iT4SE-EP: Accurate Identification of Bacterial Type IV Secreted Effectors by Exploring Evolutionary Features from Two PSI-BLAST Profiles

Many gram-negative bacteria use type IV secretion systems to deliver effector molecules to a wide range of target cells. These substrate proteins, which are called type IV secreted effectors (T4SE), manipulate host cell processes during infection, often resulting in severe diseases or even death of the host. Therefore, identification of putative T4SEs has become a very active research topic in bioinformatics due to its vital roles in understanding host-pathogen interactions. PSI-BLAST profiles have been experimentally validated to provide important and discriminatory evolutionary information for various protein classification tasks. In the present study, an accurate computational predictor termed iT4SE-EP was developed for identifying T4SEs by extracting evolutionary features from the position-specific scoring matrix and the position-specific frequency matrix profiles. First, four types of encoding strategies were designed to transform protein sequences into fixed-length feature vectors based on the two profiles. Then, the feature selection technique based on the random forest algorithm was utilized to reduce redundant or irrelevant features without much loss of information. Finally, the optimal features were input into a support vector machine classifier to carry out the prediction of T4SEs. Our experimental results demonstrated that iT4SE-EP outperformed most of existing methods based on the independent dataset test.

Analysis of impedance matching for a spherical multi-degree-of-freedom ultrasonic motor

A novel spherical multi-degree-of-freedom ultrasonic motor is designed, which can achieve three-degree-of-freedom motion through the cooperative drive of three built-in traveling wave stators. The novel ultrasonic motor has the characteristics of compact structure and high power density. Additionally, in order to solve the problem of impedance mismatch between the ultrasonic motor and the driving power supply, a semi-analytical method of impedance matching based on parallel resonance is proposed according to the impedance characteristics of ultrasonic motor. Through the combination of theoretical derivation and finite element simulation, the ultrasonic motor impedance matching on the impedance circle is analyzed. By this method, the optimum matching inductor of the motor is determined. After matching, the motor obtains a larger vibration amplitude and higher transmission efficiency. Finally, the reliability of the method is verified by simulation and experiment, which provides a reference for further improving the motor performance.

Histone methyltransferase DOT1L coordinates AR and MYC stability in prostate cancer

The histone methyltransferase DOT1L methylates lysine 79 (K79) on histone H3 and is involved in Mixed Lineage Leukemia (MLL) fusion leukemogenesis; however, its role in prostate cancer (PCa) is undefined. Here we show that DOT1L is overexpressed in PCa and is associated with poor outcome. Genetic and chemical inhibition of DOT1L selectively impaired the viability of androgen receptor (AR)-positive PCa cells and organoids, including castration-resistant and enzalutamide-resistant cells. The sensitivity of AR-positive cells is due to a distal K79 methylation-marked enhancer in the MYC gene bound by AR and DOT1L not present in AR-negative cells. DOT1L inhibition leads to reduced MYC expression and upregulation of MYC-regulated E3 ubiquitin ligases HECTD4 and MYCBP2, which promote AR and MYC degradation. This leads to further repression of MYC in a negative feed forward manner. Thus DOT1L selectively regulates the tumorigenicity of AR-positive prostate cancer cells and is a promising therapeutic target for PCa.

Histone methyltransferase, DOTL1 is implicated in the pathogenesis of MLL-rearranged leukemia, however, not much is known of its role in prostate cancer (PCa). Here, the authors report that DOTL1 inhibition suppresses both androgen receptor and MYC pathways in a negative feed forward manner to reduce growth of AR-positive PCa.

