Consequences of medical negligence and litigations on health care providers - A narrative review

Medical professionals face high stress due to the type of work they do and the prolonged working hours. Frequent burnout results due to the challenging nature of their work. Added to the stress of work, malpractice lawsuits add to their burden. In India, most doctors work in compromised settings with poor infrastructure and manpower but are expected to follow the best practices. In court, they are judged with the Bolam and Bolitho tests being essential considerations. Several tragic incidents have been reported, including depression, anger issues, and even suicide deaths of healthcare professionals (HCPs) after accusations of negligence and subsequent inquiry. Such incidents demonstrate the multitude of challenges an HCP faces in day-to-day practice. It is crucial to find ways to tackle these problems and enhance the capacity of HCP to handle such demanding circumstances. Malpractice litigation can significantly impact the mental health of HCPs. It is common to experience emotional turmoil when faced with a lawsuit. Second victim syndrome (SVS) is a term used to describe a set of symptoms experienced by HCPs who make an error leading to injury to a patient. However, it also happens if he is traumatized by the consequences of violence during healthcare services or a lawsuit or defamation article in newspaper/social media. Following a litigation crisis in their career, many HCPs go through various stages of grief, including shock, denial, anger, bargaining, depression, and acceptance. At times, death by suicide of the HCPs is well known. SVS is known to profoundly affect the personal, family, economic, professional (defensive practice), and social life of HCPs. HCPs should accept the allegations of negligence as an occupational hazard and prepare for the eventual litigation at least once in a lifetime by knowing about the medical laws, HCP's rights, becoming aware of the emotional turmoil of the lawsuit, preparing to cope with the lawsuit, and seeking help from colleagues and indemnity insurance. Frequent training of the HCPs is strongly recommended to know about the changing laws and also to undergo periodic professional competence enhancement to reduce the incidents of errors amounting to medical negligence. Medical and hospital administration should debrief after any incident and conduct internal investigations to identify systemic flaws and prevent future recurrence, resolve issues within their control at their level, and manage media (mainstream and social media) appropriately. If established, a reporting system with online and offline services will ease the internal administrative investigation process and take appropriate, timely actions. During the crisis, HCPs should have adequate and appropriate insurance or indemnity coverage and mental health support systems.

Early Bone Mineral Density Changes and Endocrinal Dysfunction in Childhood Brain Tumor Patients: A Prospective Study

PURPOSE/OBJECTIVE(S)

Reduced bone mineral density (BMD) and hormonal dysfunction are considered as a late effect of cranial radiation (RT). Only few studies have reported the occurrence of these problems soon after the diagnosis of brain tumor or RT initiation, emphasizing that these are not necessarily the late effects of RT. Thus, we conducted the study to analyze the incidence of low BMD and hormonal dysfunction prior to or within 6 months of RT (early change) in children with brain tumors.

MATERIALS/METHODS

The study was conducted as a part of intramural funding program at a tertiary care center in India. Childhood and adolescent brain tumor patients were advised for dual energy X-ray absorptiometry scan (DXA) and hormonal evaluation prior to RT. In some patients, first DXA was done within 6 months of RT due to logistics. To see the effect of radiation, we have planned to repeat hormonal evaluation after 6 and 12 months and DXA after 12 months of RT.

RESULTS

Twenty-five patients were analyzed. Median age at diagnosis was 11 years with a male to female ratio of 5.2:1. Medulloblastoma was the commonest diagnosis (n = 12), followed by glioma (n = 8), pineal tumors (n = 3) and ependymoma (n = 2). Nineteen and six patients underwent DXA before RT and within 6 months of RT respectively. For BMD assessment, Z score was calculated at hip and lumbar spine. BMD was defined as low (Z score = -1 to-1.99), very low (Z score = -2 to -2.5) and secondary osteoporosis (Z score ≤ -2.5). Median Z score at femur neck and spine was -2 and -1.9 respectively. Overall; 6, 3 and 9 patients had normal, low and very low BMD respectively. Seven patients had secondary osteoporosis (Table 1). Two patients with secondary osteoporosis had low vitamin D levels. None of the patient had compression fracture. On statistical analysis, no correlation was found between BMD changes and age, sex and site of the tumor. Pre RT endocrinal assessment (N = 25) was done by tanner staging and serum hormonal levels (GH, T3/T4/TSH, ACTH, cortisol and prolactin). Gonadal hormonal assessment was done in children with early or delayed puberty. Three patients were found to have endocrinal abnormality before RT (precautious puberty, central hypothyroidism and low sex hormones in 1 patient each). Follow up DXA and hormonal evaluation are awaited to see the effect of RT.

CONCLUSION

The index study is one of the very few studies evaluating the early changes in BMD and hormonal dysfunction soon after brain tumor diagnosis or within 6 months of RT. We observed that a significant proportion of children had reduced BMD and hormonal dysfunction before RT, highlighting the importance of early assessment and referral to the specialist for better quality of life. Table 1: BMD and endocrinal dysfunction before or within 6 months of RT.

Olfactomedin-4 + neutrophils exacerbate intestinal epithelial damage and worsen host survival after Clostridioides difficile infection

Neutrophils are key first responders to Clostridioides difficile infection (CDI). Excessive tissue and blood neutrophils are associated with worse histopathology and adverse outcomes, however their functional role during CDI remains poorly defined. Utilizing intestinal epithelial cell (IEC)-neutrophil co-cultures and a pre-clinical animal model of CDI, we show that neutrophils exacerbate C. difficile -induced IEC injury. We utilized cutting-edge single-cell transcriptomics to illuminate neutrophil subtypes and biological pathways that could exacerbate CDI-associated IEC damage. As such, we have established the first transcriptomics atlas of bone marrow (BM), blood, and colonic neutrophils after CDI. We found that CDI altered the developmental trajectory of BM and blood neutrophils towards populations that exhibit gene signatures associated with pro-inflammatory responses and neutrophil-mediated tissue damage. Similarly, the transcriptomic signature of colonic neutrophils was consistent with hyper-inflammatory and highly differentiated cells that had amplified expression of cytokine-mediated signaling and degranulation priming genes. One of the top 10 variable features in colonic neutrophils was the gene for neutrophil glycoprotein, Olfactomedin 4 (OLFM4). CDI enhanced OLFM4 mRNA and protein expression in neutrophils, and OLFM4 + cells aggregated to areas of severe IEC damage. Compared to uninfected controls, both humans and mice with CDI had higher concentrations of circulating OLFM4; and in mice, OLFM4 deficiency resulted in faster recovery and better survival after infection. Collectively, these studies provide novel insights into neutrophil-mediated pathology after CDI and highlight the pathogenic role of OLFM4 + neutrophils in regulating CDI-induced IEC damage.

One Sentence Summary

Utilizing single-cell transcriptomics, IEC-epithelial co-cultures, and pre-clinical models of CDI, we have identified a subset of neutrophils that are marked by OLFM4 expression as pathogenic determinants of IEC barrier damage after CDI.

