Assessment of the Validity of Nuclear-Localized Androgen Receptor Splice Variant 7 in Circulating Tumor Cells as a Predictive Biomarker for Castration-Resistant Prostate Cancer

Importance

A blood test to determine whether to treat patients with metastatic castration-resistant prostate cancer (mCRPC) with an androgen receptor signaling (ARS) inhibitor or taxane is an unmet medical need.

Objective

To determine whether a validated assay for the nuclear-localized androgen receptor splice variant 7 (AR-V7) protein in circulating tumor cells can determine differential overall survival among patients with mCRPC treated with taxanes vs ARS inhibitors.

Design, Setting, and Participants

This blinded correlative study conducted from December 31, 2012, to September 1, 2016, included 142 patients with histologically confirmed mCRPC and who were treated at Memorial Sloan Kettering Cancer Center, The Royal Marsden, or the London Health Sciences Centre. Blood samples were obtained prior to administration of ARS inhibitors or taxanes as a second-line or greater systemic therapy for progressing mCRPC.

Main Outcomes and Measures

Overall survival after treatment with an ARS inhibitor or taxane in relation to pretherapy AR-V7 status.

Results

Among the 142 patients in the study (mean [SD] age, 69.5 [9.6] years), 70 were designated as high risk by conventional prognostic factors. In this high-risk group, patients positive for AR-V7 who were treated with taxanes had superior overall survival relative to those treated with ARS inhibitors (median overall survival, 14.3 vs 7.3 months; hazard ratio, 0.62; 95% CI, 0.28-1.39; P = .25). Patients negative for AR-V7 who were treated with ARS inhibitors had superior overall survival relative to those treated with taxanes (median overall survival, 19.8 vs 12.8 months; hazard ratio, 1.67; 95% CI, 1.00-2.81; P = .05).

Conclusions and Relevance

This study suggests that nuclear-localized AR-V7 protein in circulating tumor cells can identify patients who may live longer with taxane chemotherapy vs ARS inhibitor treatment.

Validation of nuclear-localized AR-V7 on circulating tumor cells (CTC) as a treatment-selection biomarker for managing metastatic castration-resistant prostate cancer (mCRPC)

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Background: A previous analysis of 161 patients (pts) tested for nuclear-localized AR-V7(+) CTCs showed a therapy interaction between AR-V7 positivity and improved overall survival (OS) on taxane chemotherapy vs. androgen receptor signaling inhibitors (ARSI). To validate the use of the biomarker result for physician decision making, we prospectively analyzed an independent, multicenter, blinded, cross-sectional cohort (n = 225) to confirm a therapy interaction with AR-V7. We corrected for possible pt selection bias by the treating physician by analyzing the association of therapy to OS in low and high risk groups defined by the test cohort. Methods: Two analyses were performed: (1) the validation of a therapy interaction between AR-V7 positivity and superior OS benefit for pts treated with taxanes in the context of use for 2nd+ line pts; and (2) as the choice between ARSI or taxanes was at the discretion of the attending physician, pt risk was incorporated into the predictive biomarker assessment. A pt-specific risk score was developed from line of therapy and other covariates to stratify pts as low and high risk, and the association of AR-V7 status and OS was performed within each risk group to correct for physician decision making and address possible confounding with treatment assignment. Results: (1) A therapy interaction between AR-V7(+) pts and lower risk of death on taxanes vs. ARSI (HR: 0.23, p = 0.003, 95% CI: 0.09 – 0.61) was validated. (2) In the validation cohort, high risk AR-V7(+) pts had an OS benefit when treated with taxanes (p = 0.02) and the AR-V7(-) pts had an improved OS with ARSI therapy (p = 0.02). AR-V7 incidence was low in the low risk pts, precluding the analysis for this sub-cohort. Conclusions: The results validate that the nuclear-localized AR-V7(+) biomarker has an interaction with therapy and improved survival on taxanes. Further, when adjusting for pt risk, the biomarker is predictive of OS in the high risk group. Nuclear-localized AR-V7 protein in CTCs can aid in the decision between ARSI and taxane chemotherapy in the 2nd or greater line of therapy for mCRPC.

Phenotypic Heterogeneity of Circulating Tumor Cells Informs Clinical Decisions between AR Signaling Inhibitors and Taxanes in Metastatic Prostate Cancer

The heterogeneity of an individual patient's tumor has been linked to treatment resistance, but quantitative biomarkers to rapidly and reproducibly evaluate heterogeneity in a clinical setting are currently lacking. Using established tools available in a College of American Pathologists-accredited and Clinical Laboratory Improvement Amendments-certified clinical laboratory, we quantified digital pathology features on 9,225 individual circulating tumor cells (CTC) from 179 unique metastatic castration-resistant prostate cancer (mCRPC) patients to define phenotypically distinct cell types. Heterogeneity was quantified on the basis of the diversity of cell types in individual patient samples using the Shannon index and associated with overall survival (OS) in the 145 specimens collected prior to initiation of the second or later lines of therapy. Low CTC phenotypic heterogeneity was associated with better OS in patients treated with androgen receptor signaling inhibitors (ARSI), whereas high heterogeneity was associated with better OS in patients treated with taxane chemotherapy. Overall, the results show that quantifying CTC phenotypic heterogeneity can help inform the choice between ARSI and taxanes in mCRPC patients. Cancer Res; 77(20); 5687-98. ©2017 AACR.

Prospective Genomic Profiling of Prostate Cancer Across Disease States Reveals Germline and Somatic Alterations That May Affect Clinical Decision Making

PURPOSE

A long natural history and a predominant osseous pattern of metastatic spread are impediments to the adoption of precision medicine in patients with prostate cancer. To establish the feasibility of clinical genomic profiling in the disease, we performed targeted deep sequencing of tumor and normal DNA from patients with locoregional, metastatic non-castrate, and metastatic castration-resistant prostate cancer (CRPC).

METHODS

Patients consented to genomic analysis of their tumor and germline DNA. A hybridization capture-based clinical assay was employed to identify single nucleotide variations, small insertions and deletions, copy number alterations and structural rearrangements in over 300 cancer-related genes in tumors and matched normal blood.

RESULTS

We successfully sequenced 504 tumors from 451 patients with prostate cancer. Potentially actionable alterations were identified in DNA damage repair (DDR), PI3K, and MAP kinase pathways. 27% of patients harbored a germline or a somatic alteration in a DDR gene that may predict for response to PARP inhibition. Profiling of matched tumors from individual patients revealed that somatic TP53 and BRCA2 alterations arose early in tumors from patients who eventually developed metastatic disease. In contrast, comparative analysis across disease states revealed that APC alterations were enriched in metastatic tumors, while ATM alterations were specifically enriched in CRPC.

CONCLUSION

Through genomic profiling of prostate tumors representing the disease clinical spectrum, we identified a high frequency of potentially actionable alterations and possible drivers of disease initiation, metastasis and castration-resistance. Our findings support the routine use of tumor and germline DNA profiling for patients with advanced prostate cancer, for the purpose of guiding enrollment in targeted clinical trials and counseling families at increased risk of malignancy.

