Multitemporal analysis of land subsidence induced by open-pit mining activity using improved combined scatterer interferometry with deep learning algorithm optimization

Mine operational safety is an important aspect of maintaining the operational continuity of a mining area. In this study, we used the InSAR time series to analyze land surface changes using the ICOPS (improved combined scatterers with optimized point scatters) method. This ICOPS method combines persistent scatterers (PS) with distributed scatterers (DS) to increase surface deformation analysis's spatial coverage and quality. One of the improvements of this study is the use of machine learning in postprocessing, based on convolutional neural networks, to increase the reliability of results. This study used data from the Sentinel-1 SAR C-band satellite during the 2016-2022 observation period at the Musan mine, North Korea. In the InSAR surface deformation time analysis, the maximum average rate of land subsidence was approximately > 15.00 cm per year, with total surface deformation of 170 cm and 70 cm for the eastern dumping area and the western dumping area, respectively. Analyzing the mechanism of land surface changes also involved evaluating the geological conditions in the Musan mining area. Our research findings show that combining machine learning and statistical methods has great potential to enhance the understanding of mine surface deformation.

Regional variations in retinopathy of prematurity incidence for preterm infants <32 weeks' gestation in China

OBJECTIVES

National-level data on the incidence of retinopathy of prematurity (ROP) in different regions of China is insufficient. This study aimed to compare ROP incidences and care practices in different regions of China and their relationship with regional gross domestic product (GDP) per capita.

STUDY DESIGN

Retrospective cohort study.

METHODS

All infants born at <32 weeks gestational age (GA) and admitted to 70 neonatal intensive care units (NICUs) from January 1, 2019, to December 31, 2020, were enrolled. Hospitals were categorised into three regional groups according to geographical locations and GDP per capita from high to low: Eastern, Central, and Western China. The incidence of death or ROP, and care practices were compared among the groups.

RESULTS

A total of 18,579 infants were enrolled. Median GA was 29.9 (interquartile range 28.4-31.0) weeks and birth weight was 1318.1 (317.2) g. The percentage of GA <28 weeks, complete administration of antenatal steroids, and weight gain velocity during NICU stay were highest in Eastern China and lowest in Western China (all P < 0.01). In Eastern, Central, and Western China, the rates of death or any stage of ROP were 33.3%, 38.5%, and 39.2%, respectively (P < 0.01).

CONCLUSIONS

There were considerable regional disparities in ROP incidence in preterm infants with GA <32 weeks in China. The incidence of death or ROP ranged from high to low in Western, Central, and Eastern China.

Is the 'safe zone' identified in preoperative computed tomography helpful for choosing optimal implant for fixation of radial head fracture?

The purpose of this study is to assess the clinical significance of the radiologic safe zone based on computed tomography and to compare the outcomes of three different implants for fixation of isolated radial head fractures. We retrospectively reviewed 367 patients who underwent internal fixation for isolated radial head fractures. We newly defined two subtypes of Mason type II fractures associated with the radiographic safe zone (IIA, two-part fracture allowing for safe fixation of plate; IIB, two-part fracture not allowing for safe fixation). 170 patients (CCS group, n = 82; HCS group, n = 31; plate group, n = 57) were investigated with no significant differences in demographics. The range of pronation and supination at 1 month postoperatively (P = 0.04 and P = 0.04) and the range of supination at 6 and 12 months postoperatively (P = 0.03 and P = 0.03) were significantly smaller in the plate group. In Mason type IIB fractures, the average MEPS was higher in the CCS and HSC groups than in the plate group (P = 0.01 and P = 0.02). And the average DASH score was lower in the CCS and HCS groups (P < 0.01 and P < 0.01). Evaluation of the radiologic safe zone is potentially helpful in selecting better surgical fixation option. For type III fractures, 2.3-mm cortical screws would be a better option than Acutrak screws. Plates would not be suitable for type IIB radial head fractures.

Characteristics of the immune microenvironment associated with RRM2 expression and its application to PD-L1/PD-1 inhibitors in lung adenocarcinoma

Recent studies have indicated that RRM2 plays a crucial part in the tumor immune microenvironment. According to the expression of RRM2, we evaluated immune cell infiltration, immunotherapy biomarkers, and the expression of immune checkpoint molecules in four lung adenocarcinoma (LUAD) datasets. We employed the Tumor Immune Dysfunction and Exclusion (TIDE) and CIBERSORTx algorithms to examine the patterns of immune cell distribution and evaluate the responses to anti-programmed death protein-1/programmed death ligand-1 (PD-1/PD-L1) therapy in three publicly available LUAD datasets. These findings were corroborated using a validation group comprising patients who received treatment with PD-1/PD-L1 inhibitors. Additionally, we conducted experiments using LUAD cell lines to investigate how RRM2 affects the expression of PD-L1. In comparison to the low RRM2 group, the high RRM2 group exhibited a high interferon gamma signature, high T-cell-inflamed signature, high CD274 expression, high CD8+ T cell levels, low cancer-associated fibroblasts, and low M2 macrophages, according to TIDE analysis in the three LUAD datasets. Analysis of the three LUAD datasets using CIBERSORTx confirmed a positive correlation between RRM2 and CD8+ T cells, and this finding was validated by immunohistochemistry in a separate validation set. In the three LUAD datasets without PD-1/PD-L1 inhibitor treatment, higher RRM2 expression was associated with a poorer prognosis. However, in the LUAD dataset treated with PD-1/PD-L1 inhibitors, higher RRM2 expression was associated with better prognosis. In the three datasets, the high-RRM2 group exhibited higher expression of inhibitory immune checkpoint molecules. In a LUAD cell line study, we discovered that RRM2 regulates PD-L1 expression through the ANXA1/AKT pathway. The expression of RRM2 shows promise as a predictive biomarker for PD-1/PD-L1 inhibitors in LUAD patients, and it may represent a new target to overcome resistance to PD-L1/PD-1 therapies.

Midline catheters in the operating room

Backgrounds

Among various vascular access devices, midline catheters (MCs) are commonly used in emergency departments, but rarely in operating rooms.

Aims

To evaluate the feasibility and safety of MCs in the operating room.

Materials and Methods

This was a retrospective study. The medical records of patients who underwent MC placement in the operating room from October 2020 to July 2022 were reviewed. The rates of successful catheter insertion as well as major and minor complications were assessed.

Results

Successful catheter insertions were achieved in 149 of 161 patients (92.5%). The median dwell time of midlines was eight days (IQR: 6-10 days). A major or minor complication occurred in 6.7% of the midlines. The rates of major complications of occlusion, upper extremity deep vein thrombosis (DVT), and catheter-related bloodstream infection were 1.3%, 0.7%, and 0%, respectively.

Conclusions

Placement of MCs in the operating room was feasible and safe. Also, the procedure provides an acceptable alternative for replacing central line catheters and peripherally inserted central catheters.

Search for the Pair Production of Dark Particles X with K_{L}^{0}→XX, X→γγ

We present the first search for the pair production of dark particles X via K_{L}^{0}→XX with X decaying into two photons using the data collected by the KOTO experiment. No signal was observed in the mass range of 40-110  MeV/c^{2} and 210-240  MeV/c^{2}. This sets upper limits on the branching fractions as B(K_{L}^{0}→XX)<(1-4)×10^{-7} and B(K_{L}^{0}→XX)<(1-2)×10^{-6} at the 90% confidence level for the two mass regions, respectively.

Comparing the efficacy of different methods of faecal microbiota transplantation via oral capsule, oesophagogastroduodenoscopy, colonoscopy, or gastric tube

BACKGROUND

The increasing prevalence of multidrug-resistant organism (MDRO) carriage poses major challenges to medicine as healthcare costs increase. Recently, faecal microbiota transplantation (FMT) has been discussed as a novel and effective method for decolonizing MDRO.

AIM

To compare the efficacy of different FMT methods to optimize the success rate of decolonization in patients with MDRO carriage.

METHODS

This prospective cohort study enrolled patients with MDRO carriages from 2018 to 2021. Patients underwent FMT via one of the following methods: oral capsule, oesophagogastroduodenoscopy (EGD), colonoscopy, or gastric tube.

FINDINGS

A total of 57 patients underwent FMT for MDRO decolonization. The colonoscopy group required the shortest time for decolonization, whereas the EGD group required the longest (24.9 vs 190.4 days, P = 0.022). The decolonization rate in the oral capsule group was comparable to that in the EGD group (84.6% vs 85.7%, P = 0.730). An important clinical factor associated with decolonization failure was antibiotic use after FMT (odds ratio = 6.810, P = 0.008). All four groups showed reduced proportions of MDRO species in microbiome analysis after FMT.

CONCLUSION

Compared to other conventional methods, the oral capsule is an effective FMT method for patients who can tolerate an oral diet. The discontinuation of antibiotics after FMT is a key factor in the success of decolonization.

Risk factors for scabies treatment resistance: a retrospective cohort study

BACKGROUND

In order to successfully treat scabies and to prevent its spread, it is important to identify the factors that can influence the outcome of scabies treatment.

OBJECTIVES

This study was designed to evaluate the risk factors associated with treatment resistance scabies during use of an effective topical medication.

METHODS

A retrospective cohort study was performed in patients with scabies infestations confirmed by potassium hydroxide (KOH) examinations. Patient characteristics, clinical features and treatment history were collected. The treatment resistance group included patients with persistent scabies infestations for more than 28 days after initiation of antiscabies treatment with 5% permethrin cream.

RESULTS

In total, 138 patients with scabies infestations treated between January 2017 and December 2020 were included in this study. Of these, 100 (72.5%) patients were treated successfully, while 38 (27.5%) patients experienced treatment resistance. In the univariable analysis, risk factors for treatment resistance scabies included impaired cognitive function (OR = 2.66, 95% CI, 1.15-6.14), limited mobility (OR = 2.97, 95% CI, 1.30-6.83), inpatient status (vs. outpatient, OR = 3.3, 95% CI, 1.28-8.54), topical steroid use before diagnosis (OR = 3.52, 95% CI, 1.61-7.81), systemic steroid use before diagnosis (OR = 3.57, 95% CI, 1.26-10.34) and a positive KOH exam after the first treatment (OR = 7.25, 95% CI, 3.24-17.11). In the multivariable analysis, limited mobility (OR = 3.46, 95% CI, 1.02-12.11) and topical steroid use before diagnosis (OR = 3.65, 95% CI, 1.41-9.75) were significant predictive factors for treatment resistance scabies.

CONCLUSIONS

Scabies patients with limited mobility and topical steroid use before diagnosis are at high risk of treatment resistance. Dermatologists should take these findings into consideration when treating patients with scabies infestations.

