[Study on the characteristics of major birth defects in 1.69 million cases of fetus in Guangxi Zhuang Autonomous Region]

Objective: Tracking the information on 1.69 million fetal cases across Guangxi Zhuang Autonomous Region (Guangxi) so as to study the occurrences of total and major birth defects in order to evaluate the ability on related prevention and control programs in Guangxi. Methods: Using the self-developed "Gui Women's System" to establish a database of 1.69 million fetal cases in Guangxi and to analyze the distribution of time, space and population, as well as the outcomes of pregnancy, using the big data. Results: During the 29 months of observation, the overall live birth rate was 99.25%, with stillbirth rate during pregnancy as 0.44%, stillbirth rate during birth as 0.02%, and the 0-6 days mortality rate as 0.14%. The total detection rate on birth defects was 197.63/10 000; the incidence rate was 103.04/10 000, the birth rate was 102.55/10 000. The overall discovery rate of major birth defects was 48.33/10 000, with the incidence rate as 783 000, the birth rate as 0.58/10 000. The discovery rates of major birth defects in 14 cities were between 35 and 68/10 000, and the birth rate dropped significantly to less than 1.00 in 10 000. Nationalities showed that the number of pregnant women with birth defects more than 50 000 would include Hui (9.68/10 000), Yao (9.57/10 000), and Jing (9.37/10 000). With the increasing age of gestation, number of birth defects, incidence of major birth defects also increased. Ninety-five percent of the major birth defects were found within <28 weeks and with the top 5 kinds of major birth defects as complicated congenital heart disease (9.11/10 000), alpha thalassemia (8.36/10 000), and 21-trisomy syndrome (7.85/10 000), beta thalassemia (5.32/10 000) and fetal edema syndrome (4.92/10 000). The top 5 major birth defects appeared as complicated congenital heart disease (9.11/10 000), alpha thalassemia (8.36/10 000), and 21-trisomy syndrome (7.85/10 000), beta thalassemia (5.32/10 000) and fetal edema syndrome (4.92/10 000). Conclusion: Programs leading to increase the rate on discovery of major birth defects were fundamental in effectively reducing the major birth defects.

Integrated analysis of different mRNA and miRNA profiles in human hypopharyngeal squamous cell carcinoma sensitive and resistant to chemotherapy

The purpose of this study was to identify potential miRNAs and mRNAs involved in chemotherapy insensitivity in hypopharyngeal squamous cell carcinoma (HSCC) and to explore the underlying mechanisms involved to provide diagnostic markers and therapeutic targets for HSCC. We used microarrays to identify differences in both the mRNA and miRNA expression profiles between a group (twelve patients) sensitive to chemotherapy and a resistant group (nine patients). We then employed bioinformatics tools to examine the functions and pathways involved. The genes and miRNAs most related to chemotherapy sensitivity in HSCC were screened. Finally, a miRNA-mRNA-phenotype network was constructed with an integrated analysis based on the identified miRNAs and mRNAs. Nine differentially expressed miRNAs and one hundred differentially expressed mRNAs were identified, and the functions of these genes and miRNAs were predicted. Bioinformatics analysis revealed a regulatory network consisting of eight genes and two miRNAs that influenced HSCC chemosensitivity. According to our analysis, CCL4L1 may be a potential molecular marker for HSCC chemotherapy, and excess CCL4L1 leads to the upregulation of PRAME and the downregulation of miR-375, thus decreasing HSPB8 expression and promoting chemotherapy sensitivity. Our work provides reliable data for further studies investigating the mechanism of HSCC chemotherapy sensitivity.

Abstract P5-05-01: Novel mechanisms of action of selective androgen receptor modulator RAD140 in AR+/ER+ breast cancer models

