Abstract P1-09-14: Demographic, clinical/disease characteristics, and treatment of patients with germline mutated metastatic breast cancer: A CancerLinQ study

Objective: To describe the demographics, clinical/disease characteristics and treatment patterns of patients with germline BRCA mutated (gBRCAm) metastatic breast cancer (mBC) as compared to those with gBRCA wild type (wt) and those who are untested for gBRCA mutations.

Methods: The CancerlinQ Discovery Database (CLQ), launched by the American Society of Clinical Oncology (ASCO) in 2016, consists of longitudinal, demographic and geographic diverse data aggregated from oncology practice electronic health record (EHR) databases. Natural language processing and technology-enabled curation are utilized to identify records of most interest, followed by manual curation to abstract information from unstructured EHR fields. This cohort consists of 7,889 patients diagnosed with mBC between 1982 and 2018, and is enriched for patients with gBRCA testing through the curation process.

Results: Overall most patients were female (99.0%), white (55.3%), and the median age at mBC diagnosis was 63 years (yrs). The majority were not tested for gBRCA mutation (88.4%); 2.0% were gBRCAm, 9.2% were gBRCAwt, 0.4% had an undetermined test result, and 0.1% had a variant of unknown significance. Among those tested for estrogen-receptor (ER) (n=6,700) and progesterone-receptor (PR) (n=6,737) status, 76.6% were ER positive (+) and 62.2% were PR+. Among those tested for human epidermal growth factor receptor 2 (HER2) (n=6,696), 21.7% were HER2+. Among those with known results for ER, PR, and HER2 (n=6,063), 10.1% were hormone receptor (HR)+/HER2+, 10.6% were HR negative (-)/HER2+, 65.0% were HR+/HER2-, and 14.3% were HR-/HER2-. The median age at mBC diagnosis was 50 yrs for gBRCAm, 51 yrs for gBRCAwt and 64 yrs among the gBRCA untested group. A similar proportion of patients were diagnosed with metastatic disease among the gBRCAm and gBRCAwt groups (25.3% and 20.3%, respectively), while the proportion was higher among the gBRCA untested group (38.0 %). The most common site of metastasis for all groups was bone (35.1% for gBRCAm, 41.7% for gBRCAwt, and 36.5 % for gBRCA untested), followed by liver (16.2% for gBRCAm, 13.3% for gBRCAwt, and 8.5% for gBRCA untested). The most common first-line therapies for gBRCAm patients were tamoxifen (7.7%), letrozole (7.0%), cyclophosphamide+doxorubicin (6.3%), and paclitaxel (6.3%); for gBRCAwt patients they were cyclophosphamide+doxorubicin (6.6%), paclitaxel (6.4%), and tamoxifen (6.4%); and for gBRCA untested patients they were letrozole (11.1%), fulvestrant (9.3%), and tamoxifen (4.6%). The mean number of lines of therapy (including lines of chemotherapy and hormone therapy) were 3.5, 3.8, and 3.4 for the gBRCAm, gBRCAwt, and gBRCA untested groups, respectively.

Conclusions: Patients with gBRCAm were younger than the gBRCA untested group, and more patients had metastatic disease at diagnosis in the gBRCA untested group. Further analyses accounting for HR and HER2 status will be conducted and presented. This is the first example of research using curated breast cancer data from ASCO's CLQ.

Citation Format: Dalvi T, Herr I, Maclachlan S, Briceno J, Bennett J, McLaurin K, Hettle R, McCutcheon S. Demographic, clinical/disease characteristics, and treatment of patients with germline mutated metastatic breast cancer: A CancerLinQ study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-09-14.

Abstract P3-08-03: Dissecting the heterogeneity of metaplastic breast cancer: A morphological, immunohistochemical and genomic analysis of a large cohort

