Development and operation of the defence COVID-19 lab as a SARS-CoV-2 diagnostic screening capability for UK military personnel

BACKGROUND

In the face of the COVID-19 pandemic, the Defence Science and Technology Laboratory (Dstl) and Defence Pathology combined to form the Defence Clinical Lab (DCL), an accredited (ISO/IEC 17025:2017) high-throughput SARS-CoV-2 PCR screening capability for military personnel.

LABORATORY STRUCTURE AND RESOURCE

The DCL was modular in organisation, with laboratory modules and supporting functions combining to provide the accredited SARS-CoV-2 (envelope (E)-gene) PCR assay. The DCL was resourced by Dstl scientists and military clinicians and biomedical scientists.

LABORATORY RESULTS

Over 12 months of operation, the DCL was open on 289 days and tested over 72 000 samples. Six hundred military SARS-CoV-2-positive results were reported with a median E-gene quantitation cycle (Cq) value of 30.44. The lowest Cq value for a positive result observed was 11.20. Only 64 samples (0.09%) were voided due to assay inhibition after processing started.

CONCLUSIONS

Through a sustained effort and despite various operational issues, the collaboration between Dstl scientific expertise and Defence Pathology clinical expertise provided the UK military with an accredited high-throughput SARS-CoV-2 PCR test capability at the height of the COVID-19 pandemic. The DCL helped facilitate military training and operational deployments contributing to the maintenance of UK military capability. In offering a bespoke capability, including features such as testing samples in unit batches and oversight by military consultant microbiologists, the DCL provided additional benefits to the UK Ministry of Defence that were potentially not available from other SARS-CoV-2 PCR laboratories. The links between Dstl and Defence Pathology have also been strengthened, benefitting future research activities and operational responses.

101 Use of Blood Cultures to Detect Bacteraemia in Surgical Patients: A Prospective, Closed Loop Quality Improvement Project

Introduction

Sepsis is a complex, life-threatening condition, posing a significant burden to both NHS resources and society in general. Bacteraemia is a common presentation in surgical pathology and requires prompt investigation and treatment. Blood cultures remain the gold standard for detecting bacteraemia and providing targeted antibiotic therapy. We aimed to improve the overall use of blood cultures in pyrexial surgical patients.

Method

A three-loop, prospective quality improvement project was performed. Patients identified as being pyrexial were reviewed to determine when it was recorded and whether blood cultures were taken. Following a departmental presentation, two further audit cycles were performed at two months and seven months post-intervention to determine long-term response.

Result

A total of 56 patients were included over the three audit cycles. Blood culture adherence improved from 58.7% at baseline to 65% at 7 months. Most notably, out-of-hours compliance improved from 44.4% to 66.6%. 2-month compliance was 85%, however, this comprised of only 7 patients.

Conclusions

Early recognition and management of sepsis remains a key area of improvement. Whilst overall and out-of-hour blood culture compliance improved, continued education is needed to further increase this.

Abstract SP139: HER2 targeted therapy: Determinants of response and mechanisms of resistance

HER2-positive (+) breast cancer (BC), accounting for 15-20% of all BCs, is characterized by overexpression, mostly via gene amplification, of HER2. HER2 is a key member of the HER family of 4 tyrosine kinase receptors. Multiple clinically available HER2-targeted therapies, including monoclonal antibodies, tyrosine kinase inhibitors (TKIs), and antibody-drug conjugates have revolutionized the outcome of patients with HER2+ BC. Despite these effective therapies, intrinsic and acquired resistance still occurs, posing a major challenge in the clinical management of this disease. A better understanding of the determinants of response and mechanisms of resistance may help develop personalized treatment approaches and new strategies to overcome resistance. Tumors that are truly addicted to HER2, clinically reflected especially under chemotherapy-sparing HER2-targeted therapy regimens, are associated with high and homogeneous levels of HER2 gene amplification, protein, and activity. Even in these HER2-addicted tumors, the efficacy of anti-HER2 therapy can be jeopardized by deregulations in the downstream PI3K pathway (e.g., PIK3CA mutations), which can lead to constitutive activation of the PI3K/AKT pathway and resistance. Given the functional redundancy of signaling from multiple HER receptor dimers and compensatory signaling within the pathway, dual anti-HER2 therapy has proven superior to single agents in achieving a more comprehensive blockade of the entire HER receptor layer and in anti-tumor efficacy. Further, in the HER2+ tumors that co-express ER, an unblocked, re-expressed and/or reactivated ER signaling can provide alternative proliferative and survival signals to evade sustained HER2 blockade, thus underscoring the need for concurrent blockade of HER2 and ER signaling. Nevertheless, effective inhibition of HER2 might prove challenging in some cases due to molecular masking of the HER receptors (e.g., mucins) or due to the de novo presence or acquisition of genetic, epigenetic or post-translational alterations in HER2 itself, including activating HER2 mutations (e.g., L755S), and p95HER2. We recently reported that acquired resistance to HER2-targeted therapy, especially TKIs, is mediated by the common HER2 L755S mutation, the clinical importance of which is underscored by the observation that this and other HER mutations are further enriched in the metastatic lesions compared to primary HER2+ tumors. On the other hand, when HER2 does remain effectively inhibited under potent HER2-targeted therapy, resistance can arise due to the upregulation of alternative escape pathways that transmit proliferative stimuli. These include activation of other receptor tyrosine kinases (e.g., AXL, FGFR), other downstream/intracellular signaling (e.g., SRC, YES1), or metabolic pathways (e.g., FASN and mevalonate pathways). Our recent data suggest that the mevalonate pathway offers an escape mechanism by providing alternative signaling through the YAP/TAZ-mTORC1-survivin axis to activate a transcriptional program that promotes resistant cell proliferation and survival, which can be overcome using inhibitors of mevalonate pathway (e.g., statins). Importantly, activation of the key cell cycle regulator cyclin D1/CDK4 complex has been shown to mediate resistance to HER2-targeted therapy and that CDK4/6 inhibitors, at least partly by also inhibiting mTORC1 activity, can overcome this resistance. Finally, the role of tumor microenvironment, including host immune components (e.g., TILs) and extracellular matrix components signaling via integrins, have been shown to play a role in modulating tumor response to treatment and in resistance. Together, these findings suggest new strategies to enhance sensitivity and overcome resistance to HER2-targeted therapy, some of which are already under clinical development.