Background: Recurrence after standard-of-care estrogen receptor α (ER)-targeted therapy presents challenges in management of metastatic ER positive (ER+) breast cancer (BC). The high prevalence of androgen receptor (AR) in ER+ BC, along with preclinical and clinical evidence showing anti-tumor activity of AR agonists in AR+/ER+ BC, suggest an opportunity to address resistance to ER-targeted agents by targeting AR. Significant anti-tumor activity has been reported with RAD140, an oral selective AR modulator (SARM), in estrogen-dependent and -independent AR+/ER+ BC models. Mechanistic investigation revealed that inhibition of tumor growth by RAD140 was in part through AR-mediated reduction of ESR1 mRNA and subsequent suppression of ER signaling, independent of ESR1 alterations. Here, we present new observations on RAD140 mechanisms of action in in vitro and in vivo models of endocrine-independent BC models. Methods: HCC1428-long term estrogen deprived (LTED) line was established by passaging cells in steroid-depleted media for &gt; 6 months. HCC1428-LTED-palbociclib resistant (-palboR) BC cell line was generated from LTED by long-term passaging in the presence of 500 nM palbociclib. Fluorescence-microscopy was used to assess annexin V/propidium iodide (PI) and phospho- H2A.X expression. The endocrine-independent BC PDX model was established in nude mice without supplemental estradiol. Prior anti-cancer therapy of the donor patient included tamoxifen, exemestane, fulvestrant and multiple lines of chemotherapy. RAD140 (3 mg/kg twice daily), elacestrant (30 mg/kg once daily), and palbociclib (10 mg/kg once daily) were administered via oral gavage for the duration of study. Fulvestrant (3 mg/mouse) was given once weekly subcutaneously. Results: In a hormone-independent BC PDX model harboring the ESR1 D538G mutation, RAD140 treatment led to 80% tumor growth inhibition (TGI) compared to the vehicle. The selective ER degrader (SERD) fulvestrant had TGI of 7%, while the oral SERD elacestrant (RAD1901) had TGI of 60%. The combination of RAD140 with elacestrant exhibited enhanced anti-tumor activity greater than that of each agent alone (93% TGI). These in vivo findings suggest the activity of the AR-targeting RAD140 may be mediated through mechanisms beyond its AR-mediated inhibition of ER signaling. We then sought to identify additional mechanisms of action of RAD140 in two hormone-independent AR+/ER+ BC cell line models, HCC1428-LTED and HCC1428-LTED-palboR. After prolonged treatment (2 weeks) at 100 nM, RAD140 induced morphological changes related to apoptosis, along with increased number of annexin V/PI-positive cells. This was further supported by increases in cleaved PARP/caspase3/caspase7 proteins by western blot analysis. A decrease in the pro-survival protein BCL-2 was also seen. These results collectively suggest that RAD140 induced apoptosis in endocrine-resistant BC cells. In line with these findings, an increase in phospho-H2A.X, a sensitive marker for DNA damage, was also observed in RAD140-treated cells. Similar changes were observed with the positive control AR agonist dihydrotestosterone (DHT), but not with fulvestrant. The AR antagonist apalutamide was found to partially reverse the apoptosis induced by RAD140 and DHT, further supporting the on-target effect. Conclusion: Our data suggest the anti-tumor activity of RAD140 may be mediated through suppression of ER signaling as well as additional mechanisms. The effect of RAD140 on DNA damage and apoptosis implies the potential for combination therapy with agents targeting cell survival and DNA damage repair pathways. RAD140 is being studied in a Phase 1, first-in-human trial in postmenopausal women with hormone receptor positive BC (NCT03088527).

Citation Format: Suqin He, Maureen G Conlan, Heike Arlt, Charles Morris, Ziyang Yu. Novel mechanisms of action of selective androgen receptor modulator RAD140 in AR+/ER+ breast cancer models [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-05-01.

Expression of Raptor and Rictor and their relationships with angiogenesis in colorectal cancer

Mammalian target of rapamycin (mTOR) has two subtypes, i.e., mTORC1 and mTORC2, which contain the Raptor and Rictor core molecules, respectively. The effect of Raptor and Rictor on hypoxia inducible factor (HIF)-1α, HIF-2α, and vascular endothelial growth factor (VEGF) in colorectal cancer (CRC) is unclear. In this work, we investigated the correlations among Raptor, Rictor, HIF-1α, HIF-2α, and VEGF expression in CRC. We subsequently analyzed the clinicopathological features of patients. Immunohistochemistry, western blot, and RT-PCR analyses were performed to detect the expression of Raptor, Rictor, HIF-1α, HIF-2α, and VEGF in 120 cases of CRC and 60 cases of normal colorectal mucosa. CD34 was used to label microvascular density (MVD), which was found to be higher in patients with positive Raptor or Rictor than in those with negative Raptor or Rictor. The positive rates of Raptor, Rictor, HIF-1α, HIF-2α, and VEGF in CRC were significantly higher than in normal colorectal mucosa. Raptor expression was positively correlated with HIF-1α and VEGF but not with HIF-2α expression. By contrast, Rictor expression was positively correlated with HIF-2α and VEGF but not with HIF-1α expression. Survival analysis further indicated that Raptor, Rictor, HIF-1α, HIF-2α, VEGF and lymph node metastasis were independent prognostic factors in CRC. To conclude, Raptor and Rictor expression was related to the initiation and development of CRC and angiogenesis in different ways. The combined detection of Raptor and Rictor is important for patients with colorectal carcinoma in prognosis and optimal therapy.