Baseline CTC subtype to predict outcomes on mCRPC patients (pts) receiving enzalutamide (E) compared to abiraterone (A)

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Background: Prior response to A or E does not predict sensitivity to E following A or A following E. The detection of AR-V7 predicts insensitivity to either drug, but identifies only a portion of non-responders. We previously identified 15 CTC subtypes based on unique phenotypic features in mCRPC pts, each with unique biology and different degree of likelihood of predicting resistance to either drug. Here we explored the relationship between individual subtypes and sensitivity to A vs. E, but not both. Methods: 107 pre-treatment blood samples from mCRPC pts starting A (n = 47) or E (n = 60) as a 1st or 2nd line of Tx were analyzed for CTCs utilizing the Epic Sciences platform. Samples were assayed for CTC subtypes based upon 15 pre-defined phenotypic CTC classifiers (Type A-O). Treatment outcomes were assessed by serial PSA changes and landmarked percent time of therapy progression on radiographs, and overall survival following either A or E. Cell type prevalence was also analyzed in relation to clinical outcomes, and subsets of the CTC subtypes subject to single cell NGS to ascertain genomic drivers common to each subtype. Results: CTCs were identified in 94% (101/107) of pt samples. One, cell Type K, found in 25% (27/107) of pts, was associated with a statistically significant inferior outcomes on E for all measures. Whereas similar outcomes were seen between K+ & K- pts treated with A. The distinct features of Cell Type K include a large nucleus, high nuclear entropy and high Nuclear/cytoplasmic AR terminal ratio; and a unique genomic profile enriched for cell cycle and DNA repair alterations relative to other CTC subtypes. Conclusions: The presence of specific CTC subtypes in pre-Rx phlebotomy samples associated with outcomes on A or E. A CTC subtype (Cell Type K) helped to identify pts with poor outcomes on E but not A vs. those without the cell type. Further biologic interrogation of K cells and ongoing clincial validation of the CTC subtype is planned. [Table: see text]

Changes in CTC burden and prevalence of specific CTC subtypes in mCRPC patients (pts) receiving alpharadin (Ra-223) as single agent or in combination with other therapuetics (Tx)

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Background: Ra-223 prolongs life in mCRPC pts with symptomatic osseous metastasis with inconsistent effects on PSA. Survival times are prolonged further when combined with Abi/Enza. Data from preclinical studies suggest that Ra-223 may sensitize tumors to DDR agents and/or biologic therapies. But predictive biomarkers of benefit to each or both combinationso are lacking. We studied CTC counts and the prevelance of specific CTC subtypes in patients before and following Ra-223 therapy, both as a single agent and in combination, to identify biomarkers of sensitivity and treatement efficacy, and effects of Ra-223 on tumor biology. Methods: Pre and ~4 week post RA-223 therapy blood samples were collected from 35 pts (2 samples each) given as a single agent (n = 20 pts) or in combination with other therapies (n = 15 pts, 9 w/ Enza, 5 w/ Abi, 1 w/ Taxane). Samples were processed and CTCs analyzed using the Epic Sciences platform. Total CTC count and the prevalence of specific CTC phenotypes present pre and post Rx were identified utilizing high content digital pathology and associated with therapy type and post-treatment change. Results: CTC declines were observed in 55% (11/20) and 60% (9/15) of pts treated with single agent and combination respectively. In Ra-223 alone pts, a novel CTC subtype (high N/C ratio, high nuclear area) was identified at baseline 11/20 samples (med = 33% of CTCs). Which was no longer detected in 10 (90%) of the pts treated. This contrasts with a second novel CTC subtype present at baseline in 4 pts (med CTC = 9%) that increased to 9 cases (med CTC = 18%) at follow-up. Conclusions: A subset of pts demonstrate post-therapy CTC declines following Ra-223 alone or in combination. A novel CTC subtype resolved by RA-223 in conjunction with total CTC kinetics may indicate pt benefit from Ra-223. A novel emergent CTC subtype has also been identified in pts already receiving Ra-223. Single CTC sequencing and protein analysys of these CTC subtypes are ongoing, and may help describe tumor evolution and sensitization to novel therapuetics.

Glucocorticoid receptor (GR) expression in circulating tumor cells (CTCs) to prognosticate overall survival (OS) for metastatic castration-resistant prostate cancer (mCRPC) patients (pts) treated with androgen receptor signaling inhibitors (ARSi)

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Background: Upregulation of GR protein expression in metastatic biopsies from pts with CRPC has previously been shown to correlate with resistance to enzalutamide and has been validated as a therapeutic target in pre-clinical studies. We sought to determine whether upregulated GR protein expression in CTCs from pts with progressing mCRPC predicted clinical outcomes following treatment with enzalutamide (E) or abiraterone (A). Methods: Pre-therapy blood samples from 54 pts with progressing mCRPC were subjected to CTC analysis using the Epic Sciences platform. Samples were examined to identify CK+ (CK+, CD45- cells, with intact nuclei, morph distinct) CTCs for GR protein expression. GR+ CTCs were defined as having expression greater than the 95th percentile of GR expression in the GR negative LNCAP cell line. Kaplan-Meier analysis was used to test the impact of GR+ CTCs on OS following treatment with A or E. A Cox proportional hazards model with CTC number and GR positivity was used in a multivariate analysis. Results: 37 out of 54 pts (69%) had detectable and viable CK+ CTCs. 28 out of 37 pts (76%) had CTCs with upregulated GR staining with a median of 6 GR+/CK+ cells/ml per patient (range 0.7 – 244 cells/ml). The OS of patients with GR+ CTCs treated with ARSi was significantly worse than that of patients without detectable GR+ CTCs (11.4 mo. vs NA, p < 0.01), an effect independent and additive to the presence of viable CTCs, a previously described prognostic biomarker (see Table). Conclusions: GR protein upregulation in CTCs can be detected in a significant percentage of pts with progressing mCRPC and the presence of GR+ CTCs predicts worse OS in response to ARSi. The data supports previously reported pre-clinical data proposing a pathogenic role for GR in mediating resistance to ARSi therapy. Detection of GR in patient CTCs may be a useful predictive biomarker to guide GR-directed therapies. [Table: see text]

Targeting reciprocal feedback inhibition: Apalutamide and everolimus in patients with metastatic castration-resistant prostate cancer (mCRPC)

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Background: Studies in xenograft CRPC and PTEN-deficient prostate cancer models have shown synergistic anti-tumor activity of next-generation anti-androgens such as apalutamide when combined with PI3K/mTOR inhibitors such as everolimus. (Carver B et al., Cancer Cell 2011) The primary hypothesis of this study was that the combination of apalutamide with everolimus would overcome resistance to prior hormonal therapy with abiraterone acetate and prednisone (AAP). Methods: The primary endpoint in mCRPC patients with prior AAP was to evaluate the safety, pharmacokinetics (PK), and recommended phase 2 dose (RP2D) of fixed dose apalutamide 240 mg po qd when combined with everolimus 5 mg po qd (cohort 1, n = 3) and everolimus 10 mg po qd (cohort 2, n = 6). The plan was to expand to treat 40 patients at the RP2D. Results: Nine patients were enrolled in phase 1. The PK for the combination was consistent with historical data of either drug given as monotherapy. The most common treatment related adverse events were < = grade 2 fatigue (67%), diarrhea (56%), and anorexia (56%). In cohort 2, 1 patient had a DLT of grade 3 rash. The median time on treatment was 17 weeks (range 7-51+). The best response was SD in all 9 patients. Patients came off study for: progression (n = 3), investigator choice (n = 3) and toxicity unrelated to treatment (n = 2). Seven patients had detectable CTCs at baseline (EPIC Sciences). One patient had a rise in CTC number that then converted to undetectable and remained on study 37 weeks. One out of 6 evaluable patients had PTEN loss in tissue at baseline (MSK IMPACT) and remained on study 12 weeks. One patient with prior AAP and enzalutamide exposure has remained on study 51+ weeks with a > 50% decline in PSA (PTEN pending). Conclusions: Although the combination of apalutamide and everolimus was safe and well tolerated, the treatment response was similar to historical data of AAP followed by apalutamide alone. (Rathkopf D et al., ASCO 2014) We elected to close this study before expansion in favor of evaluating novel AR/PI3K pathway combinations in patients who have not yet been exposed to AAP. Drug provided by Janssen and Novartis. Trial support: PCF and MSK Experimental Therapeutics Center. Clinical trial information: NCT02106507.