Study of the K_{L}→π^{0}νν[over ¯] Decay at the J-PARC KOTO Experiment

The rare decay K_{L}→π^{0}νν[over ¯] was studied with the dataset taken at the J-PARC KOTO experiment in 2016, 2017, and 2018. With a single event sensitivity of (7.20±0.05_{stat}±0.66_{syst})×10^{-10}, three candidate events were observed in the signal region. After unveiling them, contaminations from K^{±} and scattered K_{L} decays were studied, and the total number of background events was estimated to be 1.22±0.26. We conclude that the number of observed events is statistically consistent with the background expectation. For this dataset, we set an upper limit of 4.9×10^{-9} on the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level.

Expression of oestrogen-α receptor in papillary thyroid carcinoma and its association with metastasis

INTRODUCTION

Papillary thyroid carcinoma (PTC) is the ninth most common malignancy among women. Although the disease prognosis is good, less favourable outcomes are predicted in those with higher disease stages and nodal metastasis. Oestrogen- α (ER-α) expression has been associated with aggressive presentation and greater disease progression and has been proposed as a predictor for lymph node metastases. The objective of this study was to evaluate the association between ER expression and clinicopathological features i.e. lymph node metastasis, tumour size, extrathyroidal extension, histological variants of PTC , age groups , ethnic and gender.

METHODS

We studied ER-α expression in 84 cases of PTC obtained within an eight-year period (2011-2018) by immunohistochemical technique (IHC). Associations between ER-α expression and clinicopathological features were evaluated using Fisher's exact test. The statistical significance was set at p < 0.05.

RESULTS

ER-α was expressed in 13.1% of all the PTC cases examined (n=11/84). There were no associations observed between ER-α expression and lymph node metastasis (p=1.000), tumour size (p=0.970), extrathyroidal extension (p=0.677), variants of PTC (p=1.000), age groups (p=0.188), gender (p=0.725) or race (p=0.920).

CONCLUSION

There was no evidence in this study to support the application of ER-α as prediction marker for lymph node metastasis or disease aggressiveness in PTC. Given that the scope of this study was limited to the protein expression of ER- α, we also propose the inclusion of molecular analysis of ESR1 gene expression, as well as inclusion of detailed clinical and radiological findings in future research investigating the role of ER-α in prognostication of PTC.

The Impact of COVID-19 on Emergent Large-Vessel Occlusion: Delayed Presentation Confirmed by ASPECTS

BACKGROUND AND PURPOSE

Our hypothesis is that the COVID-19 pandemic led to delayed presentations for patients with acute ischemic stroke. This study evaluates the impact of the coronavirus disease 2019 pandemic on presentation, treatment, and outcomes of patients with emergent large-vessel occlusion using data from a large health system in the Bronx, New York.

MATERIALS AND METHODS

We performed a retrospective cohort study of 2 cohorts of consecutive patients with emergent large-vessel occlusion admitted to 3 Montefiore Health System hospitals in the Bronx from January 1 to February 17, 2020, (prepandemic) and March 1 to April 17, 2020 (pandemic). We abstracted data from the electronic health records on presenting biomarker profiles, admission and postprocedural NIHSS scores, time of symptom onset, time of hospital presentation, time of start of the thrombectomy procedure, time of revascularization, presenting ASPECTS, TICI recanalization score, mRS, functional outcomes, and mortality.

RESULTS

Of 179 patients admitted with ischemic stroke during the study periods, 80 had emergent large-vessel occlusion, of whom 36 were in the pandemic group. Patients in the pandemic group were younger (66 versus 72 years, P < .061) and had lower ASPECTS (7 versus 9, P < .001) and took longer to arrive at the hospital (361  versus 152 minutes, P < .004) with no other major differences. There was a decreased rate of thrombolysis administration (22% versus 43%, P < .049) and a decreased number of patients treated with mechanical thrombectomy (33% versus 61%, P < .013).

CONCLUSIONS

The pandemic led to delays in patients arriving at hospitals, leading to decreased patients eligible for treatment, while in-hospital evaluation and treatment times remain unchanged.

Trabecular bone score value is associated with new bone formation independently of fat metaplasia on spinal magnetic resonance imaging in patients with ankylosing spondylitis

OBJECTIVE

To evaluate the association between trabecular bone score (TBS) and new bone formation in ankylosing spondylitis (AS) patients, and to investigate whether TBS is independently associated with new bone formation.

METHOD

Sixty-eight patients with AS underwent spinal magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry of the lumbar spine to measure TBS and bone mineral density at baseline. Lateral radiographs of the cervical and lumbar spine (baseline and 2 years) were assessed for new bone formation (syndesmophyte formation and/or growth combined), and spinal MRIs were assessed for the presence or absence of fat metaplasia (FM) at the first to fourth lumbar vertebrae. The factors associated with new bone formation were analysed at the patient level and the vertebral level.

RESULTS

New bone formation had developed in 17 patients (25%) at 2 year follow-up. Patients with new bone formation had a higher prevalence of FM and lower TBS at baseline than patients without new bone formation (p = 0.013 and p = 0.041). At the patient level, FM on MRI and low TBS (< 1.23) were significantly associated with new bone formation. At the vertebral level, new bone formation had developed in 25 out of 231 vertebrae (11%) after 2 years. Vertebrae with both FM on MRI and low TBS tended to have more new bone formation (p < 0.001). Syndesmophytes and low TBS (< 1.23) independently increased the risk of new bone formation at the level of individual vertebrae.

CONCLUSION

At both patient and individual vertebral levels, low TBS was associated with new bone formation independently of FM on MRI.

Traumatic intradural ruptured lumbar disc with a spinal compression fracture: A case report

RATIONALE

We present a rare case of a traumatic intradural ruptured disc associated with a mild vertebral body compression fracture along with a review of the relevant medical literature. An intradural ruptured disc often occurs due to chronic degenerative diseases and is rarely due to trauma. It can cause irreversible neurological complications if the appropriate treatment is not planned.

PATIENT CONCERNS

A 32-year-old male presented with motor paraparesis (grade 3/5), right ankle dorsiflexion, and great toe dorsiflexion (grade 1/5), along with radiating pain at his right L4 and L5 sensory dermatome following a fall.

DIAGNOSES

Computed tomography revealed a compression fracture of the L2 body. Lumbar magnetic resonance imaging showed an intradural mass-like lesion on the ventral side of his spinal cord and an epidural mass-like lesion on the dorsal side of his spinal cord, indicating a hematoma.

INTERVENTIONS

An emergency L2 laminectomy was performed to remove the space-occupying lesions and to decompress the cauda equina and nerve root. The mass-like lesion was removed. No other lesions were found in the spinal canal.

OUTCOMES

Pathologic examination of the intradural mass lesion revealed fibrocartilage similar to that found in disc material. The patient still continued to experience motor weakness at the 1-year follow-up examination.

LESSONS

We report a rare case of a traumatic lumbar disc rupture into the dural sac associated with a mild vertebral body compression fracture. Early diagnosis and prompt surgical intervention are essential, as is performing a magnetic resonance imaging or computed tomography myelogram promptly to evaluate the spinal canal when there are unexplained neurologic symptoms. An intraspinal canal evaluation should be completed before the postural reduction of the vertebral body fracture to prevent any neurological complications.

An Ultrasonically Powered Implantable Microprobe for Electrolytic Ablation

Electrolytic ablation (EA) is a promising nonthermal tumor ablation technique that destroys malignant cells through induction of a locoregional pH change. EA is typically performed by inserting needle electrodes inside the tumor followed by application of direct current (DC), thus inducing electrolysis and creating localized pH changes around the electrodes. In this paper, we report an ultrasonically powered implantable EA microprobe that may increase the clinical relevance of EA by allowing wireless control over device operation (capability to remotely turn the device on and off) and providing flexibility in treatment options (easier to administer fractionated doses over a longer period). The wireless EA microprobe consists of a millimeter-sized piezoelectric ultrasonic receiver, a rectifier circuit, and a pair of platinum electrodes (overall size is 9 × 3 × 2 mm³). Once implanted through a minimally invasive procedure, the microprobe can stay within a solid tumor and be repeatedly used as needed. Ultrasonic power allows for efficient power delivery to mm-scale devices implanted deep within soft tissues of the body. The microprobe is capable of producing a direct current of 90 µA at a voltage of 5 V across the electrodes under low-intensity ultrasound (~200 mW/cm²). The DC power creates acidic (pH < 2) and alkaline (pH > 12.9) regions around the anode and the cathode, respectively. The pH change, measured using tissue-mimicking agarose gel, extends to 0.8 cm³ in volume within an hour at an expansion rate of 0.5 mm³/min. The microprobe-mediated EA ablative capability is demonstrated in vitro in cancer cells and ex vivo in mouse liver.

The Reappraisal of the Slide-Swing Skin Flap: A Versatile Technique for Surgical Defects

Background

The slide-swing skin flap is a combination of transposition and adjacent skin sliding and can be used to close large, round defects with a flap that is smaller than the primary defect to produce aesthetically good results.

Objective

To evaluate the efficacy and safety of the slide-swing skin flap for various surgical defects caused by skin tumor excisions.

Methods

This retrospective case series, which includes 33 Asian patients between the ages of 25 and 86 years, describes the slide-swing skin flap after primary excision for malignant or premalignant skin conditions. The outcomes were assessed 12 weeks after surgery using the patient and observer scar assessment scale (POSAS).

Results

Patients were 25 male and 8 female, and the causes of surgery were various malignant skin tumors including malignant melanoma, dermatofibrosarcoma protuberans, and malignant nodular hidradenoma. Tumors were on the lower limb in eleven patients, back in nine patients, chest in five patients, face in three patients, buttock in three patients and two patients had tumors in other locations. The mean defect size was 3.5×3.1±1.9×2.2 cm (range, 1.4×0.9~9.0×12.0 cm). The mean patient POSAS total score was 9.7±3.0 and mean patient overall opinion score was 1.8±0.7. The mean observer POSAS total score was 11.0±2.7 and mean observer overall opinion score was 1.9±0.5. All flaps survived and postoperative recoveries were uneventful.

Conclusion

The slide-swing skin flap is highly versatile and can be used to cover various surgical defects, irrespective of size and location, with excellent functional and cosmetic results.

