACKGROUND: Prognostic factors associated with clinical outcomes in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with a novel androgen receptor-directed therapies (ARDT) in the second line setting has not been formally evaluated. PATIENTS AND METHODS: We retrospectively reviewed and analyzed medical records of all patients with mCRPC who received sequential treatment with ARDT. We analyzed potential clinical factors associated with post treatment endpoints including 50% decline in prostatic-specific antigen (PSA), PSA-progression-free survival (PFS), clinical or radiographic PFS and overall survival (OS). Prognostic univariate and multivariate Cox proportional hazard models were developed and assessed. RESULTS: One hundred twenty-six patients with mCRPC treated with a second-line novel ARDT were included. Overall, 50% decline in PSA was observed in 22% of patients and a median PSA-PFS of 2.9 months and a PFS of 3.6 months. After adjusting for potential confounders including prior exposure to docetaxel and number of prior antiandrogen agents, time to development of CRPC was an independent factor associated with PSA-PFS (hazard ratio [HR]: 0.99; 95% confidence interval [CI]: 0.99-1; P = 0.02) and PFS (HR: 0.99; CI: 0.98-1; P= 0.01). PSA response (50% decline) to first-line novel ARDT correlated negatively with PSA-PFS with second-line novel ARDT (HR: 1.7; 95% CI: 1.14-2.53; P = 0.009) and lower pre-treatment levels of albumin were associated with shorter PFS (HR: 0.56; 95% CI: 0.32-0.97; P = 0.03). Performance status, pre-treatment levels of albumin, extent of disease and time to development CRPC were associated with OS. CONCLUSIONS: Second-line ARDT is associated with modest outcomes in patients with mCRPC. Time to development of CRPC is the strongest predictor of PSA response, PSA-PFS and OS which suggest that intrinsic resistance to AR directed treatment is the major treatment outcome factor in these patients. Future studies in patients receiving long term ARTD should include the identification of predictive biomarkers to facilitate treatment selection.

Phytotherapeutic interventions in the management of biochemically recurrent prostate cancer: a systematic review of randomised trials.

OBJECTIVE: To evaluate the evidence from randomised trials for the efficacy and safety of phytotherapeutic interventions in the management of biochemically recurrent (BCR) prostate cancer, indicated by prostate-specific antigen (PSA) progression, numbers progressing to/time to initiation of androgen-deprivation therapy or salvage therapy. PATIENTS AND METHODS: MEDLINE (Ovid), EMBASE (Ovid), AMED (Ovid), CINAHL (EBSCO) and the Cochrane Library databases were searched. Clinical trials investigating phytotherapeutic interventions as dietary supplements or dietary components, including multi-component herbal formulations, in men with BCR prostate cancer were located. Eight of nine authors contacted for further information responded. Methodological quality was assessed using the Cochrane Collaboration's risk of bias assessment tool. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement for reporting systematic reviews was followed. RESULTS: Of 23 full-text articles assessed for eligibility, five met the criteria for inclusion. Two studies were placebo controlled; two were active control trials; and one a high-/low-dose trial. The interventions were administered as isolated phytochemicals (sulphoraphane), phytotherapeutic extracts [Pomi-T (pomegranate, turmeric, green tea and broccoli sprout extract), soy, lycopene, and POMx (pomegranate extract)], or plant-derived dietary items (soy and lycopene). All studies found serum PSA levels to stabilise, decrease or rise more slowly in a significant number of men, and three studies reported stabilising or lengthening of PSA-doubling time. Studies were generally of good quality, but sample sizes were predominantly small, and durations short. CONCLUSIONS: High-quality studies in this area are lacking. Sulphoraphane, lycopene, soy isoflavones, POMx, and Pomi-T are safe and well tolerated. There is limited evidence that they can affect PSA dynamics. No recommendation can be made for the use of these agents in managing prostate cancer morbidity and mortality until high-quality, fully powered studies are available. Recommendations are made for improving reproducibility and translation of findings with regard to study population, study endpoints, design, and the reporting of phytotherapeutic interventions.