Single cell phenogenomic subtyping of circulating tumor cells (CTCs) identify intercellular tumor heterogeneity (het) and multiple resistance mechansisms in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC)

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Background: Genomic profiling of metastatic tumors can identify mCRPC pts w/ “actionable” targets. However, responses from this approach are infrequent and not durable, broadly attributed to intra-tumor and intrer-cellular het. We sought to understand relationships between single CTC phenotypic and genomic patterns present when starting ARSi or taxane therapy (Tx) to develop more effective biomarker-directed treatment approaches. Methods: 9225 CTCs from 319 blood samples from 179 mCRPC pts were detected and digital phenotypically profiled using the Epic Sciences platform. Unsupervised clustering revealed 15 phenotypic CTC subtypes based on digital pathology features (Type ‘A’-‘O’). Phenotypic diversity was determined by a Shannon index of these subtypes in pt samples. Next, 856 CTCs representing each subtype were individually whole genome sequenced for copy number variation and genomic instability, to define phenogenomic single cell profile and taxonomy. Tx outcomes were associated with CTC profiles. Results: Pre-therapy identification of certain CTC phenotypic subtypes was associated with poor overall survival (OS) following ARSi and/or taxanes. 5/15 subtypes existed primarily in pts w/ high CTC het (84-94%, Bonferroni adjusted p < 0.05, permutation test), and linked to amp of AR and cMYC, and loss of TP53 and PTEN. Clusters of genomic events were linked to phenotypic features (i.e. small cell CTC w/AuroraK & nMYC amp) and provide single cell phenogenomic associations with pathways such as AR/PTEN feedback and DNA repair machinery. Conclusions: Presence ofspecific CTC subtypes was associated w/ poor survival on ARSi and/or taxanes and may inform Tx selection. Identifying CTC subtypes present in high het samples can provide insight into individual pt disease evolution and potential approaches to maximize benefit. Longitudinal monitoring of CTC phenogenomics is being studied in novel Tx trials.[Table: see text]

Association of AR-V7 on Circulating Tumor Cells as a Treatment-Specific Biomarker With Outcomes and Survival in Castration-Resistant Prostate Cancer

Importance

A critical decision in the management of metastatic castration-resistant prostate cancer (mCRPC) is when to administer an androgen receptor signaling (ARS) inhibitor or a taxane.

Objective

To determine if pretherapy nuclear androgen-receptor splice variant 7 (AR-V7) protein expression and localization on circulating tumor cells (CTCs) is a treatment-specific marker for response and outcomes between ARS inhibitors and taxanes.

Design, Setting, and Participants

For this cross-sectional cohort study at Memorial Sloan Kettering Cancer Center, 265 men with progressive mCRPC undergoing a change in treatment were considered; 86 were excluded because they were not initiating ARS or taxane therapy; and 18 were excluded for processing time constraints, leaving 161 patients for analysis. Between December 2012 and March 2015, blood was collected and processed from patients with progressive mCRPC immediately prior to new line of systemic therapy. Patients were followed up to 3 years.

Main Outcomes and Measures

Prostate-specific antigen (PSA) response, time receiving therapy, radiographic progression-free survival (rPFS), and overall survival (OS).

Results

Overall, of 193 prospectively collected blood samples from 161 men with mCRPC, 191 were evaluable (128 pre-ARS inhibitor and 63 pretaxane). AR-V7-positive CTCs were found in 34 samples (18%), including 3% of first-line, 18% of second-line, and 31% of third- or greater line samples. Patients whose samples had AR-V7-positive CTCs before ARS inhibition had resistant posttherapy PSA changes (PTPC), shorter rPFS, shorter time on therapy, and shorter OS than those without AR-V7-positive CTCs. Overall, resistant PTPC were seen in 65 of 112 samples (58%) without detectable AR-V7-positive CTCs prior to ARS inhibition. There were statistically significant differences in OS but not in PTPC, time on therapy, or rPFS for patients with or without pretherapy AR-V7-positive CTCs treated with a taxane. A multivariable model adjusting for baseline factors associated with survival showed superior OS with taxanes relative to ARS inhibitors when AR-V7-positive CTCs were detected pretherapy (hazard ratio, 0.24; 95% CI, 0.10-0.57; P = .035).

Conclusions and Relevance

The results validate CTC nuclear expression of AR-V7 protein in men with mCRPC as a treatment-specific biomarker that is associated with superior survival on taxane therapy over ARS-directed therapy in a clinical practice setting. Continued examination of this biomarker in prospective studies will further aid clinical utility.

Nuclear-specific AR-V7 Protein Localization is Necessary to Guide Treatment Selection in Metastatic Castration-resistant Prostate Cancer

BACKGROUND

Circulating tumor cells (CTCs) expressing AR-V7 protein localized to the nucleus (nuclear-specific) identify metastatic castration-resistant prostate cancer (mCRPC) patients with improved overall survival (OS) on taxane therapy relative to the androgen receptor signaling inhibitors (ARSi) abiraterone acetate, enzalutamide, and apalutamide.

OBJECTIVE

To evaluate if expanding the positivity criteria to include both nuclear and cytoplasmic AR-V7 localization ("nuclear-agnostic") identifies more patients who would benefit from a taxane over an ARSi.

DESIGN, SETTING, AND PARTICIPANTS

The study used a cross-sectional cohort. Between December 2012 and March 2015, 193 pretherapy blood samples, 191 of which were evaluable, were collected and processed from 161 unique mCRPC patients before starting a new line of systemic therapy for disease progression at the Memorial Sloan Kettering Cancer Center. The association between two AR-V7 scoring criteria, post-therapy prostate-specific antigen (PSA) change (PTPC) and OS following ARSi or taxane treatment, was explored. One criterion required nuclear-specific AR-V7 localization, and the other required an AR-V7 signal but was agnostic to protein localization in CTCs.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES

Correlation of AR-V7 status to PTPC and OS was investigated. Relationships with survival were analyzed using multivariable Cox regression and log-rank analyses.

RESULTS AND LIMITATIONS

A total of 34 (18%) samples were AR-V7-positive using nuclear-specific criteria, and 56 (29%) were AR-V7-positive using nuclear-agnostic criteria. Following ARSi treatment, none of the 16 nuclear-specific AR-V7-positive samples and six of the 32 (19%) nuclear-agnostic AR-V7-positive samples had ≥50% PTPC at 12 weeks. The strongest baseline factor influencing OS was the interaction between the presence of nuclear-specific AR-V7-positive CTCs and treatment with a taxane (hazard ratio 0.24, 95% confidence interval 0.078-0.79; p=0.019). This interaction was not significant when nuclear-agnostic criteria were used.

CONCLUSIONS

To reliably inform treatment selection using an AR-V7 protein biomarker in CTCs, nuclear-specific localization is required.

PATIENT SUMMARY

We analyzed outcomes for patients with metastatic castration-resistant prostate cancer on androgen receptor signaling inhibitors and standard chemotherapy. Patients with circulating tumor cells that had AR-V7 protein in the cellular nuclei were very likely to survive longer on taxane-based chemotherapy, and tests unable to distinguish where the protein is located in the cell are not as predictive of benefit.