On the glacial-interglacial variability of the Asian monsoon in speleothem δ18O records

While Asian monsoon (AM) changes have been clearly captured in Chinese speleothem oxygen isotope (δ¹⁸O) records, the lack of glacial-interglacial variability in the records remains puzzling. Here, we report speleothem δ¹⁸O records from three locations along the trajectory of the Indian summer monsoon (ISM), a major branch of the AM, and characterize AM rainfall over the past 180,000 years. We have found that the records close to the monsoon moisture source show large glacial-interglacial variability, which then decreases landward. These changes likely reflect a stronger oxygen isotope fractionation associated with progressive rainout of AM moisture during glacial periods, possibly due to a larger temperature gradient and suppressed plant transpiration. We term this effect, which counteracts the forcing of glacial boundary conditions, the moisture transport pathway effect.

Amphiphilic poly(caprolactone-b-N-hydroxyethyl acrylamide) micelles for controlled drug delivery

To increase the bioavailability and water solubility of hydrophobic medicine, an amphiphilic block copolymer, polycaprolactone-block-polyhydroxyethyl acrylamide (PCL-b-PHEAA), was synthesized.

[The diagnostic utility of thin-slice CT navigation combined with radial endobronchial ultrasound for peripheral pulmonary lesions]

Objective: To evaluate the diagnostic value of thin-slice CT navigation combined with radial endobronchial ultrasound in peripheral lung lesions. Methods: The clinical data of patients with peripheral lung lesions diagnosed by thin-slice CT navigation combined with radial endobronchial ultrasound in National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College from November 2015 to August 2018 were retrospectively analyzed. The success rate of thin-slice CT for guiding radial endobronchial ultrasound was statistically analyzed, and the diagnostic rate, sensitivity and specificity of thin-slice CT combined with radial endobronchial ultrasound were analyzed. Results: 140 consecutive patients with 145 lesions were included, 139 lesions in 136 patients were found by thin-layer CT guidance, the success rate was 95.9%; 137 lesions in 135 patients were examined by histology and/or cytology, and 106 lesions were finally diagnosed, the diagnostic rate was 77.37%; and the diagnosis sensitivity and specificity was 88.45% and 99.96%. Histological and cytological diagnostic rate, sensitivity and specificity was 72.18% versus 63.50%, 70.58% versus 66.85%, 100% versus 88.23%, respectively. Factors influencing the diagnostic rate of thin-slice CT navigation combined with radial endobronchial ultrasound include the relationship between the lesion and the target bronchus, the location of the probe and the lesion, and the size of the lesion, and the difference between the farthest generation of bronchoscopy insertion and the bronchial generation of lesions. Five patients had mild bleeding and one ultrasonic probe was damaged. Conclusion: Thin-slice CT has a higher positive rate in guiding peripheral lung lesions with radial ultrasound, and this method has a higher diagnostic value for peripheral lung lesions.

Genome-wide association study shows that microtia in Altay sheep is caused by a 76 bp duplication of HMX1

Microtia is a congenital malformation of the external ear that can be observed in many species including sheep. However, the genetic basis of microtia still remains unclear. Here, a GWAS was conducted to investigate the genetic basis underlying microtia. A total of 55 samples from 26 microtia and 29 normal animals were genotyped with Illumina OvineHD BeadChip. The strongest significant SNP was identified on OAR6, approximating the evolutionarily conserved region of the HMX1 gene, which is related to congenital malformations of the external ear in other species such as cattle and rats. Sequencing an evolutionarily conserved region surrounding HMX1 revealed a duplication of 76 bp, which is concordant with microtia, suggesting a dominant inheritance mode. Identification of this causal mutation in the HMX1 gene indicates the role of this particular gene in the development of the external ear and provides a genetic marker for selection against microtia.