Citation Format: R Schiff, J Veeraraghavan, C De Angelis, C Osborne, MF Rimawi. HER2 targeted therapy: Determinants of response and mechanisms of resistance [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr SP139.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Abstract P2-04-20: PD-L1 expression in triple negative breast cancer (TNBC) is associated with improved outcomes

Background: Breast cancer (BC) evolution is influenced by tumor microenvironment. Presence of CD8+ cytotoxic T lymphocytes (TILs) has been proposed as surrogate marker of adaptive immune response, and programmed death ligand-1 (PD-L1) is a negative regulator of the tumor immune microenvironment. However, whether PD-L1 expression adversely affects breast cancer outcome is unknown (Oncotarget 2014; 6:5449). Tumor-associated macrophages (TAMs) in the tumor microenvironment may contribute to BC progression and metastagenicity. We assessed the potential correlations between PD-L1 expression, the presence of TAMs and TILs, and BC outcomes.

Methods: 59 primary BCs (16 HR+, 16 HER2+, and 27 TNBC) with known clinical and pathological features and patient (pt) follow-up for a median of 3.9 years were evaluated by immunohistochemistry for expression of CD8, CD68, and PD-L1 within tumor and stroma. The average number of CD8+ cells within 10 high power fields was determined separately for invasive tumor cell nests and for stroma within each sample, and the median number of CD8+ cells within tumor vs stroma was calculated (Breast Cancer Res Treat 2011 128:703–711). Non-lymphocyte mononuclear cells in tumor and stroma were used in counting CD68+ TAMs. BCs were positive for CD8+ TILs (Cell Marque clone #C8144B) or CD68+ TAMs (Cell Marque clone #KP1) if the number of cells positive in the sample was greater than the median. PD-L1 (Dako 28-8 pharmDx) was positive if at least 1% of tumor cells expressed PD-L1. The log-rank was used to compare the survival and progression free survival between groups and Spearman's rank-order correlation tests were conducted to determine associations between CD8, CD68, and PD-L1.

Results: 57% of TN, 26% of HER2+ and 13% of HR+ BCs expressed PD-L1 in tumor. TNBC pts received anthracycline/ taxane chemotherapy (62%) or taxane therapy alone (22%). HR+ and HER2+ pts received standard endocrine therapy and trastuzumab-based therapy. Stromal CD8+ TILs were associated with improved OS in the overall population (log rank p=0.026). In TNBC, PD-L1 expression was positively correlated with the presence of TILs (p=0.0002) and TAMs (p=0.0005) as well as with improved 3 year PFS and OS (log rank p=0.04 and p=0.03, respectively). Furthermore, stromal CD8+ TILs and stromal CD68+ TAMs correlated positively with each other in the TNBC group (p=0.0094).

Conclusions: PD-L1 expression correlated with TILs and TAMs in TNBC and was associated with a favorable outcome. PD-L1+ TNBCs with high levels of TILs and TAMs may be primed for exceptional response to immunogenic chemotherapy alone. Whether some pts with PD-L1+ TNBCs with high TILs/TAMs will benefit additionally from an anti-PD-L1/PD-1 agent is being investigated currently.

Citation Format: Mardones MA, Grosser D, Levin MK, Daoud Y, Palucka K, O'Shaughnessy J, Osborne C. PD-L1 expression in triple negative breast cancer (TNBC) is associated with improved outcomes [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-04-20.

Quality of initial HIV care in Canada: extension of a composite programmatic assessment tool for HIV therapy

OBJECTIVES

To document the quality of initial HIV care in Canada using the Programmatic Compliance Score (PCS), to explore the association of the PCS with mortality, and to identify factors associated with higher quality of care.

METHODS

We analysed data from the Canadian Observational Cohort Collaboration (CANOC), a multisite Canadian cohort of HIV-positive adults initiating combination antiretroviral therapy (ART) from 2000 to 2011. PCS indicators of noncompliance with HIV treatment guidelines include: fewer than three CD4 count tests in the first year of ART; fewer than three viral load tests in the first year of ART; no drug resistance testing before initiation; baseline CD4 count < 200 cells/mm³ ; starting a nonrecommended ART regimen; and not achieving viral suppression within 6 months of initiation. Indicators are summed for a score from 0 to 6; higher scores indicate poorer care. Cox regression was used to assess the association between PCS and mortality and ordinal logistic regression was used to explore factors associated with higher quality of care.

RESULTS

Of the 7460 participants (18% female), the median score was 1.0 (Q1-Q3 1.0-2.0); 21% scored 0 and 8% scored ≥ 4. In multivariable analysis, compared with a score of 0, poorer PCS was associated with mortality for scores > 1 [score = 2: adjusted hazard ratio (AHR) 1.64; 95% confidence interval (CI) 1.13-2.36; score = 3: AHR 2.02; 95% CI 1.38-2.97; score ≥ 4: AHR 2.14; 95% CI 1.43-3.21], after adjustments for age, sex, province, ART start year, hepatitis C virus (HCV) coinfection, and baseline viral load. Women, individuals with HCV coinfection, younger people, and individuals starting ART earlier (2000-2003) had poorer scores.

CONCLUSIONS

Our findings further validate the PCS as a predictor of all-cause mortality. Disparities identified suggest that further efforts are needed to ensure that care is equitably accessible.