Abstract 4954: Nuclear localized AR-V7 protein as a predictive biomarker for treatment selection in metastatic castration resistant prostate cancer (mCRPC)

Background: A critical decision in the management of patients (pts) with mCRPC is when to administer an androgen receptor signaling (ARS) directed or a taxane therapy. The detection of AR-V7 mRNA in CTCs has been shown to predict for resistance to ARS,but not to taxane chemotherapy. We evaluated the relationship between AR-V7 protein expression and localization on CTCs to treatment outcomes in a separate, larger cohort as a predictive biomarker for clinical decision making.

Methods: 193 prospectively collected blood samples from 161 unique pts with progressive mCRPC about to start an ARS or taxane therapy were evaluated with an Epic Sciences CTC immunoflorescent assay that assesses CTC AR-V7 protein expression and localization in individual

cells. Associations between the presence AR-V7(+) CTCs pre-therapy and anti-tumor effects post-therapy included prostate-specific antigen (PSA) changes, radiographic progression free survival (rPFS), time on therapy, and overall survival (OS).

Results: 130 pre-ARS inhibitor and 63 pre-taxane samples were assessed of which 191 (99%) were evaluable. AR-V7(+) CTCs were found in 34 (18%) samples including 3% of the 1st, 18% of the 2nd and 31% of the 3rd+ line baseline pre-therapy samples. Patients with AR-V7 positive CTCs in a pre-ARS sample showed no PSA response and had shorter rPFS, time on therapy, and OS than those without AR-V7(+) CTCs. PSA resistance to ARS was also seen in 65 of 112 (58%) of the AR-V7(-) samples. There was no association between PSA response, rPFS, and time on therapy between AR-V7(+) and AR-V7(-) pts treated with taxane therapy. In a multivariate model adjusting for age, type of therapy, line of therapy, and pre-therapy LDH, Hgb, and presence of visceral metastasis, AR-V7(+) pts had a superior OS on taxane therapy relative to ARS (HR: 0.242, CI: 0.103 to 0.569, p = 0.0350). Conclusions: The results validate the expression of the AR-V7 protein in the nucleus of CTCs in men with mCRPC as a treatment specific biomarker that predicts resistance to ARS inhibitor therapy and separately, clinical benefit with taxane therapy over ARS-directed therapy in a clinical practice setting. Continued examination of this biomarker in prospective studies will further determine its clinical utility.

Citation Format: Howard I. Scher, David Lu, Nicole A. Schreiber, Jessica Louw, Ryon P. Graf, Ann Johnson, Adam Jendrisak, Glenn Heller, Richard Bambury, Herbert A. Vargas Alverez, Brigit McLaughlin, Justin Wahl, Stephanie Greene, Martin Fleisher, Ryan Dittamore. Nuclear localized AR-V7 protein as a predictive biomarker for treatment selection in metastatic castration resistant prostate cancer (mCRPC). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4954.

Single CTC characterization to identify phenotypic and genomic heterogeneity as a mechanism of resistance to AR signaling directed therapies (AR Tx) in mCRPC patients

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Background: AR directed Tx, including Abiraterone (A) and Enzalutamide (E), prolong survival in patients with mCRPC and are FDA approved. After primary Tx with either A or E, the response to E or A is decreased as is the duration of response. NGS tissue sequencing of mCRPC shows a range of disease phenotypes and genotypes which are associated with increased tumor heterogeneity. Single site biopsy, may not represent the diversity of disease. Our objective is to develop biomarkers of heterogeneity from the analysis of single cells from patients with mCRPC. Methods: 221 blood samples from 179 unique patients (pts) were collected from pts about to begin AR Tx (n = 150) or Taxanes (n = 71). Samples were analyzed with the Epic Sciences platform. Analysis included digital pathology of 20 discrete phenotypic cell features inclusive of AR, CK, size and shape measures. 9225 single CTCs were characterized, data standardized, features clustered and categorized into 15 phenotypically distinct CTC subtypes. Individual pt samples were then analyzed for the frequency and heterogeneity (Shannon Index) of CTC subtypes and monitored for clinical endpoints. A subset of CTCs (n = 350) were individually sequenced and analyzed for clonality and CNV to assess genomic heterogeneity. Results: A diversity of CTC phenotypes were observed at each line of therapy. In AR Tx pts, high heterogeneity predicts 6mo PFS (OR = 2.57, p = 0.01) and shorter OS (HR = 4.5, p < 0.001). Separately, specific CTC phenotypes also predict 6mo PFS (OR = 5, p < 0.001) and shorter OS (HR = 5.8, p < 0.001). Heterogeneity scores were not associated with taxane resistance. NGS analysis identified subclonal drivers of disease progression including multiple private and/or clustered genomic drivers. Conclusions: Single CTC characterization of phenotype and genotype supports the concept of tumor heterogeneity as a driver of disease resistance. The heterogeneity observed supports the potential value of single cell characterization to identify rare somatic sub-clonal alterations and can aid in the development of rational therapeutic trials.

Clinical validation of CTC subtype frequency to prognosis OS in mCRPC patients

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Background: CellSearch is an FDA cleared assay that enumerates intact CK+, DAPI+, CD45- cells via EpCAM capture. CTC number is prognostic for survival pre- and post- systemic therapy. These cells are a subset of confirmed genomically altered CTC’s in blood. We report the prognostic significance for OS in mCRPC of CTC subtypes not enumerated by CellSearch including apoptotic CTCs, CK- CTCs, small CTCs, and CTC clusters. Methods: 221 blood samples from 179 unique patients were collected from pts about to begin AR directed (n = 150) or taxane (n = 71) therapy for progressive CRPC. Samples were analyzed utilizing the Epic Sciences platform to enumerate traditional (CK+, abnormal morph), apoptotic (CK+, fragmented nuclei), CK- (CK-/abnormal morph), small (CK+, normal morph), and CTC clusters. Patients were followed for up to 2.3 yrs. Paired CellSearch and Epic traditional CTC counts were collected on 173 patient samples. Results: In paired analysis, Epic traditional CTCs were identified in 86% of patients vs. 67% by CellSearch, and any Epic CTC subtype was found in 96% of the patient samples. Increased frequency of any CTC subtype was a univariate predictor of OS (see table). Conclusions: Epic identified CTC subtypes not identified by CellSearch or other technologies that select or sort based upon size or epithelial expression. Cells were detected in 96% of the patient samples and all 5 subtypes were found to be prognostic for survival. The biologic characterization of CTC subtypes as a biomarker of drug sensitivity is ongoing. The increased clinical sensitivity of subtypes and prevalence of CTCs identified on the Epic platform provides a greatly expanded array of clinically relevant biomarkers to develop predictive liquid biopsy signatures in the metastatic setting. [Table: see text]

Genetic characterization of healthy and sebaceous adenitis affected Standard Poodles from the United States and the United Kingdom

The degree of heterogeneity associated with geographic origin and sebaceous adenitis (SA) status in Standard Poodles from the United States (US) and the United Kingdom (UK) was assessed. Healthy and SA-affected Standard Poodles from the US and the UK shared a major mitochondrial DNA (mtDNA) haplotype and a single Y chromosome haplotype. However, minor mtDNA haplotypes and frequencies were somewhat different between US and UK dogs and were significantly less associated with SA than major haplotypes across both populations. The US and UK populations exhibited recent divergence from a common gene pool, based on allele frequencies of 24 highly polymorphic short tandem repeats and principle coordinates and cluster analyses of genotype frequencies. However, there was no differentiation between SA affected and unaffected dogs. Over 90% of US and UK Poodles shared a common dog leukocyte antigen (DLA) class II haplotype, but showed some differentiation in minor haplotype frequency. No difference was observed in haplotype heterozygosity between SA affected and unaffected dogs from the same country and no disease association for SA was found within the DLA region by a high density single nucleotide polymorphism (SNP) scan. Zygosity mapping in the DLA region of Poodles indicated much lower site-specific diversity than in an outbred population of street dogs from Bali, Indonesia, reflecting the degree that breed associated historical bottlenecks have reduced diversity in a polymorphic region of the genome. This study shows possible pitfalls in more extensive genome-wide association studies, such as case and control numbers, population stratification, the involvement of multiple genes, and/or the possibility that SA susceptibility is fixed or nearly fixed within the breed, which can reduce power to detect genetic associations.

