Citations

Abstract Background: Obesity is a well established risk factor not only for increased prostate cancer incidence, but for poorer survival from prostate cancer. However, there is limited knowledge on the role of the circulating lipidome in prostate cancer. In order to target lipid metabolism optimally, it is critical to understand the spectrum of changes in circulating lipid profiles and the association with clinical outcome across the natural history of prostate cancer. Aim: To assess the relationship between the plasma lipidome and clinical outcome in localized and metastatic prostate cancer. Methods: Liquid chromatography-tandem mass spectrometry was used to quantitate over 500 lipid species in plasma samples from 3 cohorts (1) 389 men with localized prostate cancer, (2) 44 men with metastatic hormone-sensitive prostate cancer (mHSPC), and (3) 137 men with metastatic castration-resistant prostate cancer (CRPC). Associations between circulating lipids with metastatic relapse, androgen-deprivation therapy (ADT) failure or overall survival for each relevant disease stage were examined by latent class analysis and cox regression. Results: Circulating lipid profiles displaying elevated levels of ceramides were associated with metastatic relapse in localized prostate cancer (HR 5.8, 95% CI 3.0-11, P 1 × 10−6), early ADT failure in mHSPC (HR 2.4, 95% CI 1.1-5.3, P 0.03), and shorter overall survival in CRPC (HR 2.5, 95% CI 1.7-3.7, P 2 × 10−6). ADT failure in mHSPC and shorter overall survival in CRPC were also associated with elevated levels of other sphingolipids (sphingomyelins, hexosylceramides). The prognostic significance of the high risk lipid profiles in localized prostate cancer was independent of clinicopathological characteristics (lipid profile HR 4.7, 95%CI 2.4-9.3, P 7 × 10−6) when modeled with Gleason score (P<0.0001) and pathological stage (P<0.0001). Furthermore, the circulating lipid profiles were independent of metabolic factors (localized prostate cancer lipid profile HR 8.2, 95% CI 2.6-25, P 0.0003 when modeled with diabetes, statin, hypertension, body mass index [BMI]; CRPC lipid profile HR 2.6, 95% CI 1.7-3.8, P x10−6 when modeled with BMI). Conclusion: Elevated circulating ceramides are associated with poorer clinical outcomes across the natural history of prostate cancer (from localized to metastatic hormone-sensitive to metastatic castration resistant prostate cancer). This demonstrates that aberrant lipid metabolism in the patients occurs early in prostate cancer and could be therapeutically targeted in prospective clinical trials to improve prostate cancer outcomes. Citation Format: Lisa Glen Horvath, Hui-Ming Lin, Blossom Mak, Kate Mahon, Nicole Yeung, Maria Docanto, Peter Sutherland, andrew Shepherd, Winston Tan, Arun Azad, Manish Kohli, Peter Meikle, Lisa Butler. Lipidomic analysis of circulating lipids across the natural history of prostate cancer identifies aberrant ceramide metabolism [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4761.