Abstract OT3-02-08: Scalp cooling alopecia prevention trial (SCALP) for patients with early stage breast cancer

Background

Adjuvant chemotherapy treats micro-metastatic disease and decreases the risk of breast cancer recurrence. However, it may be associated with distressing side effects, including alopecia. Women with breast cancer rate chemotherapy-induced alopecia as one of the most severe, troublesome, and distressing side effects of chemotherapy. In many countries, scalp cooling has been introduced to prevent or reduce chemotherapy-induced alopecia. The theory is that scalp cooling causes cutaneous vasoconstriction, which reduces blood flow to the hair follicles during peak plasma concentrations of the chemotherapeutic agents and therefore reduces cellular uptake of these agents. It also results in reduced biochemical activity, which makes hair follicles less susceptible to the damage of the chemotherapy agents. Historically success rates are have been variable, but based on non-randomized studies, scalp cooling appears to be effective in preventing chemotherapy-induced alopecia especially in more recent studies.

Methods

We are conducting a prospective multi-center randomized controlled non-blinded trial to evaluate the safety and efficacy of the Orbis Paxman Hair Loss Prevention System in reducing the incidence of chemotherapy-induced alopecia. Women with stage I-II breast cancer who will receive neoadjuvant or adjuvant anthracycline- or taxane-based chemotherapy, for at least four cycles are eligible. Participants are randomized in a 2:1 ratio to scalp-cooling or no cooling. Scalp-cooling is done using the Orbis Paxman Hair Loss Prevention System prior to, during and after each chemotherapy administration. The primary efficacy endpoints are hair preservation, defined as CTCAE v4 alopecia &lt;2, and device safety. Two hundred and thirty five (235) patients are planned to be enrolled which will provide 85% power to detect a 20% difference in hair preservation, 15% in control group and 35% in scalp-cooling group . Secondary endpoints include: wig/scarf use and quality of life assessed by the EORTC QLQ-30, HADS and BIS. Study participants will be followed for 5 years post-study for time to first recurrence, overall survival, site of first recurrence, and incidence of isolated scalp metastasis.

Citation Format: Nangia JR, Wang T, Rude M, Osborne C, Papish S, Abraham J, Holmes F, Savin M, Paxman R, Hilsenbeck SG, Osborne CK, Rimawi M. Scalp cooling alopecia prevention trial (SCALP) for patients with early stage breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT3-02-08.

Analysis of 14,008 uroliths from dogs in the UK over a 10-year period

OBJECTIVES

To identify breed-associated risk factors for urolithiasis in dogs from the UK.

METHODS

Records of all canine uroliths submitted to Hills Pet Nutrition UK for analysis at the University of Minnesota Urolith Centre over 10 years (1997 to 2006) were reviewed. The results, along with the request forms completed by the submitting veterinarian, were analysed. The most commonly affected breeds, age and gender of the dogs were identified for each of the most common types of uroliths (struvite, calcium oxalate, urate, cystine and mixed). Pearson's chi-squared tests were performed to assess whether certain breeds of dogs were over-represented relative to a reference population (from an insurance database).

RESULTS

The records of 14,008 urolith submissions were analysed. The relative frequency of struvite remained stable over time, whereas calcium oxalate decreased over the study period. Breeds found to be significantly over-represented for calcium oxalate uroliths included the Chihuahua, miniature poodle and Yorkshire terrier. Staffordshire bull terriers and English bulldogs were at increased risk for cystine uroliths.

CLINICAL SIGNIFICANCE

Associations between breed, gender, age and urolith formation were similar to those reported elsewhere. However, temporal trends and novel breed predispositions were identified.

Abstract P4-11-08: A Pilot Safety and Feasibility Study of Concurrent Capecitabine and External Beam Irradiation in the Adjuvant Treatment of High Risk Early Stage Breast Cancer

Background: Capecitabine (Xeloda ®) is an oral 5-FU pro-drug that is preferentially converted to the active form 5-FU within tumor tissue, offering many of the same benefits of continuous 5-FU infusion with the convenience of oral delivery. In studies of patients receiving chemotherapy with or without radiation therapy, combination therapy has proved more efficacious than either modality alone. If radiation therapy can more effectively eliminate local microscopic residual disease, this will resultin improved local control and may potentially increase overall survival. This phase II study was performed to ascertain the safety and feasibility of capecitabine concurrent with radiation therapy in high risk non-metastatic breast cancer.

Materials and methods: Eligible patients had undergone surgery and chemotherapy for high risk breast cancer, defined for this study as either a T3 or T4 primary tumor, or N2 (≥4 nodes involved) or greater nodal status. Capecitabine was administered at 825 mg/m2 twice daily on days of radiotherapy. The primary endpoint of this study was toxicity, scored using CTCAE v 3.0, evaluated during therapy and in follow-up at intervals up to 12 months. Clinically significant toxicities were defined as skin toxicity or hematological toxicity of grade 3 or greater, or other toxicity felt related to capecitabine of grade 2 or greater. Feasibility was defined as percent of patients completing the course of drug, and the percent of patients completing radiation therapy to a dose of at least 50.4 Gy. Cosmesis was rated by the physician and the patient separately.

Results: 50 women were enrolled in this study; the mean age was 52 (range 33-77). T stage distribution was as follows: T0 4%, T1 16%, T2 50%, T3 18%, and T4 12%. N stage N0 6%, N1 18%, N2 44%, and N3 32%. Mean number of pathologically involved nodes was 8 (range 0-36); 56 % of patients were treated with neoadjuvant chemotherapy prior to definitive surgery, which for 84% was mastectomy. Four patients withdrew prior to starting or within the first week; of the remaining 46 patients, 10 had capecitabine discontinued or dose-reduced, and one patient died during treatment. Those patients who did not receive the full drug dose had on average 3.8 weeks of capecitabine therapy; of the overall 46 patients, 76 % received the intended dose of drug throughout the radiation treatments; 98% of patients received at least 50.4 Gy. Toxicities observed included 7 pts with grade 3 radiation dermatitis, 3 with grade 3 hand-foot syndrome, 1 with grade 4 diarrhea, and 1 with grade 5 cardiac arrest felt possibly related to capecitabine; 2 other grade 3 toxicities (range of motion limitation and bone pain) were felt not related to the study. Mean cosmesis scores at baseline were assessed to be “good” by both patients and physicians; these were stable at 12 months of follow-up. 90 % of patients were alive at 12 months, and 2 (4 %) were observed to suffer local, in-field failure. Discussion: Radiation therapy in combination with capecitabine is a well tolerated adjuvant therapy for patients with high risk breast cancer, with most patients completing all therapy. Controlled studies examining efficacy are warranted.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-11-08.