P5250Diastolic strain rate ratio as determined on MRI on detecting left ventricle stiffness and predict heart failure in post-STEMI patients

Background

ST-elevation myocardial infarction (STEMI) Patients suffered from progressive heart failure, for which progressive and aggravated Left ventricle stiffness was one of the major culprit. Myocardial deformation in the early diastole is largely affected by the left ventricle compliance which could partly reflect chamber stiffness and potentially predict left ventricular remodeling for post-STEMI patients.

Purpose

To determine the value of diastolic strain rate in detecting left ventricle stiffness and early heart failure in post-STEMI patients.

Methods

A number of 52 (M/F: 46/6, age: 54.27 [46.8–62.3]yrs) patients with STEMI three months ago were prospectively recruited from 2016 to 2017. Follow-up was done until 2018. The primary end points were the symptoms of heart failure (NYHA II-IV). Consent was acquired from each patient and 3.0 T MRI was arranged. Imaging analysis was performed on Cvi 42 (V5.9.3 Canada). Peak radial strain (PS) and strain rate (SR) were extracted both from 2D short- and long-axis cine images, while peak circumferential parameters only from the short axis slices and longitudinal the long axis slices. The diastolic strain rate ratios (DSRRs) were calculated as the peak early diastolic SR divided by the peak late diastolic SR, which were derived from the two peak points on the corresponding curve of time-to-SR curve in the diastole (Figure 1a). Receiver-operating characteristics curve analysis and Logistic regression test were done for statistical analysis on R project and P<0.05 was considered as significant.

Results

Three patients were excluded due to unsatisfied cine images. Among the 52 patients, none of the patients died or had congestive heart failure. 23/52 (44.2%) patients complained of heart failure symptoms at the one-year follow-up. No significant difference was found in LVEF and three directional peak strain values or systolic peak strain rates between the patients with and without heart failure. Patients with symptoms had lower Longitudinal PS (P=0.049), early diastolic radial SR (P=0.01798), longitudinal SR (P=0.0042), and decreased DSRR in all directions (Figure 1b). Multivariate Logistic regression test showed that only DSRR in the radial direction on the short axis (DSRR-SR) was the independent predictor of the heart failure symptoms (6.59; range, 6.71–3.68; P=0.026). ROC analysis demonstrated that the DSRR-SR of 2.35 had sensitivity 91.3% and specificity 58.6% for the prediction of heart failure (Figure 1c).

Figure 1

Conclusion

DSRR especially DSRR-SR was more sensitive to left ventricle stiffness change and help predict the progression of heart failure for Post-STEMI patients. Further studies were needed to verify the its association with other cardiovascular clinical events.

Acknowledgement/Funding

the National Natural Science Foundation of China (81600299,81471721, 81471722, 81771887, and 81771897,);

Capacity of different anthropometric measures to predict diabetes in a Chinese population in southwest China: a 15-year prospective study

AIM

To investigate whether conicity index, abdominal volume index, body adiposity index, body roundness index, cardiometabolic index and lipid accumulation product compared with waist circumference could predict future diabetes in a 15-year prospective study.

METHODS

The data were collected in 1992 and recollected in 2007 from the same group of 687 individuals. Anthropometric indices and biochemical data were obtained. Cox's proportional hazards regression models were used to estimate the hazard ratios of anthropometric measures. The discriminatory power of anthropometric measures for incident diabetes were assessed by Harrell's C-statistic.