Abstract Background: Androgen receptor (AR) amplification is a common genomic event in advanced prostate cancer, in particular, the metastatic castration-resistant prostate cancer (mCRPC) and is associated with poor treatment response and short overall survival (OS). Recent studies also show more frequent amplification at AR enhancer region in the mCRPC patients. The aim of this study is to evaluate clinical utility of multiplex digital PCR assay to detect amplification at AR locus in cell-free DNA (cfDNA) for prognostication of mCRPC. Methods: Plasma samples were collected from 108 patients with mCRPC before stage-specific treatment. The target regions were selected based on our previous sequencing data showing frequent amplification in mCRPC patients at AR loci, including AR enhancer, AR (AR exon 1 and exon 8) and OPHN1 (downstream of AR). Multiplex digital PCR assays to detect four targets were developed by adjusting the concentrations of primers and probes. The Kaplan-Meier (KM) estimate was used for OS analysis. Results: We first examined existing databases to determine relative stable genomic regions in prostate cancer. This analysis showed most stable regions in three gene loci including C2orf16 at 2p23.2, FAM111B at 11q12.1, and GRIA3 at Xq25, which were then used as reference controls for copy number normalization. We then designed two multiplex digital PCR assays to quantify copy number of selected targets. To separate two different targets with same fluorescence, we adjusted ratio of FAM-labeled probes with 1: 0.4 and HEX-labeled probes with 1:0.4. The ratio of FAM to HEX probes was 1:1.5 in final assays. The combination of four different targets in one reaction gave 9 possible clusters in the 2D amplitude space. We defined the amplification as the normalized ratio ≥ 1.8 between target and reference loci. By applying this cutoff in 108 mCRPC samples, we detected the amplification of AR-enhancer, AR and OPHN1 in 38, 34, and 25 samples, respectively. KM analysis showed the significant association of amplification in AR-enhancer (p=0.0053, HR=2.16[1.41-6.53]), AR (p=0.04, HR=1.74[1.04-4.03]) and OPHN1 (p=0.031, HR=1.91[1.07-5.53]) with OS. This result was consistent with whole genome sequencing data in the same group of patients. Conclusions: We established a highly sensitive multiplex digital PCR assay to detect copy number changes of AR, AR enhancer and OPHN1 in plasma cfDNA and demonstrated its potential clinical use as non-invasive testing tool for mCRPC prognosis. The easy-to-use and low-cost multiplex digital PCR assay covers multiple gene loci, which can aid in improving the sensitivity of detecting amplification at AR locus in the highly heterogeneous mCRPC patients. Citation Format: Meijun Du, Chiang-Ching Huang, Winston Tan, Manish Kohli, Liang Wang. Clinical utility of multiplex digital PCR to detect androgen receptor amplification in cell-free DNA for prognosis of metastatic castration-resistant prostate cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4319.

Objective: High plasma ceramide levels and ratios are associated with poor outcomes in individuals with cardiovascular disease; less is known about their relation to cerebral small vessel disease. We examined whether high plasma ceramide levels or ratios were associated with cerebral microbleeds (CMBs) and lacunes and whether associations differ by sex. Approach and Results: We included 548 participants enrolled in the MCSA (Mayo Clinic Study of Aging) with concurrent plasma ceramide assays and magnetic resonance imaging. CMBs were quantified on T2* magnetic resonance imaging and lacunes on T2 fluid-attenuated inversion recovery magnetic resonance imaging. Fasting plasma ceramides were assayed using liquid chromatography-electrospray ionization tandem mass spectrometry. We used logistic regression models adjusting for age, sex, hypertension, and diabetes mellitus to examine the relationship between ceramides and presence of a lacune; hurdle models were used for presence and number of CMBs. Each SD increase in the log ceramide C16:0/24:0 ratio was associated with greater odds of a CMB (odds ratio, 1.28 [95% CI, 1.01–1.64]). There was an interaction between sex and the ceramide C16:0/24:0 ratio ( P =0.049). The association between this ratio and presence of a CMB was stronger for women (odds ratio, 1.87 [95% CI, 1.20–3.00]) than men (odds ratio, 1.09 [95% CI, 0.80–1.46]). Several ceramides and all ceramide ratios were associated with number of CMBs. We did not find associations between plasma ceramides and lacunes. Conclusions: In a population-based sample, the plasma ceramide C16:0/24:0 ratio was associated with CMBs and was stronger for women. Plasma ceramides are differentially associated with cerebral small vessel pathologies.

1020 Background: Trastuzumab-containing regimes have dramatically improved outcome of patients with HER2+ breast cancer. Efforts to improve efficacy and tolerability of combination regimens with this monoclonal antibody are important for patient care. Thus, we conducted a multi-institutional phase II study of a triplet combination in patients eligible to receive either first- or second-line treatment for HER2+ metastatic breast cancer (MBC). Methods: A phase II study designed to test that the true confirmed response rate (CRR) was at most 45% versus a true CRR of at least 65% was done (March 2005-June 2008). This design required that at least 25/45 confirmed responses in evaluable patients for the treatment to be considered promising. Patients received capecitabine 825 mg/m2 po (days 1–14), vinorelbine intravenously (IV) 25 mg/m2 days 1 and 8 every 3 weeks and trastuzumab IV 8mg/kg day 1, week 1, and then 6 mg/kg q 3 weeks. Tissue and blood have been collected for future studies on biomarkers. Results: 47 women were accrued, one patient cancelled participation prior to receiving any study drug, and another had a major protocol violation. 45 patients were evaluable and 30 (67%) achieved a confirmed response, (26 patients, 58% had a confirmed partial response and 4 patients, 9% had a confrimed complete response). Median progression free survival was 11.3 months (95% CI 8.4–23.2 months), median overall survival was 27.2 months (95% CI: 26.6-NA months), and among the 30 responders, the median duration of response time was 15.5 months (95% 7.7–26.1 months). The most common grade 3 events include neutropenia 61%, fatigue 13%, skin reaction-hand-foot 11%, and leukopenia 11%. Alopecia was not noted with this regimen. Conclusions: This triplet combination is effective, safe, and is promising in patients with HER2+ MBC. A phase III study should be conducted to compare the best doublet with this triplet combination whether this would lead to better clinical outcomes. [Table: see text]