Estimated frequency of the canine hyperuricosuria mutation in different dog breeds

BACKGROUND

Hyperuricosuria is a condition that predisposes dogs to urate urolithiasis. A mutation that causes canine hyperuricosuria was previously identified in 3 unrelated dog breeds. The occurrence of the mutation in additional breeds was not determined.

HYPOTHESIS/OBJECTIVES

Identify additional breeds that have the hyperuricosuria mutation and estimate the mutant allele frequency in those breeds.

ANIMALS

Three thousand five hundred and thirty dogs from 127 different breeds were screened for the hyperuricosuria mutation.

METHODS

DNA samples were genotyped by pyrosequencing and allele-specific polymerase chain reaction methods.

RESULTS

Mutant allele frequencies that range from 0.001 to 0.15 were identified in the American Staffordshire Terrier, Australian Shepherd, German Shepherd Dog, Giant Schnauzer, Parson (Jack) Russell Terrier, Labrador Retriever, Large Munsterlander, Pomeranian, South African Boerboel, and Weimaraner breeds.

CONCLUSIONS AND CLINICAL IMPORTANCE

The hyperuricosuria mutation has been identified in several unrelated dog breeds. The mutant allele frequencies vary among breeds and can be used to determine an appropriate breeding plan for each breed. A DNA test is available and may be used by breeders to decrease the mutant allele frequency in breeds that carry the mutation. In addition, veterinarians may use the test as a diagnostic tool to identify the cause of urate urolithiasis.

A cluster-randomized trial to improve stroke care in hospitals

OBJECTIVE

We evaluated the effect of performance feedback on acute ischemic stroke care quality in Minnesota hospitals.

METHODS

A cluster-randomized controlled trial design with hospital as the unit of randomization was used. Care quality was defined as adherence to 10 performance measures grouped into acute, in-hospital, and discharge care. Following preintervention data collection, all hospitals received a report on baseline care quality. Additionally, in experimental hospitals, clinical opinion leaders delivered customized feedback to care providers and study personnel worked with hospital administrators to implement changes targeting identified barriers to stroke care. Multilevel models examined experimental vs control, preintervention and postintervention performance changes and secular trends in performance.

RESULTS

Nineteen hospitals were randomized with a total of 1,211 acute ischemic stroke cases preintervention and 1,094 cases postintervention. Secular trends were significant with improvement in both experimental and control hospitals for acute (odds ratio = 2.7, p = 0.007) and in-hospital (odds ratio = 1.5, p < 0.0001) care but not discharge care. There was no significant intervention effect for acute, in-hospital, or discharge care.

CONCLUSION

There was no definite intervention effect: both experimental and control hospitals showed significant secular trends with performance improvement. Our results illustrate the potential fallacy of using historical controls for evaluating quality improvement interventions.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that informing hospital leaders of compliance with ischemic stroke quality indicators followed by a structured quality improvement intervention did not significantly improve compliance more than informing hospital leaders of compliance with stroke quality indicators without a quality improvement intervention.

The kinder side of killer proteases: caspase activation contributes to neuroprotection and CNS remodeling

Caspases are a family of cysteine proteases that are expressed as inactive zymogens and undergo proteolytic maturation in a sequential manner in which initiator caspases cleave and activate the effector caspases 3, 6 and 7. Effector caspases cleave structural proteins, signaling molecules, DNA repair enzymes and proteins which inhibit apoptosis. Activation of effector, or executioner, caspases has historically been viewed as a terminal event in the process of programmed cell death. Emerging evidence now suggests a broader role for activated caspases in cellular maturation, differentiation and other non-lethal events. The importance of activated caspases in normal cell development and signaling has recently been extended to the CNS where these proteases have been shown to contribute to axon guidance, synaptic plasticity and neuroprotection. This review will focus on the adaptive roles activated caspases in maintaining viability, the mechanisms by which caspases are held in check so as not produce apoptotic cell death and the ramifications of these observations in the treatment of neurological disorders.

p38 activation is required upstream of potassium current enhancement and caspase cleavage in thiol oxidant-induced neuronal apoptosis

Oxidant-induced neuronal apoptosis has been shown to involve potassium and zinc dysregulation, energetic dysfunction, activation of stress-related kinases, and caspase cleavage. The temporal ordering and interdependence of these events was investigated in primary neuronal cultures exposed to the sulfhydryl oxidizing agent 2,2'-dithiodipyridine (DTDP), a compound that induces the intracellular release of zinc. We previously observed that tetraethylammonium (TEA), high extracellular potassium, or cysteine protease inhibitors block apoptosis induced by DTDP. We now report that both p38 and extracellular signal-regulated kinase phosphorylation are evident in neuronal cultures within 2 hr of a brief exposure to 100 microm DTDP. However, only p38 inhibition is capable of blocking oxidant-induced toxicity. Cyclohexamide or actinomycin D does not attenuate DTDP-induced cell death, suggesting that posttranslational modification of existing targets, rather than transcriptional activation, is responsible for the deleterious effects of p38. Indeed, an early robust increase in TEA-sensitive potassium channel currents induced by DTDP is attenuated by p38 inhibition but not by caspase inhibition. Moreover, we found that activation of p38 is required for caspase 3 and 9 cleavage, suggesting that potassium currents enhancement is required for caspase activation. Finally, we observed that DTDP toxicity could be blocked with niacinamide or benzamide, inhibitors of poly (ADP-ribose) synthetase. Based on these findings, we conclude that oxidation of sulfhydryl groups on intracellular targets results in intracellular zinc release, p38 phosphorylation, enhancement of potassium currents, caspase cleavage, energetic dysfunction, and translationally independent apoptotic cell death.

Selective inhibitors of apoptotic caspases: implications for novel therapeutic strategies

Caspases are essential for apoptosis. A crucial question regarding the role(s) of these proteases is whether the selective inhibition of an effector caspase will prevent cell death. We have identified potent, selective non-peptide inhibitors of the effector caspases 3 and 7. Apoptosis can be inhibited and cell functionality maintained using an inhibitor selective for caspases 3 and 7. This has important therapeutic implications and the potential to generate novel anti-apoptotic strategies in diseases that involve dysregulated apoptosis.