Challenges of conducting clinical trials of natural products to combat cancer.

Numerous drugs that the US Food and Drug Administration (FDA) has approved for use in cancer therapy are derived from plants, including taxanes such as paclitaxel and vinca alkaloids such as vinblastine. Dietary supplements are another category of natural products that are widely used by patients with cancer, but without the FDA-reviewed evidence of safety and efficacy--be it related to survival, palliation, symptom mitigation, and/or immune system enhancement-that is required for therapy approval. Nearly half of patients in the United States with cancer report that they started taking new dietary supplements after being given a diagnosis of cancer. Oncologists are challenged in providing advice to patients about which supplements are safe and effective to use to treat cancer or the side effects of cancer therapy, and which supplements are antagonistic to standard treatment with chemotherapy, radiation, and/or immunotherapy. Despite the large number of trials that have been launched, the FDA has not approved any dietary supplement or food to prevent cancer, halt its growth, or prevent its recurrence. In this article, we review the primary challenges faced by researchers attempting to conduct rigorous trials of natural products, including shortages of funding due to lack of patentability, manufacturing difficulties, contamination, and lack of product consistency. We also highlight the methods used by dietary supplement marketers to persuade patients that a supplement is effective (or at least safe) even without FDA approval, as well as the efforts of the US government to protect the health and safety of its citizens by ensuring that the information used to market natural products is accurate. We close with a summary of the most widely used databases of information about the safety, efficacy, and interactions of dietary supplements.

A phase I study of muscadine grape skin extract in men with biochemically recurrent prostate cancer: Safety, tolerability, and dose determination.

BACKGROUND: New therapies are being explored as therapeutic options for men with biochemically recurrent prostate cancer (BRPC) who wish to defer androgen deprivation therapy. MPX is pulverized muscadine grape (Vitis rotundifolia) skin that contains ellagic acid, quercetin, and resveratrol and demonstrates preclinical activity against prostate cancer cells in vitro. METHODS: In the phase I portion of this phase I/II study, non-metastatic BRPC patients were assigned to increasing doses of MPX (Muscadine Naturals. Inc., Clemmons, NC) in cohorts of two patients, with six patients at the highest dose, using a modified continual reassessment method. Initial dose selection was based on preclinical data showing the equivalent of 500 to 4,000 mg of MPX to be safe in mouse models. The primary endpoint was the recommended phase II dosing regimen. RESULTS: The cohort (n = 14, 71% Caucasian, 29% black) had a median follow-up of 19.2 (6.2-29.7) months, median age of 61 years, and median Gleason score of 7. Four patients had possibly related gastrointestinal symptoms, including grade 1 flatulence, grade 1 soft stools, and grade 1 eructation. No other related adverse events were reported and one patient reported improvement of chronic constipation. Six of 14 patients came off study for disease progression (five metastatic, one rising PSA) after exposure for a median of 15 months. One patient came off for myasthenia gravis that was unrelated to treatment. Seven patients remain on study. The lack of dose-limiting toxicities led to the selection of 4,000 mg/d as the highest dose for further study. Median within-patient PSADT increased by 5.3 months (non-significant, P = 0.17). No patients experienced a maintained decline in serum PSA from baseline. CONCLUSION: These data suggest that 4,000 mg of MPX is safe, and exploratory review of a lengthening in PSADT of a median of 5.3 months supports further exploration of MPX. Both low-dose (500 mg) and high-dose (4,000 mg) MPX are being further investigated in a randomized, multicenter, placebo-controlled, dose-evaluating phase II trial.

Clinical activity of enzalutamide in Docetaxel-naïve and Docetaxel-pretreated patients with metastatic castration-resistant prostate cancer.