Triple-negative breast cancer (TNBC), characterized by the absence or low expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (HER2), is the most aggressive subtype of breast cancer. TNBC accounts for about 15% of breast cancer cases in the U.S., and is known for high relapse rates and poor overall survival (OS). Chemo-resistant TNBC is a genetically diverse, highly heterogeneous, and rapidly evolving disease that challenges our ability to individualize treatment for incomplete responders and relapsed patients. Currently, the frontline standard chemotherapy, composed of anthracyclines, alkylating agents, and taxanes, is commonly used to treat high-risk and locally advanced TNBC. Several FDA-approved drugs that target programmed cell death protein-1 (Keytruda) and programmed death ligand-1 (Tecentriq), poly ADP-ribose polymerase (PARP), and/or antibody drug conjugates (Trodelvy) have shown promise in improving clinical outcomes for a subset of TNBC. These inhibitors that target key genetic mutations and specific molecular signaling pathways that drive malignant tumor growth have been used as single agents and/or in combination with standard chemotherapy regimens. Here, we review the current TNBC treatment options, unmet clinical needs, and actionable drug targets, including epidermal growth factor (EGFR), vascular endothelial growth factor (VEGF), androgen receptor (AR), estrogen receptor beta (ERβ), phosphoinositide-3 kinase (PI3K), mammalian target of rapamycin (mTOR), and protein kinase B (PKB or AKT) activation in TNBC. Supported by strong evidence in developmental, evolutionary, and cancer biology, we propose that the K-RAS/SIAH pathway activation is a major tumor driver, and SIAH is a new drug target, a therapy-responsive prognostic biomarker, and a major tumor vulnerability in TNBC. Since persistent K-RAS/SIAH/EGFR pathway activation endows TNBC tumor cells with chemo-resistance, aggressive dissemination, and early relapse, we hope to design an anti-SIAH-centered anti-K-RAS/EGFR targeted therapy as a novel therapeutic strategy to control and eradicate incurable TNBC in the future.

AbstractBackgroundSpinal cord stimulation (SCS) has been shown to provide pain relief for chronic back and leg pain due to failed back surgery syndrome. But many patients with chronic back pain have not had major back surgery or are not good candidates for surgery, and conventional medical management (CMM) provides limited relief. We have termed this condition nonsurgical refractory back pain (NSRBP). Level 1 evidence does not yet exist showing the therapeutic benefit of SCS for NSRBP.ObjectiveTo compare 10‐kHz SCS plus CMM (10‐kHz SCS + CMM) to CMM alone for treatment of NSRBP in terms of clinical and cost effectiveness.Study DesignMulticenter, randomized controlled trial (RCT), with subjects randomized 1:1 to either 10‐kHz SCS + CMM or CMM alone. Optional crossover occurs at 6 months if treatment does not achieve ≥50% pain relief.MethodsPatients with NSRBP as defined above may be enrolled if they are ineligible for surgery based on surgical consultation. Subjects randomized to 10‐kHz SCS + CMM will receive a permanent implant if sufficient pain relief is achieved in a temporary trial. Both groups will receive CMM per standard of care and will undergo assessments at baseline and at follow‐ups to 12 months. Self‐report outcomes include pain, disability, sleep, mental health, satisfaction, healthcare utilization, and quality of life.ResultsEnrollment was initiated on September 10, 2018. Prespecified independent interim analysis at 40% of the enrollment target indicated the sample size was sufficient to show superiority of treatment at the primary endpoint; therefore, enrollment was stopped at 211.ConclusionsThis large multicenter RCT will provide valuable evidence to guide clinical decisions in NSRBP.