A Single Nucleotide Polymorphism in Steroid Receptor Coactivator-1 Diminishes the Coactivation of ERα

Estrogen signaling is critical in the progression of a large fraction of breast cancers as well as in the maintenance of bone mineral density. Generally speaking, Tamoxifen, a selective estrogen receptor modulator (SERM), blocks estrogen signaling in the breast by acting as an antagonist at the same time as promoting estrogen signaling in the bone by acting as an agonist. This tissue specific action characteristic of SERMs is thought to be maintained by the balance of levels and/or activities of estrogen receptor (ER) coregulators. Because of this critical role, single nucleotide polymorphisms (SNPs) in ER coregulators could have a dramatic effect on tamoxifen action.Previous studies have implicated steroid receptor coactivator-1 (SRC-1) as a critical coregulator for the mixed antagonist-agonist specificity of tamoxifen. By using an ERE-Tk-Luciferase transient transfection assay, we have shown that a SNP causing the amino acid change P1272S in SRC-1 dramatically reduces its ability to coactivate ERα.To assess the impact of this SNP on tamoxifen action in breast cancer we decided to genotype the SRC-1 P1272S SNP in a breast tumor DNA bank. This bank was generated from archived tumors from individuals either exclusively receiving adjuvant tamoxifen or not receiving any adjuvant therapy following surgical resection. Currently, the bank is composed of 1000 samples divided equally among the two groups. Genotyping for the SRC-1 P1272S SNP is currently underway.Since SRC-1 has also been shown to be important in proper maintenance of bone mineral density (BMD) and in the agonist action of tamoxifen in certain tissues, we also assessed the impact of the P1272S SNP in bone following tamoxifen therapy. We genotyped breast cancer patients exclusively receiving tamoxifen therapy (i.e. no chemotherapy, no radiation) who had lumbar (n=113) and/or hip (n=108) BMD scans before and after 12 months of tamoxifen therapy. We observed a significant association between the SNP and bone loss; women harboring the P1272S SNP lost 6.4% of their lumbar BMD, while women with the WT version lost only 1.3% of their lumbar BMD.These findings illustrate the critical role of SRC-1 in tamoxifen action in bone, and potentially other hormone responsive tissues. Studies are ongoing to decipher the mechanism for decreased coactivation activity of the SNP, and also to extend the clinical association studies.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 66.

A BRCA1-Like, 25-Gene Assay Predicts for Anthracycline-Chemosensitivity in Sporadic Triple-Negative Breast Cancer

Background Studies have shown higher chemosensitivity to anthracyclines in BRCA1-associated breast cancer (BABC) when compared to sporadic triple-negative breast cancers (TNBC), possibly due to differences in DNA repair function. We hypothesized that a subset of TNBC with acquired BRCA1 deficiency and defective DNA repair function will benefit most from DNA-damaging agents, such as anthracyclines. Methods We applied a previously published BRCA1 gene expression signature that differentiates BABC from sporadic TNBC to three datasets of sporadic TNBC from Baylor College of Medicine (BCM, n=68), GSE2034 (n=49), and the Netherlands Cancer Institute (NKI2, n=40). The signature separated the sporadic TNBC samples into those with a gene expression profile similar to BABC, or BRCA1-like, versus those with an expression pattern similar to sporadic TNBC, nonBRCA1-like. A list of 92 genes was obtained from the overlap of the most differentially expressed genes between the BRCA1-like samples and nonBRCA1-like samples in each of the three datasets. We then confirmed a subset of the 25 most differentially expressed genes by quantitative RTPCR. We validated the predictive value of this BRCA1-based, 25-gene assay in anthracycline response in three neoadjuvant studies of fluorouracil, epirubicin, and cyclophosphamide (FEC 6 cycles, n=53), doxorubicin and cyclophosphamide (AC 4 cycles, n=12), and T-FAC (paclitaxel-FAC, n=16). Results We determined gene expression of the 92 candidate genes by RT-PCR on 30 available samples of the BCM database. 25 genes were found to have the highest correlation between the microarray and RTQPCR gene expression. Gene expression profile using these 25-gene assay was obtained for three databases which included neoadjuvant anthracycline response data. The 25-gene assay predicted for anthracycline response in sporadic triple-negative breast cancers. In a neoadjuvant FEC study, this assay predicted for pathologic complete response (pCR) in 14/25 patients with BRCA1-like pattern, vs. 7/25 with sporadic-like pattern, p&lt;0.05. In the AC study, 6/9 patients in the BRCA1-like group achieved pCR, vs. 0/3 in nonBRCA1-like group, p&lt;0.05. Finally, in the T-FAC study, 5/7 patients in the BRCA1-like group achieved pCR vs. 3/9 patients in the nonBRCA1-like group, p=0.15. Analysis of the microarray data of triple negative breast cancer revealed higher PARP1 expression levels in the BRCA1-like group when compared to nonBRCA1-like group. Conclusion We present a promising BRCA1-based 25-gene assay that can be used on formalin-fixed paraffin-embedded tissue that may guide therapy in triple- negative breast cancer. The assay differentiates TNBC that are very sensitive to anthracyclines, and it should now be tested and validated prospectively in clinical trials with anthracyclines, other DNA-damaging agents, and PARP1 inhibitors.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 110.