Induction of neuronal apoptosis by thiol oxidation: putative role of intracellular zinc release

The membrane-permeant oxidizing agent 2,2'-dithiodipyridine (DTDP) can induce Zn(2+) release from metalloproteins in cell-free systems. Here, we report that brief exposure to DTDP triggers apoptotic cell death in cultured neurons, detected by the presence of both DNA laddering and asymmetric chromatin formation. Neuronal death was blocked by increased extracellular potassium levels, by tetraethylammonium, and by the broad-spectrum cysteine protease inhibitor butoxy-carbonyl-aspartate-fluoromethylketone. N,N,N', N'-Tetrakis-(2-pyridylmethyl)ethylenediamine (TPEN) and other cell-permeant metal chelators also effectively blocked DTDP-induced toxicity in neurons. Cell death, however, was not abolished by the NMDA receptor blocker MK-801, by the intracellular calcium release antagonist dantrolene, or by high concentrations of ryanodine. DTDP generated increases in fluorescence signals in cultured neurons loaded with the zinc-selective dye Newport Green. The fluorescence signals following DTDP treatment also increased in fura-2- and magfura-2-loaded neurons. These responses were completely reversed by TPEN, consistent with a DTDP-mediated increase in intracellular free Zn(2+) concentrations. Our studies suggest that under conditions of oxidative stress, Zn(2+) released from intracellular stores may contribute to the initiation of neuronal apoptosis.

The role of clinical opinion leaders in guideline implementation and quality improvement

BACKGROUND

The lag between the publication of clinical and health-services research and the application of this information is substantial and delays health-care improvement. A wide range of corrective strategies are being used to address this issue.

OBJECTIVES

Evolution in the use of significant opinion leaders is described. Hospital quality improvement projects, undertaken by the Healthcare Education and Research Foundation (HERF), are used to illustrate the roles assumed by clinical opinion leaders. Specific theoretical frameworks are reviewed that are fundamental to successful implementation of opinion leader strategies, as well as key research on the use of clinical opinion leaders.

RESULTS

Over the past 12 years, HERF has identified the need to address not only the information needs of clinicians and organizations but also the social and organizational factors that interfere with the application of research and guidelines. The complexity of this task cannot be underestimated. However, armed with well-developed guidelines and the opportunity to work within structured guideline implementation programs with well-defined objectives and systematically applied methods, HERF's experience suggest local clinicians and communities can meet this challenge.

Levels of endothelial cell stimulating angiogenesis factor and vascular endothelial growth factor are elevated in psoriasis

Neovascularization appears to play an early and important part in the evolution of psoriatic plaques. We studied the distribution and production of two known angiogenesis factors, endothelial cell stimulating angiogenesis factor (ESAF) and vascular endothelial growth factor (VEGF), in the skin of patients with chronic plaque psoriasis and normal control subjects. Our results showed that tissue levels of ESAF and VEGF were significantly elevated in involved as compared with normal control skin (P = 0.006 and P < 0. 0001, respectively). Tissue levels of ESAF and VEGF were also raised in involved skin as compared with uninvolved skin in patients with psoriasis (P = 0.001 and P < 0.0001, respectively). Tissue levels of ESAF and VEGF in plaques of psoriasis correlated closely with the clinical severity of psoriasis (r = 0.6 and r = 0.9, respectively). Serum levels of ESAF and VEGF were significantly raised in patients with psoriasis as compared with control subjects (P = 0.001 and P = 0.02, respectively). In vitro culture studies revealed that ESAF is produced by both keratinocytes and fibroblasts in approximately equal quantities in normal skin, whereas VEGF is secreted predominately by keratinocytes. A similar pattern is seen in both involved and uninvolved skin of patients with psoriasis. However, there is increased secretion of both factors in keratinocytes and fibroblasts from involved and uninvolved skin as compared with normal control skin (P < 0.001). The increased levels and secretion in plaques of psoriasis of two molecules, ESAF and VEGF, known to promote new blood vessel formation, suggest a pathogenetic role for them in this disease.

Timeliness and quality of care for elderly patients with acute myocardial infarction under health maintenance organization vs fee-for-service insurance

BACKGROUND

A commonly voiced concern is that health maintenance organizations (HMOs) may withhold or delay the provision of urgent, essential care, especially for vulnerable patients like the elderly.

OBJECTIVE

To compare the quality of emergency care provided in Minnesota to elderly patients with acute myocardial infarction (AMI) who are covered by HMO vs fee-for-service (FFS) insurance.

METHODS

We reviewed the medical records of 2304 elderly Medicare patients who were admitted with AMI to 20 urban community hospitals in Minnesota (representing 91% of beds in areas served by HMOs) from October 1992 through July 1993 and from July 1995 through April 1996.

MAIN OUTCOME MEASURES

Use of emergency transportation and treatment delay (>6 hours from symptom onset); time to electrocardiogram; use of aspirin, thrombolytics, and beta-blockers among eligible patients; and time from hospital arrival to thrombolytic administration (door-to-needle time).

RESULTS

Demographic characteristics, severity of symptoms, and comorbidity characteristics were almost identical among HMO (n = 612) and FFS (n = 1692) patients. A cardiologist was involved as a consultant or the attending physician in the care of 80% of HMO patients and 82% of FFS patients (P = .12). The treatment delay, time to electrocardiogram, use of thrombolytic agents, and door-to-needle times were almost identical. However, 56% of HMO patients and 51% of FFS patients used emergency transportation (P = .02); most of this difference was observed for patients with AMIs that occurred at night (60% vs 52%; P = .02). Health maintenance organization patients were somewhat more likely than FFS patients to receive aspirin therapy (88% vs 83%; P = .03) and beta-blocker therapy (73% vs 62%; P = .04); these differences were partly explained by a significantly larger proportion of younger physicians in HMOs who were more likely to order these drug therapies. All differences were consistent across the 3 largest HMOs (1 staff-group model and 2 network model HMOs). Logistic regression analyses controlling for demographic and clinical variables produced similar results, except that the differences in the use of beta-blockers became insignificant.

CONCLUSIONS

No indicators of timeliness and quality of care for elderly patients with AMIs were lower under HMO vs FFS insurance coverage in Minnesota. However, two indicators of quality care were slightly but significantly higher in the HMO setting (use of emergency transportation and aspirin therapy). Further research is needed in other states, in different populations, and for different medical conditions.

Consultation between cardiologists and generalists in the management of acute myocardial infarction: implications for quality of care

BACKGROUND

The rapid expansion of managed care in the United States has increased debate regarding the appropriate mix of generalist and specialist involvement in medical care.

OBJECTIVE

To compare the quality of medical care when generalists and cardiologists work separately or together in the management of patients with acute myocardial infarction (AMI).

METHODS

We reviewed the charts of 1716 patients with AMI treated at 22 Minnesota hospitals between 1992 and 1993. Patients eligible for thrombolytic aspirin, beta-blockers, and lidocaine therapy were identified using criteria from the 1991 American College of Cardiology guidelines for the management of AMI. We compared the use of these drugs among eligible patients whose attending physician was a generalist with no cardiologist input, a generalist with a cardiologist consultation, and a cardiologist alone.

RESULTS

Patients cared for by a cardiologist alone were younger, presented earlier to the hospital, were more likely to be male, had less severe comorbidity, and were more likely to have an ST elevation of 1 mm or more than generalists' patients. Controlling for these differences, there was no variation in the use of effective agents between patients cared for by a cardiologist attending physician and a generalist with a consultation by a cardiologist. However, there was a consistent trend toward increased use of aspirin, thrombolytics, and beta-blockers in these patients compared with those with a generalist attending physician only (P<.05 for beta-blockers only). Differences between groups in the use of lidocaine were not statistically significant. The adjusted probabilities of use of thrombolytics for consultative care and cardiologist attending physicians were 0.73 for both. Corresponding probabilities were 0.86 and 0.85 for aspirin and 0.59 and 0.57 for beta-blockers, respectively.

CONCLUSIONS

For patients with AMI, consultation between generalists and specialists may improve the quality of care. Recent policy debates that have focused solely on access to specialists have ignored the important issue of coordination of care between generalist and specialist physicians. In hospitals where cardiology services are available, generalists may be caring for patients with AMI who are older and more frail. Future research and policy analyses should examine whether this pattern of selective referral is true for other medical conditions.