Lutetium-177-PSMA-617: A Vision of the Future

In the last decade, many life-prolonging therapeutic options have emerged for metastatic castration-resistant prostate cancer (mCRPC). The recent VISION trial is the first to demonstrate a survival benefit of Lutetium-177[¹⁷⁷Lu]Lu-PSMA-617 in post-chemotherapy mCRPC. This journal club reviews the VISION trial in the context of the earlier TheraP trial of [¹⁷⁷Lu]Lu-PSMA-617 in mCRPC post docetaxel and androgen pathway inhibition, to provide direction for the real-world application of [¹⁷⁷Lu]Lu-PSMA-617. Treatment in the control groups differed significantly between both trials and may have influenced outcomes: TheraP mandated cabazitaxel whereas VISION’s design could not allow it. In both trials, [¹⁷⁷Lu]Lu-PSMA-617 had a good safety profile, with common adverse events being fatigue, nausea, dry mouth, marrow suppression and diarrhea. Given its efficacy and favorable safety even in heavily pre-treated patients, [¹⁷⁷Lu]Lu-PSMA-617 provides hope to mCRPC patients and may be applied to earlier disease stages in future investigations.

487 NC410, a fusion protein of LAIR-2 (Leukocyte Associated Immunoglobulin-like Receptor) with human IgG1 Fc, is safe & tolerable with evidence of immune modulation in subjects with advanced solid tumors

Background

Collagen and C1q in the extracellular matrix (ECM), are the predominant ligands for LAIR-1, an inhibitory receptor expressed on the cell surface of several immune cell subsets that inhibits immune activation and migration. LAIR-2, a soluble homolog of LAIR-1, competes for binding to collagen and C1q and serves as a natural decoy to promote immune function under normal conditions. Dysregulation of the ECM and increased expression of collagen and C1q within the tumor microenvironment (TME) plays a critical role in promoting tumor progression. NC410 was engineered to overcome this highly immunosuppressive environment by blocking LAIR-1 function, reversing immune suppression, and inducing ECM remodeling to promote immune cell infiltration within the TME.

Methods

This is a first in human, phase 1/2, open-label, single-armed dose-escalation study to determine the safety, tolerability, dose-limiting toxicity (DLT), maximum tolerated dose (MTD), recommended phase 2 dose, preliminary efficacy and to explore pharmacodynamic biomarkers of NC410 (figure 1). Key eligibility criteria include subjects with advanced or metastatic solid tumors with measurable disease based on RECIST v1.1.

Results

As of 07/22/2021, a total of 16 patients have been enrolled, treated, and completed the DLT period. NC410 (up to 60 mg), was well tolerated, with no safety concerns, infusion-related toxicities, or DLT reported. No anti-drug antibody (ADA) was detected post-NC410 up to 60 mg treatment. As expected, the C1Q level decreased immediately after the NC410 infusion and was replenished after two hours. Evaluation from samples to date available up to cycle 5 suggests that there was no reduction in the baseline C1Q level with subsequent dosing (figure 2). LAIR-2 levels continued to increase in a dose-dependent fashion post-NC410 dosing and marginal increase pre-dose (figure 3). Interestingly, we observed an increase in soluble LAIR-1 over time in a similar pattern to LAIR-2 (figure 4). Furthermore, immunophenotyping of patient whole blood suggests a trend towards an increase in CD4+ and CD8+ T cells including LAIR-1+ T cells in cohort 4, although overall expression levels of LAIR-1 did not appear to increase (ongoing analysis). Cytokines, chemokines, and collagen degradation products (CDP) will be evaluated as potential pharmacodynamic biomarkers as we continue through higher dose cohorts.

Abstract 487 Figure 1

NC410: study schema

Abstract 487 Figure 2

C1Q levels show immediate reduction after NC410 dosing with no accumulated depletion

Abstract 487 Figure 3

LAIR-2 levels show an increase in dose-dependent fashion after NC410 dosing with marginal increase pre-dose

Abstract 487 Figure 4

Soluble LAIR-1 levels show a similar pattern to LAIR-2 levels

Conclusions

Preliminary evaluation of NC410 in subjects with advanced or metastatic solid tumors appears to be safe and well-tolerated with evidence of immune modulation consistent with predictive PK/PD modeling in a Phase 1/2 open-label study. Further evaluation will be done with increasing doses to confirm these initial findings.

Trial Registration

NCT04408599

Ethics Approval

This study has been approved by the IRB of all the participating institutions, and all participants have given informed consent before taking part in the study.

Consent

Written informed consent was obtained from the patient for publication of this abstract and any accompanying images. A copy of the written consent is available for review by the Editor of this journal.

420 PROSTVAC in combination with nivolumab enhanced immune cell infiltration in prostate cancer

Background

Prostate cancer (PC) is the most common non-cutaneous diagnosed cancer among men in USA.1 Although clinical outcomes are favorable for patients with localized disease, 20–30% of patients will develop metastatic prostate cancer (mPC) and have poor prognosis. Immunotherapy, as a single agent, provides benefit to a small subset of PC patients, which is thought to be partially due to its known cold tumor immune microenvironment (TIME). Combination studies are needed to enhance benefit.2 Prostvac is a therapeutic cancer vaccine engineered to activate an immune response against prostate-specific Antigen (PSA).3 Prostvac alone could induce systemic immune response by increasing immune-cell infiltrates in and around the tumor.4 In this study, we are exploring the effect of Prostvac in combination with nivolumab in TIME in prostate cancer.

Methods

We treated locally advanced prostate cancer patients (n=6) undergoing radical prostatectomy (RP) with neoadjuvant Prostvac in combination with nivolumab, an immune checkpoint PD-1 inhibitor. Dynamic changes in TIME before and after treatment were studied using multiplex immunofluorescence (Opal Method). Formalin fixed paraffin-embedded sections from matched pre-treated prostate biopsies and post-treated RP samples were stained with a validated T cell panel (DAPI, CD4, CD8, FOXP3, Ki67, Pan CK and PD-L1). To analyze the data, TIME was segmented into 3 compartments: intratumoral, invasive margin and benign.

Results

Combination immunotherapy significantly increased CD4+ T cell density in the invasive margin (mean 211.5 cells/mm2 vs 592.2 cells/mm2, p<0.05), with similar trend in the intratumoral and the benign compartments. CD8+ T cell density increased after treatment in the invasive margin (mean 47.25 cells/mm2 vs 157cells/mm2) and the benign compartment. 5/6 and 4/6 patients showed more than 2-fold increase of CD4 and CD8 T cells in the TIME, respectively, in at least one of the three compartments. Increased proliferative indices in CD4+ and CD8+ T cells were also seen after treatment. Tregs were present in low frequencies in TIME (maximum of 12 cells/mm2) with no significant changes. Moreover, a significant drop in tumor cell Ki67 after treatment (mean 252.8 cells/mm2 vs 100.5 cells/332, p<0.05) suggests that the combination may control tumor growth.

Conclusions

The combination of Neoadjuvant Prostvac and nivolumab was associated with increased immune cell infiltration in a cohort of early prostate cancer patients. A broader examination of the TIME and the role immune cells undertake to control tumor growth is on-going.