Different Mechanisms for Acquired Resistance to Trastuzumab and Lapatinib in HER2 Positive Breast Cancers: Role of ER and HER2 Reactivation

About 25% of human breast cancers are amplified for HER2 with half of these tumors also expressing estrogen receptor (ER). Therapies targeting HER2 are very effective in the metastatic and the adjuvant settings, especially, although de novo or acquired resistance are still major problems. Trastuzumab (T) and lapatinib (L) are approved drugs now used in the clinic for treatment of HER2+ tumors. Data suggest that T works primarily by blocking signals generated by HER2 homodimers, while L is a small molecule tyrosine kinase inhibitor that more completely blocks the pathway by inhibiting HER1 in addition to HER2. In the clinic, these drugs demonstrate incomplete cross-resistance since L is active in some patients with T-resistant tumors. However, the mechanisms for this resistance have not been clarified.To investigate the mechanisms for acquired resistance, we developed a panel of HER2+ cell lines resistant to T, L, and L+T by long-term exposure to increasing drug concentration in vitro. Two of these lines, BT474 and UACC812, are amplified for HER2 and also express ER, and they, together with subclones resistant to L, T, and L+T, were used to better understand potential resistance mechanisms. Western blot analysis of the parental BT474 and its resistant subclones showed that subclones resistant to T had reactivated the HER2 signaling pathway, while subclones resistant to L or L+T in which the HER receptor layer was more completely inhibited showed continued complete blockade of the HER2 pathway at the receptor layer but high levels of ER activity and phosphorylated-AKT. L, but not L+T, subclones after more prolonged time in culture did reactivate the HER pathway. UACC812 resistant cells were similar to BT474: T-resistant clones showed evidence of reactivation of HER signaling while L and L+T resistant clones showed enhanced ER activity. These cells showed no reactivation of HER signaling even after prolonged exposure in vitro. Consistent with these data, both BT474 and UACC812 T-resistant clones were still sensitive to and cell proliferation was inhibited by L. L-resistant clones, however, were also resistant to T. The potent anti-estrogen fulvestrant (F) was used to evaluate the role of ER in these resistant clones. T-resistant clones from both parental lines were resistant to F, indicating that ER had no role in resistance. In contrast, L and L+T-resistant clones, but not parental cells, were extremely sensitive to F with significant inhibition of cell proliferation in vitro.These data demonstrate that only partial inhibition of the HER2 pathway in breast cancer cells by T can be overcome by activating other components of the HER pathway. Resistance to more complete HER2 blockade with L or L+T requires reactivation of a redundant cell survival pathway, in this case ER, which is upregulated by HER2 blockade. Optimal therapy in those tumors may require both ER and HER2-targeted therapy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 708.

Efficacy of BSI-201, a poly (ADP-ribose) polymerase-1 (PARP1) inhibitor, in combination with gemcitabine/carboplatin (G/C) in patients with metastatic triple-negative breast cancer (TNBC): Results of a randomized phase II trial

3

Background: TNBC is an aggressive breast cancer subtype that shares molecular and pathologic features with BRCA1-related breast cancers. BRCA-deficient cells are sensitive to inhibition of PARP1, a critical enzyme of cell proliferation and DNA repair, and thus represent a rational target of PARP inhibitor-based cancer therapy. The objectives of this study were to evaluate BSI-201, a potent PARP1 inhibitor, in combination with gemcitabine/carboplatin (G/C) in subjects with metastatic TNBC. Methods: Eligible subjects had measurable disease and had ≤2 prior cytotoxic regimens for ER-, PR-, and HER2-negative metastatic breast cancer. Patients were randomized (1:1) to G/C alone or G/C + BSI-201. Gemcitabine (1000 mg/m2) and carboplatin (AUC=2) were given on days 1 and 8, and BSI-201 (5.6 mg/kg; iv; biweekly) on days 1, 4, 8, and 11 every 21 days. Endpoints were clinical benefit rate (CBR = CR + PR + SD ≥6 months), progression-free survival (PFS) and overall survival (OS). Results: Analyses of the first 86 of a planned 120 patients showed that BSI-201 + G/C had improved CBR, median PFS, and median OS, compared with G/C alone. The frequency and nature of adverse events (AEs) did not differ between arms. Conclusions: This preliminary analysis demonstrates that BSI-201 + G/C significantly improves CBR, PFS, and OS, compared with G/C alone. BSI-201 + G/C was well tolerated, with BSI-201 adding no significant toxicity to G/C. Updated CBR, PFS, and OS for all 120 patients and exploratory correlative analyses of PARP expression and clinical response will be presented.

[Table: see text] [Table: see text]

Preliminary safety and activity results of trabectedin in a phase II trial dedicated to triple-negative (ER-, PR-, HER2-), HER2+++, or BRCA1/2 germ-line-mutated metastatic breast cancer (MBC) patients (pts)

1010

Background: Trabectedin ([T]; Yondelis) binds to the minor groove of DNA; its cytotoxicity is determined by the synergistic action of two DNA repair mechanisms, the efficient nucleotide excision repair (NER) and deficient homologous recombination repair (HRR) machinery. T has EMEA authorization in soft tissue sarcoma after failure of standard treatment. Preliminary data have shown activity of T as single agent in MBC. Clinical and preclinical data suggested T may display specific activity among certain NER-intact or HRR-deficient MBC, and prompted this phase II trial dedicated to 3 subgroups: triple-negative (TN), HER-2-overexpressed, and BRCA1/2 germline-mutated MBC. Methods: T was given at 1.3 mg/m2 as a 3- hour iv infusion every 3 weeks to pts with pretreated progressive MBC: Group A: TN; Group B: HER-2+++; Group C: BRCA1/2 mutation carriers. Endpoints were objective response (OR) rate by RECIST, duration of response, progression free survival (PFS), tumor volume changes, safety and exploratory pharmacogenomics (PGx). Results: A total of 95 women (median [med] age 52, ECOG 0/1 48/52%) have been enrolled (A:50, B:24, C:21) with data available for 72 pts. Med number of prior chemotherapy regimens: 4 (1–10). Med number of T cycles administered: 2 (1–12) for all groups. The most commonly reported grade 3/4 AEs are neutropenia (29/21%), ALT (28/2%) and AST (13/0). Alopecia/stomatitis, only G1, was reported in <2% each. Long-lasting disease stabilizations were described in all groups. While OR were rare among TN MBC pts (2PR/43 evaluable), preliminary analysis by investigator shows efficacy in group C (4PR/11 evaluable). Tissue samples from 36 pts were collected for RNA expression analysis (XPG + ERCC1 + BRCA1). Preliminary results show high XPG is associated with longer PFS: 4.1 months (95% CI 2.6-not reached) versus 1.3 months (95% CI 1.2–3.7), p = 0.01. Analyses are ongoing. Conclusions: Trabectedin shows a manageable safety profile in the 3 groups of MBC with promising efficacy in certain DNA-repair machinery sub-categories defined molecularly. TN group was closed due to low response. More mature PGx results will be discussed to help selecting the patients who are at highest chance for response.