Clinical characteristics of pediatric cutaneous lupus erythematosus: experience from a tertiary referral center in Korea

The clinical characteristics of cutaneous lupus erythematosus (CLE) are well delineated in adults, but pediatric data, particularly in Asian populations, are limited. Therefore, we evaluated the characteristics of pediatric cases by retrospectively reviewing the medical records of children with CLE during a 15-year period in a tertiary care dermatology clinic in South Korea. The study included 21 children (8 males and 13 females), 4 of whom had neonatal lupus erythematosus (NLE). Among 17 patients with CLE, discoid lupus erythematosus (DLE) was most common (47.1%), followed by acute CLE (ACLE, 35.3%). All ACLE cases had systemic lupus erythematosus (SLE). Female predominance was conspicuous in ACLE/SLE (6/11 females versus 0/6 males), as was older age, whereas DLE and NLE showed near-equal sex distributions. The median age at the diagnosis of CLE was significantly higher in females than in males (15 years versus 4.5 years, p = 0.02). All patients with ACLE/SLE simultaneously showed skin and systemic symptoms from onset. The kidney was the most commonly involved organ. This study revealed unique characteristics of pediatric CLE, further warranting a comprehensive review among various ethnicities to understand the wide spectrum of CLE in the pediatric population.

Curcumin Treatment in Combination with Glucose Restriction Inhibits Intracellular Alkalinization and Tumor Growth in Hepatoma Cells

Dysregulation of cellular energy metabolism is closely linked to cancer development and progression. Calorie or glucose restriction (CR or GR) inhibits energy-dependent pathways, including IGF-1/PI3K/Akt/mTOR, in cancer cells. However, alterations in proton dynamics and reversal of the pH gradient across the cell membrane, which results in intracellular alkalinization and extracellular acidification in cancer tissues, have emerged as important etiopathogenic factors. We measured glucose, lactate, and ATP production after GR, plant-derived CR-mimetic curcumin treatment, and curcumin plus GR in human hepatoma cells. Intracellular pH regulatory effects, in particular, protein-protein interactions within mTOR complex-1 and its structural change, were investigated. Curcumin treatment or GR mildly inhibited Na+/H+ exchanger-1 (NHE1). vATPase, monocarboxylate transporter (MCT)-1, and MCT4 level. Combination treatment with curcumin and GR further enhanced the inhibitory effects on these transporters and proton-extruding enzymes, with intracellular pH reduction. ATP and lactate production decreased according to pH change. Modeling of mTOR protein revealed structural changes upon treatments, and curcumin plus GR decreased binding of Raptor and GβL to mTOR, as well as of Rag A and Rag B to Raptor. Consequently, 4EBP1 phosphorylation was decreased and cell migration and proliferation were inhibited in a pH-dependent manner. Autophagy was increased by curcumin plus GR. In conclusion, curcumin treatment combined with GR may be a useful supportive approach for preventing intracellular alkalinization and cancer progression.

Effects of laser-assisted thinning versus opening on clinical outcomes according to maternal age in patients with repeated implantation failure

Laser-assisted thinning (LAT) and laser-assisted opening (LAO) are performed as part of human in vitro fertilization (IVF) to increase the implantation rate in patients with a poor prognosis and in cases of repeated implantation failure. However, an insufficient number of studies have directly compared LAT and LAO using the same methods. Therefore, we compared the effects of LAT and LAO on clinical outcomes according to maternal age in patients with repeated implantation failure. This retrospective study was performed in 509 IVF cycles (458 patients). The cycles were divided based on maternal age and the method used (< 38 years LAT, n = 119 vs. LAO, n = 179 and ≥ 38 years LAT, n = 72 vs. LAO, n = 139). Cleavage-stage embryos before transfer were either thinned or opened using a 1.46-μm noncontact diode laser. We compared the implantation rates and pregnancy outcomes of cycles between LAT and LAO according to maternal age. The characteristics of patients did not differ significantly among the groups (p > 0.05), with the exception of mixed factor infertility, which was more common in the LAT group than in the LAO group among patients < 38 years of age (10.1% vs. 2.8%, p = 0.008). The LAT and LAO groups showed similar rates of biochemical pregnancy, clinical pregnancy, ongoing pregnancy, abortion, implantation, singleton pregnancy, and twin pregnancy (p > 0.05). In conclusion, LAT and LAO had similar clinical outcomes. Therefore, we did not find any evidence that LAT is superior to LAO. In fact, the patients ≥ 38 years of age who underwent LAO tended to have a lower abortion rate. Further study is necessary to confirm these results in a larger population.

Abstract P3-08-12: PIK3CA mutations in breast cancer: Mutational landscape and clinical implications in ER+/HER2- subtype

Introduction: PIK3CA mutation is one of the most frequent genomic alterations in breast cancer. We evaluated PIK3CA mutational status including spatial and temporal heterogeneity, clinical characteristics and prognostic impact focused on ER+/HER2- subtype.

Methods: We performed targeted ultra-deep sequencing (CancerSCAN™) of breast cancer tissue in a prospective cohort. Burden of disease was assessed by metabolic tumor volume(MTV) in 18F-FDG-PET scan. Association with clinical characteristics or survival were tested in ER+/HER2- subtype, using Chi square test or Kaplan-Meier method.

Results: PIK3CA analyses were performed in 1274 breast cancer specimens from 1091 patients. 957 patients had early breast cancer. PIK3CA alterations were found in 397 patients(36.3%), and frequency of PIK3CA mutation was significantly lower in triple negative breast cancer(19.0%), compared with 40.4% in ER+/HER2-, 40.9% in ER+/HER2+, and 45.2% in ER-/HER2+ subtype(p&lt;0.0001). 158 patients had more than two biopsies. Among 92 patients with second biopsy within one month, 11%(10/92) had spatial heterogeneity of PIK3CA mutation. After neoadjuvant chemotherapy, 10%(3/30) of patients had change of PIK3CA mutational status. Serial biopsy at time of recurrence revealed loss or gain of PIK3CA mutation in 10 out of 59 patients (17%). In ER+/HER2- subtype, PIK3CA had a trend toward longer distant disease free survival without statistical significance. In patients with stage IV ER+/HER2- disease, PIK3CA hotspot mutations were associated with significant longer overall survival(OS) (71.0 vs. 37.8 months, p=0.048) and better progression free survival(PFS) at 1st line palliative treatment (37.7 vs. 9.4 months, p = 0.0004). Frequency of symptomatic recurrence, recurrence as oligometastases, and specific metastatic sites were not associated with PIK3CA mutational status, except that bone metastases at first distant metastases was less prevalent in patients with PIK3CA hotspot mutations(35.6% vs. 53.8% in PIK3CA wt, p=0.048). Metabolic tumor volume(MTV) at time of first distant metastases was not associated with presence of PIK3CA mutation.

Conclusion: We observed variations in PIK3CA mutational status in more than 10% of patients with &gt;1 repeated biopsy. In stage IV ER+/HER2- disease, PIK3CA hotspot mutation seemed to be associated with longer PFS and OS, however metabolic tumor burden was not associated with PIK3CA alterations.

Citation Format: Ahn HK, Park S, Hyun SH, Park K, Lee E, Kim J-Y, Nam SJ, Kim SW, Lee JE, Lee SK, Yu JH, Ahn JS, Im Y-H, Park YH. PIK3CA mutations in breast cancer: Mutational landscape and clinical implications in ER+/HER2- subtype [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 P3-08-12.

Abstract P1-09-11: Prognostication of genetic alterations of ESR 1 in estrogen receptor positive metastatic breast cancers using targeted ultra-deep sequencing data analysis

Introduction: Genetic alteration of Estrogen Receptor 1(ESR1) gene have been associated with acquired endocrine resistance and occurred in about 20% of endocrine resistant estrogen receptor(ER)-positive metastatic breast cancer(MBC). Mutations in ligand binding domain of ESR1 lead to constitutive activity of the ER without ligand estrogen and stimulated down stream cell growth signal. Therefore, ESR1 ligand binding domain alteration is known resistant mechanism of aromatase inhibitor. Among these ESR1 mutations, Y537S, one of the ligand binding domain mutations, caused ER antagonist, fulvestrant resistance. Therefore, assessment of ESR1 mutation in ER-positive MBC had significant benefit to further precision medicine for MBCs. In this study, we explored to identify the frequency and type of ESR1 genetic alterations of ER-positive MBC.

Methods: We performed targeted ultra-deep sequencing (CancerSCAN™) using BC tissue specimens. This sequencing was covered entire coding area of ESR1 gene and also detected copy number alteration and translocation of ESR1.

Results: Targeted ultra-deep sequencing of ESR1 was performed using 990 BC tissues. Of 990 tissue samples, 341(34.5%) were MBCs. Of MBCs, 112(11.3%) were ER-positive and human epidermal growth factor receptor 2(HER2)-negative BCs. In ER-positive HER2-negative MBCs (N=112), 21 ESR1 genetic alterations were identified in 19 BCs (17.0%). Nineteen were single nucleotide variats (SNVs) and three were copy number (CN) amplification. Most commonly detected single nucleotide variant (SNV) was D538G (6 of 19, 31.6%) followed by Y537N, Y537S, V382I (4, 2 and 2 cases, respectively). Three mutations occurred in non-ligand binding domain (G415V, V392I and P79A). Two BC samples harbored two ESR1 mutations, respectively (Y537S and D538G, L536P and Y537N). In terms of treatment, 11 of 12 patients with ER-positive MBC harboring ESR1 mutation received palliative endocrine therapies. Eight patients received aromatase inhibitor and two patients received tamoxifen. One patient received letrozole plus palbociclib. In 2 MBCs with Y537S mutation, progression free survival (PFS) of endocrine therapy was 1.4 and 5.3 months. MBCs with D538G had 12.3months of PFS (range, 5.3-23.7(months)) and BCs harboring another ligand binding domain mutations (Y537N, L536H and L536P) had 15.7months of PFS of endocrine therapy (range, 8.4-17.3(months)). BC with mutation observed in non-lignand binding domain had short PFS (1.8 (V392I) and 2.7 (P79A) months, respectively). In terms of ESR1 CN amplification, patients could not receive endocrine therapy because their BCs rapidly progressed and extensive distant metastases were occurred within 3 months after curative surgery.

Conclusion: In this exploratory study, ESR1 genetic alterations were detected in about 20% of ER-positive MBC. The type of genetic alterations varied including SNVs, CNAs. Each locus of ESR1 mutation predicted endocrine resistance. In addition, we might suggest that ESR1 CN amplification is prognostic marker of ER-positive BCs.

Citation Format: Kim J-Y, Park KH, Park W-Y, Nam SJ, Kim SW, Lee JE, Lee SK, Yu JH, Ahn JS, Im Y-H, Park YH. Prognostication of genetic alterations of ESR 1 in estrogen receptor positive metastatic breast cancers using targeted ultra-deep sequencing data analysis [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 P1-09-11.