RESULTS

During follow-up, 74 participants were newly diagnosed with diabetes. In multivariable Cox regression analysis after adjusting potential for confounders, log₁₀ -conicity index [HR: 1.67 (95% CI: 1.31-2.11) per sd; P < 0.0001], log₁₀ -abdominal volume index [HR: 1.95 (95% CI: 1.50-2.55) per sd; P < 0.0001], log₁₀ -body adiposity index [HR: 1.82 (95% CI: 1.33-2.50) per sd; P < 0.0001], log₁₀ -body roundness index [HR: 2.16 (95% CI: 1.63-2.88) per sd; P < 0.0001], log₁₀ -cardiometabolic index [HR: 1.70 (95% CI: 1.39-2.09) per sd; P < 0.0001], log₁₀ -lipid accumulation product [HR: 2.06 (95% CI: 1.56-2.73) per sd; P < 0.0001] and log₁₀ -waist circumference [HR: 1.99 (95% CI: 1.51-2.46) per sd; P < 0.0001] were significantly associated with incident diabetes. Additionally, lipid accumulation product had the highest Harrell's C-statistic at 0.715 (95% CI: 0.656-0.775), followed by body roundness index at 0.714 (95% CI: 0.658-0.770) and cardiometabolic index at 0.704 (95% CI: 0.643-0.764) then by waist circumference at 0.701 (95% CI: 0.644-0.759).

CONCLUSIONS

Conicity index, abdominal volume index, body adiposity index, body roundness index, cardiometabolic index and lipid accumulation product were independent predictors of future diabetes. The discriminatory power of body roundness index, cardiometabolic index and lipid accumulation product for diabetes prediction were higher than that of waist circumference.

Finite element analysis on the hollow porous design at the proximal end of cementless femoral prosthesis stem

Aims

The present study aims to improve the design of cementless femoral prosthesis stem and achieve better bone ingrowth and long-term stability.

Materials and Methods

Four models with different directional hollow holes at the proximal end of femoral prosthesis were designed and finite element analysis was applied to calculate the magnitude of conducting force within the differently angled holes and the stress distribution of the femur and prosthesis.

Results

Holes in prostheses make no difference on the stress values of femoral inner walls. The conducting forces in models trepanned on the lateral plane were 6.60N (0° pore) and 8.40N (45° pore) while forces in models trepanned on the anterior-posterior planes were 0.45N (upper 0° pore), 0.48N (lower 0° pore) and 1.57N (upper 45° pore), 1.51N (lower 45° pore), respectively.

Conclusion

The position and direction of hollow holes influenced the conducting force in holes but had no influence on stress values of femoral inner walls. Prostheses with one 45° hole trepanned on the lateral plane of proximal prostheses presented best in elevating conducting force.

[Clinical application of the Chinese version of Cornell assessment of pediatric delirium: a pilot study]

Objective: To evaluate the clinical application of Chinese version of Cornell assessment of pediatric delirium (CAPD) scale in children by a pilot study. Methods: A prospective observational study. From June 2017 to December 2017, the original CAPD screen was translated into Chinese and debugged cross-culturally according to the guidelines, which was further applied in the Department of Critical Care Medicine, Children's Hospital of Chongqing Medical University. The clinical data of 250 patients who were evaluated with the Chinese version of CAPD scale and Richmond agitation-sedation scale were extracted and analyzed with chi-square test or Mann-Whitney U test. Cronbach's α coefficient,Split-half coefficient and intra-group correlation coefficient were used to evaluate the reliability, while exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to evaluate the structural validity of the scale. The result was compared with the gold standard diagnostic results to evaluate the diagnostic efficacy of the CAPD. Results: Sixty-one (24.4%) patients had delirium during pediatric intensive care unit hospitalization,and significant differences existed between them and 189 patients without delirium in age (χ(2)=11.220, P=0.011), rates of mechanical ventilation (χ(2)=6.691, P=0.010) and length of PICU hospitalization (Z=10.656, P=0.001). The Chinese version of the CAPD scale had high discrimination among the 8 items in the main table without skewed distribution and discrete items. The internal and external reliability of the scale were preferable as the Cronbach's α coefficient was 0.819 and ICC value was 0.835. The KMO value of EFA was 0.834 and Bartlett spherical test showed statistical significance (χ(2)=661.440, P<0.01). CFA constructed a two-factor structural equation model with favorable fit index:Chi-square/degree of freedom (DF) ratio was 1.786 (χ(2)=33.930, P=0.019), goodness of fit index (GFI) was 0.967,adjusted GFI was 0.938,root mean square of the approximate error (RMSEA) was 0.056. A good diagnostic efficacy of this scale was demonstrated by receiver operating characteristic curve analysis as when the cut-off was 10, the area under curve was 0.99 (95%CI: 0.97-0.99), sensitivity was 96.7% (95%CI: 88.7-99.6), specificity was 93.1% (95%CI: 88.5-96.3), positive likelihood ratio was 14.0 (95%CI: 13.2-14.9), and the negative likelihood ratio was 0.035 (95%CI: 0.008-0.200). Conclusion: The Chinese version of the CAPD Scale has favorable reliability,validity,diagnostic efficacy, as well as feasibility, which should be applied in evaluation of pediatric delirium in clinical observation and research in the future.