Trial Registration

NCT02933255

References

Siegel RL, Miller KD, Jemal A. Cancer statistics, 2020. CA Cancer J Clin (Internet) 2020;70:7–3

Zhao SG, Lehrer J, Chang SL, et al. The immune landscape of prostate cancer and nomination of PD-L2 as a potential therapeutic target. J Natl Cancer Inst 2018;111:301–10.

Madan RA, Arlen PM, Mohebtash M, et al. Prostvac-VF: a vectorbased vaccine targeting PSA in prostate cancer. Expert Opin Investig Drugs 2009;18:1001–11

Abdul Sater H, Marté JL, Donahue RN, et al. Neoadjuvant PROSTVAC prior to radical prostatectomy enhances T-cell infiltration into the tumor immune microenvironment in men with prostate cancer. J Immunother Cancer 2020;8(1):655–64

Ethics Approval

This study was performed in compliance with ethical standard and was approved by the NIH IRB, 17C-0007. All patients participating in this study gave an informed consent before taking part.

483 Initial safety results and immune responses induced by a novel human papillomavirus (HPV)-specific gorilla adenovirus immunotherapy vaccine, PRGN-2009, in patients with advanced HPV-associated cancers

Background

PRGN-2009 is a novel gorilla adenovirus vaccine containing 35 non-HLA-restricted epitopes of HPV 16 and 18 which is being tested in an open-label, NCI-sponsored, single-center Phase I/II study alone and combined with the bifunctional TGF-β ”trap”/anti-PD-L1 fusion protein bintrafusp alfa (BA) (NCT04432597).

Methods

For the Phase I of the trial, eligible patients are adults with previously treated (checkpoint blockade allowed) recurrent/metastatic HPV-associated cancers. Objectives are to assess the safety and determine the recommended phase 2 dose (RP2D) of PRGN-2009 alone and combined with BA. Treatment followed a single-agent 3+3 dose escalation at two dose levels of PRGN-2009 (dose level 1: 1x1011 viral particle units (VPU), dose level 2: 5x1011 VPU) subcutaneously Q2W for 3 times, then Q4W for up to one year in total. After determination of RP2D, a combination cohort of 10 patients treated with PRGN-2009 at the RP2D combined with BA (1200 mg IV Q2W for 52 weeks) opened. Peripheral blood mononuclear cells collected from patients before and after vaccination with PRGN-2009 were stimulated with overlapping peptide pools and assessed by intracellular cytokine staining to identify HPV-16 and HPV-18 specific T-cells, as well as T-cells targeting cascade antigens not encoded by the vaccine.

Results

Six patients were enrolled in the single-agent PRGN-2009 dose-escalation phase (3 with cervical cancer, 2 with anal cancer, 1 with vaginal cancer). Observed adverse events were Grade 1-2 flu-like syndrome (headache, body aches), injection site reactions (erythema, pruritus, soreness, localized edema), fatigue, and rash. There were no dose limiting toxicities, and 5x1011 VPU was selected as RP2D. Four patients had stable disease as best response, (one ongoing, 10 months on treatment).T-cells targeting HPV-16 and/or HPV-18 were increased after vaccination in 100% of patients, with 3/6 (50%) developing HPV-16 T cells and 5/6 (83%) developing HPV-18 T cells. In some patients, the magnitude and breadth of HPV-16 and HPV-18 specific T cells were notably increased after repeated vaccination. T cells that target the cascade antigens brachyury and MUC1 were also increased in all patients evaluated. Multifunctional T-cell responses against all these antigens were also developed after vaccination in the majority of patients. No differences in immunogenicity were noted between the two dose levels. Enrollment is underway in combination with BA. Updated data will be presented.

Conclusions

The Phase 1 results demonstrate the safety of single-agent PRGN-2009 and induction of anti-HPV T-cell immune responses, supporting the hypothesis that PRGN-2009 could potentially induce anti-tumor effects in HPV-associated cancers.

Acknowledgements

This research was supported in part by the Intramural Research Program of the NIH, NCI.

Trial Registration

NCT04432597

Ethics Approval

Approved by the NIH IRB (Ref No 543876). All participants have given informed consent before taking part in the study.

416 Prospective Multicentre Study of Impact of COVID-19 on Colorectal Cancer Resections

Introduction

COVID-19 pandemic has posed a major challenge to healthcare systems globally. In NHS, around 36,000 cancer operations have been estimated to be cancelled during the peak time alone. This regional study evaluated the risk of COVID-19 in patients undergoing surgery for colorectal cancer during the peak time.

Method

This prospective multicentre observational study conducted in four busy district hospitals included 52 patients with colorectal cancer who underwent surgery during the COVID lockdown period (23^rd March to 5^th May). PCR swab testing was used to detect COVID. Data was collected from patient notes, MDT files and pathology results.

Results

73% (38/52) underwent elective procedures, 90% with curative intent. Overall, mean (SD) age was 70 (12.2) years, 50% were female. 60% (32/52) had left sided cancers and a total of 48% (25/52) patients had stage 3 or above. 27% (14/52) had post-operative complications, with 4% (2/52) being Grade 3 Clavien-Dindo. Total mortality was 6% (3/52) of which 1 was elective patient. Only one patient developed COVID infection during the inpatient stay.

Conclusions

Data suggests, local policies to prevent COVID spread have been effective. Local lockdown in case of second peak may be a reasonable option. Improvement in COVID testing could have major impact on outcomes.

Embryonal tumors with multilayered rosettes: A tertiary care centre experience

BACKGROUND

Embryonal tumors with multilayered rosettes (ETMR) is an extremely rare and highly aggressive tumor. It includes three distinct entities i.e, embryonal tumor with abundant neuropil and true rosettes (ETANTR), ependymoblastoma (EBL) and medulloepithelioma (MEPL). Here, we present our institutional experience of seven ETMR cases treated over a period of five years.

MATERIALS AND METHODS

Patients' records from 2015 to 2019 were reviewed manually and electronically to retrieve the data. Clinicopathological and outcome details of ETMR cases were entered in a predesigned proforma.

RESULTS

A total of seven cases of ETMR were registered from 2015 to 2019 with a median age at presentation of four years (range 3-7 years). All patients underwent surgery. However, only three patients completed the planned adjuvant treatment, comprising of focal radiotherapy (RT) alone, craniospinal irradiation (CSI) alone and CSI followed by six cycles of chemotherapy in one patient each respectively. Two patients commenced CSI but deteriorated during RT and thereafter needed best supportive care. Two patients could not be started on any adjuvant treatment. Unfortunately, six patients succumbed to their disease within one year of their diagnosis. Only one patient who received both CSI and adjuvant chemotherapy is alive at 15 months of diagnosis.

CONCLUSION

ETMR is a rare and aggressive entity. Majority of the patients die within one year of the diagnosis despite multimodality treatment.