[The surgical treatment of male perineum Paget's disease]

Objective: To evaluatethe clinical efficacy and complications of skin graft and flap plastic technique covered the defect in perineal Paget's disease postoperatively. Methods: The study comprised 6 patients diagnosed with perineal Paget's disease at Beijing Chao-Yang Hospital from June 2017 to July 2019, with all available clinical data reviewed. The defects after resection of lesions were reconstructed with skin graft, advancement skin flap during the operation, respectively. The operation time, the skin graft or flap survival situation, intraoperative and postoperative complications were recorded. Results: Of all 6 patients, Ray stage A1consisted of 1 case, A2 5 cases. The age was (68±9) years, the hospitalization time was (14.8±8.1) days, the BMI was (25.6±3.7) kg/m(2), the operation time was (132.0±80.7) min, and the average blood loss was (18.3±11.7) ml. Five cases was with Paget's disease, and 1 case with skin adenocarcinoma with Paget's disease were diagnosed by pathology. The defects of 4 cases and 2 cases after removal of the tumor were reconstructed with scrotal advancement skin flap and skin graft, respectively. The skin graft and flap survived well during afollow-up of (15.3±8.1) months.There has been no local recurrence. The foreskin edema and wound infection were noted in 4 cases and 1 case, respectively. There was no other related complications. Conclusion: Perineal Paget's disease can be managed by resection and immediate reconstruction with skin graft or flap according to the size and location of the defect, and the clinical efficacy is distinct.

Overexpression of lncRNA NLIPMT Inhibits Colorectal Cancer Cell Migration and Invasion by Downregulating TGF-β1

Background

NLIPMT, as a tumor suppressive lncRNA, has only been investigated in breast cancer, while its roles in other types of cancer remain unknown. This study aimed to explore the role of NLIPMT in colorectal cancer (CRC).

Methods

Expression levels of NLIPMT and TGF-β1 in two types of CRC tissue (Non-tumor tissues and tumor tissues) were measured and compared by qRT-PCR and paired t-test, respectively. Correlations between the expression of NLIPMT and TGF-β1 were analyzed by performing linear regression. The effects of transfections on cell invasion and migration were evaluated by Transwell assays.

Results

We found that NLIPMT was downregulated, while TGF-β1 was upregulated in CRC. In CRC tumor, a negative correlation was found between the expression of NLIPMT and TGF-β1. In CRC cells, overexpression of NLIPMT resulted in downregulation, while silencing of NLIPMT resulted in upregulation of TGF-β1. Analysis of cell invasion and migration showed that overexpression of NLIPMT suppressed the tumor cell invasion and migration. In contrast, overexpression of TGF-β1 could promote CRC cell invasion and migration and also reduce the role of NLIPMT. Through the overall survival evaluation, NLIPMT-high groups of CRC represented better survival rate compared to that of the NLIPMT-low group patients.

Conclusion

The expression of lncRNA NLIPMT was negatively correlated with TGF-β1 in CRC. Overexpression of NLIPMT inhibited the colorectal cancer cell migration and invasion by downregulating TGF-β1. Furthermore, the expression of NLIPMT in CRC patients predicted better prognosis, which suggested that NLIPMT could be considered as a novel diagnosis biomarker.

miR-146a alleviates the apoptosis of hippocampal neurons induced by microglia activation via targeting TRAF6

OBJECTIVE

To identify the role of miR-146a and tumor necrosis factor receptor-associated factor 6 (TRAF6) for improving the apoptosis of hippocampal neurons induced by microglia activation.

METHODS

Mouse microglial cell line (BV2 cell) was employed and treated with lipopolysaccharide. Mouse hippocampal nerve cell line (HT22 cell) was then grown in BV2 conditioned medium, and miR-146a overexpression and silencing cell lines were constructed. CCK8 and clone formation test were utilized to evaluate the proliferation ability of the transfected cells, and the level of inflammatory factors was measured by ELISA. Apoptosis was determined extensively by flow cytometry. The apoptosis-related protein and TRAF6 protein expressions were verified by Western blot. TRAF6 was identified to be the target gene of miR-146a based on double Luciferase Report. Finally, both TRAF6 and miR-146a were used to treat HT22 cells and the above indexes were detected repeatedly.

RESULTS

Interleukin (IL)-1β, tumor necrosis factor-α, and IL-6 expressions in BV2 cells increased significantly. miR-146a overexpression distinctly increased the cell proliferation ability and B-cell lymphoma-2 expression ((Bcl-2, p < 0.05); meanwhile, the apoptosis rate of cells, apoptosis-related proteins (Bcl-2 associated X and cleaved caspase-3), and TRAF6 gene and protein expressions were significantly decreased (p < 0.05). However, these above results were reversed for miR-146a silence. There is a targeting relationship between miR-146a and TRAF6. Silencing TRAF6 gene can promote HT22 cells' proliferation and inhibit apoptosis. The effect of miR-146a on HT22 cells was reversed by adding TRAF6 mimics to miR-146a overexpression cells.

