A Nationwide Study on HER2-low Breast Cancer in South Korea: Its Incidence of 2022 Real World Data and the Importance of Immunohistochemical Staining Protocols

Purpose

Notable effectiveness of trastuzumab deruxtecan (T-DXd) in patients with HER2-low advanced breast cancer (BC) has focused pathologists' attention. We studied the incidence and clinicopathologic characteristics of HER2-low BC, and the effects of immunohistochemistry (IHC) associated factors on HER2 IHC results.

Materials and Methods

The Breast Pathology Study Group of the Korean Society of Pathologists conducted a nationwide study using real-world data on HER2 status generated between January 2022 and December 2022. Information on HER2 IHC protocols at each participating institution was also collected.

Results

Total 11,416 patients from twenty-five institutions included in this study. Of these patients, 40.7% (range: 6.0%-76.3%) were classified as HER2-zero, 41.7% (range: 10.5%-69.1%) as HER2-low, and 17.5% (range: 6.7%-34.0%) as HER2-positive. HER2-low tumors were associated with positive ER and PR statuses (p<0.001 and p<0.001, respectively). Antigen retrieval times (≥ 36 min vs. < 36 min) and antibody incubation times (≥ 12 min vs. < 12 min) affected on the frequency of HER2 IHC 1+ BC at institutions using the PATHWAY HER2 (4B5) IHC assay and BenchMark XT or Ultra staining instruments. Furthermore, discordant results between core needle biopsy (CNB) and subsequent resection specimen HER2 statuses were observed in 24.1% (787/3259) of the patients.

Conclusion

The overall incidence of HER2-low BC in South Korea concurs with those reported in previously published studies. Significant inter-institutional differences in HER2 IHC protocols were observed, and it may have impact on HER2-low status. Thus, we recommend standardizing HER2 IHC conditions to ensure precise patient selection for targeted therapy.

A Comparison Between GalT-/-;hCD39;hCD55 and GalT-/-;hCD39;hCD46;hCD55;TBM Pig Kidneys Transplanted in Nonhuman Primates

Because there is a shortage of donor kidneys, researchers are exploring the possibility of using genetically modified pig kidneys for transplantation. Approaches involving knockout of carbohydrate genes or knockin of protective proteins have been attempted to determine the best gene modifications. In this study, we utilized GalT-/-;hCD39;hCD55 and GalT-/-;hCD39;hCD46;hCD55;thrombomodulin (TBM) pigs for transplantation in nonhuman primates (NHPs). The NHPs survived for 4 weeks after kidney transplantation (4 WAT) from the GalT-/-;hCD39;hCD55 pig and for 6 WAT from the GalT-/-;hCD39;hCD46;hCD55;TBM pig. However, messenger RNA (mRNA) sequencing and immunohistochemistry analysis revealed that the 6 WAT kidney exhibited more severe apoptosis, inflammation, loss of renal function, and renal fibrosis than the 4 WAT kidney. These results indicate that additional knockin of complement regulator (hCD46) and coagulation regulator (TBM) is not enough to prevent renal damage, suggesting that improved immune suppression is needed for more prolonged survival.

Phase I dose escalation and expansion study of golidocitinib, a highly selective JAK1 inhibitor, in relapsed or refractory peripheral T-cell lymphomas

BACKGROUND

Relapsed or refractory peripheral T-cell lymphomas (r/r PTCLs) are a group of rare and aggressive diseases that lack effective therapies. Constitutive activation of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway is reported to be associated with PTCLs. Golidocitinib is an oral, potent JAK1 selective inhibitor evaluated in a phase I/II multinational study in patients with r/r PTCLs.

PATIENTS AND METHODS

Patients with r/r PTCLs were eligible. The primary objectives were to assess safety and tolerability of golidocitinib and to define its recommended phase II dose (RP2D). The secondary objectives were to evaluate its antitumor activity and pharmacokinetics (PK).

RESULTS

A total of 51 patients were enrolled and received golidocitinib treatment at 150 or 250 mg once daily (QD). The median prior lines of therapies were 2 (range: 1-8). Golidocitinib was tolerated at both doses tested, while a higher incidence of serious adverse events and dose modifications at 250 mg were observed. The most common grade ≥3 drug-related treatment-emergent adverse events were neutropenia (27.5%) and thrombocytopenia (11.8%). An objective response rate of 39.2% and a complete response rate of 21.6% were observed. With median follow-up time of 14.7 and 15.9 months, the median duration of response (DoR) and progression-free survival were 8.0 and 3.3 months, respectively. Based on these data, 150 mg QD was defined as the RP2D. Golidocitinib demonstrated a favorable PK profile as an oral agent. Biomarker analysis suggested a potential correlation between JAK/STAT pathway aberrations and clinical activity of golidocitinib.

CONCLUSIONS

In this phase I study, golidocitinib demonstrated an acceptable safety profile and encouraging antitumor efficacy in heavily pretreated patients with r/r PTCLs. These results support the initiation of the multinational pivotal study in patients with r/r PTCLs.

Comparative transcriptome analysis between long- and short-term survival after pig-to-monkey cardiac xenotransplantation reveals differential heart failure development

Cardiac xenotransplantation is the potential treatment for end-stage heart failure, but the allogenic organ supply needs to catch up to clinical demand. Therefore, genetically-modified porcine heart xenotransplantation could be a potential alternative. So far, pig-to-monkey heart xenografts have been studied using multi-transgenic pigs, indicating various survival periods. However, functional mechanisms based on survival period-related gene expression are unclear. This study aimed to identify the differential mechanisms between pig-to-monkey post-xenotransplantation long- and short-term survivals. Heterotopic abdominal transplantation was performed using a donor CD46-expressing GTKO pig and a recipient cynomolgus monkey. RNA-seq was performed using samples from POD60 XH from monkey and NH from age-matched pigs, D35 and D95. Gene-annotated DEGs for POD60 XH were compared with those for POD9 XH (Park et al. 2021). DEGs were identified by comparing gene expression levels in POD60 XH versus either D35 or D95 NH. 1,804 and 1,655 DEGs were identified in POD60 XH versus D35 NH and POD60 XH versus D95 NH, respectively. Overlapped 1,148 DEGs were annotated and compared with 1,348 DEGs for POD9 XH. Transcriptomic features for heart failure and inhibition of T cell activation were observed in both long (POD60)- and short (POD9)-term survived monkeys. Only short-term survived monkey showed heart remodeling and regeneration features, while long-term survived monkey indicated multi-organ failure by neural and hormonal signaling as well as suppression of B cell activation. Our results reveal differential heart failure development and survival at the transcriptome level and suggest candidate genes for specific signals to control adverse cardiac xenotransplantation effects.