Abstract P4-08-30: Prognostication of immune related gene expression in patients with triple negative breast cancer

Introduction: To date, the role of immunotherapy with check point inhibitors and/or vaccines in the treatment of breast cancer (BC) is still debating, and the main focus of immunotherapy in BC is on triple negative subtype as a target population in many ongoing clinical trials. Translational research into identifying predictive and prognostic immune biomarkers is of particular clinical relevance, but, there are currently no definite prognostic and predictive immune biomarkers in BC, especially in triple negative breast cancer(TNBC). We investigated the expression profiles of immune genes in patients with TNBC to identify the prognostic value of immune genes in search of clinical implications.

Methods : We investigated expression profiles of 770 pan-cancer immune related genes using the nCounter mRNA expression assay (NanoString®) from paraffin-embedded tumor tissues in 200 patients diagnosed as TNBC who received curative surgery at Samsung Medical Center from 2000 to 2004. We analyzed the relationship between stage adjusted level of gene expressions and patients' survival outcomes using Cox regression model.

Results: Of 770 genes, 186 genes were selected from univariate analysis with clinical stage adjustment. In multivariate analysis using Cox regression, expressions of CD1B, CD45, CD53, CT45A1, GTF3C1, IL11RA, IL1RN, LRRN3, MAPK1, NEFL, PRKCE, SPACA3 and RANKL were associated with distant recurrence free survival (p&lt;0.05, respectively). Among these 13 genes, expression of MAPK1, NEFL, CD45, SPACA3 and RANKL were correlated with favorable outcome in terms of distant recurrence free survival (p&lt;0.05, respectively). In terms of overall survival, C3, IL1RL1, IL1RN, IL7 and PRKCE were associated with poor prognosis (p&lt;0.05, respectively) and expression of SAA1 CXCL9 and RANKL resulted in favorable outcome (p&lt;0.05, respectively).

Table 1ParameterParameter EstimateStandard Errorp-valueHazard Ratio95% Confidence Interval(a) distant recurrence free survival     Stage2.487350.680570.000312.0293.169, 45.661CD1B1.141910.2753&lt;.00013.1331.826, 5.374CD531.531650.34851&lt;.00014.6262.336, 9.159CT45A10.426110.134210.00151.5311.177, 1.992GTF3C11.193110.579720.03963.2971.059, 10.271IL11RA1.671120.461750.00035.3182.151, 13.146IL1RN0.980280.24657&lt;.00012.6651.644, 4.321LRRN31.424170.28742&lt;.00014.1542.365, 7.297MAPK1-0.542740.258240.03560.5810.35, 0.964NEFL-1.12170.335610.00080.3260.169, 0.629PRKCE2.378340.49659&lt;.000110.7874.076, 28.549CD45-2.736780.43154&lt;.00010.0650.028, 0.151SPACA3-0.745930.272270.00610.4740.278, 0.809RANKL-1.288920.2976&lt;.00010.2760.154, 0.494(b) overall survival     Stage1.359280.497810.00633.8931.468, 10.329C30.329830.150350.02831.3911.036, 1.867CXCL9-0.379190.100680.00020.6840.562, 0.834IL1RL10.679360.262940.00981.9731.178, 3.303IL1RN0.437130.172370.01121.5481.104, 2.171IL70.507280.206250.01391.6611.109, 2.488PRKCE0.835340.272910.00222.3061.35, 3.936SAA1-0.564250.13449&lt;.00010.5690.437, 0.74RANKL-0.604990.234510.00990.5460.345, 0.865

Conclusion: High expression of IL1RN, PRKCE were associated with short distant recurrence free survival and overall survival in patients with TNBCs who received curative surgery. In contrast, RANKL expression resulted in prolonged distant recurrence free survival and overall survival.

Citation Format: Kim J-Y, Jung HH, Lim JE, Cho EY, Lee SK, Yu JH, Lee JE, Kim SW, Nam SJ, Park YH, Ahn JS, Im Y-H. Prognostication of immune related gene expression in patients with triple 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 P4-08-30.

Abstract P2-08-52: A predictive model for distant metastasis in breast cancer patients using machine learning

Introduction

Tumor metastasis is a major clinical challenge accounting for the vast majority of cancer related deaths.In previous studies, prediction of distant metastasis was based on subtypes,clinical status and sometimes gene expression were used however clinical application was difficult.

In this study, we develop the easy to use prediction tool for distant metastasis using clinical characteristics and gene profiles which came from CancerSCANTM, Next Generation Sequencing based targeted-sequencing platform designed at Samsung Medical Center(SMC).

Methods

We performed a retrospective chart review of 326 breast cancer patients who underwent surgery and CancerSCAN TM between Jan 2001 and Dec 2014 at SMC. Median follow up period was 83 months (Range 1˜190). Cancer scanTM cover 381 genes but 27 genes and 34 occasions (loss of function, mutation or copy number variation) were selected for analysis through gradient boosting and Wilcoxon Signed rank test. Azure Machine Learning is a cloud service that enables the execution of machine learning processes.This was accomplished using the steps of (1) edit the data, (2) split the data, (3) train the model, (4) score the model, and (5) evaluate the model. We split the modeling data into training and testing sets using a randomized 50–50 split. Two-class Decision Forest method was used. After deploying the Azure ML predictive model as a web service, we used a Representational State Transfer application programming interface to send data and obtained predictions in real-time.

Results

No distant metastasis group and distant metastasis group consisted of 267 and 59 patients, respectively. HR-/HER2+ and 50 years old and over patients were higher in metastasis group (p-value = 0.003 and p-value = 0.000). Nuclear grade 3 and N2,3 were higher in metastasis group (p-value = 0.010 and p-value = 0.000, p-value = 0.001 respectively). Stage III was also higher in metastasis group (p-value = 0.000). Among 59 patients with distantmetastasis, multiple sites metastasis was 21 cases (35.6%) and then lung metastasis was 19 cases (32.2%). In the 21 cases of multiple sites metastasis, triple sites was 6 cases (28.6%) and double sites was 15 cases (71.4%). PIK3CA mutation was the most frequent gene variation in all patients (34.5% of no metastasis group and 27.1% of metastasis group) but there was no difference between two groups(p-value = 0.278). BRCA 1 loss of function and BRCA2 loss of function were more frequent in metastasis group than no metastasis group(p-value = 0.033 and p-value = 0.024, respectively) but total counts was too small. We assessed the area under the curve (AUC) of the receiver operating characteristic (ROC) curve for predictive value. The AUC of ROC curve was 1.000 and also accuracy, precision, recall were 1.000. In addition, we conducted internal validation using 83 patients during 2015. When we applied a 0.5 threshold value with our predictive model, true negative was 81 and true positive was 2 among 83 patients. Finally, the accuracy of validation was 1.000.

Conclusion

Our predicted model could represent a useful and easy-to-access tool for the selection of patients with distant metastasis. After additional evaluation with large data and external validation, worldwide use of our model could be expected.

Citation Format: Kim I, Choi HJ, Ryu JM, Lee SK, Yu JH, Kim SW, Nam SJ, Seo SW, Lee JE. A predictive model for distant metastasis in breast cancer patients using machine learning [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 P2-08-52.

Abstract PD5-08: Neoadjuvant chemotherapy alters the genomic landscape and immune microenvironment of breast cancers

Understanding how standard-of-care drug treatments affect tumor intrinsic biology and microenvironment is critical for elucidating drug resistance mechanisms and developing better combination therapies as well as new therapies. To characterize the effects of neoadjuvant chemotherapy (NAC) on the genome, transcriptome and tumor infiltrating leukocytes (TILs), we have conducted whole exome and whole transcriptome sequencing of a large longitudinal breast cancer cohort consisting of 146 cases and 281 paired tumor samples. In total, 52 (38%) patients achieved pathologic complete response (pCR) while 85 patients (62%) had residual disease with standard chemotherapy regimen. Tumor biopsies were collected for each patient at three time points – pre-treatment, three weeks after the first cycle of anthracycline and cyclophosphamide (AC) and at the time of surgery after 3 more cycles of AC followed by 4 cycles of taxane or taxane plus Herceptin in case of HER2+ subtype. We detected 5,955 protein-altering somatic mutations affecting 4,414 genes in pretreatment samples and 502 acquired mutations in surgery samples affecting 477 genes including 19recurrently mutated genes such as TP53 and NOTCH1. Across all subtypes, 4,346 genes were differentially expressed (DE) following NAC treatment and significantly enriched in pathways such as cell cycle, ER signaling, PI3K/mTOR, immune and metabolism. Expression-based virtual microdissection analysis indicated that NAC treatment induced an increase in the fractions of stromal and adjacent normal tissue compartment, consistent with observed reduction in tumor cellularity. To assess the NAC induced changes in the molecular landscape of these tumors, we compared molecular features including gene expression signatures, mutation prevalence and copy number alteration between three time points while adjusting for confounding effects of molecular subtype and tumor cellularity. We found that NAC induced dynamic changes in gene expression signatures associated with proliferation and immunomodulatory treatment response. We further validated the observed pattern of change in TILs through histopathology and digital imaging analyses. In pretreatment tumors, 116 genes were DE between patients with pCR vs. those with residual disease with significant enrichment in immune/inflammatory pathways. Further, pre-treatment TIL levels were found to be significantly associated with pCR, echoing previous reports in breast cancers that implicated anti-tumor immunity in mediating the efficacy of chemotherapies. Our analyses also revealed associations between NAC response and baseline genomic attributes such as genomic alterations that affect DNA damage repair pathways. Taken together, these results suggest that NAC induced a multitude of changes on the genomic landscape and immune microenvironment of breast cancers, some of which point to combination strategies with immunomodulatory therapies and therapies that target DNA damage repair.

Citation Format: Kan Z, Lal S, Ding Y, Lee JE, Lee S-H, Lee SK, Yu JH, Choi Y-l, Kim SW, Nam SJ, Kim J-Y, Ram S, Powell E, Ching K, Cho SY, Bonato V, Deng S, Park W-Y, Rejto P, Bienkowska J, Park Y-H. Neoadjuvant chemotherapy alters the genomic landscape and immune microenvironment of breast cancers [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 PD5-08.

Abstract P1-15-18: Not presented

This abstract was not presented at the conference.

Citation Format: Choi HJ, Kim SW, Ryu JM, Kim I, Nam SJ, Yu J, Lee SK, Lee JE. Not presented [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 P1-15-18.

Abstract P2-08-29: The impact of time interval between diagnosis and surgery in each type and stage of breast cancer

Background: There are many factors that might contribute to the delay of surgery in patients with breast cancer. Previous studies investigate the influence of delay of surgery, but they reported inconsistent results. The purpose of this study was to evaluate the impact of time of surgery on prognosis of breast cancer.