CONCLUSION

miR-146a can inhibit the apoptosis of hippocampal neurons caused by microglia activation via targeting TRAF6 and down-regulating its expression.

A systematic survey of randomised trials that stopped early for reasons of futility

Background

Randomised trial protocols may incorporate interim analyses, with the potential to stop the study for futility if early data show insufficient promise of a treatment benefit. Previously, we have shown that this approach will theoretically lead to mis-estimation of the treatment effect. We now wished to ascertain the importance of this phenomenon in practice.

Methods

We reviewed the methods and results in a set of trials that had stopped for futility, identified through an extensive literature search. We recorded clinical areas, interventions, study design, outcomes, trial setting, sponsorship, planned and actual treatment effects, sample sizes; power; and if there was a data safety monitoring board, or a published protocol. We identified: if interim analyses were pre-specified, and how many analyses actually occurred; what pre-specified criteria might define futility; if a futility analysis formed the basis for stopping; who made the decision to stop; and the conditional power of each study, i.e. the probability of statistically significant results if the study were to continue to its complete sample size.

Results

We identified 52 eligible trials, covering many clinical areas. Most trials had multiple centres, tested drugs, and 40% were industry sponsored. There were 75% where at least one interim analysis was planned a priori; a majority had only one interim analysis, typically with about half the target total sample size. A majority of trials did not pre-define a stopping rule, and a variety of reasons were given for stopping. Few studies calculated and reported low conditional power to justify the early stop. When conditional power could be calculated, it was typically low, especially under the current trend hypothesis. However, under the original design hypothesis, a few studies had relatively high conditional power. Data collection often continued after the interim analysis.

Conclusions

Although other factors will typically be involved, we conclude that, from the perspective of conditional power, stopping early for futility was probably reasonable in most cases, but documentation of the basis for stopping was often missing or vague. Interpretation of truncated trials would be enhanced by improved reporting of stopping protocols, and of their actual execution.

Constructing [CoII6] hexagon-centered heterometallic {Ln6Co6} (Ln = Y, Eu and Dy) clusters with a calix[8]arene ligand

Three isostructural 3d–4f polynuclear clusters {(LnIII6CoII6)(C8A)₃} (Ln = Y, Eu, Dy; C8A = p-tert-butylcalix[8]arene) feature some tripod-like entities in which three Ln₂-C8A SBUs bolster a [Co₆] hexagon.

TRIM24 aggravates the progression of ovarian cancer through negatively regulating FOXM1 level

OBJECTIVE

This study aims to uncover the biological functions of the feedback loop tripartite motif-containing 24 (TRIM24)/Forkhead Box M1 (FOXM1) in the pathological progression of ovarian cancer (OC) and the underlying mechanism.

PATIENTS AND METHODS

The expression levels of TRIM24 and FOXM1 in OC tissues and cells were determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The potential correlation between TRIM24 level and clinical indexes of OC patients was analyzed. The Kaplan-Meier curves were depicted for evaluating the prognostic potentials of TRIM24 and FOXM1 in OC patients. The regulatory effects of TRIM24 and FOXM1 on proliferative, migratory, and invasive capacities of SKOV3 and OVCAR3 cells were assessed through functional experiments. The rescue experiments were performed to clarify the feedback loop TRIM24/FOXM1 in influencing the progression of OC.

RESULTS

TRIM24 was upregulated in OC tissues and cells. The high level of TRIM24 was linked to higher rates of lymphatic and distant metastasis and worse survival in OC patients. The silence of TRIM24 attenuated proliferative, migratory, and invasive capacities of SKOV3 and OVCAR3 cells. FOXM1 level was negatively regulated by TRIM24, which was downregulated in OC. The low level of FOXM1 predicted worse survival in OC patients. Besides, the rescue experiments demonstrated that the feedback loop TRIM24/FOXM1 aggravated the malignant progression of OC.