A prospective phase 2 study of expeditious EGFR genotyping and immediate therapeutic initiation through extracellular vesicles (EV)-based bronchoalveolar lavage fluid (BALF) liquid biopsy in advanced NSCLC patients

Background

In our previous study, epidermal growth factor receptor (EGFR) genotyping using extracellular vesicles (EV)-derived DNA isolated from bronchoalveolar lavage fluid (BALF) was proven to be highly concordant with conventional tissue-based genotyping and its turn-around-time (TAT) was only 1-2 days. On this background, we prospectively validated the performance of EV-based BALF liquid biopsy for EGFR genotyping in the real practice of advanced non-small cell lung cancer (NSCLC) patients.

Methods

After screening 120 newly diagnosed stage III-IV NSCLC patients, 51 cases were detected as EGFR-mutated by EV-based BALF EGFR genotyping and 40 patients were enrolled for gefitinib treatment. BALF EV were isolated by ultracentrifuge method and EGFR genotyping was performed with PCR-based PNA-clamping assisted fluorescence melting curve analysis. The objective response rate, progression-free survival (PFS), TAT, time to treatment initiation (TTI), and concordance rate were analyzed with clinical parameters.

Results

There was only one false positive case among the 120 screened patients and the overall concordance rate between tissue biopsy and EV-based BALF liquid biopsy was 99.2% including the subtype of EGFR mutations. TAT for EV-based BALF EGFR genotyping was 1.9±1.1 days, while tissue-based TAT was 12.1±7.2 days (P<0.001). EGFR genotyping was determined even before obtaining histopathologic report in most cases. TTI in BALF EGFR genotyping was faster than tissue genotyping (7.8±6.5 vs. 13.8±12.9 days). Therapeutic outcomes of response rate and PFS were almost similar to tissue-based results.

Conclusions

We demonstrated, for the first time, that EV-based BALF liquid biopsy should be an excellent platform for expeditious EGFR genotyping and rapid therapeutic intervention even before obtaining the result of histopathology in advanced NSCLC patients.

Current Status of Genetically Engineered Pig to Monkey Kidney Xenotransplantation in Korea

BACKGROUND

In South Korea, pig-to-nonhuman primate trials of solid organs have only been performed recently, and the results are not sufficiently satisfactory to initiate clinical trials. Since November 2011, we have performed 30 kidney pig-to-nonhuman primate xenotransplantations at Konkuk University Hospital.

METHODS

Donor αGal-knockout-based transgenic pigs were obtained from 3 institutes. The knock-in genes were CD39, CD46, CD55, CD73, and thrombomodulin, and 2-4 transgenic modifications with GTKO were done. The recipient animal was the cynomolgus monkey. We used the immunosuppressants anti-CD154, rituximab, anti-thymocyte globulin, tacrolimus, mycophenolate mofetil, and steroids.

RESULTS

The mean survival duration of the recipients was 39 days. Except for a few cases for which survival durations were <2 days because of technical failure, 24 grafts survived for >7 days, with an average survival duration of 50 days. Long-term survival was observed 115 days after the removal of the contralateral kidney, which is currently the longest-recorded graft survival in Korea. We confirmed functioning grafts for the surviving transplanted kidneys after the second-look operation, and no signs of hyperacute rejection were observed.

CONCLUSIONS

Although our survival results are relatively poor, they are the best-recorded results in South Korea, and the ongoing results are improving. With the support of government funds and the volunteering activities of clinical experts, we aim to further improve our experiments and contribute to the commencement of clinical trials of kidney xenotransplantation in Korea.

Comparison of Graft Survival Between Full-Thickness and Lamellar Pig-to-Monkey Corneal Xenotransplantation from the Same Genetically Engineered Pig Model with Minimal Immunosuppression

BACKGROUND

The graft survival rate of full-thickness corneal xenotransplantation (XTP) with minimal immunosuppression in genetically engineered pigs is unknown, whereas lamellar corneal XTP shows satisfactory results. We compared graft survival between full-thickness and lamellar transplantations in the same genetically engineered pig.

METHODS

Six pig-to-monkey corneal transplantations were performed on 3 transgenic pigs. Two corneas harvested from 1 pig were transplanted into 2 monkeys using full-thickness and lamellar corneal xenotransplantation. The transgenic donor pigs used were α1,3-galactosyltransferase gene-knockout + membrane cofactor protein (GTKO+CD46) in one recipient and GTKO+CD46+ thrombomodulin (TBM) in the other.

RESULTS

The graft survival time for GTKO+CD46 XTP was 28 days. With the addition of TBM, the survival differences between lamellar and full-thickness XTP were 98 days versus 14 days and >463 days (ongoing) versus 21 days, respectively. An excessive number of inflammatory cells was observed in failed grafts, but none were in the recipient's stromal bed.

CONCLUSIONS

Unlike full-thickness corneal XTP, lamellar xenocorneal transplantation does not exhibit surgical complications, such as retrocorneal membrane or anterior synechia. The graft survival of lamellar XTP in this study was not as good as in our previous experiments, although the survival period was superior to that of full-thickness XTP. The difference in graft survival based on transgenic type is not definitive. Further studies using transgenic pigs and minimal immunosuppression need to focus on improving graft survival of lamellar XTP and using a larger sample size to determine the potential of full-thickness corneal XTP.

Current state of cytopathology residency training: a Korean national survey of pathologists

BACKGROUND

Although the Korean Society for Cytopathology has developed educational goals as guidelines for cytopathology education in Korea, there is still no systematic approach to cytopathology education status for pathology residents. Furthermore, satisfaction with cytopathology education and with the outcome of the current training/educational program has not been investigated in Korea. This study aimed to obtain comprehensive data on the current state of cytopathology education for residents and evaluate education outcomes.

METHODS

An online survey was conducted in December 2020 for the board-certified pathologists and training residents registered as members of the Korean Society for Cytopathology. The questionnaire comprised questions that investigated the current status of cytopathology at each training institution, the degree of satisfaction with the work and education related to cytopathology, outcomes of cytopathology training, and educational accomplishments.

RESULTS

Of the participants surveyed, 12.3% (132/1,075) completed the questionnaire, and 36.8% (32/87) of cytopathology residents participated. The mean overall satisfaction with cytopathology education was 3.1 points (on a 1- to 5-point scale, 5: very satisfied). The most frequent suggestion among the free description format responses was to expand educational opportunities, such as online education opportunities, outside of the individual institutions.