Methods: We performed a retrospective review of the patients with breast cancer, who received surgery between 1992 and 2009, by using data from Korea Breast Cancer Society Registry. Kaplan-Meier survival analysis and Cox regression model were used to evaluate the impact of time to surgery in breast cancer and subgroup analyses were performed for each disease stage and molecular subtype.

Result: A total 14727 patients were included for analysis. Delay of surgery more than 31 days was associated with worse survival for breast cancer [hazard ratio (HR) = 2.16; 95% confidence interval (CI), 1.936-2.408, p&lt;0.001]. Subgroup analyses revealed that over 31 days of surgical delay were significantly associated with worse survival in hormone receptor positive and HER-2 negative (p&lt;0.001), hormone receptor positive and HER-2 positive (p&lt;0.001), hormone receptor negative and HER-2 positive (p&lt;0.001), triple negative (p&lt;0.001) and stage II, III breast cancer patients (p&lt;0.001).

Conclusion: Surgical delay of more than 31 days were independent risk factors for worse outcome of breast cancer in each molecular subtype and breast cancer group except stage 0 and I. Although preoperative evaluation is required, surgical delay should be shortened to enhance survival of breast cancer, especially in patients with tumor size more than 2cm or presence of lymph node metastasis.

Citation Format: Kim J-M, Choi HJ, Kim I, Ryu JM, Yu J, Lee JE, Kim SW, Nam SJ, Lee SK. The impact of time interval between diagnosis and surgery in each type and stage of 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 P2-08-29.

Transcatheter arterial embolization for iatrogenic bleeding after endoscopic ultrasound-guided pancreaticobiliary drainage

PURPOSE

The purpose of this study was to report the incidence of massive bleeding after endoscopic ultrasound-guided transmural pancreaticobiliary drainage (EUS-TPBD) and the clinical outcomes in patients with this condition treated with transcatheter arterial embolization (TAE).

PATIENTS AND METHODS

We performed a 9-year retrospective analysis of 797 EUS-TPBD procedures (excluding gallbladder or pseudocysts) in 729 patients. Among them, twelve (12/729, 1.65%) patients were referred for TAE to manage active bleeding adjacent to the TPBD sites. There were 8 men and 4 women with a mean age of 66.1 years±13.4 (SD) (range: 45-89 years). The clinical and procedure data of these 12 patients were reviewed.

RESULTS

Thirteen TAE procedures in 12 patients were performed. The bleeding sites were the left hepatic artery (n=7), the right hepatic artery (n=3), the left gastric artery (n=1), the left accessory gastric artery (n=1) and gastroduodenal artery (n=1). TAE was performed with gelatin sponge particles (n=1), coil (n=1) and n-butyl-2 cyanoacrylate with/without coils (n=11), with technical and clinical success rates of 100% (13/13) and 85% (11/13), respectively. Re-bleeding following embolization with gelatin sponge particles occurred in one patient. Procedure-related ischemic hepatitis was observed in another patient with pancreatic cancer with portal vein involvement.

CONCLUSION

On the basis of our results, TAE using n-butyl-2 cyanoacrylate seems safe and effective for the treatment of bleeding after EUS-TPBD procedures. When the portal vein is compromised, TAE of the hepatic artery can cause ischemic liver damage.

Abstract P6-09-08: Identification of ESR1 mutation in breast cancers using targeted ultra-deep sequencing data analysis

Introduction: Estrogen Receptor 1 (ESR1) gene encodes an estrogen receptor, which regulates cell proliferation and promotes tumor progression in estrogen receptor(ER)-positive breast cancer (BC). Therefore, endocrine therapy that inhibiting ER downstream signal, is the most effective treatment strategy in ER-positive BC. However, about 25% of patients with primary disease and almost all patients with metastases will present with or eventually develop endocrine resistance. And genetic alteration of ESR1 is now identified as the endocrine resistance mechanism. However, a few data from clinical trials or public data base exists and could not reflect real world clinic. Therefore, we aimed to identify the frequency and type of ESR1 genetic alterations in BCs through this large scaled study.

Methods: We performed targeted ultra-deep sequencing (CancerSCAN™) using BC tissue specimens. This sequencing was covered entire coding area of ESR1 gene and also detected copy number alteration and translocation of ESR1.

Results: Targeted ultra-deep sequencing of ESR1 was performed using 618 BC tissues. Of 618 tissue samples, 253(40.9%) were MBCs, 362(58.6%) were early BCs (EBCs) and 3 were not identified. In terms of subtypes, 220 ER-positive BCs, 122 ER-positive and HER2-positive BCs, 119 HER2-positive and 153 triple-negative BCs (TNBCs) were included. BCs from patients under 40 year-old were 277(44.8%)(Median: 43.0, range: 23.5 -75.6). ESR1 genetic alterations were identified in 21 BCs (5 EBCs and 16 MBCs). In EBCs, 3 cases were observed in TNBCs and 2 cases were in ER-positive BCs (2.6% and 1.2%, respectively). All five EBC were treatment naïve status. Of 16 cases of ESR1 alterations in MBCs, 10 cases of ESR1 alterations were detected in ER-positive BCs (17.6%), 5cases in ER and HER2-positive BCs(6.7%) and 1 in HER2-positive BCs (1.2%). All ER-positive MBCs were treated with more than one line of endocrine therapy. Most commonly detected genetic alteration was single nucleotide variant (SNV) (15 of 21, 71.4%). Thirteen were in ligand binding domain and two cases occurred in activation function-1 (AF-1) domain (P79A and G145S). D538G and V392I were most frequently mutated loci followed by Y537N (3, 3 and 2 cases, respectively) and only metastatic ER-positive BCs harbored ESR1 activating mutation. Four copy number (CN) amplification in 2 ER-positive and 2 ER and HER2-positive BCs, one CN deletion in TNBC and one ESR1 fusion in ER and HER2-positive BC were also detected (19.0%, 4.8% and 4.8%, respectively). In frame ESR1 fusion was occurred between ESR1 and NPHS1 genes.

Conclusion: In this experimental study, ESR1 genetic alterations were frequently detected in ER-positive MBC but ER-negative or EBC also harbored. The type of genetic alterations varied including SNVs, CN alterations and translocation and ESR1-NPHS1 fusion is the novel genetic alteration that has not been reported. To identify the role of ESR1 genetic alteration in ER-negative BCs and novel translocation, further functional validation would be warranted (Clinical trials.gov Number :NCT02591966).

Citation Format: Kim J-Y, Park K, Park W-Y, Nam SJ, Kim SW, Lee JE, Lee SK, Jung HH, Yu JH, Ahn JS, Im Y-H, Park YH. Identification of ESR1 mutation in breast cancers using targeted ultra-deep sequencing data analysis [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-09-08.

Abstract P1-07-25: Differences among young breast cancer patients based on subtype: A study from the Korean Breast Cancer Society – Running head: Do breast cancers in 20s have worse prognosis than 30s?

Purpose Numerous studies demonstrated that breast cancer in young women (BCY) has unfavorable prognostic features and unfavorable subtype. However, there were few studies to evaluate the effect on the prognosis of breast cancer according to the subtype disparities by age especially BCY. We analyzed breast cancer mortality stratified tumor subtype according to age among the patients with less than 50 year-old. Patients and Methods Data obtained from the Korean Breast Cancer Society Registry (KBCSR), patients diagnosed with invasive breast cancer were retrospectively between 2003 and 2010. We excluded patients with male breast cancer, underwent neoadjuvant chemotherapy, distant metastasis or inflammatory breast cancer at presentation, and other histopathology except invasive ductal or invasive lobular carcinoma. We also excluded patients with lack of immunohistochemistry data and short-term follow-up duration (&lt;12 months). Results We identified 37,865 patients, and excluded by study protocol. Among those, 30,793 patients with breast cancer for eligible for analysis, 793 (2.6%) were 20-29 years and 8,926 (28.8%) were 30-39 years of age. Median follow-up duration was 84 months. Mean age was 42.4 years old. Younger patients with breast cancer were more likely to have advanced stage, higher nuclear grade, present lymphovascular invasion, and more likely to be unfavorable subtype such as triple negative breast cancer (TNBC)

Table 1. Baseline Characteristics Age at Presentation 20-29, N(%)30-39, N(%)40-49, N(%)P-valueOverall793 (2.6)8,133 (26.4)21,867 (71.0) Pathologic stage   &lt;.0001I295 (37.2)2,928 (36.0)9,288 (42.5) II373 (47.0)3,644 (44.8)9,078 (41.5) III119 (15.0)1,442 (17.7)3,211 (14.7) Family history   &lt;.0001Yes81 (10.2)674 (8.3)1,391 (6.4) No712 (89.8)7,459 (91.7)20,476 (93.6) Nuclear grade   &lt;.0001Low85 (10.2)941 (11.6)3,824 (17.5) Intermediate288 (36.3)3,340 (41.1)9,688 (44.3) High331 (41.7)3,165 (38.9)6,650 (30.4) LVI   &lt;.0001Yes249 (31.4)2,840 (34.9)6,711 (30.7) No433 (54.6)4,367 (53.7)13,005 (59.5) Subtype   &lt;.0001Luminal A314 (39.6)3,529 (43.4)11,716 (53.6) Luminal B190 (24.0)1,895 (23.3)4,775 (21.8) Her-252 (6.6)724 (8.9)1,723 (7.9) TNBC237 (29.8)1,895 (24.4)3,653 (16.7) HER-2, human epidermal growth factor-2; TNBC, triple negative breast cancer

. Patients with younger age group showed worse prognosis than patients with older age patients. In multivariate analysis for overall survival, as patients were younger group, hazard ratio was increased, and the patients with TNBC showed higher HR than HER-2, Luminal B, and Luminal A subtype (P&lt; .0001, P&lt; .0001, P&lt; .0001, and P&lt; .0001, respectively). Stratified by subtype, luminal subtype showed significant worse prognosis as the age group was younger, while as, Her-2 and TNBC subtype showed no significantly difference by the age group. Conclusion Patients with 20s breast cancer showed unfavorable characteristics and worse prognosis than 30s and older aged group. Stratified by tumor subtype, breast cancer in 20s with luminal subtype showed worse prognosis, while as HER-2 and TNBC showed no significantly different compare to breast cancer in 30s.

Citation Format: Ryu JM, Yu J, Nam SJ, Kim I, Lee JE, Lee SK, Kim JM, Choi HJ, Kim SW. Differences among young breast cancer patients based on subtype: A study from the Korean Breast Cancer Society – Running head: Do breast cancers in 20s have worse prognosis than 30s? [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-25.