Abstract New approaches are needed to overcome intrinsic therapy resistance in glioblastoma (GBM). Because GBMs exhibit sexual dimorphism and are reported to express steroid hormone receptors, we reasoned that signaling through the androgen receptor (AR) could mediate therapy resistance in GBM, much as it does in AR-positive prostate and breast cancers. We found that nearly half of GBM cell lines, patient-derived xenografts (PDX), and human tumors expressed AR at the transcript and protein level—with expression levels overlapping those of primary prostate cancer. Analysis of gene expression datasets also revealed that AR expression is higher in GBM patient samples than normal brain tissue. Multiple clinical-grade antiandrogens slowed the growth of and radiosensitized AR-positive GBM cell lines and PDXs in vitro and in vivo. Antiandrogens blocked the ability of AR-positive GBM PDXs to engage adaptive transcriptional programs following radiation and slowed the repair of radiation-induced DNA damage. These results suggest that combining blood–brain barrier permeable antiandrogens with radiation may have promise for patients with AR-positive GBMs.

Amplification of androgen receptor (AR) is a common genomic event in metastatic castration-resistant prostate cancer (mCRPC). To evaluate the prognostic value of the amplifications of specific loci in the AR gene in cell-free DNA, we developed a multiplex digital PCR (dPCR) assay that targeted AR enhancer (AR-En), AR exon 1 (AR-E1), AR exon 8 (AR-E8) and OPHN1 (downstream of AR). We selected three relatively stable genes, C2orf16, FAM111B, and GRIA3, as reference controls for copy number normalization. One hundred and eight mCRPC patients were recruited to test the association of specific AR loci amplification with clinical outcome. Using a normalized ratio ≥ 1.92 as cutoff, amplification of AR-En, AR-E1, AR-E8 and OPHN1 was observed in 28, 25, 24 and 19 of 108 mCRPC patients, respectively. Among the 41 patients with AR region amplification, 9 (21.9%) showed amplification at all four selected regions and 15 (36.6%) showed amplification at AR-En, AR-E1, and AR-E8. Six (14.6%) patients showed independent AR-En amplification, while the remaining 3 (7.3%) demonstrated AR-E8 amplification only. Kaplan–Meier analysis showed overall survival’s association with the amplification of AR-En (p = 0.02, HR = 1.68 (1.07–2.65)), AR-E8 (p = 0.02, HR = 1.78 (1.08–2.92)) and AR-En-E8 (the combination of AR-En and AR-E8 (p = 0.009, HR = 1.77 (1.15–2.73)). Multivariate models that included AR-En-E8 amplification and clinical factors significantly improved prognostic performance (p = 0.0001). With further validation, the multiplex dPCR assay may assist in prognostication of mCRPC patients.

Abstract Background The risk factors for development of viremia in high-risk donor cytomegalovirus (CMV)-seropositive and recipient CMV-seronegative (D+R−) transplant recipients are incompletely defined. Methods The study population comprised patients in the preemptive therapy (PET) arm of a randomized, controlled trial of PET versus prophylaxis using valganciclovir in D+R− liver transplant recipients. Weekly surveillance monitoring for viremia for 100 days was performed using a sensitive CMV-DNA polymerase chain reaction assays. Risk factors for viremia and time to onset (≤4 vs >4 weeks) of viremia were examined using logistic regression models. Results Viremia developed in 84% (79/94) of recipients and older donor age was the only independent factor associated with viremia (odds ratio, 2.20 for each quartile increase in donor age; 95% confidence interval [CI], 1.07–4.52; P = .031). Recipients who developed early-onset viremia (within 4 weeks) also had significantly older donors than those with later-onset viremia (difference in age 10.1 years; 95% CI, 2–19; P = .03). Conclusions Older donor age was an independent predictor of viremia and earlier-onset of viremia in D+R− liver transplant recipients. Future studies should assess the mechanistic links underlying this novel association. Clinical Trial Registration NCT01552369.