456 Impact of angiotensin II pathway inhibition on tumor response to anti PD(L)1 based therapy

Background

Angiotensin II (Ang II) has been shown preclinically to increase VEGF and TGF-β expression through AT1 receptor signaling but to decrease VEGF and TGF-β through AT2. Thus, we hypothesized that the ang II pathway might have a role in carcinogenesis and immune evasion and selectively inhibiting AT1 via angiotensin receptor blockers (ARBs) would enhance responses in combination with PD(L)1 blockade.

Methods

We pooled data on 597 patients with advanced solid tumors on 20 prospective anti-PD(L)1 based trials. Fisher’s exact tests were used to compare objective response rates (ORR) and complete response rates (CRR) in patients receiving ARBs or ACE inhibitors (ACEi) to those in patients not receiving ARBs nor ACEi. Log-rank tests and Kaplan-Meier curves were used to compare overall survival (OS) in these same groups. Data were analyzed in tumor types where at least 5 patients were taking ARBs or ACEi. Multiple logistic regression and Cox regression analyses were performed to assess the effect of ARBs on ORR/CR and OS respectively.

Results

In total, 597 patients with dozens of tumor types were pooled. Of these, 71 were taking ARBs and 82 were taking ACEi. Three tumor types had at least 5 patients taking ARBs: bladder, ovarian and prostate. ARB use was associated with improvement in ORR (77.8% vs 30.2% ; p=0.019), CRR (55.6% vs 9.3%; p=0.005) and OS (median: not reached vs 14.2 months (95% CI: 7.1–22.0 months; p=0.005) in patients with bladder cancer (n=52), but not ovarian nor prostate cancer. On multivariable analysis, ARB use remained associated with improved ORR, CRR and OS in patients with bladder cancer. Five tumor types had at least 5 patients taking ACEi: prostate, ovarian, colorectal, cervical and bladder. For all five, no benefit was seen in ORR, CRR nor OS with ACEi use (all p>0.10).

Conclusions

ARB use was associated with improvement in ORR, CRR and OS in patients with urothelial or bladder cancer receiving anti PD(L)1 based therapy. No benefit was was seen with ARBs in prostate or ovarian cancer nor with ACEi in any tumor type evaluated. The associated benefit seen in bladder cancer with ARBs but not ACEi may be due to selective AT1 blockade by ARBs versus dual AT1/AT2 blockade by ACEi. This data is hypothesis generating and further study is needed to determine if selective AT1 inhibition can improve outcomes when combined with anti PD(L)1 based therapy in bladder cancer and other tumor types.

Local failure after definitive radiation treatment of lymph-node positive prostate cancer: supporting the use of novel imaging techniques to personalize treatment options

Patients with lymph-node positive prostate cancer are often treated with external beam radiotherapy with androgen deprivation therapy¹, but are expected to have a high rate of biochemical failure. Recently, MRI and molecular imaging have afforded the opportunity to elucidate otherwise occult sites of recurrence after conventional imaging. We present an unusual case of local failure within the prostate after definitive radiation treatment of lymph-node positive prostate cancer, in which advanced imaging allowed for a potentially curative salvage treatment option.

Evaluating Biochemically Recurrent Prostate Cancer: Histologic Validation of 18F-DCFPyL PET/CT with Comparison to Multiparametric MRI

Background Prostate cancer recurrence is found in up to 40% of men with prior definitive (total prostatectomy or whole-prostate radiation) treatment. Prostate-specific membrane antigen PET agents such as 2-(3-{1-carboxy-5-[(6-[18F]fluoro-pyridine 3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid (¹⁸F-DCFPyL) may improve detection of recurrence compared with multiparametric MRI; however, histopathologic validation is lacking. Purpose To determine the sensitivity, specificity, and positive predictive value (PPV) of ¹⁸F-DCFPyL PET/CT based on histologic analysis and to compare with pelvic multiparametric MRI in men with biochemically recurrent prostate cancer. Materials and Methods Men were prospectively recruited after prostatectomy and/or radiation therapy with rising prostate-specific antigen level (median, 2.27 ng/mL; range, 0.2-27.45 ng/mL) and a negative result at conventional imaging (bone scan and/or CT). Participants underwent ¹⁸F-DCFPyL PET/CT imaging and 3.0-T pelvic multiparametric MRI. Statistical analysis included Wald and modified χ² tests. Results A total of 323 lesions were visualized in 77 men by using ¹⁸F-DCFPyL or multiparametric MRI, with imaging detection concordance of 25% (82 of 323) when including all lesions in the MRI field of view and 53% (52 of 99) when only assessing prostate bed lesions. ¹⁸F-DCFPyL depicted more pelvic lymph nodes than did MRI (128 vs 23 nodes). Histologic validation was obtained in 80 locations with sensitivity, specificity, and PPV of 69% (25 of 36; 95% confidence interval [CI]: 51%, 88%), 91% (40 of 44; 95% CI: 74%, 98%), and 86% (25 of 29; 95% CI: 73%, 97%) for ¹⁸F-DCFPyL and 69% (24 of 35; 95% CI: 50%, 86%), 74% (31 of 42; 95% CI: 42%, 89%), and 69% (24 of 35; 95% CI: 50%, 88%) for multiparametric MRI (P = .95, P = .14, and P = .07, respectively). In the prostate bed, sensitivity, specificity, and PPV were 57% (13 of 23; 95% CI: 32%, 81%), 86% (18 of 21; 95% CI: 73%, 100%), and 81% (13 of 16; 95% CI: 59%, 100%) for ¹⁸F-DCFPyL and 83% (19 of 23; 95% CI: 59%, 100%), 52% (11 of 21; 95% CI: 29%, 74%), and 66% (19 of 29; 95% CI: 44%, 86%) for multiparametric MRI (P = .19, P = .02, and P = .17, respectively). The addition of ¹⁸F-DCFPyL to multiparametric MRI improved PPV by 38% overall (P = .02) and by 30% (P = .09) in the prostate bed. Conclusion Findings with 2-(3-{1-carboxy-5-[(6-[18F]fluoro-pyridine 3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid (¹⁸F-DCFPyL) were histologically validated and demonstrated high specificity and positive predictive value. In the pelvis, ¹⁸F-DCFPyL depicted more lymph nodes and improved positive predictive value and specificity when added to multiparametric MRI. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Zukotynski and Rowe in this issue.

Effect of prophylactic granulocyte-colony stimulating factor (G-CSF) on acute hematological toxicity in medulloblastoma patients during craniospinal irradiation (CSI)

OBJECTIVES

Haematological toxicity and treatment breaks are common during cranio-spinal irradiation (CSI) due to irradiation of large volume of bone marrow. We conducted this study to see the effect of prophylactic granulocyte colony stimulating factor (GCSF) in reducing treatment breaks.

PATIENTS AND METHODS

The study was conducted over a period of 15 months from August 2017 to November 2018. Histopathologically proven Medulloblastoma patients received prophylactic GCSF during CSI. Acute hematological toxicities and treatment breaks were noted and effect of age and pretreatment blood counts were analyzed by SPSS (Statistical Package for Social Sciences) version 23.