CONCLUSIONS

Our results showed that cytopathology training in Korea needs further improvement. We expect that this study will inform systematic training of competent medical personnel armed with broad cytopathology knowledge and strong problem-solving abilities.

Subungual Osteochondromas of the Toe: Two Case Reports for Diagnosis and Treatment

Benign cartilaginous tumors, known as chondrogenic tumors, show cartilage components in the microscopic diagnosis. We present two clinical cases with cartilaginous tumors of the toes showing distinctive clinical manifestations. Two juvenile patients visited our outpatient clinic due to tumors with toenail deformities. A 10-year-old girl presented with a palpable mass with a nail deformity on the left third toe. The initial pathology report was soft tissue chondroma until complete resection. Another 15-year-old male patient visited the dermatology department with a toenail deformity and underwent a punch biopsy. The pathology report was fibrosis with myxoid degeneration. Excisional biopsies were performed for both patients. In the operative field, we observed exophytic tumors connected to the distal phalangeal bones. The final pathology reports were subungual osteochondroma on both patients. The specimen exhibited mature bone trabeculae with a focal cartilaginous cap. Benign cartilaginous tumors have a slow, progressive course and do not show significant symptoms. However, tumors in subungual areas are accompanied by toenail deformities and they can cause pain. Their clinical characteristics lead to a delayed diagnosis. Surgeons can be confused between soft tissue and chondrogenic tumors. When they conduct physical examinations, these categories should be considered in the differential diagnosis.

Search for Subsolar-Mass Binaries in the First Half of Advanced LIGO's and Advanced Virgo's Third Observing Run

We report on a search for compact binary coalescences where at least one binary component has a mass between 0.2  M_{⊙} and 1.0  M_{⊙} in Advanced LIGO and Advanced Virgo data collected between 1 April 2019 1500 UTC and 1 October 2019 1500 UTC. We extend our previous analyses in two main ways: we include data from the Virgo detector and we allow for more unequal mass systems, with mass ratio q≥0.1. We do not report any gravitational-wave candidates. The most significant trigger has a false alarm rate of 0.14  yr^{-1}. This implies an upper limit on the merger rate of subsolar binaries in the range [220-24200]  Gpc^{-3} yr^{-1}, depending on the chirp mass of the binary. We use this upper limit to derive astrophysical constraints on two phenomenological models that could produce subsolar-mass compact objects. One is an isotropic distribution of equal-mass primordial black holes. Using this model, we find that the fraction of dark matter in primordial black holes in the mass range 0.2  M_{⊙}<m_{PBH}<1.0  M_{⊙} is f_{PBH}≡Ω_{PBH}/Ω_{DM}≲6%. This improves existing constraints on primordial black hole abundance by a factor of ∼3. The other is a dissipative dark matter model, in which fermionic dark matter can collapse and form black holes. The upper limit on the fraction of dark matter black holes depends on the minimum mass of the black holes that can be formed: the most constraining result is obtained at M_{min}=1  M_{⊙}, where f_{DBH}≡Ω_{DBH}/Ω_{DM}≲0.003%. These are the first constraints placed on dissipative dark models by subsolar-mass analyses.

Extracellular Vesicle-Based Bronchoalveolar Lavage Fluid Liquid Biopsy for EGFR Mutation Testing in Advanced Non-Squamous NSCLC

To overcome the limitations of the tissue biopsy and plasma cfDNA liquid biopsy, we performed the EV-based BALF liquid biopsy of 224 newly diagnosed stage III-IV NSCLC patients and compared it with tissue genotyping and 110 plasma liquid biopsies. Isolation of EVs from BALF was performed by ultracentrifugation. EGFR genotyping was performed through peptide nucleic acid clamping-assisted fluorescence melting curve analysis. Compared with tissue-based genotyping, BALF liquid biopsy demonstrated a sensitivity, specificity, and concordance rates of 97.8%, 96.9%, and 97.7%, respectively. The performance of BALF liquid biopsy was almost identical to that of standard tissue-based genotyping. In contrast, plasma cfDNA-based liquid biopsy (n = 110) demonstrated sensitivity, specificity, and concordance rates of 48.5%, 86.3%, and 63.6%, respectively. The mean turn-around time of BALF liquid biopsy was significantly shorter (2.6 days) than that of tissue-based genotyping (13.9 days; p < 0.001). Therefore, the use of EV-based BALF shortens the time for confirmation of EGFR mutation status for starting EGFR-TKI treatment and can hence potentially improve clinical outcomes. As a result, we suggest that EV-based BALF EGFR testing in advanced lung NSCLC is a highly accurate rapid method and can be used as an alternative method for lung tissue biopsy.

The ECHELON-2 Trial: 5-year results of a randomized, phase 3 study of brentuximab vedotin with chemotherapy for CD30-positive peripheral T-cell lymphoma

Background:

For patients with peripheral T-cell lymphoma (PTCL), outcomes using frontline treatment with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or CHOP-like therapy are typically poor. The ECHELON-2 study demonstrated that brentuximab vedotin plus cyclophosphamide, doxorubicin, and prednisone (A+CHP) exhibited statistically superior progression-free survival (PFS) per independent central review and improvements in overall survival versus CHOP for the frontline treatment of patients with systemic anaplastic large cell lymphoma or other CD30-positive PTCL.

Patients and methods:

ECHELON-2 is a double-blind, double-dummy, randomized, placebo-controlled, active-comparator phase III study. We present an exploratory update of the ECHELON-2 study, including an analysis of 5-year PFS per investigator in the intent-to-treat analysis group.

Results:

A total of 452 patients were randomized (1 : 1) to six or eight cycles of A+CHP (N = 226) or CHOP (N = 226). At median follow-up of 47.6 months, 5-year PFS rates were 51.4% [95% confidence interval (CI): 42.8% to 59.4%] with A+CHP versus 43.0% (95% CI: 35.8% to 50.0%) with CHOP (hazard ratio = 0.70; 95% CI: 0.53–0.91), and 5-year overall survival (OS) rates were 70.1% (95% CI: 63.3% to 75.9%) with A+CHP versus 61.0% (95% CI: 54.0% to 67.3%) with CHOP (hazard ratio = 0.72; 95% CI: 0.53–0.99). Both PFS and OS were generally consistent across key subgroups. Peripheral neuropathy was resolved or improved in 72% (84/117) of patients in the A+CHP arm and 78% (97/124) in the CHOP arm. Among patients who relapsed and subsequently received brentuximab vedotin, the objective response rate was 59% with brentuximab vedotin retreatment after A+CHP and 50% with subsequent brentuximab vedotin after CHOP.