Although rare, Metaplastic Breast Carcinomas (MBC) account for significant global breast cancer mortality. This subgroup is extremely heterogeneous and by definition exhibits metaplastic change to squamous and/or mesenchymal elements, including but not limited to spindle, squamous, chondroid, osseous and rhabdomyoid elements. The WHO working group recognizes that the current classification is inadequate and in the interim, has suggested a purely descriptive classification. The mixed epithelial-mesenchymal morphology has led to speculation that MBC represent 'stem cell tumours'; in support of this, MBC have been shown to have a CD44+/CD24-/low phenotype. Clinically, patients present with tumours that are larger (higher stage), have increased likelihood of distant metastases at presentation and overall, have a reduced 5-year survival rate compared to Invasive Carcinoma-NST. Hence, this is a unique subtype with poor outcome but without a robust classification or understanding of the biology to aid clinical management. We present a detailed morphological, immunohistochemical and genomic analysis of a large series of MBC (n=347), as amassed through the Asia-Pacific MBC consortium. We consider our morphological dissection using the WHO subtyping guidelines and show that an increasing number of phenotypes in a mixed MBC (classified as WHO_1) significantly associates with a poor prognosis. Immunohistochemical analysis showed that a pure spindle (WHO_5) is significantly less likely to express vimentin, CK5/6, CK14, and CK19 than a mixed WHO_1 with spindle features. Similarly, a WHO_1 with chondroid features is less likely to express EGFR than WHO_1 with chondroid features and rhabdoid or osseous differentiation. Across the cohort, positivity for the AE1/3 antibody and a lack of EGFR expression both significantly associate with a better outcome. We report no significant association between patient age at diagnosis and breast cancer specific survival, nor between age and specific WHO MBC subtypes. We report a significant association between WHO_1 types and increasing tumour grade, and also between tumour size and grade, with tumour size being a highly significant prognostic indicator in this cohort. Our exome sequencing confirms a significant enrichment for TP53 and PTEN mutations in MBC, and intriguingly for concurrent mutations of TP53, PTEN and PIK3CA. A novel enrichment for NF1 mutations is also presented. In summary, we provide a thorough assessment of a large cohort of MBC, including morphology, survival, IHC and exome sequencing, and present our analysis contextualized by the WHO guidelines, extending the existing knowledge base of this rare tumour type.

Citation Format: McCart Reed AE, Kalaw E, Nones K, Bettington M, Lim M, Bennett J, Johnstone K, Kutasovic JR, Kazakoff S, Xu QC, Saunus JM, Reid LE, Black D, Niland C, Ferguson K, Gresshoff I, Raghavendra A, Liu JC, Kalinowski L, Reid AS, Davidson M, Pearson JV, Yamaguchi R, Harris G, Tse G, Papadimos D, Pathmanathan R, Pathmanathan N, Tan PH, Fox S, O'Toole S, Waddell N, Simpson PT, Lakhani SR. Dissecting the heterogeneity of metaplastic breast cancer: A morphological, immunohistochemical and genomic analysis of a large cohort [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-08-03.

Abstract P1-09-13: A real world evidence study of BRCA mutations and survival in HER2-negative breast cancer

Background: Limited data exist on the natural history (treated with standard of care) of metastatic breast cancer (mBC) characterized by germline breast cancer susceptibility gene mutations (gBRCAm). Real-world data examining survival for patients with gBRCAm mBC, overall and separated into gBRCA1m and gBRCA2m, compared to gBRCA wild type (wt) mBC, can help to clarify the prognostic outlook associated with the gBRCA mutation.

Methods: Adults with human epidermal growth factor receptor 2 negative (HER2-) mBC diagnosed from January 2013 – August 2017 were retrospectively selected from the Flatiron Health Oncology electronic medical record database. Patients were classified as having gBRCA1m, gBRCA2m, or gBRCAwt disease. Those who did not receive the genetic testing or who had equivocal results were classified as gBRCA unknown. Overall survival (OS) was calculated from first diagnosis of mBC, as well as from the start of first- and second-line therapy for metastatic disease. Lines of therapy included both hormonal and systemic therapies. Kaplan-Meier analyses provided median OS with 95% confidence interval (CI). Unadjusted log-rank tests compared OS between gBRCA1m and gBRCA2m, and between overall gBRCAm and gBRCAwt.