RESULTS

A total of 28 patients were included in the study. During CSI, hematological toxicity leading to treatment breaks was observed in 11 (39.3 %) patients, of which grade 3 and 2 toxicities were seen in ten and one patients respectively. Younger age (<10 years) at diagnosis was significantly associated with the development of hematological toxicity (p = 0.028, Chi-Square). No correlation was found with pre-treatment blood counts.

CONCLUSION

Prophylactic use of GCSF may be effective in preventing radiation induced hematological toxicity and treatment breaks.

SUN-739 Next Generation AR Antagonists Increase Systemic Active Glucocorticoid Exposure by Altering Glucocorticoid Metabolism

Enzalutamide and apalutamide are potent next-generation androgen receptor (AR) antagonists used in metastatic and non-metastatic prostate cancer. Despite the increased survival benefits of these agents, resistance normally occurs and the disease transitions to its lethal form. We hypothesized that enzalutamide and apalutamide suppress 11β-hydroxysteroid dehydrogenase-2 (11β-HSD2), which normally converts cortisol to cortisone, leading to elevated cortisol concentrations and increased ratio of active to inactive glucocorticoids. We measured cortisol and cortisol/cortisone ratio (substrate/product of 11β-HSD2) in serum using mass spectrometry before and 1 month on-treatment in 3 clinical trials: 1) neoadjuvant apalutamide + leuprolide (n=25) 2) enzalutamide +/- PROSTVAC for metastatic castration-resistant prostate cancer (n=54) and 3) enzalutamide +/- PROSTVAC for non-metastatic castration-sensitive prostate cancer (n=38 patients). Progression-free survival (PFS) was determined in the metastatic CRPC study of enzalutamide +/- PROSTVAC for those with glucocorticoid changes above and below the median. A statistically significant rise in cortisol concentration and cortisol/cortisone ratio with AR antagonist treatment occurred uniformly across all 3 clinical trials. For example, a rise in cortisol/cortisone ratio occurred in 23/25 (92%) patients (p < 0.001), 36/54 (67%) patients (p < 0.001), and 30/38 (79%) patients (p = 0.051), in the 3 respective trials. In the trial of enzalutamide +/- PROSTVAC for metastatic CRPC, high cortisol/cortisone ratio in the enzalutamide arm was associated with significantly improved PSA progression-free survival and radiographic progression-free survival. However, in the enzalutamide + PROSTVAC arm, the opposite trend was observed. In conclusion, treatment with enzalutamide or apalutamide increases systemic exposure to active glucocorticoids. These findings have potential consequences for immune suppression and the efficacy of treatment combinations using next-generation AR antagonists. On-treatment, glucocorticoid changes might serve as a pharmacodynamic biomarker.

P14.06 Phase II randomized trial of short course hypofractionated radiotherapy with or without temozolomide in elderly patients with Glioblastoma

BACKGROUND

Glioblastoma (GBM) is the most aggressive primary brain tumor. Although treatment advances and introduction of temozolomide has improved the outcome in young patients, it is still a concern in elderly patients. Elderly population is often excluded from the trials, thus established treatment guidelines are not available. Trials have shown that short course hypofractionated radiotherapy (HRT) is equally effective in terms of overall survival (OS) and progression free survival (PFS) as compared to standard RT in elderly population. While the benefit of adding Temozolomide (TMZ) to standard dose radiotherapy is well established, there is lack of evidence that addition of TMZ to HRT improves survival in elderly patients.We conducted this study to see if addition of temozolomide to HRT improves OS, PFS and quality of life (QOL) in elderly GBM patients.

MATERIAL AND METHODS

The study was conducted over a period of 21 months from January 2017 to September 2018. Histologically proven 70 newly diagnosed Glioblastoma patients (age>60 years) were enrolled and randomized into two arms (Arm I- HRT alone, Arm II- HRT and TMZ) using computer generated randomization table (1:1 ratio). The radiotherapy dose in both arms was same and consisted of a dose of 25Gy in 5 daily fractions over 1 week. In addition, arm II patients received daily concurrent TMZ 75mg/m2 1 hour prior to RT followed by adjuvant TMZ 175mg/m2 from Day1-5 for 6 cycles (q 4weeks), started after a month of RT completion. Quality of life score and global health status was assessed in both arms at baseline, 1, 3, 6 and 9 months after the treatment using QOL questionnaire EORTC QLQ-C 30 and QLQ-BN20. Data entry was done in Microsoft Excel 2016 and analysis was done in SPSS version 18. Kaplan Meier survival analysis was done for OS and PFS. To see the trend of time related observations at different point of time repeated ANOVA was used. A p value of <0.05 was taken significant.

RESULTS

The median OS in arm I and II was 121 (range 40–360 days) and 146 (range 40–450 days) days respectively (P=0.146). The median PFS in arm 1 and arm 2 were 77 (range 30–300 days) and 109.50 (range 30–300) days respectively (p-0.028). On further analysis, the prognostic factors were type of surgery (Median PFS 159 days in gross total excision and 129 days in subtotal excision or biopsy, p-0.03) and KPS (0.04). QOL score for symptom and functional domain was comparable in both arms. However score of nausea and vomiting was higher during concurrent chemoradiotherapy. A non significant improvement in QLQ BN 20 score was observed at 9 months in arm I.

CONCLUSION

Addition of Temozolomide to HRT is a compelling option in elderly Glioblastoma patients as it significantly improves the PFS and a non significant improvement in OS without compromising quality of life.

A population pharmacokinetic analysis of the oral CYP17 lyase and androgen receptor inhibitor seviteronel in patients with advanced/metastatic castration-resistant prostate cancer or breast cancer

PURPOSE

Seviteronel is an orally-administered selective cytochrome P450c17a 17,20-lyase and androgen receptor inhibitor with anti-tumor activity in vitro and in vivo, and clinical activity in men with advanced castration-resistant prostate cancer (CRPC) and men and women with advanced breast cancer. The purpose of this study was to assess the pharmacokinetics (PK) of seviteronel across the aforementioned populations.

METHODS

This report describes the PK of seviteronel (50-750 mg, QD or BID) using noncompartmental and population approaches from 243 patients with advanced breast or prostate cancer pooled across 4 clinical studies. First dose and steady-state PK were examined, as well as covariates including prandial status, sex and concomitant dexamethasone.

RESULTS

Seviteronel PK can be characterized by transit absorption and a bi-phasic first-order elimination while accounting for covariance between random effects. Prandial status did not significantly affect any parameters to a clinically-relevant extent. Both sex and body weight were significant covariates on clearance, explaining 37% of the interindividual variability on that parameter. There were no significant effects from the race or the presence of a corticosteroid (either dexamethasone or prednisone).

CONCLUSIONS

Seviteronel demonstrates linear PK over the dose range of 50-750 mg given either BID or QD in men with advanced CRPC or men and women with breast cancer. The disposition of seviteronel following oral administration is well described by this population PK model and can be used for accurate simulations for future studies with body weight and sex affecting clearance, but not to a clinically-meaningful degree requiring a change in the current dosing scheme.