[Table: see text]

Efficacy of BSI-201, a poly (ADP-ribose) polymerase-1 (PARP1) inhibitor, in combination with gemcitabine/carboplatin (G/C) in patients with metastatic triple-negative breast cancer (TNBC): Results of a randomized phase II trial

3

The full, final text of this abstract will be available in Part II of the 2009 ASCO Annual Meeting Proceedings, distributed onsite at the Meeting on May 30, 2009, and as a supplement to the June 20, 2009, issue of the Journal of Clinical Oncology.

[Table: see text]

Triple negative breast cancer: a phase 2, multi-center, open-label, randomized trial of gemcitabine/carboplatin (G/C), with or without BSI-201, a PARP inhibitor

Abstract #2120

Background: PARP is a critical enzyme of cell proliferation and DNA repair and BSI-201 has been shown to be a potent inhibitor of PARP-1 in humans. Triple negative breast cancer (TNBC) shares important features with BRCA1-related breast cancer, a validated target for PARP inhibition. Our studies demonstrate that PARP-1 gene expression is statistically significantly upregulated in TNBC compared with normal breast tissue. The primary objective of this study is to assess the Clinical Benefit Rate (CBR=CR+PR+SD &gt; 6 months) of Gemcitabine/Carboplatin with or without BSI-201 in patients with TNBC.&#x2028; Methods: Eligible subjects are ≥ 18 years old who had received ≤ 2 prior chemotherapies for metastatic disease with histologically documented breast cancer that is ER-negative, PR-negative, and HER2-negative. Patients were randomized (1:1 ratio) to one of 2 study arms: a) arm 1: G/C alone; b) arm 2: BSI-201 + G/C. G/C was given on days 1 and 8; G = 1000 mg/m2, C at an AUC=2. In study arm 2, BSI-201 was administered I.V. twice weekly (days 1, 4, 8 and 11) at a dose of 5.6 mg/kg. Cycles were defined as being 21 days in duration. Modified RECIST criteria are used to assess tumor response every 6 weeks (every 2 cycles). Subjects who have progressive disease may crossover to receive BSI-201 and continue G/C. Archived tissue samples were retrieved for the assay of cancer related genes including PARP-1 by multiplex quantitative RT-PCR.&#x2028; Results: To date, 50 subjects have been enrolled and treated for up to 8 cycles of therapy. Overall 39 of 50 (78%) subjects experienced at least 1 adverse event. The frequency and nature of the AE's do not differ between the two treatment groups. Gene expression profiling results from the first 28 patients enrolled confirm that the cancers of patients enrolled have uniformly low hormone receptor expression, variable HER2 receptor expression and significant upregulation of PARP-1 compared with normal breast tissue.&#x2028; Conclusions: This is the first randomized study of a PARP inhibitor in cancer patients. BSI-201 is safe and well tolerated when given in combination with G/C and adverse events observed were consistent with the known safety profiles of G / C regimens. An updated evaluation of toxicity profile and PARP-1 expression analysis will be presented.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2120.

Characteristics of a high-risk minority population

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Background: Black and Hispanic breast cancer patients have a worse outcome when compared to Caucasians. This could be due to socioeconomic, cultural or biologic factors. We hypothesized that host and tumor biologic characteristics associated with a poor outcome may be found more often in minority women. Methods: Race/ethnicity, menopausal status, tumor histological features, and patient characteristics including age and body mass index (BMI) were reviewed from a prospective neoadjuvant trial of docetaxel vs. doxorubicin/cyclophosphamide at Baylor College of Medicine Breast Center, from September 2002 to September 2006. The data were analyzed using Chi-square and Fisher's exact tests, while the Kruskal-Wallis method was used to analyze BMI. Results: Of the 167 patients, 63% (n=105) were Caucasian, 15% (n=26) were Hispanic and 22% (n=36) were Black. The mean age was 47.6 years (range: 30–72). Fifty-nine percent were premenopausal. Overall, mean BMI was 29, with Caucasians having a mean BMI of 27.5, Hispanics with 29.8 and Blacks with a BMI of 34.6 (P<0.001). Sixty-five percent of the Caucasians and 58% of Hispanics were ER+ or PR+ versus 44% of Blacks (P=0.09). Sixteen percent of Caucasians were HER-2 positive compared to 4% of Hispanics and 9% of Blacks (p=0.25). In addition, 22% of Caucasians and 38% of Hispanics were ER-, PR-, HER-2- compared to 50% of tumors from Blacks (p=0.007). There was a trend linking BMI and triple negative status in breast cancers, which did not achieve statistical significance (p=0.21). Conclusion: In this study we found that black and Hispanic women were more likely to be obese and have ER-, PR-, HER-2- tumor phenotypes, both of which have been associated with poorer outcomes. Ongoing studies are being performed to elucidate the link between clinical and biological characteristics and understand the underlying molecular mechanisms associated with these findings.

No significant financial relationships to disclose.