Results: Of 8,080 patients selected, mean age at first mBC diagnosis was 64 years, 98.7% were female, and 82.0% had evidence of hormone receptor positive disease. gBRCA status was known for 1,852 (22.9%) of patients, of whom 89 (4.8%) had gBRCA1m, 152 (8.2%) had gBRCA2m, and 8 (0.4%) had both gBRCA mutations. Patients with known gBRCA status were younger, with mean ages of 52 years for gBRCAm, 55 years for gBRCAwt, and 67 years for gBRCA unknown. Hormone receptor positive disease was less common among those with known gBRCA status (71.9%, 77.2%, and 83.6% for gBRCAm, gBRCAwt, and gBRCA unknown, respectively). Median (95% CI) OS from mBC diagnosis was 22 (14 - 26) months for gBRCA1m and 30 (27 - 37) months for gBRCA2m (p = 0.01), though numbers were quite small by the median timepoint. Overall gBRCAm disease was associated with median survival of 28 (25 - 32) months, compared to 32 (30 - 35) months for gBRCAwt (p = 0.07); survival was similar between groups for the first 24 months but declined thereafter in the gBRCAm group. Similar patterns were observed for OS after the start of first- and second-line therapy, although no comparisons were significant. Further analyses will present adjusted results and comparisons with outcomes for the patients with gBRCA unknown.

Conclusions: This real-world study of patients receiving care in largely community oncology clinics suggests that survival after diagnosis of mBC is reduced in patients with gBRCA1m compared to gBRCA2m disease and may be reduced in gBRCAm mBC overall. Effective treatments targeted for the gBRCAm subtypes of mBC appear to be needed.

Citation Format: Dalvi T, McLaurin K, Briceno J, Nordstrom B, Bennett J, Hettle R, Murphy B, Collins J, McCutcheon S. A real world evidence study of BRCA mutations and survival in HER2-negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-09-13.

Endoluminal Vacuum Therapy (E-Vac): A Treatment Option in Oesophagogastric Surgery

Background

Leaks from the upper gastrointestinal tract often pose a management challenge, particularly when surgical treatment has failed or is impossible. Vacuum therapy has revolutionised the treatment of wounds, and its role in enabling and accelerating healing is now explored in oesophagogastric surgery.

Methods

A piece of open cell foam is sutured around the distal end of a nasogastric tube using a silk suture. Under general anaesthetic, the foam covered tip is placed endoscopically through the perforation and into any extra-luminal cavity. Continuous negative pressure (125 mmHg) is then applied. Re-evaluation with change of the negative pressure system is performed every 48–72 h depending on the clinical condition. Patients are fed enterally and treated with broad-spectrum antibiotics and anti-fungal medication until healing, assessed endoscopically and/or radiologically, is complete.

Results

Since April 2011, twenty one patients have been treated. The cause of the leak was postoperative/iatrogenic complications (14 patients) and ischaemic/spontaneous perforation (seven patients). Twenty patients (95%) completed treatment successfully with healing of the defect and/or resolution of the cavity and were subsequently discharged from our care. One patient died from sepsis related to an oesophageal leak after withdrawing consent for further intervention following a single endoluminal vacuum (E-Vac) treatment. In addition, two patients who were successfully treated with E-Vac for their leak subsequently died within 90 days of E-Vac treatment from complications that were not associated with the E-Vac procedure. In two patients, E-Vac treatment was complicated by bleeding. The median number of E-Vac changes was 7 (range 3–12), and the median length of hospital stay was 35 days (range 23–152).

Conclusions

E-Vac therapy is a safe and effective treatment for upper gastrointestinal leaks and should be considered alongside more established therapies. Further research is now needed to understand the mechanism of action and to improve the ease with which E-Vac therapy can be delivered.

Alimentary microbes of winter-form Drosophila suzukii

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is a damaging pest of fruit. Reproductively diapausing adults overwinter in woodlands and remain active on warmer winter days. It is unknown if this adult phase of the lifecycle feeds during the winter period, and what the food source may be. This study characterized the flora in the digestive tract of D. suzukii using a metagenomics approach. Live D. suzukii were trapped in four woodlands in the south of England and their guts dissected for DNA extraction and amplicon-based metagenomics sequencing (internal transcribed spacer and 16S rRNA). Analysis at genus and family taxonomic levels showed high levels of diversity with no differences in digestive tract bacterial or fungal biota between woodland sites of winter-form D. suzukii. Female D. suzukii at one site appeared to have higher bacterial diversity in the alimentary canal than males, but there was a site, sex interaction. Many of the biota were associated with cold, wet climatic conditions and decomposition. This study provides the first evidence that winter-form D. suzukii may be opportunistic feeders during the winter period and are probably exploiting food sources associated with moisture on decomposing vegetation during this time. A core gut microbiome has been identified for winter-form D. suzukii.