BACKGROUND: Two randomized clinical trials have demonstrated a survival advantage with enzalutamide over placebo in both docetaxel (D)-pretreated and D-naïve metastatic castration-resistant prostate cancer (mCRPC) patients. Cross-resistance between androgen receptor-directed therapies and taxanes has been suggested, possibly leading to lower efficacy of enzalutamide in the post-D setting. METHODS: We aimed to examine the impact of prior D treatment on the clinical activity of enzalutamide in patients with mCRPC. We retrospectively reviewed an institutional database to identify men with mCRPC treated with standard-of-care enzalutamide. Patients were classified as D-naïve or D-pretreated. The efficacy end points were prostate-specific antigen (PSA) response rates (≥ 50% PSA decline), time to PSA progression (TTPP) and clinical/radiographic progression-free survival (PFS) in response to enzalutamide. Differences between groups (D-naïve and D-pretreated) were assessed by univariate and multivariable analyses using logistic and Cox regression models. RESULTS: One-hundred-seven (107) consecutive patients were included: 60 were D-pretreated and 47 were D-naïve. PSA responses were 43.2% in D-naïve patients and 25.4% in D-pretreated patients (P = 0.089). Median TTPP was 7.2 months (95% CI = 4.5 - 17.2) in the D-naïve group versus 2.6 mo (95% CI = 1.9 - 3.5) in the D-pretreated group (P < 0.0001). Median PFS was not reached for D-naïve men and was 3.3 mo (95% CI = 2.5 - 4.8) for D-pretreated men (P < 0.0001). After adjusting for potential confounders including prior abiraterone use, differences remained statistically significant for TTPP (HR = 2.32; 95% CI = 1.19 - 4.50; P = 0.013) and marginally significant for PFS (HR = 1.90; 95% CI = 0.94 - 3.84; P = 0.073) in multivariable analyses. Among patients who achieved a PSA response to enzalutamide (n = 34), results suggested a trend towards shorter duration of response in D-pretreated patients. CONCLUSIONS: The clinical activity of enzalutamide appears to be blunted in patients who have previously received docetaxel chemotherapy. These results support the concept of cross-resistance between these two agents.

Therapeutic Approaches to Targeting Androgen Receptor Splice Variants.

Therapeutic options for advanced prostate cancer have vastly expanded over the last decade and will continue to expand in the future. Drugs targeting the androgen receptor (AR) signaling pathway, i.e., androgen receptor targeting agents (ARTAs), remain the mainstream treatments that are increasingly transforming the disease into one that can be controlled for an extended period of time. Prostate cancer is inherently addicted to AR. Under the treatment pressure of ARTA, molecular alterations occur, leading to the clonal expansion of resistant cells in a disease state broadly categorized as castration-resistant prostate cancer (CRPC). One castration resistance mechanism involves AR splice variants (AR-Vs) lacking the ligand-binding domain. Some AR-Vs have been identified as constitutively active, capable of activating AR signaling pathways without androgenic ligands. Among these variants, AR-V7 is the most extensively studied and may be measured non-invasively using validated circulating tumor cell (CTC) tests. In the context of the evolving prostate cancer treatment landscape, novel agents are developed and evaluated for their efficacy in targeting AR-V7. In patients with metastatic CRPC (mCRPC), the availability of the AR-V7 tests will make it possible to determine whether the treatments are effective for CTC AR-V7-positive disease, even though the treatments may not be specifically designed to target AR-V7. In this review, we will first outline the current prostate cancer treatment landscape, followed by an in-depth review of relatively newer prostate cancer therapeutics, focusing on AR-targeting agents under clinical development. These drugs are categorized from the standpoint of their activities against AR-V7 through direct or indirect mechanisms.

Phytonutrients and outcomes following breast cancer: a systematic review and meta-analysis of observational studies.