CONCLUSIONS

TRIM24 is upregulated in OC tissues, and closely linked to the occurrence of lymphatic and distant metastasis. Through negatively regulating FOXM1 level, TRIM24 aggravates the progression of OC.

Prospects of Application of Microbial Biofilm to Estimate PMI of Corpses in Water

Abstract

In forensic pathology, the estimation of postmortem interval （PMI） has always been a difficult issue, and there is still lack of effective methods to estimate PMI of corpses in water. Microbial biofilm refers to the microbial population attached to non-biological or biological surfaces by microorganisms during microbial growth, that has a three-dimensional structure, surrounded by extracellular polymers and matrix networks created by itself. A series of community succession phenomena of microorganisms occur during the occurrence and development of microbial population. The microbial community and its succession process of this kind of biofilm attached to the surface of a corpse in water may become a new basis for estimation of the PMI of corpses in water. This review elucidates on the concept, classification, research methods, and influencing factors of biofilm and analyzes its application prospects in PMI estimation of corpses in water, which would provide new ideas for the researches in this field.

P3466Cardiac output in end-stage liver disease increases with the severity of liver dysfunction

Background

End-stage liver disease is associated with significant systemic and haemodynamic alterations that affect cardiac function. Cirrhotic cardiomyopathy remains an ill-defined entity among cardiologists. Understanding the complex interplay between liver dysfunction and cardiac function can lead to a better understanding of the compensatory mechanisms of the heart in liver failure.

Purpose

To investigate whether severity of liver disease affects baseline cardiac output in a large contemporary cohort of patients undergoing liver transplant work-up.

Methods

Consecutive patients that underwent pre-liver transplant (LT) workup between 2010–2017 were included. All patients underwent a resting echocardiogram. Cardiac output (CO) was prospectively recorded at baseline by pulsed-wave Doppler examination of the left ventricular outflow tract from the apical window and systemic vascular resistance (SVR) was calculated as 80 x (mean arterial pressure (MAP)/CO). Severity of liver disease was characterized by the model of end-stage liver disease (MELD) and Child-Pugh scores.

Results

560 patients were included (mean age 57.5±7.7, 74.8% male). Mean MELD score was 19±7 and Child-Pugh Score was 9±3. There was an inverse linear relationship between the severity of liver disease by the MELD score and baseline SVR (rho 0.40, P<0.001). As SVR reduced, there was also a significant rise in baseline CO with a strong inverse correlation between the two variables (rho 0.86, p<0.001). There was a significant linear correlation between the severity of liver disease and baseline CO with both the scores (MELD Score rho 0.42, p<0.001; Child Pugh rho 0.44, p<0.001) (Figure).

Baseline CO in LT Patients by Severity

Conclusions

Baseline CO increased with the severity of liver dysfunction due to a reduced afterload. A higher resting CO may lead to patients encroaching on their cardiac reserve at rest. This provides a pathophysiological insight suggesting a limited role for beta-blockers, particularly in patients with advanced liver cirrhosis.

P3465Inducible left ventricular outflow tract obstruction is associated with a higher incidence of perioperative cardiac arrest in liver transplantation

Background

Inducible left ventricular outflow tract obstruction (LVOTO) is not infrequently encountered in liver transplant (LT) candidates undergoing cardiac workup. While the impact of LVOTO on adverse cardiovascular haemodynamics is well reported, it is unclear whether it predisposes to perioperative cardiovascular complications following LT.

Purpose

To investigate the effect of inducible left ventricular outflow tract obstruction on perioperative cardiovascular complications in a modern cohort of liver transplant patients.

Methods

Consecutive patients undergoing dobutamine stress echocardiography (DSE) were evaluated from a quaternary LT centre between 2010 and 2017. Inducible LVOTO was defined as LVOT gradient ≥36mmHg. Perioperative major adverse cardiovascular events (MACE) at 30 days and all-cause death were recorded from a prospectively maintained transplantation database and augmented by electronic medical record review.