Correlation between extension-block K-wire insertion angle and postoperative extension loss in mallet finger fracture

INTRODUCTION

Extension-block pinning represents a simple and reliable surgical technique. Although this procedure is commonly performed successfully, some patients develop postoperative extension loss. To date, the relationship between extension-block Kirschner wire (K-wire) insertion angle and postoperative extension loss in mallet finger fracture remains unclear.

HYPOTHESIS

We aimed to clarify this relationship and further evaluate how various operative and non-operative factors affect postoperative extension loss after extension-block pinning for mallet finger fracture.

MATERIALS AND METHOD

A retrospective study was conducted to investigate a relationship between extension block K-wire insertion angle and postoperative extension loss. The inclusion criteria were: (1) a dorsal intra-articular fracture fragment involving 30% of the base of the distal phalanx with or without volar subluxation of the distal phalanx; and (2) <3 weeks delay from the injury without treatment. Extension-block K-wire insertion angle and fixation angle of the distal interphalangeal (DIP) joint were assessed using lateral radiograph at immediate postoperative time. Postoperative extension loss was assessed by using lateral radiograph at latest follow-up. Extension-block K-wire insertion angle was defined as the acute angle between extension block K-wire and longitudinal axis of middle phalangeal head. DIP joint fixation angle was defined as the acute angle between the distal phalanx and middle phalanx longitudinal axes.

RESULTS

Seventy-five patients were included. The correlation analysis revealed that extension-block K-wire insertion angle had a negative correlation with postoperative extension loss, whereas fracture size and time to operation had a positive correlation (correlation coefficient for extension block K-wire angle: -0.66, facture size: +0.67, time to operation: +0.60). When stratifying patients in terms of negative and positive fixation angle of the DIP joint, the independent t-test showed that mean postoperative extension loss is -3.67° and +4.54° (DIP joint fixation angles of <0° and ≥0°, respectively, P=0.024). When stratifying patients in terms of extension-block K-wire insertion angle (30°, 30°-40°, >40°), ANOVA showed significantly less postoperative extension loss for higher insertion angles (>40°) than for medium insertion angles (30°-40°). Mean postoperative extension loss difference between higher insertion angle (>40°) and medium insertion angle (30°-40°) was 11° (P=0.002).

DISCUSSION

Using an insertion angle of the extension-block K-wire of 40°-45° and a slightly hyperextended position of the DIP joint may help reducing postoperative extension loss.

LEVEL OF EVIDENCE

Therapeutic level III.

The association between season of birth, age at onset, and clozapine use in schizophrenia

OBJECTIVE

This study aimed to determine whether the rate of clozapine use, an indicator of refractoriness in schizophrenia, is associated with the season of birth and age at onset in patients with schizophrenia based on nationwide data.

METHODS

Patients with schizophrenia (n = 114 749) who received prescriptions for antipsychotic medication between 2008 and 2014 were retrospectively identified from the Korean National Health Insurance Service database. The study population was divided into three groups based on their age at the onset of schizophrenia (early, middle, and late onset). We assessed differences in the month of birth between patients and the general population. In addition, the cumulative clozapine use was calculated.

RESULTS

Compared to the late-onset schizophrenia group, the early- and middle-onset groups showed a higher probability of birth during the winter season. In addition, the early-onset group showed the highest cumulative clozapine use rate. In the middle-onset group, the initiation of clozapine use was significantly earlier for patients born in winter compared to those born in summer.

CONCLUSION

Our results indicate that the age at onset is an important factor in predicting the prognosis of schizophrenia patients. The season of birth also affects the prognosis, but with less robustness. Specifically, it appears that early disease onset and winter birth might be associated with poor outcomes in Korean patients with schizophrenia.

Neurodevelopmental outcomes of preterm infants resuscitated with different oxygen concentration at birth

OBJECTIVE

To compare the neurodevelopmental outcomes at 18 to 21 months corrected age (CA) of infants born at <29 weeks that received room air, an intermediate oxygen concentration or 100% oxygen at the initiation of resuscitation.

STUDY DESIGN

In this retrospective cohort study, we compared neonatal and neurodevelopmental outcomes at 18 to 21 months CA among inborn infants born before 29 weeks' gestation that received room air, intermediate oxygen concentration or 100% oxygen at the initiation of resuscitation.

RESULTS

Of 1509 infants, 445 received room air, 483 received intermediate oxygen concentrations and 581 received 100% oxygen. Compared to infants that received room air, the primary outcome of death or neurodevelopmental impairment (NDI) was not different in intermediate oxygen (adjusted odds ratio (aOR) 1.01; 95% confidence interval (CI) 0.77, 1.34) or 100% oxygen (aOR 1.03; 95% CI 0.78, 1.35). Compared to room air, there was no difference in odds of death or severe NDI in intermediate oxygen (aOR 1.14; 95% CI 0.82, 1.58) or 100% oxygen group (aOR 1.22; 95% CI 0.90, 1.67). The odds of severe NDI among survivors were significantly higher in infants that received 100% oxygen as compared to room air (aOR 1.57, 95% CI 1.05, 2.35).

CONCLUSIONS

We observed no significant difference in the primary composite outcomes of death or NDI and death or severe NDI at 18 to 21 months CA between infants that received room air, intermediate oxygen concentration or 100% oxygen at the initiation of resuscitation. However, use of 100% oxygen was associated with increased odds of severe NDI among survivors as compared to room air.

Efficacy of embryo transfer on day 2 versus day 3 according to maternal age in patients with normal ovarian response

Objective

Delaying embryo transfer (ET) enables us to select among the embryos available for transfer and is associated with positive effects on implantation and pregnancy outcomes. However, the optimal day for ET of human cleavage-stage embryos remains controversial.

Methods

A retrospective study of 3,124 in vitro fertilization/intracytoplasmic sperm injection cycles (2,440 patients) was conducted. We compared the effects of day 2 and 3 ET on rates of implantation and pregnancy outcomes between young maternal age (YMA; <38 years old, n=2,295) and old maternal age (OMA; ≥38 years old, n=829) patient groups.

Results

The YMA and OMA groups did not differ in terms of patient characteristics except for the proportion of unexplained factor infertility, which was significantly greater in the OMA group, and the proportion of arrested embryos, which was significantly greater in the YMA group. However, the biochemical pregnancy, clinical pregnancy, ongoing pregnancy, abortion, and implantation rates per cycle were not significantly different between day 2 and 3 ET in the YMA group or the OMA group.

Conclusion

We suggest that offering patients the opportunity to decide which day would be suitable for ET could be part of a patient-friendly protocol that takes into consideration an infertile woman's circumstances and work schedule by allowing ET to be performed on day 2 instead of the traditional transfer on day 3.

Utility of digital subtraction angiography-based collateral evaluation in medically treated acute symptomatic basilar artery stenosis

BACKGROUND AND PURPOSE

Although a stroke from atherosclerosis in the basilar artery (BA) often presents with mild initial stroke severity, it has heterogeneous clinical courses. We investigated the efficacy of digital subtraction angiography (DSA)-based collateral perfusion evaluation in association with long-term outcomes of medically treated symptomatic basilar artery stenosis.

METHODS

From a registry database of all consecutive patients with stroke, we included 98 medically treated patients (due to mild initial stroke severity) [National Institute of Health Stroke Scale (NIHSS) scores ≤ 4; symptomatic basilar artery stenosis, 70-99%] with available initial diagnostic DSA. Basilar collateral scoring was performed via the DSA, using a modified version of the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology grading system in both the superior cerebellar artery and anterior/posterior-inferior cerebellar artery territories (score 0-8). The outcomes were designated as the 90-day modified Rankin Scale (mRS90) score (poor, 3-6). Student's t-test, chi-square test and logistic regression analyses were used to identify factors associated with a poor outcome.

RESULTS

The median initial NIHSS score was 2 [interquartile range (IQR), 0-3], median posterior circulation Alberta Stroke Program Early CT Score was 8 (IQR, 7-10), median collateral score was 7 (IQR, 7-8) and 20 (20.4%) had poor mRS90 scores. In multivariate analysis, poorer collateral scores (P = 0.003), higher NIHSS scores (P = 0.005) and lower posterior circulation Alberta Stroke Program Early CT Score (P = 0.017) were independently associated with a poor mRS90 score.

CONCLUSIONS

The DSA-based collateral scoring of the BA large branches might predict long-term outcome in medically treated symptomatic basilar artery stenosis with mild initial severity. Evaluation of BA collateral perfusion status might be useful to determine appropriate treatment strategies.

Perinatal health services organization for preterm births: a multinational comparison

OBJECTIVE

To explore population characteristics, organization of health services and comparability of available information for very low birth weight or very preterm neonates born before 32 weeks' gestation in 11 high-income countries contributing data to the International Network for Evaluating Outcomes of Neonates (iNeo).

STUDY DESIGN

We obtained population characteristics from public domain sources, conducted a survey of organization of maternal and neonatal health services and evaluated the comparability of data contributed to the iNeo collaboration from Australia, Canada, Finland, Israel, Italy, Japan, New Zealand, Spain, Sweden, Switzerland and UK.

RESULTS

All countries have nationally funded maternal/neonatal health care with >90% of women receiving prenatal care. Preterm birth rate, maternal age, and neonatal and infant mortality rates were relatively similar across countries. Most (50 to >95%) between-hospital transports of neonates born at non-tertiary units were conducted by designated transport teams; 72% (8/11 countries) had designated transfer and 63% (7/11 countries) mandate the presence of a physician. The capacity of 'step-down' units varied between countries, with capacity for respiratory care available in <10% to >75% of units. Heterogeneity in data collection processes for benchmarking and quality improvement activities were identified.

CONCLUSIONS

Comparability of healthcare outcomes for very preterm low birth weight neonates between countries requires an evaluation of differences in population coverage, healthcare services and meta-data.

Abstract P3-14-12: Oncologic outcomes of immediate breast reconstruction after neoadjuvant chemotherapy in breast cancer patients: A matched case control study

Introduction: Although the indication for total mastectomy (TM) with immediate breast reconstruction (IBR) has been expanded, IBR after neoadjuvant chemotherapy (NACT) is still controversy. We assumed that TM with IBR after NACT is feasible surgical treatment in breast cancer patients. Methods: A retrospective review of breast cancer patients who underwent TM with IBR after NACT between 2008 and 2015 at a single center was conducted. These cases were matched by 1:5 to patients who underwent mastectomy alone after NACT. Matching variables included age, clinical T and N staging before NACT, response to NACT, and pathologic staging after NACT. Pathological stage was followed by seventh American Joint Committee on Cancer (AJCC) classification. Results: Overall, 31 patients were identified in the TM with IBR group (Study group) and 85 patients (Control group) were matched. In the study group, 13 (41.9%) patients underwent nipple-sparing mastectomy (NSM) and 18 (58.1%) underwent skin-sparing mastectomy (SSM). Median follow-up duration was 29.2 (7-31) and 38.8 (11-85) months for the study and control group, respectively. Median age was 37.0 (26-57) and 40.0 (24-56) years for the study and control group, respectively. The clinicopathologic characteristics of both groups are summarized in Table1. Disease-free survival (p=0.520), local recurrence-free survival (p=0.610), distant metastasis-free survival (p=0.795), and over survival (p=0.971) did not differ significantly between two groups. Conclusion: TM with IBR after NACT is feasible surgical treatment option in breast cancer patients.