BACKGROUND: Phytonutrient intakes may improve outcomes following breast cancer, but the impact of postdiagnosis introduction vs established prediagnostic exposure as well as optimum doses has not been established. Evidence from observational studies for key exposures was evaluated, including dosage and intake time frames. METHODS: MEDLINE, EMBASE, CINAHL, Cochrane Library, ClinicalTrials.gov, and the ISRCTN registry were searched for prospective and retrospective observational studies investigating the impact of soybean, lignans, cruciferous (cabbage-family) vegetables, green tea, or their phytonutrients on breast cancer survival outcomes. A random-effects model was used to calculate summary hazard ratios (HRs) and 95% confidence intervals (CIs). Nonlinear dose-response analyses were conducted using restricted cubic splines. RESULTS: Thirty-two articles were included. Soy isoflavones were associated with a 26% reduced risk of recurrence (HR = 0.74, 95% CI = 0.60 to 0.92), particularly among postmenopausal (HR = 0.72, 95% CI = 0.55 to 0.94) and estrogen receptor-positive survivors (HR = 0.82, 95% CI = 0.70 to 0.97), with the greatest risk reduction at 60 mg/day. In mortality outcomes, the reduction was mostly at 20 to 40 mg/day. Soy protein and products were inversely associated with cancer-specific mortality for estrogen receptor-positive disease (HR = 0.75, 95% CI = 0.60 to 0.92). An inverse association was observed for serum or plasma enterolactone, measured prediagnosis and early postdiagnosis, with cancer-specific mortality (HR = 0.72, 95% CI = 0.58 to 0.90) and all-cause mortality (HR = 0.69, 95% CI = 0.57 to 0.83). No effects were observed for cruciferous vegetables. There was a 44% reduced risk of recurrence with prediagnostic green tea for stage I and II breast cancer (HR = 0.56, 95% CI = 0.38 to 0.83). CONCLUSIONS: Soy, enterolactone, and green tea demonstrated significant risk reductions in outcomes following breast cancer. Evidence is needed regarding the impact of postdiagnostic introduction or substantial increase of these exposures.

Abiraterone or Enzalutamide for Patients With Metastatic Castration-Resistant Prostate Cancer.

Importance: Abiraterone acetate and enzalutamide are recommended as preferred treatments for metastatic castration-resistant prostate cancer (mCRPC), but differences in their relative efficacy are unclear due to a lack of head-to-head clinical trials. Clear guidance is needed for making informed mCRPC therapeutic choices. Objective: To compare clinical outcomes in patients with mCRPC treated with abiraterone acetate or enzalutamide. Design, Setting, and Participants: This retrospective, multicenter cohort study included patients with mCRPC in the US Department of Veterans Affairs health care system who initiated treatment with abiraterone acetate or enzalutamide between January 1, 2014, and October 30, 2022. Exposures: Abiraterone acetate or enzalutamide. Main Outcomes and Measures: The study used inverse probability of treatment weighting to balance baseline characteristics between patients initiating abiraterone acetate or enzalutamide and evaluated restricted mean survival time (RMST) differences in overall survival (OS), prostate cancer-specific survival (PCS), time to next treatment switching or death (TTS), and time to prostate-specific antigen (PSA) response (TTR) at different time points after treatment initiation. Results: The study included 5779 patients (median age, 74.42 years [IQR, 68.94-82.14 years]). Median follow-up was between 38 and 60 months. Patients initiating enzalutamide on average had longer OS than those initiating abiraterone acetate, with RMSTs of 24.29 months (95% CI, 23.58-24.99 months) and 23.38 months (95% CI, 22.85-23.92 months), respectively, and a difference in RMST of 0.90 months (95% CI, 0.02-1.79 months) at 4 years. Similarly, TTS and TTR were improved in patients initiating enzalutamide, with an RMST at 4 years of 1.95 months (95% CI, 0.92-2.99 months) longer for TTS and 3.57 months (95% CI, 1.76-5.38 months) shorter for TTR. For PCS, the RMST at 2 years was 0.48 months (95% CI, 0.01-0.95 months) longer. An examination of subgroups identified that enzalutamide initiation was associated with longer RMST in OS among patients without prior docetaxel treatment (1.14 months; 95% CI, 0.19-2.10 months) and in those with PSA doubling time of 3 months or longer (2.23 months; 95% CI, 0.81-3.66 months) but not among patients with prior docetaxel (-0.25 months; 95% CI, -2.59 to 2.09 months) or with PSA doubling time of less than 3 months (0.05 months; 95% CI, -1.05 to 1.15 months). Conclusions and Relevance: In this cohort study of patients with mCRPC, initiation of enzalutamide was associated with small but statistically significant improvements in OS, PCS, TTS, and TTR compared with initiation of abiraterone acetate. The improvements were more prominent in short-term outcomes, including TTS and TTR, and in patient subgroups without prior docetaxel or with PSA doubling time longer than 3 months.