Effect of local medical opinion leaders on quality of care for acute myocardial infarction: a randomized controlled trial

CONTEXT

The effectiveness of recruiting local medical opinion leaders to improve quality of care is poorly understood.

OBJECTIVE

To evaluate a guideline-implementation intervention of clinician education by local opinion leaders and performance feedback to (1) increase use of lifesaving drugs (aspirin and thrombolytics in eligible elderly patients, beta-blockers in all eligible patients) for acute myocardial infarction (AMI), and (2) decrease use of a potentially harmful therapy (prophylactic lidocaine).

DESIGN

Randomized controlled trial with hospital as the unit of randomization, intervention, and analysis.

SETTING

Thirty-seven community hospitals in Minnesota.

PATIENTS

All patients with AMI admitted to study hospitals over 10 months before (1992-1993, N=2409) or after (1995-1996, N=2938) the intervention.

INTERVENTION

Using a validated survey, we identified opinion leaders at 20 experimental hospitals who influenced peers through small and large group discussions, informal consultations, and revisions of protocols and clinical pathways. They focused on (1) evidence (drug efficacy), (2) comparative performance, and (3) barriers to change. Control hospitals received mailed performance feedback.

MAIN OUTCOME MEASURES

Hospital-specific changes before and after the intervention in the proportion of eligible patients receiving each study drug.

RESULTS

Among experimental hospitals, the median change in the proportion of eligible elderly patients receiving aspirin was +0.13 (17% increase from 0.77 at baseline), compared with a change of -0.03 at control hospitals (P=.04). For beta-blockers, the respective changes were +0.31 (63% increase from 0.49 at baseline) vs +0.18 (30% increase from baseline) for controls (P=.02). Lidocaine use declined by about 50% in both groups. The intervention did not increase thrombolysis in the elderly (from 0.73 at baseline), but nearly two thirds of eligible nonrecipients were older than 85 years, had severe comorbidities, or presented after at least 6 hours.

CONCLUSIONS

Working with opinion leaders and providing performance feedback can accelerate adoption of some beneficial AMI therapies (eg, aspirin, beta-blockers). Secular changes in knowledge and hospital protocols may extinguish outdated practices (eg, prophylactic lidocaine). However, it is more difficult to increase use of effective but riskier treatments (eg, thrombolysis) for frail elderly patients.

Endothelial cell stimulating angiogenesis factor

Endothelial cell stimulating angiogenesis factor (ESAF) is a small (> 1000 Da) dialysable non-peptide molecule with potent angiogenic activity. ESAF activates the major pro-matrix metalloproteinases and also uniquely reactivates the complex of these active enzymes with their tissue inhibitors resulting in both active enzyme and inhibitor. These actions may be pivotal in its role as an angiogenic factor. ESAF is primarily involved in angiogenic conditions where inflammatory cells are not evident such as foetal bone growth and electrically stimulated skeletal muscles and proliferative retinopathy. However, high levels also occur in actively growing human intracranial tumours but it is not noticeably elevated in rheumatoid arthritic synovial fluid. Its extreme potency and low molecular mass make its structural determination difficult. Possible therapeutic applications would be in the treatment of ischaemic ulcers, acceleration of fracture repair, infertility and more modestly in the correction of baldness. Analogues of ESAF could be of value in treating angiogenic diseases such as psoriasis and proliferative retinopathy.

General practitioner and public health nurse views of nutritional risk factors in the elderly

A number of risk factors for malnutrition in the elderly have been identified, but their relative importance has yet to be established. General practitioners and public health nurses were interviewed to elicit the relative weights placed on 6 major risk factors when assessing nutritional risk in the elderly (living alone, recent bereavement, denture problems, mobility problems, psychiatric morbidity and multiple medication use). Participants rated risk for 35 hypothetical cases, described by their status on the 6 risk factors. Multiple regression models of these judgments revealed a consistently high weight for psychiatric morbidity compared to the other factors. Little group variation in diagnostic policies was observed between general practitioners and public health nurses or by case gender. These policies may reflect the perception that psychiatric problems pervade many areas of life functioning related to nutritional intake and are therefore more likely to cause malnutrition than other, more specific risk factors.

Endothelial-cell-stimulating angiogenesis factor (ESAF) activates progelatinase A (72 kDa type IV collagenase), prostromelysin 1 and procollagenase and reactivates their complexes with tissue inhibitors of metalloproteinases: a role for ESAF in non-inflammatory angiogenesis

Endothelial-cell-stimulating angiogenesis factor (ESAF) has been shown to activate procollagenase and reactivate complexes of collagenase and gelatinase A with tissue inhibitor of metallo-proteinase (TIMP)-1. In the present paper we show a purification protocol for bovine pineal ESAF and that purified ESAF activates progelatinase A and prostromelysin-1. Unlike the activation of procollagenase by plasmin/plasminogen activator, which requires the presence of stromelysin for full activation, ESAF is able to activate fully all three proenzymes. Purified ESAF is also shown to reactivate the complexes of gelatinase A, collagenase and stromelysin-1 with TIMP-2. Once separated, both enzyme and inhibitor are active; however, ESAF binds to the enzyme in a manner preventing it from further inhibition by TIMP. ESAF is the only physiological molecule able to reactivate the TIMP/enzyme complex.

Noise levels in a cardiac surgical intensive care unit: a preliminary study conducted in secret

Noise in hospitals frequently exceeds recommended levels and has detrimental psychological and physiological effects on patients and staff. The aim of this study was to record the noise levels within the cardiac surgical intensive care unit (CSICU) environment in secret. The device used was a CEL Instruments environmental noise meter concealed in a dummy box featuring temperature and humidity digital displays. It allowed greater than 16 hours recording time at a 1-minute resolution. The 24-hour period was covered by overlapping recordings. The data collected were downloaded onto a personal computer for analysis. The maximum sound level recorded was 100.9 decibel level (dBA), 1 min Lmax (the maximum sound level occurring in a 1-min period). The minimum sound level was 61.3 dBA 1 min Lmax. The continuous background noise was at its lowest at 57.5 dBA 1 min equivalent continuous sound pressure levels (Leq) and at its peak 77.3 dBA 1 min Leq. Noise in the CSICU was above the recommended levels for patients and staff well-being. Future studies will be designed to establish a correlation between sound levels and events.

Adherence to national guidelines for drug treatment of suspected acute myocardial infarction: evidence for undertreatment in women and the elderly

BACKGROUND

Evidence-based guidelines for the treatment of patients with acute myocardial infarction (AMI) have been published and disseminated by the American College of Cardiology and the American Heart Association. Few studies have examined the rates of adherence to these guidelines in eligible populations and the influence of age and gender on highly effective AMI treatments in community hospital settings.

METHODS

Medical records of 2409 individuals admitted to 37 Minnesota hospitals between October 1992 and July 1993 for AMI, suspected AMI, or rule-out AMI, and meeting electrocardiographic, laboratory, and clinical criteria suggestive of AMI were reviewed to determine the proportion of eligible patients who received thrombolytic, beta-blocker, aspirin, and lidocaine hydrochloride therapy. The effects of patient age, gender, and hospital teaching status on the use of these treatments were estimated using logistic regression models.