Analysis of 4495 canine and feline uroliths in the Benelux. A retrospective study: 1994?2004

From 1994 to 2004, Hill's Pet Nutrition received 4495 canine (65%) and feline (35%) uroliths from Benelux veterinary practitioners. They were sent to the Minnesota Urolith Center, USA for analysis. In 1994, 110 uroliths were analysed - 85% from dogs - and in 2003, 1067 uroliths were analysed - 59% from dogs. During this period, substantial changes were observed in composition. In 1994, 77% of the cats had uroliths composed of struvite, and 12% had uroliths composed of calcium oxalate. In 2003, feline uroliths were composed of 32% struvite, and 61% calcium oxalate. The same evolution was observed in the dogs. In 1994, 51% of canine uroliths were composed of struvite, and 33% of calcium oxalate. In 2003, 40% had struvite uroliths, and 46% had calcium oxalate uroliths. A significant effect of the size, the breed, and the gender were noticed in the dogs. The mean age of uroliths appearance was 7.3 years in the dogs and 7.2 years in the cats. The findings are similar to those previously published in the USA.

Comparison of non-coplanar and coplanar irradiation techniques to treat cancer of the pancreas

We compared two different techniques of pancreatic irradiation using measures associated with normal tissue complications. Seven consecutive patients with pancreatic cancer were planned for both coplanar and non-coplanar (NCP) external beam radiation treatments, using the same defined anatomical volumes for each patient, in each case. Each pair of plans was then compared using a range of objective criteria. Individual normal tissues were assessed against traditional tolerance limits. Selected dose-points, normal tissue complication probability (NTCP) and equivalent uniform doses (EUD) were also compared, as were indices combining information from individual tissues - total NTCP and total weighted EUD. All individual normal tissues doses were within established tolerance limits. For NCP relative to coplanar planning, NTCP and EUD were lower for all individual tissues in four cases and one case, respectively, i.e. in most cases a benefit to one tissue was offset by detriment to others. Summary measures demonstrated overall benefits for NCP techniques, with the total NTCP in six patients, and with the total weighted EUD in all patients. NCP techniques show potentially useful benefits. We present a new objective measure, the total weighted EUD, which may be particularly useful comparing plans where there are multiple critical tissues.

Phase II trial of intravenous lobradimil and carboplatin in childhood brain tumors: a report from the Children’s Oncology Group

BACKGROUND

[corrected] Lobradimil is a synthetic bradykinin analog that rapidly and transiently increases the permeability of the blood-brain barrier (BBB). The combination of lobradimil and carboplatin was studied in pediatric patients with primary brain tumors in a phase II trial, the primary endpoints of which were to estimate the response rate and time to disease progression.

PATIENTS AND METHODS

Patients were stratified by histology into five cohorts: brainstem glioma, high-grade glioma, low-grade glioma, medullobastoma/primitive neuroectodermal tumor (PNET), and ependymoma. Patients received carboplatin adaptively dosed to achieve a target AUC of 3.5 mg min/ml per day (7 mg.min/ml/cycle) intravenously over 15 min on 2 consecutive days and lobradimil 600 ng/kg ideal body weight/day on 2 consecutive days each 28 day cycle.

RESULTS

Forty-one patients, age 2-19 years, were enrolled; 38 patients, including 1 patient ultimately determined to have atypical neurocytoma, were evaluable for response. No objective responses were observed in the brainstem glioma (n=12) and high-grade glioma (n = 9) cohorts, although two patients with high-grade glioma had prolonged disease stabilization (>6 months). The study was closed for commercial reasons prior to achieving the accrual goals for the ependymoma (n = 8), medulloblastoma/PNET (n = 6) and low-grade glioma (n = 2) cohorts, although responses were observed in 1 patient with PNET and 2 patients with ependymoma.

CONCLUSION

The combination of lobradimil and carboplatin was inactive in childhood high-grade gliomas and brainstem gliomas.

Bone density, body composition and menstrual history of sedentary female former gymnasts, aged 20-32 years

Few studies have examined the effects of retirement from sports involving regular, high impact and weight bearing activity on bone mass. This cross-sectional study compared total body and regional areal bone mineral density (aBMD, g/cm(2)) within female former gymnasts and women who had never participated in structured sport or exercise, and explored relations between aBMD of these former gymnasts and their duration of retirement. Eighteen sedentary female former gymnasts (GYM) and 18 sedentary controls (CON) were recruited. GYM displayed a broad range of duration of retirement (3-12 years) and a wide age range (20-32 years). GYM and CON were paired individually to match for age, body mass and stature. GYM had commenced training at least 3 years pre-menarche and had trained post-menarche for 2 or more years. They had trained continuously for 5-12 years and had retired between age 14 and 22 years. Measurements of aBMD and body composition were made using dual energy X-ray absorptiometry (DXA). Group mean values of physical and skeletal characteristics were compared using paired t-tests. Linear regression was used to explore possible relations of aBMD within GYM to duration of retirement. GYM displayed a higher aBMD than CON at all measurement sites, which ranged in magnitude from 6% for the total body ( P=0.004), to 11% for the total femur ( P=0.006). Elevations of aBMD within GYM equated to T-scores ranging from +0.8 (arms) to +1.7 (legs). There were no differences in body composition or age of menarche between groups, although 11 of 18 GYM reported a history of irregular menses. There was no significant decline of aBMD with increasing duration of retirement in GYM. The results suggested that an elevated bone mass in female former gymnasts was retained during early adulthood, in spite of a cessation of training for up to 12 years.

Mother-to-child transmission of HIV: developing integration of healthcare programmes with clinical, social and basic research studies. Report of the International Workshop held at Chobe Marina Lodge, Kasane, Botswana, 21-25 January 2003

Considerable efforts are still needed in the public health sector, as well as in clinical, social and basic research, to improve programmes for HIV-1 MTCT (mother-to-child transmission) prevention and care. Advantage should be taken of the remarkable amount of expertise and resources that have accumulated over the past few years to accelerate the process of integration. Future initiatives should include integrating specialists and people with diverse backgrounds and targeting their scientific and programmatic ideas to address real-world problems in the area of MTCT of HIV-1.