Conclusions:

In this 5-year update of ECHELON-2, frontline treatment of patients with PTCL with A+CHP continues to provide clinically meaningful improvement in PFS and OS versus CHOP, with a manageable safety profile, including continued resolution or improvement of peripheral neuropathy.

Targeted Next-Generation Sequencing Analysis Predicts the Recurrence in Resected Lung Adenocarcinoma Harboring EGFR Mutations

Targeted NGS, widely applied to identify driver oncogenes in advanced lung adenocarcinoma, may also be applied to resected early stage cancers. We investigated resected EGFR-mutated lung adenocarcinoma mutation profiles to evaluate prognostic impacts. Tissues from 131 patients who had complete resection of stage I-IIIA EGFR-mutated lung adenocarcinoma were analyzed by targeted NGS for 207 cancer-related genes. Recurrence free survival (RFS) was estimated according to genetic alterations using the Kaplan-Meier method and Cox proportional regression analysis. The relapse rate was 25.2% (33/131). Five-year RFS of stages IA, IB, II, and IIIA were 82%, 75%, 35%, and 0%, respectively (p < 0.001). RFS decreased with the number of co-mutations (p = 0.025). Among co-mutations, the CTNNB1 mutation was associated with short RFS in a multivariate analysis (hazard ratio: 5.4, 95% confidence interval: 2.1-14.4; p = 0.001). TP53 mutations were associated with short RFS in stage IB-IIIA (p = 0.01). RFS was shorter with EGFR exon 19 deletion (19-del) than with mutation 21-L858R in stage IB-IIIA tumors (p = 0.008). Among 19-del subtypes, pL747_P753delinS (6/56, 8.9%) had shorter RFS than pE746_A750del (39/56, 69.6%), the most frequent subtype (p = 0.004).

Abstract 1196: BALF liquid biopsy provides a novel platform for speedy and accurate EGFR mutation testing in advanced NSCLC patients

Background

EGFR mutation testing is an essential step for the therapeutic decision in newly diagnosed advanced NSCLC patients and usually performed by using DNA extracted from biopsied tumor tissue with a turnaround time(TAT) of 2-3 weeks. Plasma liquid biopsy using ctDNA is minimally invasive and less time-consuming, but shows limited usefulness due to low sensitivity. We conducted a prospective study to demonstrate clinical usefulness of bronchoalveolar lavage fluid (BALF) liquid biopsy using extracellular vesicle(EV)-derived DNA in advanced NSCLC patients by comparing the sensitivity and TAT with conventional tissue biopsy and plasma liquid biopsy

Methods

The analysis set for liquid EGFR genotyping is 224 BALF samples and 110 plasma samples obtained from newly diagnosed 224 advanced non-squamous NSCLC patients. EGFR genotyping was done through peptide nucleic acid(PNA)-mediated real-time PCR after extracting BALF EV DNA and plasma cfDNA separately. The sensitivity, specificity, and concordance rate of BALF liquid biopsy were calculated in comparison to matched tissue genotyping and plasma liquid biopsy. In addition, TAT was compared between BALF liquid biopsy and tissue genotyping.

Results

Tissue genotyping revealed 93 EGFR mutant cases (41.5%) and 131 wild-type cases (58.5%). The sensitivity, specificity, positive predictive value, negative predictive value, and concordance rate of BALF liquid biopsy to tissue genotyping were 97.8%, 96.9%, 96.8%, 98.4%, and 97.7%, respectively. BALF liquid biopsy showed almost identical performance with standard tissue genotyping, while only 5 cases were mismatched each other. On the other hand, plasma liquid biopsy using cfDNA (n=110) revealed 48.5% sensitivity, 86.3% specificity, and 63.6% concordance rate in comparison to tissue genotyping. The mean turnaround times of BALF liquid biopsy was significantly shortened to 2.6±2.0 days in contrast to 13.9±12.4 days of tissue genotyping. (p&lt;0.001).

Conclusion

BALF liquid biopsy can be developed as a novel platform for EGFR mutation testing in advanced NSCLC with almost identical performance with conventional tissue genotyping and significantly shorten TAT to 1-2 days.

Citation Format: In Ae Kim, Jae Young Hur, Hee Joung Kim, Wan Seop Kim, Kye Young Lee. BALF liquid biopsy provides a novel platform for speedy and accurate EGFR mutation testing in advanced NSCLC patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1196.

Targeted Next-Generation Sequencing Analysis for Recurrence in Early-Stage Lung Adenocarcinoma

BACKGROUND

Despite surgical resection, early lung adenocarcinoma has a recurrence rate of 20-50%. No clear predictive markers for recurrence of early lung adenocarcinoma are available. Targeted next-generation sequencing (NGS) is rarely used to identify recurrence-related genes. We aimed to identify genetic alterations that can predict recurrence, by comparing the molecular profiles of patient groups with and without recurrence.

METHODS

Tissues from 230 patients with resected stage I-II lung adenocarcinoma (median follow-up: 49 months) were analyzed via targeted NGS for 207 cancer-related genes. The recurrence-free survival according to the number and type of mutation was estimated using the Kaplan-Meier method. Independent predictive biomarkers related to recurrence were identified using the Cox proportional hazards model.

RESULTS

Recurrence was observed in 64 patients (27.8%). In multivariate analysis adjusted for age, sex, smoking history, stage, surgical mode, and visceral pleural invasion, the CTNNB1 mutation and fusion genes (ALK, ROS1, RET) were negative prognostic factors for recurrence in early-stage lung adenocarcinoma (HR 4.47, p = 0.001; HR 2.73, p = 0.009). EGFR mutation was a favorable factor (HR 0.51, p = 0.016), but the CTNNB1/EGFR co-mutations were negative predictors (HR 19.2, p < 0.001). TP53 mutation was a negative predictor compared with EGFR mutation for recurrence (HR 5.24, p = 0.02).

CONCLUSIONS

Targeted NGS can provide valuable information to predict recurrence and identify patients at high recurrence risk, facilitating selection of the treatment strategy among close monitoring and adjuvant-targeted therapy. Larger datasets are required to validate these findings.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Programmed Death Ligand 1 Immunohistochemistry in Triple-Negative Breast Cancer: Evaluation of Inter-Pathologist Concordance and Inter-Assay Variability

Purpose

The programmed death ligand 1 (PD-L1) SP142 assay with a 1% immune cell (IC) cutoff is approved for the selection of advanced triple-negative breast cancer (TNBC) patients for atezolizumab treatment. We aimed to evaluate the interobserver concordance of PD-L1 scoring and inter-assay variability of various PD-L1 assays in TNBC.