RESULTS

Eligibility for treatment ranged from 68% (n=1627) for aspirin therapy, 38% (n=906) for lidocaine therapy, and 30% (n=734) for thrombolytic therapy to 19% (n=447) for beta-blocker therapy. Seventy-two percent of patients eligible to receive a thrombolytic agent received this therapy; 53% received beta-blockers; 81% received aspirin; and 88% received lidocaine. Among patients ineligible for lidocaine therapy (n=1503), 20% received this agent. Use of study drugs was lower among eligible elderly patients, especially those older than 74 years (thrombolytic agent: odds ratio, 0.2; 95% confidence interval, 0.1 to 0.4; aspirin: odds ratio, 0.4, 95% confidence interval, 0.3 to 0.6; beta-blocker: odds ratio, 0.4; 95% confidence interval, 0.2 to 0.8). Female gender was associated with lower levels of aspirin use among eligible patients (odds ratio, 0.7; 95% confidence interval, 0.6 to 0.9); and there was a trend toward lower levels of beta-blocker and thrombolytic use among eligible women.

CONCLUSIONS

Use of lifesaving therapies for eligible patients with AMI is higher than previously reported, particularly for aspirin and thrombolytic use in nonelderly patients. Lidocaine is still used inappropriately in a substantial proportion of patients with AMI. Increased adherence to AMI treatment guidelines is required for elderly patients and women.

Prevalence of human immunodeficiency virus and associated risk behaviour in injection drug users in Toronto

During 1989-90, interviews were conducted with 582 current injection drug users in the City of Toronto, 535 of whom also provided blood and/or saliva for anonymous unlinked HIV antibody testing. The rate of seropositivity identified was 4.3% (95% CI 3-6). The subjects were predominantly male, with a mean age of 28.3. The commonest drug of choice was cocaine (70%). Forty-six percent of the subjects reported using someone else's needle in the preceding six months, 60% of these indicating that they always cleaned it first. Eighty-one percent of those interviewed had been in jail at some time since they began injecting; 25% of these had injected while in custody, and of these 61% had shared injection equipment. Eighty-two percent of the men and 85.4% of the women reported opposite sex partners in the previous six months. Only about 20% of men reported consistent condom use, while 22% of females reported condom use at least 75% of the time.

The outcomes of elective laparoscopic and open cholecystectomies

BACKGROUND

The demand for evidence of effectiveness for medical care has prompted the development of epidemiologic approaches to relating the outcomes of care to treatment. This study compares the outcomes of care for patients undergoing the newly introduced laparoscopic cholecystectomy with the results from conventional open cholecystectomies.

METHODS

Consecutive cases of elective cholecystectomy from 35 hospitals (all of the metropolitan and selected rural hospitals in Minnesota) were enrolled in the study. Patients were interviewed on admission to establish baseline symptoms and functional status and to confirm risk factors. Their medical records were abstracted to yield information on risk factors, treatment, and hospital complications. To establish outcomes, patients were sent a questionnaire about their symptoms and functional status six months postoperatively.

RESULTS

Of 3,448 patients studied, 2,490 (72 percent) had a laparoscopic procedure, including 195 cases that were converted to open cholecystectomies. Functional status data were obtained on 2,481 cases (76 percent). Laparoscopic operation was associated with more operative complications (odds ratio 3.02, p < 0.001), but with fewer general complications (odds ratio 0.32, p < 0.001). The mean time to return to work was 15 days for laparoscopic cases compared to 31 days for open procedures (p < 0.001). The only functional outcome difference between the two procedures was that patients who underwent laparoscopic cholecystectomies were more likely than those with conventional cholecystectomies to be able to perform their usual activities at follow-up evaluation (p < .001). There was evidence of a learning curve; the more laparoscopic procedures a surgeon performed, the fewer the operative (p < 0.01) and general (p < 0.0001) complications. There was no indication that the availability of laparoscopic operation was associated with more operations being performed.

CONCLUSIONS

Laparoscopic operation seems to represent a significant advance in getting patients back to a normal life sooner. More attention needs to be given to which patients are most likely to benefit from cholecystectomy of either type. Epidemiologic approaches can be useful in assessing the effectiveness of care. Partnerships between providers and researchers can produce useful effectiveness data by supplementing available clinical records with more detailed outcome data.

Raised endothelial cell stimulating angiogenesis factor in ankylosing spondylitis

Endothelial cell stimulating angiogenesis factor (ESAF) is important in the neovascularisation that precedes new bone formation, and raised levels are found in association with healing fractures and osteoarthritis. We investigated its relevance to the new bone growth that is found at inflammatory sites in ankylosing spondylitis (AS). Forty-one patients with AS were studied clinically and radiographically and had their serum ESAF levels measured. In comparison to age-matched controls the AS patients had significantly raised ESAF levels (p < 0.0001). Within the AS group, patients with relatively higher ESAF levels had no characteristic clinical or radiological features.

Collagenase and gelatinase production by calcifying growth plate chondrocytes

The regulation of cartilage resorption is important both in cartilage pathophysiology and angiogenesis. Previous work has identified a link between calcification and activation of collagenolysis. The aim here was to test whether production of collagenase itself is also calcification-dependent, using a high-density growth plate chondrocyte culture model of calcification. Ultrastructural studies indicated that calcification occurred around large hypertrophic cells. There was no indication of phagocytosis of crystals even by cells lying next to mineral aggregates, although remodeling of the organic matrix by cell processes was evident. Release of collagenase activity increased dramatically between 24 and 48 h postcalcification, from low or undetectable basal levels. In contrast, gelatinase production was not calcification-dependent. Collagenase was released almost entirely in the latent form, being a consequence of increased protein synthesis rather than activation of existing enzyme. This linkage of calcification with latent collagenase production represents part of a coordinated remodeling of both collagenous and mineral components of the matrix which may also extend, in vivo, to the control of microvascular invasion and resorption.

Prevalence of bloodborne infective agents among people admitted to a Canadian hospital

OBJECTIVE

To determine the prevalence rates of hepatitis B surface antigen (HBsAg) and antibodies to the human immunodeficiency virus (anti-HIV) and the hepatitis C virus (anti-HCV) among people admitted to an urban Canadian hospital.

DESIGN

Anonymous unlinked serosurvey.

SETTING

A 420-bed teaching hospital in Toronto.

PARTICIPANTS

All 3000 patients admitted to the hospital on weekdays from January to June 1990. An attempt was made to exclude those who were readmitted during the study period.

INTERVENTIONS

Serum samples from all the patients were tested for HBsAg and anti-HIV, and 1306 samples were also tested for anti-HCV by means of enzyme immunosorbent assays; reactions were confirmed by means of specific antibody neutralization or immunoblot assay.

MAIN RESULTS

The prevalence rates of HBsAg, anti-HIV and anti-HCV were 2.1% (95% confidence interval [CI] 1.6% to 2.6%), 0.6% (95% CI 0.3% to 0.9%) and 0.5% (95% CI 0.1% to 0.9%) respectively.

CONCLUSIONS

This is the first report defining rates of infection with these bloodborne agents among patients admitted to a Canadian hospital. The observed rates likely reflect the patient population served by our hospital and do not necessarily apply to other Canadian centres. The results support the use of universal precautions in health care settings.

Concentrations of endothelial-cell-stimulating angiogenesis factor, a major component of human uterine angiogenesis factor, in human and bovine embryonic tissues and decidua

Embryonic development involves the establishment of new patterns of vascular growth in the fetus and within the lining of the womb. A factor, human uterine angiogenesis factor, has been purified from the decidua and stimulates the growth of blood vessels in collagen sponge implants and in the chick chorioallantoic membrane. Evidence is presented that suggests that a major active component of human uterine angiogenesis factor is an activator of latent matrix metalloproteinases, of low M(r), called endothelial-cell-stimulating angiogenesis factor and that this factor is present in substantial quantities in a number of embryonic tissues.