Results

We evaluated 560 patients who underwent DSE as part of a workup for LT. Of these, 319 progressed to transplant. Inducible LVOTO was observed in 68 patients (21.3%). A higher baseline cardiac output (7.7 L/min vs 7.0 L/min, p=0.002) predicted for development of inducible LVOTO. Seventy-seven patients (4.1%) experienced a MACE including five deaths, 19 cases of heart failure, 11 cardiac arrests, 10 acute coronary syndromes and 46 cases of arrhythmias (VT/AF). Overall MACE occurred in 17/68 patients (25.0%) with LVOTO and 60/251 patients (23.9%) without LVOTO (p=0.85). However, there was a significantly increased risk of resuscitated perioperative cardiac arrest in patients with LVOTO (7.4% vs 2.4%, p=0.04). Patients with LVOTO also required significantly greater volumes of fluid intra-operatively (8.37L vs. 6.71L, p=0.043).

Cardiac Arrest in LT Patients with LVOTO

Conclusions

Inducible LVOTO is a frequent finding occurring in 21.3% of LT candidates. Despite higher intraoperative fluid resuscitation, LVOTO increased the risk of a perioperative cardiac arrest. Further studies are required to confirm these findings and to assess whether patients with LVOTO undergoing liver transplantation may benefit from heightened perioperative surveillance.

Towards continuous-to-continuous 3D imaging in the real world

Imaging systems are often modeled as continuous-to-discrete mappings that map the object (i.e. a function of continuous variables such as space, time, energy, wavelength, etc) to a finite set of measurements. When it comes to reconstruction, some discretized version of the object is almost always assumed, leading to a discrete-to-discrete representation of the imaging system. In this paper, we discuss a method for single-photon emission computed tomography (SPECT) imaging that avoids discrete representations of the object or the imaging system, thus allowing reconstruction on an arbitrarily fine set of points.

Hormone replacement therapies, oral contraceptives, reproductive factors and colorectal adenoma risk: a systematic review and dose-response meta-analysis of observational studies

AIM

The association between the use of oral contraceptives and hormone replacement therapy (HRT) or other reproductive factors and the risk of colorectal adenoma (CRA) remains controversial. Our study aimed to review the evidence by conducting a dose-response meta-analysis to investigate this association.

METHODS

We searched PubMed and Embase databases for relevant studies published until May 2017. Traditional and dose-response meta-analyses were conducted. Sensitivity analysis was performed to evaluate the robustness of the results. Cumulative meta-analysis was used to assess the risk of different oral contraceptive formulations or generations.

RESULTS

A total of 19 observational studies, with 21 923 CRA cases and 1 030 711 participants, were included in the meta-analysis. Ever HRT use showed a potential inverse association with CRA risk [relative risk (RR) 0.83, 95% CI 0.70-1.00]. The dose-response meta-analysis further demonstrated that HRT use could reduce CRA risk. Compared with no HRT use, the predicted RRs were 0.82 (95% CI 0.67-0.99), 0.76 (95% CI 0.59-0.98) and 0.77 (95% CI 0.62-0.96) for 3, 6 and 9 years of HRT use, respectively. All other factors were not statistically significantly associated with CRA risk.

CONCLUSIONS

This study indicated that only HRT use might reduce the risk of developing CRA. Any advice regarding HRT use to prevent CRA should be tailored to the individual risks and potential benefits. Large, well-designed prospective studies with long-term follow-up are required to further clarify the aetiology of CRA.

Intermittent lead-induced stress on antioxidant enzyme activity and subcellular distribution of Pb in Pogonatherum crinitum seedlings