Methods

Thirty patients with primary TNBC were selected, and SP142, SP263, 22C3, and E1L3N assays were performed. PD-L1 staining in ICs and tumor cells (TCs) was scored by 10 pathologists who were blinded to the assay. The interobserver concordance among pathologists and the inter-assay variability of the four PD-L1 assays were analyzed. For SP142, the intraobserver concordance among the six pathologists was analyzed after training.

Results

The adjusted means of PD-L1 IC scoring ranged from 6.2% to 12.9% for the four assays; the intraclass correlations showed moderate (0.584–0.649) reader concordance. The PD-L1 IC scoring with a 1% cutoff resulted in identical scoring in 40.0%–66.7% of cases and a poor to moderate agreement (Fleiss κ statistic [FKS] = 0.345–0.534) for the four assays. The SP142 assay had the widest range of positive rate (56.5%–100.0%), lowest number of cases with identical scoring, and lowest FKS at 1% cutoff. Pairwise comparison of adjusted means showed significantly decreased PD-L1 staining in SP142 compared with the other assays in both ICs and TCs. As for the intraobserver concordance in the SP142 assay, the overall percent agreement was 87.8% with a 1% IC cutoff. After training, the proportion of cases with identical scoring at a 1% IC cutoff increased to 70.0%; the FKS also increased to 0.610.

Conclusion

The concordance of PD-L1 IC scoring among pathologists was low, at the 1% cutoff for the SP142 assay without training. SP142 showed the lowest PD-L1 expression in both IC and TC.

Molecular biomarker testing for non-small cell lung cancer: consensus statement of the Korean Cardiopulmonary Pathology Study Group

Molecular biomarker testing is the standard of care for non–small cell lung cancer (NSCLC) patients. In 2017, the Korean Cardiopulmonary Pathology Study Group and the Korean Molecular Pathology Study Group co-published a molecular testing guideline which contained almost all known genetic changes that aid in treatment decisions or predict prognosis in patients with NSCLC. Since then there have been significant changes in targeted therapies as well as molecular testing including newly approved targeted drugs and liquid biopsy. In order to reflect these changes, the Korean Cardiopulmonary Pathology Study Group developed a consensus statement on molecular biomarker testing. This consensus statement was crafted to provide guidance on what genes should be tested, as well as methodology, samples, patient selection, reporting and quality control.

Comprehensive Analysis of Cardiac Xeno-Graft Unveils Rejection Mechanisms

Porcine heart xenotransplantation is a potential treatment for patients with end-stage heart failure. To understand molecular mechanisms of graft rejection after heart transplantation, we transplanted a 31-day-old alpha-1,3-galactosyltransferase knockout (GTKO) porcine heart to a five-year-old cynomolgus monkey. Histological and transcriptome analyses were conducted on xenografted cardiac tissue at rejection (nine days after transplantation). The recipient monkey's blood parameters were analyzed on days -7, -3, 1, 4, and 7. Validation was conducted by quantitative real-time PCR (qPCR) with selected genes. A non-transplanted GTKO porcine heart from an age-matched litter was used as a control. The recipient monkey showed systemic inflammatory responses, and the rejected cardiac graft indicated myocardial infarction and cardiac fibrosis. The transplanted heart exhibited a total of 3748 differentially expressed genes compared to the non-transplanted heart transcriptome, with 2443 upregulated and 1305 downregulated genes. Key biological pathways involved at the terminal stage of graft rejection were cardiomyopathies, extracellular interactions, and ion channel activities. The results of qPCR evaluation were in agreement with the transcriptome data. Transcriptome analysis of porcine cardiac tissue at graft rejection reveals dysregulation of the key molecules and signaling pathways, which play relevant roles on structural and functional integrities of the heart.

Genomic profiling of extracellular vesicle-derived DNA from bronchoalveolar lavage fluid of patients with lung adenocarcinoma

Background

Extracellular vesicles (EVs) are membrane-bound and nanometer-sized particles released from most types of cells, containing double-stranded DNA reflecting mutational status of the parental tumor cells. Furthermore, epidermal growth factor receptor (EGFR) genotyping using EV-derived DNA (EV DNA) in bronchoalveolar lavage fluid (BALF) showed almost 100% sensitivity in patients with advanced non-small cell lung cancer (NSCLC).

Methods

We assessed the technical performance of DNA derived from BALF-EV (BALF EV DNA) in targeted next-generation sequencing (NGS) for detection and quantification of mutations compared with the matching tissue DNA in 20 lung adenocarcinomas.

Results

DNA yields, tumor purity, and depth of coverage were higher using the tissue DNA than using the BALF EV DNA. However, estimated library size was not significantly different between the two samples, and BALF EV DNA yielded longer fragments than tissue DNA. Overall mutation concordance between the two samples were 56% for nonsynonymous somatic mutations and increased to 81% for clinically significant mutations. By-variant sensitivity for clinically significant somatic mutations increased from 62% to 83% in the NGS of BALF EV DNA. Allele frequencies of EGFR and TP53 were higher in tissue DNA (10–25%) than in BALF EV DNA (<5%). Tumor mutation burden of BALF EV DNA correlated with that of tissue DNA.

Conclusions

Our findings demonstrate, for the first time, that BALF EV DNA in patients with NSCLC can be a reliable DNA source for targeted NGS for the identification of actionable genetic alterations and that this approach has high clinical feasibility and utility.

Association between depression and hostile attribution bias in hostile and non-hostile individuals: An ERP study

BACKGROUND

Hostility and aggression have been found to be highly prevalent among depressed patients and are associated with higher comorbidity and illness severity levels. Although negative interpretation biases are a fundamental element of cognitive models of depression, few studies have examined the specific biases in information processing, mainly the hostile attribution bias, found in hostile individuals who present depressive symptoms.

METHOD

Using pre-collected data from a sample of 72 (male=41,6%, female=58,3%) undergraduate and community-based hostile (n = 26) and non-hostile (n = 46) adult participants, the authors aimed to examine the association between depression and the hostile attribution bias by determining whether depression level scores were uniquely related to electrophysiological measures of the hostile attribution bias.

RESULTS

The hostile group showed higher measured levels of depression and reactive aggression compared to the non-hostile group. Also, depression scores were significant predictors of the N400 effect in the non-hostile task condition, while reactive aggression was not, whereas in the hostile condition, the overall model was significant, with depression and reactive aggression levels both showing strong trends towards significance.