A Protocol for Transverse Cardiac Slicing and Optical Mapping in Murine Heart

Thin living tissue slices have recently emerged as a new tissue model for cardiac electrophysiological research. Slices can be produced from human cardiac tissue, in addition to small and large mammalian hearts, representing a powerful in vitro model system for preclinical and translational heart research. In the present protocol, we describe a detailed mouse heart transverse slicing and optical imaging methodology. The use of this technology for high-throughput optical imaging allows study of electrophysiology of murine hearts in an organotypic pseudo two-dimensional model. The slices are cut at right angles to the long axis of the heart, permitting robust interrogation of transmembrane potential (Vm) and calcium transients (CaT) throughout the entire heart with exceptional regional precision. This approach enables the use of a series of slices prepared from the ventricles to measure Vm and CaT with high temporal and spatial resolution, allowing (i) comparison of successive slices which form a stack representing the original geometry of the heart; (ii) profiling of transmural and regional gradients in Vm and CaT in the ventricle; (iii) characterization of transmural and regional profiles of action potential and CaT alternans under stress (e.g., high frequency pacing or β-adrenergic stimulation) or pathological conditions (e.g., hypertrophy). Thus, the protocol described here provides a powerful platform for innovative research on electrical and calcium handling heterogeneity within the heart. It can be also combined with optogenetic technology to carry out optical stimulation; aiding studies of cellular Vm and CaT in a cell type specific manner.

Deep Learning-Based Automatic Segmentation of Lumbosacral Nerves on CT for Spinal Intervention: A Translational Study

BACKGROUND AND PURPOSE

3D reconstruction of a targeted area ("safe" triangle and Kambin triangle) may benefit the viability assessment of transforaminal epidural steroid injection, especially at the L5/S1 level. However, manual segmentation of lumbosacral nerves for 3D reconstruction is time-consuming. The aim of this study was to investigate the feasibility of deep learning-based segmentation of lumbosacral nerves on CT and the reconstruction of the safe triangle and Kambin triangle.

MATERIALS AND METHODS

A total of 50 cases of spinal CT were manually labeled for lumbosacral nerves and bones using Slicer 4.8. The ratio of training/validation/testing was 32:8:10. A 3D U-Net was adopted to build the model SPINECT for automatic segmentations of lumbosacral structures. The Dice score, pixel accuracy, and Intersection over Union were computed to assess the segmentation performance of SPINECT. The areas of Kambin and safe triangles were measured to validate the 3D reconstruction.

RESULTS

The results revealed successful segmentation of lumbosacral bone and nerve on CT. The average pixel accuracy for bone was 0.940, and for nerve, 0.918. The average Intersection over Union for bone was 0.897 and for nerve, 0.827. The Dice score for bone was 0.945, and for nerve, it was 0.905. There were no significant differences in the quantified Kambin triangle or safe triangle between manually segmented images and automatically segmented images (P > .05).

CONCLUSIONS

Deep learning-based automatic segmentation of lumbosacral structures (nerves and bone) on routine CT is feasible, and SPINECT-based 3D reconstruction of safe and Kambin triangles is also validated.

[Submucosal tunneling endoscopic resection for submucosal tumors originating from muscularis propria layer at esophagogastric junction]