Efficacy of Low-dose Dexamethasone for Preventing Postoperative Nausea and Vomiting following Strabismus Repair in Children

We studied the efficacy of a range of doses of dexamethasone for prevention of postoperative nausea and vomiting following strabismus repair in children in a hospital-based, prospective, double-blinded, randomized, placebo-controlled trial.

Two hundred and ten children were randomized to receive either dexamethasone in one of four dosages: 50 μg/kg (Group 1), 100 μg/kg (Group 2), 200 μg/kg (Group 3) and 250 μg/kg (Group 4) or normal saline (Group 5) prior to corrective surgery for strabismus. Anaesthesia was standardized and included nitrous oxide, pethidine, intubation and the use of muscle relaxant and reversal with neostigmine. Postoperative nausea and vomiting were evaluated in epochs of 0-2 hours, 2-6 hours and 6-24 hours after surgery. Parent satisfaction was assessed 24 hours after surgery and the operated eye was examined for wound infection and delayed healing one week later.

Dexamethasone was effective in preventing nausea and vomiting after strabismus repair: 57.1% children in Group 1, 42.9% in Group 2, 52.4% in Group 3, and 59.5% in Group 4 were free from postoperative nausea and vomiting compared with 7.1% in placebo group. The lowest dose of 50 μg/kg was as efficacious as the higher dosages of dexamethasone during the 24 hours studied. Of the children who developed postoperative nausea and vomiting, those who received dexamethasone had significantly fewer episodes than those in the placebo group.

We conclude that dexamethasone 50 μg/kg is effective for the prevention of postoperative nausea and vomiting following strabismus repair in children.

A Phase II Multi-Center Study of Bevacizumab in Combination with Ixabepilone in Subjects with Advanced Renal Cell Carcinoma

Lessons Learned.

Accrual to renal cell carcinoma trials remains a challenge despite the lack of prolonged response to the available treatments.

The observation of three responses among the 30 patients with median progression‐free survival and overall survival of 8.3 and 15 months, respectively, indicates the combination has some activity, but it is not sufficient for further development.

Background.

Treatment of metastatic renal cell carcinoma (mRCC) remains suboptimal. Preclinical data have previously shown that ixabepilone, a microtubule‐stabilizing agent approved for the treatment of breast cancer, is active in taxane‐sensitive and ‐resistant cells. In this single‐arm phase II trial, we investigated a combination of ixabepilone plus bevacizumab in patients with refractory mRCC.

Methods.

We enrolled 30 patients with histologically confirmed mRCC, clear cell subtype, who had not been previously treated with ixabepilone or bevacizumab but had received at least one prior U.S. Food and Drug Administration (FDA)‐approved treatment for renal cell carcinoma (RCC). The treatment regimen consisted of 6 mg/m² ixabepilone per day for 5 days and 15 mg/kg bevacizumab every 21 days. After 6 cycles, the treatment interval could be extended to every 28 days. The primary endpoint was the objective response rate according to the Response Evaluation Criteria in Solid Tumors (RECIST). Secondary endpoints were progression‐free survival (PFS), overall survival (OS), and the toxicity of the combination.

Results.

The median number of prior therapies was two (range per patient one to five). Patients received a median of 8 cycles of ixabepilone plus bevacizumab (range 2–54). The median follow‐up was 36.4 months (range 23.5–96.5). Nineteen patients (63.3%) had stable disease as a best response. Three patients (10%) had a partial response. The median PFS was 8.3 months (95% confidence interval [CI], 4.9–10.6) and the median OS was 15.0 months (95% CI, 11.3–28.8). The total number of cycle for safety evaluation was 289. Grade 3/4 adverse events (>5% incidence) included lymphopenia (16.7%), hypertension (6.7%), and leukopenia (6.7%).

Conclusion.

The combination of ixabepilone and bevacizumab was well tolerated, with modest activity in second ‐ or later‐line mRCC, but it is not recommended as a therapy without further clinical development. Alternative combinations with these agents could be explored in future studies.

Abstract CT058: A phase 2 open-label study to evaluate the efficacy and safety of VT-464 in patients with androgen receptor positive triple-negative breast cancer patients, and men with ER positive breast cancer

Background: The androgen receptor (AR) is expressed in 20-30% of patients with triple negative breast cancer (TNBC). In phase 2 trials androgen blockade with bicalutamide demonstrated a clinical benefit rate (CBR = Partial Response + Complete Response + Stable Disease) of 19% at 24 weeks and enzalutamide showed a CBR of 35% at 16 weeks. VT-464 is an oral non-steroidal, small molecule that is a potent anti-androgen through both inhibition of CYP17 lyase and through direct inhibition of AR. Studies in breast cancer cell lines have shown that VT-464 inhibits growth in a soft agar assay of MCF7 (ER positive/low AR expression), tamoxifen-resistant MCF7, and MDA-MB-453 (ER negative/AR positive) cells in a dose dependent manner and with higher potency than enzalutamide. Patients with AR+ TNBC may benefit from treatment with VT-464. In addition, since VT-464 will deplete androgen available for aromatization, men with ER-positive (ER+) breast cancer may benefit from use of VT-464.

Methods: This is a Phase 2, open label study evaluating the potential benefit of VT-464 in female patients with TNBC with AR 1 to 9% (cohort 1) and AR ≥ 10% (cohort 2), and men with ER+ breast cancer (cohort 3) (NCT02130700; NIH 14-c-0090). VT-464 will be administered once daily in continuous 28-days cycles. Due to differences in drug metabolism, women with TNBC will receive VT-464 450mg by mouth daily while men with ER+ breast cancer will receive VT-464 600mg by mouth daily. In the two female TNBC cohorts the primary endpoint is CBR at 16 weeks. In the ER+ male breast cancer cohort the primary endpoint is progression free survival at 24 weeks. Secondary objectives include evaluation of response rate and the safety profile of the drug in both populations. Women with TNBC with &gt; 1% AR expression per IHC are eligible. Males with ER+ breast cancer, who have failed at least one prior endocrine therapy and are undergoing gonadal suppression using LHRH agonists or antagonists are eligible for the study. All patients must be at least 18 years old and have a ECOG of 0 to 1. Consenting patients must have biopsiable disease which will be used for genomic and transcriptomic evaluation before and after treatment with VT-464. Correlative studies including serum hormone levels, circulating tumor cells, and immune subset will be analyzed. Patients must also have adequate hematopoietic, hepatic and renal function. Exclusions include symptomatic CNS metastases, radiotherapy within 28 days of study entry and active HIV, hepatitis B or hepatitis C infection. This trial opened in December 2016. While no patients have been enrolled at this time, multiple patients are currently being screened.