LIMITATIONS

A small sample size limited the scope of our conclusions. Also, sample selection prevented us from examining specific group differences regarding the hostile attribution bias in depressed and non-depressed groups.

CONCLUSION

Clinical and research implications include the necessity to apply cognitive restructuring techniques to counter biased interpretation processes in settings where depression and aggression intersect, and the need to consider alternatives to self-evaluative methodologies.

Liquid biopsy using extracellular vesicle-derived DNA in lung adenocarcinoma

Blood liquid biopsy has emerged as a way of overcoming the clinical limitations of repeat biopsy by testing for the presence of acquired resistance mutations to therapeutic agents. Despite its merits of repeatability and non-invasiveness, this method is currently only used as a supplemental test due to a relatively low sensitivity rate of 50%–60%, and cannot replace tissue biopsy. The circulating tumor DNAs used in blood liquid biopsies are passive products of fragmented DNA with a short half-life released following tumor cell death; the low sensitivity seen with liquid blood biopsy results from this instability, which makes increasing the sensitivity of this test fundamentally difficult. Extracellular vesicles (EVs) are ideal carriers of cancer biomarkers, as cancer cells secret an abundance of EVs, and the contents of tumor cell-originated EVs reflect the molecular and genetic composition of parental cells. In addition, EV-derived DNAs (EV DNAs) consist of large-sized genomic DNAs and tumor-specific oncogenic mutant DNAs. For these reasons, liquid biopsy using EV DNA has the potential to overcome issues arising from tissue shortages associated with small biopsies, which are often seen in lung cancer patients, and the biopsy product can be used in other diagnostic methods, such as epidermal growth factor receptor (EGFR) mutation testing and next-generation sequencing (NGS). A higher sensitivity can be achieved when EV DNAs obtained from bronchoalveolar lavage fluid (BALF) are used rather than those from blood. BALF, when obtained close to the tumor site, is a promising liquid biopsy tool, as it enables the gathering of both cellular and non-cellular fractions of the tumor microenvironment, and provides increased diagnostic sensitivity when compared to blood.

GW190521: A Binary Black Hole Merger with a Total Mass of 150 M_{⊙}

On May 21, 2019 at 03:02:29 UTC Advanced LIGO and Advanced Virgo observed a short duration gravitational-wave signal, GW190521, with a three-detector network signal-to-noise ratio of 14.7, and an estimated false-alarm rate of 1 in 4900 yr using a search sensitive to generic transients. If GW190521 is from a quasicircular binary inspiral, then the detected signal is consistent with the merger of two black holes with masses of 85_{-14}^{+21}  M_{⊙} and 66_{-18}^{+17}  M_{⊙} (90% credible intervals). We infer that the primary black hole mass lies within the gap produced by (pulsational) pair-instability supernova processes, with only a 0.32% probability of being below 65  M_{⊙}. We calculate the mass of the remnant to be 142_{-16}^{+28}  M_{⊙}, which can be considered an intermediate mass black hole (IMBH). The luminosity distance of the source is 5.3_{-2.6}^{+2.4}  Gpc, corresponding to a redshift of 0.82_{-0.34}^{+0.28}. The inferred rate of mergers similar to GW190521 is 0.13_{-0.11}^{+0.30}  Gpc^{-3} yr^{-1}.

Abstract 5896: Targeted NGS analysis to predict recurrence in resected EGFR- mutated lung adenocarcinoma

Background: Targeted next-generation sequencing (NGS) is widely applied in personalized therapy of NSCLC patients by identifying driver oncogenes. Another important application of targeted NGS analysis is to predict recurrence in resected early stage NSCLC patients. We investigated targeted NGS analysis to identify the genetic alterations related to the recurrence in resected EGFR-mutated lung adenocarcinoma.

Methods: Tissues from 130 patients who had complete resection of stage I to IIIA EGFR mutated adenocarcinoma (median follow-up: 45 months), were analyzed by targeted NGS with 170 cancer-related genes. The DFS according to the numbers and types of gene alterations were estimated using the Kaplan-Meier method. The independent biomarkers related to recurrence were identified by Cox proportional hazard regression analysis.

Results: The relapses after surgical resections were observed in 32 patients of 130 (24.6%). The relapses were associated not with sex and smoking history but with visceral-pleural invasion (p=0.001), lympho-vascular invasion (p=0.002), and stage(p=0.001). Relapse rates were increased in order by L858R (11/59, 18.6%), exon 19 deletion (16/56, 28.6%), compound EGFR mutation (3/10, 30%) and exon 20 mutation (2/5, 40%), but there was no statistical difference. 13 of 16 (81%) relapse patients with 19 deletion had E746_A750 del. It indicates that the hot spot of exon 19 deletion related to recurrence is E746_A750 del. In the aspect of the number of mutations, the patients with single mutation were 68(51.5%). 44(33.8%) had dual mutation, 13(10.8%) had triple mutation. DFS was associated with the number of genetic mutations (p=0.025). The 5-year DFS rates were 83%, 62% and 25% for single, dual and triple mutation respectively(p&lt;0.001). Besides, we found the CTNNB1 mutation was associated with worse DFS in a multivariate analysis adjusted by sex, age, stage, smoking history and operation methods (hazard ratio [HR]: 5.4, 95% confidence interval: 2.1-14.4; p=0.001). The patients with CTNNB1/EGFR co-mutation were expected to have shorter DFS than the patients with single EGFR mutation (p=0.003).

Conclusions: The number of co-occurring mutations, CTNNB1 mutation and del E746_A750 in exon19 was negative prognostic factors for DFS in resected EGFR-mutated lung adenocarcinoma. We recommend that the targeted NGS should be performed to identify the genetic alterations so we can predict the outcome and plan adjuvant chemotherapy or EGFR tyrosine kinase inhibitor therapy to patients with a higher risk of recurrence.

Citation Format: In Ae Kim, Hee Jung Kim, Jae Young Hur, Seung En Lee, Jung Hoon Park, Song Am Lee, Jae Jun Hwang, Wan Seop Kim, Kye Young Lee. Targeted NGS analysis to predict recurrence in resected EGFR- mutated lung adenocarcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5896.