Objective: To evaluate the short-term outcomes and safety of submucosal tunneling endoscopic resection (STER) for submucosal tumors (SMT) originating from muscularis propria (MP) layer at esophagogastric junction. Methods: The clinical data of 31 patients with SMT originating from MP layer at esophagogastric junction underwent STER were collected and retrospectively analyzed. Results: The success rate of STER of the thirty-one patients was 100%. The mean tumor size was (2.5±1.3) cm and the average operative time was (95.9±56.7) min. Perforation occurred in 3 patients and was successfully clipped by endo-clips during operation. One patient developed delayed bleeding and the bleeding was stopped by endoscopic hemostasis. Twenty-nine leiomyomas and two stromal tumors (GIST) were finally pathologically diagnosed. No local recurrence and distant metastasis were noted during the mean 15.4 months follow-up of 20 cases. According to the lesion size, 31 patients who received STER were divided into two groups. The operation time of maximum diameter ≥3.5 cm group was (134.0±70.6) min, significantly longer than (80.3±42.6) min of maximum diameter <3.5 cm group (P=0.014). However, the en bloc removal rate, postoperative hospital stay and the complication incidence between the two groups had no obvious differences (P>0.05). Univariate analysis showed that the piecemeal removal group had longer tumor diameter, higher incidence of irregular tumor morphology, and longer operative time than the en bloc removal group (all P<0.05). Stepwise logistic regression analysis showed that irregular shape was a risk factor for failure of en bloc removal (OR=18.000, 95% CI: 1.885~171.88, P=0.012). Conclusion: As a new method of minimally invasive treatment, STER technology appears to be a safe and effective option for patients with SMT originating from MP layer at esophagogastric junction.

Abstract P4-13-02: Selective androgen receptor modulator RAD140 inhibits the growth of endocrine-resistant breast cancer models with defined genetic backgrounds

Estrogen receptor α-positive (ER+) breast cancer is routinely treated with therapies targeting the ER axis. However, de novo and acquired resistance to the standard-of-care treatment occur in a significant subset of patients. Multiple mechanisms have been proposed for the resistance, among which genetic alterations to the coding gene of ERα, ESR1, have been extensively studied. Notably, ESR1 hotspot mutations within the ligand binding domain (LBD), novel fusion proteins consisting of the N-terminal domain of ER and the C-terminal domain of a partner gene, and ESR1 gene amplification have been found to be enriched in endocrine-resistant, metastatic breast cancers. Together these ER gene alterations present new challenges in the management of ER+ breast cancer and call for the development of new agents to supplement the current standard-of-care. Around 90% of the ER+ breast cancer cases are also androgen receptor (AR) positive (AR+). Mounting preclinical evidence has demonstrated that AR agonists suppress AR and ER positive (AR/ER+) breast cancer cell growth, in line with clinical activity of androgens. We recently reported the oral selective androgen receptor modulator (SARM) RAD140 is a potent, tissue-selective AR agonist in breast cancer cells which significantly inhibited the growth of AR/ER+ patient-derived xenograft (PDX) models, partly via inhibiting ESR1 gene expression and ER signaling. It also elicited enhanced tumor growth inhibition when combined with a CDK4/6 inhibitor.

Here we further examine the activity of RAD140 in AR/ER+ breast cancer models that are endocrine-independent with a spectrum of ESR1 genetic alterations. In PDX models harboring ESR1 amplification or fusion, RAD140 inhibited tumor growth to a greater degree than fulvestrant, a standard-of-care selective ER degrader (SERD). These results are consistent with the clinical history of the donor patients whose diseases relapsed from or progressed rapidly on fulvestrant. In PDX models with ESR1 Y537S mutation, RAD140 showed anti-tumor activity comparable to that of fulvestrant. Notably, RAD140 treatment also led to substantial reduction of proliferation and colony formation in cell line models recapitulating resistance to the combination of estrogen deprivation and CDK4/6 inhibition.

In summary, RAD140 showed marked anti-tumor activity in AR/ER+, endocrine-resistant breast cancer models with defined genetic background. Importantly, in models with ESR1 amplification and fusion, the AR-targeting RAD140 exhibited more profound inhibitory activity compared with fulvestrant. In models with an ESR1 mutation, the efficacy of RAD140 and fulvestrant was comparable. These results lend support to a clinical hypothesis that AR/ER+, endocrine-resistant tumors with these genetic backgrounds may benefit from AR agonist-based treatment. RAD140 is currently being evaluated in hormone receptor positive (HR+) breast cancer patients (NCT03088527).

Citation Format: Yu Z, He S, Miller C, Saeh J, Hattersley G, O'Neill A. Selective androgen receptor modulator RAD140 inhibits the growth of endocrine-resistant breast cancer models with defined genetic backgrounds [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 P4-13-02.