Pan-Cancer Interrogation of MUTYH Variants Reveals Biallelic Inactivation and Defective Base Excision Repair Across a Spectrum of Solid Tumors.

PURPOSE: Biallelic germline pathogenic variants of the base excision repair (BER) pathway gene MUTYH predispose to colorectal cancer (CRC) and other cancers. The possible association of heterozygous variants with broader cancer susceptibility remains uncertain. This study investigated the prevalence and consequences of pathogenic MUTYH variants and MUTYH loss of heterozygosity (LOH) in a large pan-cancer analysis. MATERIALS AND METHODS: Data from 354,366 solid tumor biopsies that were sequenced as part of routine clinical care were analyzed using a validated algorithm to distinguish germline from somatic MUTYH variants. RESULTS: Biallelic germline pathogenic MUTYH variants were identified in 119 tissue biopsies. Most were CRCs and showed increased tumor mutational burden (TMB) and a mutational signature consistent with defective BER (COSMIC Signature SBS18). Germline heterozygous pathogenic variants were identified in 5,991 biopsies and their prevalence was modestly elevated in some cancer types. About 12% of these cancers (738 samples: including adrenal gland cancers, pancreatic islet cell tumors, nonglioma CNS tumors, GI stromal tumors, and thyroid cancers) showed somatic LOH for MUTYH, higher rates of chromosome 1p loss (where MUTYH is located), elevated genomic LOH, and higher COSMIC SBS18 signature scores, consistent with BER deficiency. CONCLUSION: This analysis of MUTYH alterations in a large set of solid cancers suggests that in addition to the established role of biallelic pathogenic MUTYH variants in cancer predisposition, a broader range of cancers may possibly arise in MUTYH heterozygotes via a mechanism involving somatic LOH at the MUTYH locus and defective BER. However, the effect is modest and requires confirmation in additional studies before being clinically actionable.

CRM1 regulates androgen receptor stability and impacts DNA repair pathways in prostate cancer, independent of the androgen receptor.

Among the known nuclear exportins, CRM1 is the most studied prototype. Dysregulation of CRM1 occurs in many cancers, hence, understanding the role of CRM1 in cancer can help in developing synergistic therapeutics. The study investigates how CRM1 affects prostate cancer growth and survival. It examines the role of CRM1 in regulating androgen receptor (AR) and DNA repair in prostate cancer. Our findings reveal that CRM1 influences AR mRNA and protein stability, leading to a loss of AR protein upon CRM1 inhibition. Furthermore, it highlights the involvement of HSP90 alpha, a known AR chaperone, in the CRM1-dependent regulation of AR protein stability. The combination of CRM1 inhibition with an HSP90 inhibitor demonstrates potent effects on decreasing prostate cancer cell growth and survival. The study further explores the influence of CRM1 on DNA repair proteins and proposes a strategy of combining CRM1 inhibitors with DNA repair pathway inhibitors to decrease prostate cancer growth. Overall, the findings suggest that CRM1 plays a crucial role in prostate cancer growth, and a combination of inhibitors targeting CRM1 and DNA repair pathways could be a promising therapeutic strategy.