Clinicopathologic characteristicsVariablesControl group (n=85)Study group (n=31)p-valueAge, years (matching variables)  0.890≤3515 (17.7)9 (29.0) 36-5061 (71.8)21 (67.7) 51≥9 (10.6)1 (3.2) BMI, m2/kg  0.13025≤62 (72.9)28 (90.3) 26-3018 (21.2)2 (6.5) 30&gt;5 (5.9)1 (3.2) Histology  0.326Ductal carcinoma in situ2 (2.4)3 (9.7) Invasive ductal carcinoma74 (87.1)28 (90.3) Invasive lobular carcinoma2 (2.4)0 (0) Others7 (8.2)0 (0) Multiplicity  0.063yes19 (22.6)12 (40.0) no65 (77.4)18 (60.0) Lymphovascular invasion  0.161yes33 (39.3)17 (54.8) no51 (60.7)14 (45.2) Nuclear grade  0.317Low10 (11.9)1 (3.3) Intermediate27 (32.1)14 (46.7) High47 (56.0)15 (24.2) Pathologic T stage (matching variable)  0.154T17 (8.2)6 (19.4) T229 (34.1)15 (48.4) T331 (36.5)4 (12.9) T418 (21.2)6 (19.4) Pathologic N stage (matching variable)  0.494N036 (42.4)13 (41.9) N123 (27.1)13 (41.9) N216 (18.8)4 (12.9) N310 (11.8)1 (3.2) Estrogen receptor  0.608positive49 (57.7)15 (48.4) negative36 (42.4)16 (51.6) Progesterone receptor  0.291positive40 (47.1)10 (32.3) negative45 (52.9)21 (67.7) HER2 status  0.345amplification29 (34.1)10 (32.3) not amplification56 (65.9)21 (67.7) Clinical T-stage (matching variable)  0.897cT12 (2.4)1 (3.2) cT231 (36.5)12 (38.7) cT346 (54.1)16 (51.6) cT46 (7.1)2 (6.5) Clinical N stage (matching variable)  0.947cN03 (3.5)1 (3.2) cN120 (23.5)10 (32.3) cN236 (42.4)10 (32.3) cN326 (30.6)10 (32.3) Response (matching variable)  1.000Partial response64 (75.3)27 (29.7) Stable disease21 (24.7)4 (12.9) 

Citation Format: Ryu JM, Lee JE, Kim SW, Yu J, Rayzah M, Lee SK, Mansoor A, Bae SY, Park S, Paik H-J, Kim I, Bang SI, Jeon BJ, Mun G-H, Pyon J-K. Oncologic outcomes of immediate breast reconstruction after neoadjuvant chemotherapy in breast cancer patients: A matched case control study [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 P3-14-12.

Abstract P6-09-50: Impact of young age on recurrence and mortality after surgery in breast cancer: 15 years active surveillance

Introduction:Substantial efforts have been made to find factors associated with breast cancer (BC) recurrence and mortality after BC treatment. So far TNM stage, ER, PR, and HER2 status are considered as the major predictive markers of BC recurrence and used for treatment decision. However, most of these factors were evaluated independent from other important confounders such as age, stage, and various anti-cancer treatments because they were mostly derived from clinical trials. In Korea, up to 50% of BC patients are premenopausal women, it is not clear how age at diagnosis affect the progression and outcomes of the disease considering all known prognostic factors including TNM stage, ER, PR, and HER2 status. We aim to evaluate the impact of young age on recurrence and mortality after surgery among Korean women with BC.

Methods: This is a retrospective cohort study conducted using the data from BC registry from 2000 to 2016 at Samsung Medical Cancer, Seoul, Korea. Patients who received curative BC surgery and who had histologically-confirmed invasive BC between 2000 to 2011 were included in the study. Patients who second primary cancer or double primary cancer were excluded. Information local, regional, or distant recurrence and death until May 2016 was collected using electronic medical records and National Health Statistics. Cumulative incidence rates of distant recurrence and morality at 3-years, 5-years and 10-years were calculated using a competing-risk model. Cox proportional hazards analysis were conducted with 3 different models to take into account for potential confounding factors including age, body mass index (BMI), stage and subtype at breast cancer diagnosis, chemotherapy, radiotherapy and hormone therapy.

Results:There were 7360 BC patients with curative BC surgery between 2000 and 2011, and the average follow up duration was 75.4 months. The mean age at diagnosis was 48.4 years old (Standard deviation (SD)=±10), and 6.2% (n=459) was diagnosed younger than 35. Of total, 13.3% were stage III BC and 73.4% of patients had hormone receptor positive BC. The cumulative incidence (95%CI) of recurrence at 3, 5, and 10 years was 4.4% (3.9-4.9), 7.5% (6.8-8.2), and 14.8% (12.9-16.7) respectively. The incidence of mortality at 3, 5, and 10 years was 1.8% (1.5-2.1), 3.8% (3.3-4.3), and 10.2% (9.1-11.5) respectively. Patients who were diagnosed BC under 35 years of age had 2.14 (95% confidence interval (CI):1.74-3.10) and 1.62 (95% CI:1.02-2.56) times higher risk of distant recurrence and mortality compared to patients whose age at diagnosis were between 50 to 60 after adjusting all well-known prognostic factors including stage, subtype, and BMI at diagnosis, chemotherapy, radiotherapy and hormone therapy.

Conclusions: Young age at diagnosis (&lt;35) was the most significant predictor on BC recurrence and mortality independently from BC stage and subtype. Further study is warranted to explain biologic background for the differences in outcomes in young women with BC.

Citation Format: Kim J-Y, Cho J, Kim H, Kang D, Jung HA, Lee S-H, Bae S, Yu JH, Lee SK, Kim SW, Lee JE, Nam SJ, Ahn JS, Im Y-H, Guallar E, Park YH. Impact of young age on recurrence and mortality after surgery in breast cancer: 15 years active surveillance [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 P6-09-50.

Abstract P1-05-15: Multi-omics and immuno-oncology profiling reveal distinct molecular signatures of young Asian breast cancers

Breast cancers (BC) in younger, premenopausal patients (YBC) tend to be more aggressive with worse prognosis, higher chance of relapse and poorer response to endocrine therapies compared to breast cancers in older patients. The proportion of YBC (age ≤ 40) among BC in East Asia is estimated to be 16-32%, significantly higher than the 7% reported in Western countries. To characterize the molecular bases of Asian YBC, we have performed whole-exome sequencing (WES) and whole-transcriptome sequencing (WTS) on tumor and matched normal samples from 134 Korean BC patients consisting of 74 YBC cases (age ≤ 40) and 60 OBC cases (age &gt; 40). We then performed comparison analyses and integrative analyses with the TCGA BC cohort consisting of 1,116 tumors from primarily Caucasian patients, also grouped by age into YBC (age ≤ 40), IBC (40 &lt; age ≤ 60) and OBC (age &gt; 60).

Somatic mutation prevalence analysis identified 7 significantly mutated genes and the same top three genes – TP53, GATA3 and PIK3CA – were reported by the TCGA BC study. To identify differentially expressed (DE) genes and pathways in YBCs vs. OBCs, we performed logistic regression analyses while controlling for the confounding effects of tumor purity and stage. We were surprised to see a significant overlap in DE pathways between a comparison of adjacent normal tissues in younger vs. older TCGA cohorts and a comparison of YBC vs. OBC tumors, indicating that normal tissue compartment could contribute to observed differences between bulk tumors. To separately examine molecular signatures from tumor, stroma and normal compartments, we used non-negative matrix factorization (NMF) analyses to virtually dissect bulk tumor expression data and identified 14 factors including 3 factors associated with normal tissues, 1 factor associated with stroma and 1 factor associated with tumor infiltrating lymphocytes (TIL). Integrative analyses of tumor associated factors and DE pathways revealed that estrogen response, endocrine therapy resistance, and oxidative phosphorylation pathways are up-regulated in YBCs compared to OBCs while cell cycle and proliferation pathways are up-regulated in Asian OBCs. Interestingly, many immune and inflammation pathways correlated with the TIL factor were significantly upregulated in OBCs vs. YBCs. Using gene expression signatures representing distinct immune cell types, we classified our cohort into four subtypes of varying TIL activities and observed significant enrichment of the TIL-high subtype in OBCs compared to YBCs. These observations were confirmed by IHC analyses of four TIL markers (CD45, CD4, CD8 and CD163) in 120 tumors.

To our knowledge, this is the first large-scale multi-omics study of Asian breast cancer and would significantly contribute to the compendium of molecular data available for studying young breast cancers. The major landmarks in the molecular landscape looked similar across BCs of different ethnicities and ages, however, we have identified a number of distinguishing molecular characteristics associated with Asian YBC. The sources for some signatures were further traced to non-tumor intrinsic compartments, indicating that tumor microenvironment may play potentially important roles in driving the carcinogenesis of young breast cancers.

Citation Format: Kan Z, Ding Y, Cho S, Lee S-H, Powell E, Jung HH, Chung W, Deng S, Choi Y-l, Kim J, Park W-Y, Vizcarra P, Fernandez-Banet J, Nichols T, Ram S, Lee SK, Kim SW, Lee JE, Ching KA, Kim J-Y, Ahn JS, Im Y-H, Nam SJ, Park YH. Multi-omics and immuno-oncology profiling reveal distinct molecular signatures of young Asian breast cancers [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 P1-05-15.

Abstract P1-02-11: Clinical utility of serial monitoring of circulating tumor DNA (ctDNA)in patients with neoadjuvant chemotherapy (NAC) for locally advanced breast cancer (LABC)

Introduction: Circulating tumor DNA (ctDNA) is a new biomarker which could guide further treatment. Characterization of tumor mutation profiles is required for informed choice of therapy, given that biological agents target specific pathways and effectiveness may be modulated by specific mutations. It would have clinical utility for neoadjuvant setting also. Thus, we assess the potency of ctDNA to predict tumor response to neoadjuvant chemotherapy(NAC) in locally advanced breast cancer(LABC).