Neural Reorganization Due to Neonatal Amygdala Lesions in the Rhesus Monkey: Changes in Morphology and Network Structure

It is generally believed that neural damage that occurs early in development is associated with greater adaptive capacity relative to similar damage in an older individual. However, few studies have surveyed whole brain changes following early focal damage. In this report, we employed multimodal magnetic resonance imaging analyses of adult rhesus macaque monkeys who had previously undergone bilateral, neurotoxic lesions of the amygdala at about 2 weeks of age. A deformation-based morphometric approach demonstrated reduction of the volumes of the anterior temporal lobe, anterior commissure, basal ganglia, and pulvinar in animals with early amygdala lesions compared to controls. In contrast, animals with early amygdala lesions had an enlarged cingulate cortex, medial superior frontal gyrus, and medial parietal cortex. Diffusion-weighted imaging tractography and network analysis were also used to compare connectivity patterns and higher-level measures of communication across the brain. Using the communicability metric, which integrates direct and indirect paths between regions, lesioned animals showed extensive degradation of network integrity in the temporal and orbitofrontal cortices. This work demonstrates both degenerative as well as progressive large-scale neural changes following long-term recovery from neonatal focal brain damage.

Complex bifurcation lesions: Randomized comparison of a fully bioresorbable modified t stenting strategy versus bifurcation reconstruction with a dedicated self-expanding stent in combination with bioresorbable scaffolds, an OCT study: Rationale and design of the COBRA II trial

OBJECTIVE

There is an ongoing controversy regarding the efficacy and safety of different percutaneous stenting techniques for coronary bifurcation lesions needing >1 stent. The promise of safe vessel restoration with bioresorbable scaffolds (BRS) may not be transferable to complex double BRS bifurcation techniques, and permanent metallic scaffolding of the bifurcation core may be needed. We identified modified-T stenting as the most promising fully bioresorbable 2-stent strategy in a preclinical setting. The objective of this study is to assess acute performance and compare long-term vessel healing with this strategy, versus an approach combining BRS with a dedicated metallic drug-eluting bifurcation stent.

STUDY DESIGN

In a single center, 60 consecutive patients with true and complex coronary bifurcation lesions will be randomly assigned to treatment with the dedicated self-expanding Axxess^™ biolimus-eluting bifurcation stent in the proximal main vessel and additional Absorb^™ everolimus-eluting BRS in the branches versus a modified T technique using Absorb^™ only. Angiography and optical coherence tomography (OCT) will be performed immediately after implantation and at 30 months, and clinical follow-up is foreseen up to 5 years after implantation. The primary endpoint is the change in minimal luminal area assessed with OCT from baseline to 30 months in pre-specified bifurcation segments.

CONCLUSION

To date the use of Absorb^™ BRS in complex coronary bifurcations has not been evaluated in a randomized clinical trial setting. The COBRA II study will examine the role and safety of a double BRS strategy in coronary bifurcations, alone or in combination with a metallic dedicated bifurcation device. © 2016 Wiley Periodicals, Inc.

An evaluation of the use of individual grass species in retaining polluted soil and dust particulates in vegetated sustainable drainage devices

A sustainable means of preventing polluted particulates carried in urban storm water entering rivers, groundwater and lakes is by employing vegetated sustainable drainage system (SUDS) devices, or best management practices to trap or biodegrade them. In the UK, a mixture of grass species is recommended for use in devices such as swales or filter strips. However, there is little evidence in support of the efficiency of the individual grasses or mixtures to deal with such contaminated material. A pot-based pollutant retention study was conducted using processed street dust from central Coventry, UK, as a simulated pollutant to be applied in different quantities to a variety of recommended grasses for vegetated SUDS devices. Analysis was conducted on compost cores, roots and shoots for heavy metals (Cd, Cu, Ni, Pb and Zn). Street dust mainly concentrated in the top compost layer for all grasses with only the finer material migrating down the profile. Analysis of roots indicated little accumulation, with ANOVA statistical tests indicating significant differences in heavy metal concentrations, with less in the compost and more in the shoots. Development of root systems on or near the surface possibly explains increased uptake of heavy metals by some species. Overall Agrostis canina and Poa pratensis showed the greatest accumulations compared to their controls although Agrostis capillaris syn.tenuis and Agrostis stolonifera also demonstrated accumulation potential. On ranking, Agrostis canina and Poa pratensis were highest overall. These rankings will assist in selecting the best grasses to address pollution of the urban environment by contaminated particulates.