Pogonatherum crinitum is a promising lead (Pb) hyperaccumulator due to its high Pb tolerance and accumulation ability. However, the mechanisms that support Pb accumulation and tolerance in P. crinitum are not yet clearly understood. An indoor hydroponic experiment was conducted by cultivating P. crinitum seedlings exposed to intermittent Pb stress for 60 days, divided into four stages (T1, T2, T3 and T4), with a 15-day duration per stage. The following concentrations of Pb were used: 0, 500, 0, 500 mg·l^-1 and 0, 1000, 0, 1000 mg·l^-1 ). Antioxidant enzyme activity, Pb concentration and subcellular distribution of Pb were measured at each of the above stages. The results showed that superoxide dismutase (SOD) activity in shoots, and SOD, peroxidase (POD) and malondialdehyde (MDA) activity in shoots and roots significantly increased from T1 (no Pb stress) to T2 (Pb stress) in both 500 mg·l^-1 and 1000 mg·l^-1 treatments; however, no significant difference was noted between stages T3 (no Pb stress) and T4 (Pb stress). There was no obvious effect of Pb stress on catalase (CAT) activity in shoots and roots among different stages. The Pb concentration in shoots was up to 5090.90 mg·kg^-1 and 7573.57 mg·kg^-1 , and the bioconcentration factor (BFC) was 10.18 and 7.57 for the 500 mg·l^-1 and 1000 mg·l^-1 treatments, respectively, which confirmed the Pb hyperaccumulator characteristics of P. crinitum. For plants under Pb stress, most of the Pb was fixed in the cell walls, with a smaller amount in leaves and root vacuoles. Both SOD and POD scavenging of reactive oxygen radicals and fixing and compartmentalisation of Pb in the cell wall might play important roles in detoxification of P. crinitum seedlings in response to Pb stress. There was no phased response of P. crinitum to intermittent Pb stress and the physiological response to Pb stress may be contiguous.

Chinese Mongolian horses may retain early domestic male genetic lineages yet to be discovered

The Mongolian horse represents one of the most ancient extant horse populations. In this study we determined the male-specific region of the Y chromosome (MSY) haplotype distribution in 60 Chinese Mongolian horses representing five distinct populations. Cosmopolitan male lineages were predominant in horses from one improved (Sanhe), one Chinese Mongolian subtype (Baicha Iron Hoof) and one indigenous (Abaga Black) population. In contrast, autochthonous Y chromosome diversity was evident among the two landrace populations (Wushen and Wuzhumuqin), as the majority of their MSY haplotypes were situated at root nodes in a network. Our results also suggest gene flow between Chinese Mongolian and Arabian horses, as an appreciable number of Wuzhumuqin horses carried haplotypes that are typically observed in Arabian horses. Although most horses carried modern haplotypes as a direct result of recent breed improvement, authentic Chinese Mongolian horses retain an ancient signature of paternal lineages that has not previously been described in extant horse populations. Therefore, further characterization of MSY variation in these populations will be important for the discovery of lost diversity in modern domestic horses and also for understanding the evolutionary history of equine paternal lineages.

[Clinical outcome of postchemotherapy retroperitoneal lymph node dissection and predicting retroperitoneal histology in advanced nonseminomatous germ cell tumours of the testis]