Methods: We performed targeted deep sequencing of 30 plasma DNAs and 10 matched germline DNAs from 10 LABC patients. Serial plasma DNAs were collected at diagnosis, after 1st NAC and curative surgery. For the target enrichment, we designed RNA baits covering a total of ~202kb regions of human genome including a total of 83 cancer-related genes. We constructed the sequencing libraries according to the optimized protocol that we recently reported and sequenced on Illumina HiSeq2500 aiming a mean sequencing depth of ~10,000. After excluding unmapped reads, PCR duplicates and off-target reads, the coverage depths for plasma DNA and germline DNA samples were 2,627x and 4,833x on average, respectively. NAC response was measured by residual cancer burden(RCB) score, calculated as a continuous index combining pathologic measurements of primary tumor and nodal metastases for prediction of distant relapse-free survival.

Results: We analyzed ctDNA and primary tumor tissues from 10 patients with LABC scheduled NAC followed by operation in Samsung Medical Center. Of ten LABCs, one excluded from analysis because of angiosarcoma of breast. Five samples were triple-negative breast cancers (BCs), 2 were HER2 positive BCs and others were ER positive BCs. In tumor response, 1 patient had pathologic complete response (pCR), 1 had RCB class I, 4 and 3 patients did RCB class II and III.

Of 83 genes, in analysis of ctDNA at BC diagnosis, we found 2 to 6 mutations in each samples and 3 mutations were detected averagely. Most common mutation was TP53 (6 patients), followed by PIK3CA mutation. By measuring these mutations in serial ctDNA, we found that ctDNA had disappeared after first cycle of NAC in patient with pCR. In two patients with RCB class I, ctDNA had decreased by more than 10 percent (the level of ctDNA(pg/ml): 455.9 to 30.4, 5.8 to 0.0) of primary plasma sample after first NAC. Two patients increased level of ctDNA had tumor response with RCB class III and one patient had distant tumor recurrence within 3 months after curative surgery. However, correlation between the level of ctDNA and initial stage was not observed.

Patient No.Initial stageSurgical stageRCB scoreRCB classct DNA at diagnosis (pg/5ml)ctDNA after 1st NAG (pg/5ml)Tumor recurrence12A11.3331455.930.4No22B00pCR446.60.0No33B2A1.31515.80.0No42A12.132246.255.4No52B11.7972107.811.6No63B3A4.09033401.15075.5Yes73A2B3.92235088.68536.7No

Conclusions: This preliminary result suggests that serial monitoring of ctDNA would be a potiential surrogate marker to predict tumor response and recurrence during NAC in LABC patients. Further results with long-term outcomes are warranted.

Citation Format: Kim J-Y, Park D, Jung HH, Bae SY, Yu JH, Lee SK, Kim SW, Lee JE, Nam SJ, Ahn JS, Im Y-H, Park YH. Clinical utility of serial monitoring of circulating tumor DNA (ctDNA)in patients with neoadjuvant chemotherapy (NAC) for locally advanced breast cancer (LABC) [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 P1-02-11.

Abstract P6-09-36: Tamoxifen resistance: EGFR expression in hormone receptor-positive and HER2 negative breast cancer

Purpose: Crosstalk between growth factor receptor tyrosine kinases (RTKs) and the estrogen receptor (ER) represents one of the most important mechanisms of endocrine resistance. EGFR and HER2 have been recognized as prominent factors associated with endocrine resistance. Most previous studies did not identify subgroups by HER2 overexpression and/or included breast cancer with HER2 overexpression. Accordingly, we analyzed HR positive (HR+) tumors without HER2 overexpression (HER2-).

Methods: We analyzed the clinical data of 2,166 patients with HR+HER2- breast tumors, between January 2007 and July 2013.We included only patients who had endocrine therapy with tamoxifen. Immunostaining for EGFR was interpreted as positive when at least 10% of the tumor cells showed moderate to strong membrane staining.

Results: EGFR expression (EGFR+) was present in 109 patients (5%). EGFR expression was significantly associated with more advanced stage and higher grades. In the univariate analyses, EGFR+ tumors were associated with poorer prognosis than EGFR- tumors (5-year DFS, EGFR+ vs. EGFR-, 91.2% vs. 96.6%, P &lt;0.001; 5-year OS, EFGR+ vs EGFR-, 93.1 % vs. 99.4%, P &lt; 0.001). In the multivariate analysis, EGFR+ tumors had a hazard ratio of 2.63 (95% CI 1.14 -6.05) for DFS. EGFR+ tumors had a hazard ratio of 8.8 (95% CI 2.68-132.25) for OS.

Conclusion: EGFR expression could be prognostic factor in hormone receptor-positive and HER2 negative breast cancer, for tamoxifen resistance.

Citation Format: Bae SY, Nam SJ, Lee SK, Kim SW, Lee JE, Yu JH. Tamoxifen resistance: EGFR expression in hormone receptor-positive and HER2 negative breast cancer [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 P6-09-36.

Gradient nonlinearity calibration and correction for a compact, asymmetric magnetic resonance imaging gradient system

Due to engineering limitations, the spatial encoding gradient fields in conventional magnetic resonance imaging cannot be perfectly linear and always contain higher-order, nonlinear components. If ignored during image reconstruction, gradient nonlinearity (GNL) manifests as image geometric distortion. Given an estimate of the GNL field, this distortion can be corrected to a degree proportional to the accuracy of the field estimate. The GNL of a gradient system is typically characterized using a spherical harmonic polynomial model with model coefficients obtained from electromagnetic simulation. Conventional whole-body gradient systems are symmetric in design; typically, only odd-order terms up to the 5th-order are required for GNL modeling. Recently, a high-performance, asymmetric gradient system was developed, which exhibits more complex GNL that requires higher-order terms including both odd- and even-orders for accurate modeling. This work characterizes the GNL of this system using an iterative calibration method and a fiducial phantom used in ADNI (Alzheimer's Disease Neuroimaging Initiative). The phantom was scanned at different locations inside the 26 cm diameter-spherical-volume of this gradient, and the positions of fiducials in the phantom were estimated. An iterative calibration procedure was utilized to identify the model coefficients that minimize the mean-squared-error between the true fiducial positions and the positions estimated from images corrected using these coefficients. To examine the effect of higher-order and even-order terms, this calibration was performed using spherical harmonic polynomial of different orders up to the 10th-order including even- and odd-order terms, or odd-order only. The results showed that the model coefficients of this gradient can be successfully estimated. The residual root-mean-squared-error after correction using up to the 10th-order coefficients was reduced to 0.36 mm, yielding spatial accuracy comparable to conventional whole-body gradients. The even-order terms were necessary for accurate GNL modeling. In addition, the calibrated coefficients improved image geometric accuracy compared with the simulation-based coefficients.

Hypertensive disorders of pregnancy and outcomes of preterm infants of 24 to 28 weeks' gestation

OBJECTIVE

To examine the relationship between hypertensive disorders of pregnancy (HDPs) and mortality and major morbidities in preterm neonates born at 24 to 28 weeks of gestation.

STUDY DESIGN

Using an international cohort, we retrospectively studied 27 846 preterm neonates born at 24⁰ to 28⁶ weeks of gestation during 2007 to 2010 from 6 national neonatal databases. The incidence of HDP was compared across countries, and multivariable logistic regression analyses were conducted to examine the association of HDP and neonatal outcomes including mortality to discharge, bronchopulmonary dysplasia, severe brain injury, necrotizing enterocolitis and treated retinopathy of prematurity.

RESULTS

The incidence of HDP in the entire cohort was 13% (range 11 to 16% across countries). HDP was associated with reduced odds of mortality (adjusted odds ratio (aOR) 0.77; 95% confidence interval (CI) 0.67 to 0.88), severe brain injury (aOR 0.74; 95% CI 0.62 to 0.89) and treated retinopathy (aOR 0.82; 95% CI 0.70 to 0.96), but increased odds of bronchopulmonary dysplasia (aOR 1.16; 95% CI 1.05 to 1.27).

CONCLUSIONS

In comparison with neonates born to mothers without HDP, neonates of HDP mothers had lower odds of mortality, severe brain injury and treated retinopathy, but higher odds of bronchopulmonary dysplasia. The impact of maternal HDP on newborn outcomes was inconsistent across outcomes and among countries; therefore, further international collaboration to standardize terminology, case definition and data capture is warranted.

Surface modulation and back reflection from foil targets irradiated by a Petawatt femtosecond laser pulse at oblique incidence

A significant level of back reflected laser energy was measured during the interaction of ultra-short, high contrast PW laser pulses with solid targets at 30° incidence. 2D PIC simulations carried out for the experimental conditions show that at the laser-target interface a dynamic regular structure is generated during the interaction, which acts as a grating (quasi-grating) and reflects back a significant amount of incident laser energy. With increasing laser intensity above 10¹⁸ W/cm² the back reflected fraction increases due to the growth of the surface modulation to larger amplitudes. Above 10²⁰ W/cm² this increase results in the partial destruction of the quasi-grating structure and, hence, in the saturation of the back reflection efficiency. The PIC simulation results are in good agreement with the experimental findings, and, additionally, demonstrate that in presence of a small amount of pre-plasma this regular structure will be smeared out and the back reflection reduced.

Long Cut Straw Provides Stable the Rates of Survival, Pregnancy and Live Birth for Vitrification of Human Blasotcysts

Most of the commercial devices for vitrification are directly immersed into the warming solution (WS) for increasing of warming rate. However, the previous modified cut standard straw (MCS) which has reported is difficult to immerse into the WS. The aim of this study was to investigate whether the long cut straw (LCS) could be useful as a stable tool for vitrified-warmed human blastocysts. A total of 138 vitrified-warmed cycles were performed between November 2013 and November 2014 (exclusion criteria: women ≥38 years old, poor responder, surgical retrieval sperm, and severe male factor). The artificial shrinkage was conducted using 29-gauge needles. Ethylene glycol and dimethyl sulfoxide (7.5% and 15% (v/v)) were used as cryoprotectants. Freezing and warming were conducted using the LCS tool. The cap of LCS was removed using the forceps in the liquid nitrogen (LN₂) and then directly immersed into the first WS for 1 min at 37℃ (1 M sucrose). Only re-expanded blastocysts were transferred after it was cultured in sequential media for 18-20 h. A total of 294 blastocysts were warmed, and all were recovered (100%). Two hundred eighty-five embryos were survived (96.9%). The vitrifiedwarmed blastocysts of all patients were transferred without any cancellation. We were able to achieve a reasonable implantation (24.2%), following by clinical pregnancy (36.2%), which then continued to ongoing pregnancy (36.2%), and live birth (31.2%). Using LCS is achieved the acceptable rates of survival, pregnancy and live birth. Therefore, the LCS could be considered as a stable and simple tool for human embryo vitrificaton.