A randomized controlled trial of artemotil (beta-arteether) in Zambian children with cerebral malaria

The efficacy and safety of intramuscular artemotil (ARTECEF) was compared to intravenous quinine in African children with cerebral malaria. This prospective block randomized open-label study was conducted at two centers in Zambia. Subjects were children aged 0 to 10 years of age with cerebral malaria and a Blantyre Coma Score of 2 or less. Ninety two children were studied; 48 received artemotil and 44 quinine. No significant differences in survival, coma resolution time, neurologic sequelae, parasite clearance time, and fever resolution time were seen between the two regimens. Rates for negative malaria smears one month after therapy were similar in both groups. Artemotil was a well-tolerated drug in the 48 patients in this study. It appears to be at least therapeutically equivalent to quinine for the treatment of pediatric cerebral malaria. It has the advantage of being able to be given intramuscularly once daily for only five days.

Comparisons of wild-type and mutant flavodoxins from Anacystis nidulans. Structural determinants of the redox potentials

The long-chain flavodoxins, with 169-176 residues, display oxidation-reduction potentials at pH 7 that vary from -50 to -260 mV for the oxidized/semiquinone (ox/sq) equilibrium and are -400 mV or lower for the semiquinone/hydroquinone (sq/hq) equilibrium. To examine the effects of protein interactions and conformation changes on FMN potentials in the long-chain flavodoxin from Anacystis nidulans (Synechococcus PCC 7942), we have determined crystal structures for the semiquinone and hydroquinone forms of the wild-type protein and for the mutant Asn58Gly, and have measured redox potentials and FMN association constants. A peptide near the flavin ring, Asn58-Val59, reorients when the FMN is reduced to the semiquinone form and adopts a conformation ("O-up") in which O 58 hydrogen bonds to the flavin N(5)H; this rearrangement is analogous to changes observed in the flavodoxins from Clostridium beijerinckii and Desulfovibrio vulgaris. On further reduction to the hydroquinone state, the Asn58-Val59 peptide in crystalline wild-type A. nidulans flavodoxin rotates away from the flavin to the "O-down" position characteristic of the oxidized structure. This reversion to the conformation found in the oxidized state is unusual and has not been observed in other flavodoxins. The Asn58Gly mutation, at the site which undergoes conformation changes when FMN is reduced, was expected to stabilize the O-up conformation found in the semiquinone oxidation state. This mutation raises the ox/sq potential by 46 mV to -175 mV and lowers the sq/hq potential by 26 mV to -468 mV. In the hydroquinone form of the Asn58Gly mutant the C-O 58 remains up and hydrogen bonded to N(5)H, as in the fully reduced flavodoxins from C. beijerinckii and D. vulgaris. The redox and structural properties of A. nidulans flavodoxin and the Asn58Gly mutant confirm the importance of interactions made by N(5) or N(5)H in determining potentials, and are consistent with earlier conclusions that conformational energies contribute to the observed potentials.The mutations Asp90Asn and Asp100Asn were designed to probe the effects of electrostatic interactions on the potentials of protein-bound flavin. Replacement of acidic by neutral residues at positions 90 and 100 does not perturb the structure, but has a substantial effect on the sq/hq equilibrium. This potential is increased by 25-41 mV, showing that electrostatic interaction between acidic residues and the flavin decreases the potential for conversion of the neutral semiquinone to the anionic hydroquinone. The potentials and the effects of mutations in A. nidulans flavodoxin are rationalized using a thermodynamic scheme developed for C. beijerinckii flavodoxin.

Reliability of taurine concentrations measured in single urine samples obtained from dogs eight hours after eating

OBJECTIVE

To evaluate the reliability of taurine concentrations measured in a single urine sample obtained from dogs 8 hours after eating, compared with taurine concentrations measured in 24-hour urine samples.

ANIMALS

18 healthy Beagles.

PROCEDURE

After emptying the urinary bladder by transurethral catheterization, dogs were fed a canned maintenance diet. Approximately 8 hours later, urine, plasma, and serum samples were obtained for determination of fractional urinary excretion of taurine and urine taurine-to-creatinine concentration ratios (Utaur:Ucr). Results were compared with 24-hour urinary taurine excretion rate.

RESULTS

Unbound and total fractional urinary taurine excretion correlated well with unbound and total 24-hour urinary taurine excretion. However, bound fractional urinary taurine excretion correlated poorly with bound 24-hour urinary taurine excretion. Unbound and total Utaur:Ucr correlated well with unbound and total 24-hour urinary taurine excretion. However, bound Utaur:Ucr correlated poorly with bound 24-hour urinary taurine excretion.

CONCLUSION AND CLINICAL RELEVANCE

Fractional urinary excretion of unbound and total taurine, and unbound and total Utaur:Ucr are reliable indicators of 24-hour urinary unbound and total taurine excretion in healthy dogs. However, determination of 24-hour urinary taurine excretion is recommended for evaluating urinary bound taurine concentrations of dogs.

Care of human immunodeficiency virus-infected children in developing countries. International Working Group on Mother-to-Child Transmission of HIV

CONTEXT

There is urgent need to strengthen the area of pediatric HIV/AIDS care in developing countries. Clinical research in this area is also scarce.

METHODOLOGY

A literature review and a postal survey were used to obtain updated information on mortality, morbidity and current standards of care of children born to HIV-infected mothers in developing countries. A 2-day workshop was organized to review the available data and to identify the key areas where clinical research should be conducted.

MAIN FINDINGS

Rates of mortality and morbidity were very different from one study to another but generally higher than in industrialized countries. Prognostic studies for HIV-1-infected children in developing countries were not available. Based on the report of 14 teams from 11 countries, specific protocols for HIV-infected children with persistent diarrhea or severe malnutrition were documented in fewer than one-half of the cases. Secondary antimicrobial prophylaxis after interstitial pneumonia or recurrent infections was still infrequent, as primary prophylaxis of opportunistic infections. The following list of clinical research priorities was identified by the workshop participants: primary prophylaxis of opportunistic and bacterial infections; case management of persistent diarrhea; reassessment of the performance of p24 antigen for diagnostic and prognosis use; studies on the etiology of pulmonary infections; long term observational pediatric cohorts; current weaning practices and duration of breast-feeding; counseling and HIV testing of children and families; prevention of HIV sexual transmission in children and adolescents.