Citation Format: Alexandra Zimmer, Margaret E. Gatti-Mays, Stan Lipkowitz, Fatima Karzai, James Gulley, William Dahut, Seth Steinberg, William D. Figg, Ravi Madan. A phase 2 open-label study to evaluate the efficacy and safety of VT-464 in patients with androgen receptor positive triple-negative breast cancer patients, and men with ER positive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT058. doi:10.1158/1538-7445.AM2017-CT058

Abstract 2048: Pharmacodynamic biomarker studies of TRC105 anti-endoglin (CD105) antibody revealed anti-angiogenic activity associated with CD105 depletion

Introduction: CD105 is involved in normal vascular development. It is over expressed on the surface of proliferating vascular endothelial cells and is implicated in tumor angiogenesis. In hypoxic conditions, CD105 is upregulated through induction of hypoxia-inducible factor 1-α. TRC105 is a chimeric IgG1 antibody specific for CD105 and the agent for this phase I trial.

Methods: 20 patients with metastatic prostate cancer were treated with TRC105 at six dose levels in a phase I trial. Blood samples were analyzed for CD105 antigen depletion, VEGF as a marker for systemic hypoxia, and PSA.

Results: Maximum tolerated dose of 20 mg/kg every two weeks was reached. Significant plasma CD105 reduction was observed at high dose levels. The reduction of CD105 was associated with induction of plasma VEGF. Ten patients had stable disease, and the reduction of CD105 is associated with PSA stabilization.

Conclusion: A significant induction of VEGF was associated with CD105 reduction at three high dose levels, suggesting the anti-angiogenic activity of TRC105. Exploratory analysis showed a tentative correlation between the reduced CD105 and a decreased PSA velocity, suggestive of potential antitumor activity of TRC105 in metastatic prostate cancer.

Citation Format: Liang Cao, Fatima Karzai, Andrea Apolo, Ravi Madan, Yunkai Yu, James Gulley, William Figg, William Dahut. Pharmacodynamic biomarker studies of TRC105 anti-endoglin (CD105) antibody revealed anti-angiogenic activity associated with CD105 depletion. [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 2048.

Metaplastic carcinoma of breast: A case series of seven patients from a tertiary care center and review of literature

PURPOSE

Metaplastic carcinoma of breast (MCB) is a rare histological subtype of breast carcinoma and accounts for less than 1 percent of the total breast cancer cases. Here we are reporting a series of seven patients of MCB from single institute along with review of literature.

MATERIAL AND METHODS

Patients records from January 2008 to August 2014 were retrieved to search for MCB patients. A etrospective review was conducted to document the clinicopathological features, treatment and outcomes of these patients. The data was entered in a predesigned proforma document.

RESULTS

Seven patients were diagnosed to have MCB during this period. Most common symptom at presentation was lump in the breast with associated discharge per nipple in one patient. On histology, there was no definite differentiation in four patients while one patient had spindle cell neoplasia, one had osteoid and chondroid neoplasia respectively. Five patients underwent modified radical mastectomy while other two patients underwent simple mastectomy. All the patients were pathologically node negative and triple negative breast cancer. Adjuvant chemo-radiotherapy was given to all patients. Median follow up was 4 years (Range 3-6 years). Three out of seven patients completed 5 years of follow up. One patient developed isolated liver metastasis six years after completion of the treatment and she lost to follow up for further treatment.

CONCLUSION

Metaplastic carcinoma of breast is a rare disease entity and there are no specific treatment guidelines. The prognosis of patients in this rare sub group remains poor and multi institutional studies evaluating role of new therapies may be required to improve outcome.

Radiation induced heart disease: Pathogenesis, management and review literature

Radiation therapy (RT) is a very important part of multimodality cancer therapy. Addition of RT improves survival in many cancers, but there are some accompaniments of radiation. One of them is radiation induced heart disease (RIHD). RT for mediastinal lymphoma, breast, lung and oesophageal cancer is associated with the development of RIHD. The problem can be intensified with the addition of chemotherapy. Therapeutic modalities for RIHD are the same as in the non-irradiated population. However, surgery may be difficult in the irradiated patients. The long latent period is the reason why RIHD is not extensively studied. Survival of cancer patients has improved over past few decades, so RIHD is a growing concern especially in younger patients. In this review article, we have discussed the pathogenesis, clinical manifestation and management of RIHD along with impact of chemotherapeutic agents.

Abstract 1586: Recovery and characterization of circulating tumor cells (CTCs) in cryopreserved metastatic castrate-resistant prostate cancer (mCRPC) patient samples

Introduction: Current CTC detection platforms require the processing of patient blood within 48 hrs after collection to preserve CTC integrity and biomarker expression. Here we demonstrate the recovery of CTCs from banked patient blood samples that have been cryopreserved for up to 7 years. Our results show that cryopreserved CTCs have equivalent morphology and protein expression patterns as CTCs in freshly processed blood and are suitable for genomic analyses. This process enables retrospective studies of banked patient blood samples inclusive of CTC enumeration, biomarker quantification, FISH and genomic analysis via the Epic Platform.

Methods: 30 cryopreserved mCRPC patient blood samples were sent to Epic Sciences alongside 10 matched fresh blood draws (&lt;48 h after draw). All nucleated cells from mCRPC patient samples or cell line-spiked healthy donor (HD) controls were plated onto glass slides and subjected to IF staining, CTC identification by fluorescent scanners and algorithmic analysis. Traditional CTCs (CK+, CD45-, intact DAPI nuclei and morphologically distinct) and CK- CTCs (CK-, CD45-, intact and distinct) were identified. Androgen receptor (AR) expression was assessed by IF staining and PTEN status determined by FISH. Relative CTC enumeration, morphology, protein expression and genomic status were compared between freshly processed and cryopreserved samples.

Results: Initial testing in VCaP (AR+) and PC3 (AR-) cell line-spiked HD blood demonstrated preservation of cell morphology and biomarker expression. In VCaP, CK signal decreased 20% and AR decreased 6% after freezing, but CK and AR expression were 90- and 8-fold higher than negative controls, respectively. In patients, CTCs were detected in 7/10 freshly processed samples and in equal relative abundance in 6/10 matched frozen samples. Cryopreserved CTCs retain CK and AR expression as compared to freshly processed samples: there were no significant differences in mean CK or AR expression among all matched samples compared, and% AR+ CTCs correlated strongly between fresh and frozen samples (r2 = 0.96). Furthermore, PTEN FISH on cryopreserved CTCs resulted in a near-equal percentage of PTEN variant cells as compared to matched fresh draws. After concordance studies, an additional 20 frozen mCRPC patient samples were processed: CTCs were detected in 16/20 samples, with 11/20 harboring AR+ CTCs.

Conclusion: Recovery of CTCs in cryopreserved patient blood samples is feasible using the Epic Platform. These data demonstrate concordance of CTC recovery, protein characterization and genomic analysis in an initial cohort of cryopreserved mCRPC samples. Further studies characterizing cryopreserved CTCs in mCRPC and in cancers of other tissues are warranted, with the goal of enabling retrospective protein and genomic characterization of banked patient samples.