Concordance of Programmed Death-Ligand 1 Expression between SP142 and 22C3/SP263 Assays in Triple-Negative Breast Cancer

PURPOSE

Triple-negative breast cancer (TNBC) represents a major clinical challenge due to its aggressive and metastatic behavior and the lack of available targeted therapies. Therefore, therapeutic strategies are needed to improve TNBC patient management. Recently, atezolizumab and nab-paclitaxel chemotherapy has been approved by the Food and Drug Administration for the first-line treatment of patients with locally advanced and metastatic TNBC. The programmed death-ligand 1 (PD-L1) immunohistochemical SP142 assay was also approved as a companion diagnostic device for selecting TNBC patients for atezolizumab treatment. This study aimed to evaluate and compare the analytical performance of the PD-L1 22C3/SP263 assays in comparison with the SP142 assay for ≥ 1% immune cells (ICs).

METHODS

Immunohistochemical expression for the PD-L1 22C3/SP263 assays, in comparison with the SP142 assay, was analyzed for the ≥ 1% ICs in 95 TNBCs.

RESULTS

At the 1% cut-off value, the proportions of positive cases were 52.6% for the SP142 assay in infiltrating ICs and 50.5% and 52.6% for the 22C3 and SP263 assays in tumor cells, respectively. The PD-L1 SP263 assay had the highest while the PD-L1 22C3 assay had the lowest total positive expression rate at all cut-off values. The concordance rate between the assays was highest at a 1% cut-off value and decreased when the cut-off value increased. The concordance rate between the SP142 and SP263 assays at 1% cut-off was high, while in comparison, the concordance rate between the SP142 and 22C3 assays at 1% cut-off was relatively lower.

CONCLUSION

This study demonstrates that although the 22C3 assay at a 1% cut-off value compared with the PD-L1 SP142 assay at the clinically relevant cut-off shows comparable but not interchangeable analytical performance, the analytical performance of the SP263 assay at a 1% cut-off value shows interchangeable performance with the PD-L1 SP142 assay at the clinically relevant cut-off.

Current status and future perspectives of liquid biopsy in non-small cell lung cancer

With advances in target therapy, molecular analysis of tumors is routinely required for treatment decisions in patients with advanced non-small cell lung cancer (NSCLC). Liquid biopsy refers to the sampling and analysis of circulating cell-free tumor DNA (ctDNA) in various body fluids, primarily blood. Because the technique is minimally invasive, liquid biopsies are the future in cancer management. Epidermal growth factor receptor (EGFR) ctDNA tests have been performed in routine clinical practice in advanced NSCLC patients to guide tyrosine kinase inhibitor treatment. In the near future, liquid biopsy will be a crucial prognostic, predictive, and diagnostic method in NSCLC. Here we present the current status and future perspectives of liquid biopsy in NSCLC.

Tannic Acid Promotes TRAIL-Induced Extrinsic Apoptosis by Regulating Mitochondrial ROS in Human Embryonic Carcinoma Cells

: Human embryonic carcinoma (EC; NCCIT) cells have self-renewal ability and pluripotency. Cancer stem cell markers are highly expressed in NCCIT cells, imparting them with the pluripotent nature to differentiate into other cancer types, including breast cancer. As one of the main cancer stem cell pathways, Wnt/β-catenin is also overexpressed in NCCIT cells. Thus, inhibition of these pathways defines the ability of a drug to target cancer stem cells. Tannic acid (TA) is a natural polyphenol present in foods, fruits, and vegetables that has anti-cancer activity. Through Western blotting and PCR, we demonstrate that TA inhibits cancer stem cell markers and the Wnt/β-catenin signaling pathway in NCCIT cells and through a fluorescence-activated cell sorting analysis we demonstrated that TA induces sub-G1 cell cycle arrest and apoptosis. The mechanism underlying this is the induction of mitochondrial reactive oxygen species (ROS) (mROS), which then induce the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated extrinsic apoptosis pathway instead of intrinsic mitochondrial apoptosis pathway. Moreover, ribonucleic acid sequencing data with TA in NCCIT cells show an elevation in TRAIL-induced extrinsic apoptosis, which we confirm by Western blotting and real-time PCR. The induction of human TRAIL also proves that TA can induce extrinsic apoptosis in NCCIT cells by regulating mROS.

Extracellular vesicle-based EGFR genotyping in bronchoalveolar lavage fluid from treatment-naive non-small cell lung cancer patients

Background

Extracellular vesicles (EV) have been proven to contain double-stranded DNA reflecting the mutational status of the parental tumor cells in non-small cell lung cancer (NSCLC), which can be translated into clinically useful EV-based liquid biopsy for Epidermal growth factor receptor (EGFR) genotyping using bronchoalveolar lavage fluid (BALF) obtained from tumor site.

Methods

Patients subjected for an initial lung cancer work-up underwent bronchoscopy and BALF was obtained from tumor site. After isolating EVs from BALF by ultracentrifugation, EV-derived DNA (EV DNA) was extracted for subsequent EGFR genotyping performed through peptide nucleic acid (PNA)-mediated Real-Time PCR. The sensitivity, specificity, and concordance rate of BALF EV-based EGFR genotyping were calculated in comparison to tissue genotyping.

Results

The average sensitivity and specificity of BALF EV-based EGFR genotyping were 76% and 87%, respectively, while the sensitivity significantly increased as the stage progressed. Especially, in stage IV, BALF EV-based EGFR typing identified all tissue-proven EGFR mutant cases (n=31) and detected 6 additional mutant cases. The concordance rate was 79% in stage I, 100% in stage II, 74% in stage III, and 92% in stage IV. As TNM stage advanced, especially in the presence of metastasis, concordance rate significantly increased (P<0.05).

Conclusions

The use of BALF for the collection of EV DNA in lung cancer patients resulted in a highly accurate diagnosis. The establishment of a fast and reliable method to identify target genes using EV DNA illustrated that it can overcome the problems of low sensitivity and instability in using cell-free DNA (cfDNA).

Search for Subsolar Mass Ultracompact Binaries in Advanced LIGO's Second Observing Run

We present a search for subsolar mass ultracompact objects in data obtained during Advanced LIGO's second observing run. In contrast to a previous search of Advanced LIGO data from the first observing run, this search includes the effects of component spin on the gravitational waveform. We identify no viable gravitational-wave candidates consistent with subsolar mass ultracompact binaries with at least one component between 0.2  M_{⊙}-1.0  M_{⊙}. We use the null result to constrain the binary merger rate of (0.2  M_{⊙}, 0.2  M_{⊙}) binaries to be less than 3.7×10^{5}  Gpc^{-3} yr^{-1} and the binary merger rate of (1.0  M_{⊙}, 1.0  M_{⊙}) binaries to be less than 5.2×10^{3}  Gpc^{-3} yr^{-1}. Subsolar mass ultracompact objects are not expected to form via known stellar evolution channels, though it has been suggested that primordial density fluctuations or particle dark matter with cooling mechanisms and/or nuclear interactions could form black holes with subsolar masses. Assuming a particular primordial black hole (PBH) formation model, we constrain a population of merging 0.2  M_{⊙} black holes to account for less than 16% of the dark matter density and a population of merging 1.0  M_{⊙} black holes to account for less than 2% of the dark matter density. We discuss how constraints on the merger rate and dark matter fraction may be extended to arbitrary black hole population models that predict subsolar mass binaries.