Objective: To explore the clinical outcome of advanced testicular nonseminomatous germ cell cancer patients undergoing post chemotherapy retroperitoneal lymph node dissection (PC-RPLND), and to analyze the relevant prognostic factors of lymph node pathological. Methods: A total of 43 consecutive testicular nonseminomatous germ cell cancer patients underwent PC-RPLND between March 2001 and December 2014 in Department of Urology at Sun Yat-sen University Cancer Center were retrospectively reviewed. The average age of the patients was (29.0±11.5) years (ranging from 12 to 58 years). Before PC-RPLND, 22 patients were classified as phase Ⅱ, while 21 were phase Ⅲ. Primary tumor histology revealed seminomatous elements in 19 cases, embryonal cell carcinoma in 22 cases, yolk sac tumor in 13 cases, chorionic carcinoma in 3 cases, mature teratomatous elements in 11 and immature teratomatous elements in 2 cases. Patients were treated with cisplatin-based chemotherapy after orchectomy and then underwent surgical resection of retroperitoneal lymph nodes.After PC-RPLND, all patients underwent a periodic review including the blood routine, biochemistry routine and computed tomography or ultrasonograph of the chest, the abdomen and the pelvis. The association of pathological data with patient's clinic features and the correlations between molecular features detected with each other were assessed by the t test, χ(2) and Fisher's exact test. Multivariate logistic regression were used to assess prognostic factors. Results: The median operative time was 278 minutes (ranging from 50 to 715 minutes). Median blood loss was 425 ml (ranging from 50 to 5 000 ml). Eight patients received blood transfusion intra-operatively, 2 patients underwent adjunctive surgical procedures, 4 patients developed ileus and 4 had an ascites chylosus following PC-RPLND, 1 patient had a postoperative hyperthermia and retrograde ejaculation was present in 10 patients. The transverse diameter of the residual tumor in patients ranged from 0.8 to 18.2 cm. Necrosis, teratoma and viable germ cell tumors were found in 15, 17 and 11 of all patients. The median follow-up time was 46 months (ranging from 6 to 169 months). There were 39 patients had no tumor recurrence, 7 patients were found recurrence after PC-RPLND, 5 died of malignant germ cell tumor. The normal serum lactate dehydrogenase (LDH) level before chemotherapy (HR=25.811, 95%CI: 0.678 to 982.624, P=0.017) and relative changes more than 50% in retroperitoneal lymph node size (HR=0.016, 95%CI: 0 to 0.698, P=0.032) were statistically significant prognostic factors of the presence of necrosis. Conclusions: Since most residual masses are not sensitive to chemotherapy, PC-RPLND is still an essential part of the treatment of metastatic testicular nonseminomatous germ cell cancer. Patients with the normal serum LDH level before chemotherapy and a shrinkage of 50% or more in retroperitoneal mass have a considerably chance of having necrosis in the retroperitoneum resection. This may help to refine the selection of candidates for PC-RPLND.

Abstract OT3-03-01: Open-label, single-arm study evaluating the antitumor activity and safety of niraparib as neoadjuvant treatment in patients with localized, HER2-negative, BRCA-mutant breast cancer

Background: Neoadjuvant chemotherapy is administered to patients with operable breast cancer to downstage the tumor to allow for less extensive surgery and to provide prognostic information about drug efficacy and risk of disease recurrence. Patients who achieve a pathological complete response (pCR) following neoadjuvant treatment have a more favorable outcome than patients with residual invasive disease. Single-agent poly(ADP-ribose) polymerase (PARP) inhibitors have clinical efficacy in BRCA-mutated breast cancer. Niraparib, a potent and selective PARP1/2 inhibitor, is approved for maintenance treatment of patients with recurrent ovarian cancer and has demonstrated strong antitumor activity in in vivo studies with BRCA1-mutant breast cancer. The objective of this study is to evaluate the antitumor activity of single-agent niraparib in the neoadjuvant treatment of patients with localized, human epidermal growth factor receptor 2 (HER2)-negative, BRCAmut breast cancer.

Trial Design: This is an open-label, single-arm pilot study with a target enrollment of 20 evaluable patients. Eligible patients are those ≥18 years old with histologically-confirmed HER2-negative localized breast cancer and either a BRCA1 or BRCA2 mutation (germline or somatic) and no prior anti-cancer therapies for the current malignancy. Patients will receive 200 mg of oral niraparib once daily for 2 months, after which they may either proceed directly to surgery or receive chemotherapy at the discretion of the physician. The primary endpoint is tumor response rate based on the change in tumor volume as measured by breast MRI after 2 months of treatment with niraparib; a response is defined as ≥30% reduction of tumor volume from baseline. Secondary endpoints include pCR rate, tumor response rate based on the change in tumor volume as measured by breast ultrasound, and safety and tolerability. Data will be summarized in a descriptive nature by frequency distributions (number and percentage of patients) for categorical variables and by the mean, median, and standard deviation for continuous variables. Tumor response rate will be tabulated together with its 95% binomial exact confidence interval.

Funding: TESARO, Inc., Waltham, MA, USA sponsored the study.

Citation Format: Han H, Hamilton E, Irie H, Isakoff S, Jelovac D, Liem A, Liu MC, Milillo A, Nangia J, Page D, Reeves J, Santa-Maria C, Duncan M, Graham JR, Chen J, Dezube BJ, Spring L. Open-label, single-arm study evaluating the antitumor activity and safety of niraparib as neoadjuvant treatment in patients with localized, HER2-negative, BRCA-mutant 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 OT3-03-01.