Citation Format: David Lu, Melissa Harvey, Ravi Madan, Christopher Heery, Jennifer Marte, Sharon Beasley, Mark Landers, Rachel Krupa, Jessica Louw, Justin Wahl, Natalee Bales, Dena Marrinucci, Jeffrey Schlom, James Gulley, Ryan Dittamore. Recovery and characterization of circulating tumor cells (CTCs) in cryopreserved metastatic castrate-resistant prostate cancer (mCRPC) patient samples. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1586. doi:10.1158/1538-7445.AM2015-1586

Abstract 366: A novel transcript variant of androgen receptor identified in circulating tumor cells from castration-resistant prostate cancer patients as a potentially prognostic biomarker

Circulating tumor cells (CTCs) are rare cancer cells in the bloodstream thought to have a key role in cancer metastasis. There are enormous interests in their analysis for castration-resistant prostate cancer (CRPC) due to their tendency to metastasize to bone. In this study, we applied a surface marker-independent microfluidic device for CTCs capture and retrieval that is based on cell size and deformability. Our device was able to capture 90% and recover 30% of tumor cells in spike experiments. We also developed and validated assays capable of detecting the transcript levels of selected molecular markers in single cells prepared with C1TM Single-Cell AutoPrep System. Blood samples drawn from 34 CRPC patients and 10 primary prostate cancer patients (PPC) were preceded for CTC isolation and molecular characterization. We found that 73% CRPC patients and 10% PPC patients were positive for EpCAM, and only about half of the EpCAM-positive CRPC cases were PSA or AR positive. It is interesting that while there is a strong association between AR and PSA expression in CTC samples, there is no correlation between AR or PSA transcripts in CTCs and serum PSA protein levels in CRPC patients. The positive detection of AR or PSA, but not EpCAM is statistically associated with poor prognosis of the CRPC patients. Very intriguingly, we identified a novel androgen receptor (AR) transcript variant -ARv from four CRPC patients’ CTCs. This ARv lacks a 554bp sequence region in the ligand binding domain (LBD), resulting in a loss of the entire LBD. Clinical data analysis revealed that the ARv is significantly associated with worse survival of CRPC patients (p&lt;0.0001). In vitro functional studies showed this novel ARv is constitutively active in the absence of testosterone. Our findings suggest that this AR variant might contribute to the late stage progression of the diseases and could be used as a potential indicator for alternative therapies. In summary, our new fluidic device is capable of isolating CTC to enable molecular marker analysis, providing value in prognosis and guidance to therapy.

Citation Format: Zhigang Kang, Avani Shah, Yunkai Yu, Yuelin Zhu, Ali Asgar Bhagat, Kyra Zhao, Andrew Wu, James Gao, Ravi Madan, James Gulley, William Dahut, Paul Meltzer, Liang Cao. A novel transcript variant of androgen receptor identified in circulating tumor cells from castration-resistant prostate cancer patients as a potentially prognostic biomarker. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 366. doi:10.1158/1538-7445.AM2015-366

Comparison of temperature rise in pulp chamber during polymerization of materials used for direct fabrication of provisional restorations: An in-vitro study

OBJECTIVE

The purpose is to compare temperature rise in the pulp chamber during fabrication of provisional crowns using different materials and on different types of teeth using direct technique.

MATERIALS AND METHODS

An extracted, sound, caries free maxillary central incisor and a mandibular molar were selected for the study and crown preparations of all ceramic and all metal were done on central incisor and mandibular molar, respectively. Materials tested were DPI tooth molding self-curing material and protemp-4. Addition silicone putty was used as a matrix and 80 provisional crowns were fabricated, of which 40 were on central incisor and 40 on mandibular molar. Depending on the type of material used, they were further divided into two subgroups: Each comprising 20 provisional crowns. Temperature readings were recorded using K type of thermocouple with 0.1°C precision digital thermometer.

STATISTICAL ANALYSIS USED

Analysis of variance, Tukey honest significant difference and Kruskall-Wallis H-test.

RESULTS

Statistically significant difference exists between two materials tested on the basis of peak temperature achieved and time taken by a particular material to reach peak temperature. Peak temperature achieved was highest for provisional crowns with DPI tooth molding self-curing material on maxillary central incisor (40.39 + 0.46), followed by DPI tooth molding self-curing material on mandibular molar (40.03 + 0.32), protemp-4 on maxillary central incisor (39.46 + 0.26) and least with protemp-4 on mandibular molar (39.09 + 0.33). The time taken to reach peak temperature was almost double in DPI tooth molding self-curing material (5 min) than in protemp-4.

CONCLUSION

Polymethyl methacrylate resin produced higher intra-pulpal rise when compared to newer generation bis-acrylic composite.

Abstract 4815: A novel AR splice variant identified in circulating tumor cells from castration-resistant prostate cancer patient blood as a potentially prognostic biomarker

Circulating tumor cells (CTCs) are rare cancer cells circulating in the bloodstream that are thought to have a key role in cancer metastasis. They have been associated with worse prognosis in several major cancer types. There is an intense interest in the molecular analysis of CTC to gain information that would assist treatment decisions and potentially improve the disease outcome. There are enormous interests in the analysis of CTCs for castration-resistant prostate cancer (CRPC) due to the nature of the tumor that tends to metastasize to bone, making them generally inaccessible to obtain biopsies. In this study, we applied a surface marker independent, label-free cell trap microfluidics device for CTCs isolation and retrieval based on cell size and deformability. A total of 47 blood samples drawn from 36 patients with CRPC were preceded for CTC isolation followed by molecular characterization using epithelial tumor markers and prostate cancer specific markers. We identified a novel androgen receptor (AR) splice variant from four patients' CTCs, and confirmed by DNA sequencing that this variant lacks a 554bp region in the ligand binding domain of the receptor in comparison with wild type human AR. Patients with this splice variant were found to be associated with poor survival (p&lt;0.0001). Our study suggests that the presence of the AR splice variant in CTC may serve as a novel prognostic biomarker for CRPC patients.

Note: This abstract was not presented at the meeting.

Citation Format: Zhigang Kang, Yunkai Yu, Liang Cao, Paul S. Meltzer, Yuelin Zhu, Avan Shah, James Gulley, William Duht, Ravi Madan, Ali Bhagat, Kyra Zhao. A novel AR splice variant identified in circulating tumor cells from castration-resistant prostate cancer patient blood as a potentially prognostic biomarker. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4815. doi:10.1158/1538-7445.AM2014-4815

Posttraumatic Intrahepatic Bilioma

Blunt injury abdomen causing biliary injury is rare in children. Collection of bile within or outside the liver after biliary injury is called bilioma. CT scan images of late presenting intra-hepatic bilioma are shown.

CT imaging findings and endovascular management of isolated spontaneous dissecting aneurysm of celiac artery

Isolated spontaneous dissecting aneurysm of celiac artery without concomitant involvement of aorta is a rare entity and only a few cases are reported in the literature. More cases are being detected recently with greater advancements in CT technology. Clinicians and emergency physicians should be aware of this condition and should include it in the differential diagnosis of patients who present with refractory postprandial epigastric pain, particularly in middle-aged men. We present a case of a 45-year-old male with isolated spontaneous dissecting celiac artery aneurysm, with special emphasis on CT findings and the role of endovascular management.