Tests of General Relativity with GW170817

The recent discovery by Advanced LIGO and Advanced Virgo of a gravitational wave signal from a binary neutron star inspiral has enabled tests of general relativity (GR) with this new type of source. This source, for the first time, permits tests of strong-field dynamics of compact binaries in the presence of matter. In this Letter, we place constraints on the dipole radiation and possible deviations from GR in the post-Newtonian coefficients that govern the inspiral regime. Bounds on modified dispersion of gravitational waves are obtained; in combination with information from the observed electromagnetic counterpart we can also constrain effects due to large extra dimensions. Finally, the polarization content of the gravitational wave signal is studied. The results of all tests performed here show good agreement with GR.

Provisional Guideline Recommendation for EGFR Gene Mutation Testing in Liquid Samples of Lung Cancer Patients: A Proposal by the Korean Cardiopulmonary Pathology Study Group

Liquid biopsy for detection of mutation from circulating tumor DNA is a new technology which is attractive in that it is non-invasive. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) is an effective first line drug for advanced non-small cell lung cancer patients who harbor activating EGFR mutation. During the course of treatment, resistance against TKI arises which can be contributed to EGFR T790M mutation in about 50-60% of patients. Third generation TKI may overcome the resistance. In patients who cannot undergo tissue biopsy due to variable reasons, liquid biopsy is an excellent alternative for the detection of EGFR T790M mutation. However, this relatively novel method requires standardization and vigorous quality insurance. Thus, a standard set of guideline recommendations for liquid biopsy for EGFR mutation testing suitable for the Korean medical community is necessary. In this article, we propose a set of provisional guideline recommendations that was discussed and approved by the Cardiopulmonary Pathology Study Group of the Korean Society of Pathologists.

Constraining the p-Mode-g-Mode Tidal Instability with GW170817

We analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy from the orbit of the binary to internal modes of the stars, accelerating the gravitational-wave driven inspiral. We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: an overall amplitude, a saturation frequency, and a spectral index. Incorporating these additional parameters, we compute the Bayes factor (lnB_{!pg}^{pg}) comparing our p-g model to a standard one. We find that the observed signal is consistent with waveform models that neglect p-g effects, with lnB_{!pg}^{pg}=0.03_{-0.58}^{+0.70} (maximum a posteriori and 90% credible region). By injecting simulated signals that do not include p-g effects and recovering them with the p-g model, we show that there is a ≃50% probability of obtaining similar lnB_{!pg}^{pg} even when p-g effects are absent. We find that the p-g amplitude for 1.4  M_{⊙} neutron stars is constrained to less than a few tenths of the theoretical maximum, with maxima a posteriori near one-tenth this maximum and p-g saturation frequency ∼70  Hz. This suggests that there are less than a few hundred excited modes, assuming they all saturate by wave breaking. For comparison, theoretical upper bounds suggest ≲10^{3} modes saturate by wave breaking. Thus, the measured constraints only rule out extreme values of the p-g parameters. They also imply that the instability dissipates ≲10^{51}  erg over the entire inspiral, i.e., less than a few percent of the energy radiated as gravitational waves.

Liquid biopsy using the supernatant of a pleural effusion for EGFR genotyping in pulmonary adenocarcinoma patients: a comparison between cell-free DNA and extracellular vesicle-derived DNA

BACKGROUND

EGFR genotyping in pulmonary adenocarcinoma patients who develop pleural effusions is mostly performed using cytology or cell block slides with low sensitivity. Liquid biopsy using the supernatant of pleural effusions may be more effective because they contain many components released by cancer cells. Extracellular vesicles (EVs) are known to carry oncogenic double-stranded DNA that is considered a notable biomarker. Here, we investigate the efficiency of liquid biopsy using cell-free DNA (cfDNA) and extracellular vesicle-derived DNA (EV-derived DNA) from the supernatant of pleural effusions for EGFR genotyping in patients with pulmonary adenocarcinoma.

METHODS

Fifty pleural effusion samples from patients with pulmonary adenocarcinoma were evaluated. The supernatant, after removing the cell pellet by centrifugation, was used for liquid biopsy, and EVs were isolated from the pleural effusion by ultracentrifugation. EV-derived DNA and cfDNA were extracted separately, and EGFR genotyping was performed by the PNA clamping method.

RESULTS

Among 32 patients who were EGFR-tyrosine kinase inhibitor (TKI) naïve with a known tissue EGFR genotype, liquid biopsy using EV-derived DNA from the pleural effusion supernatant showed 100% matching results with tissue EGFR genotyping in 19 EGFR mutant cases and detected three additional EGFR mutations in patients with wild-type (WT) tissue. Liquid biopsy using cfDNA from pleural effusion supernatants missed two cases of tissue-based EGFR mutations and found two additional EGFR mutation cases. In 18 patients who acquired resistance to EGFR-TKI, EGFR genotyping using EV-derived DNA from the pleural effusion supernatant detected the T790 M mutation in 13 of 18 (72.2%) patients, and this mutation was detected in 11 (61.1%) patients using cfDNA. By contrast, only three patients were found to present the T790 M mutation when using cell block or cytology slides.

CONCLUSIONS

Liquid biopsy using the supernatant of pleural effusions showed significantly improved results for EGFR genotyping compared to those using conventional cell block or cytology samples. Liquid biopsy using EV-derived DNA is promising for EGFR genotyping, including T790 M detection in pulmonary adenocarcinoma patients who develop pleural effusions.

Search for Subsolar-Mass Ultracompact Binaries in Advanced LIGO's First Observing Run

We present the first Advanced LIGO and Advanced Virgo search for ultracompact binary systems with component masses between 0.2  M_{⊙}-1.0  M_{⊙} using data taken between September 12, 2015 and January 19, 2016. We find no viable gravitational wave candidates. Our null result constrains the coalescence rate of monochromatic (delta function) distributions of nonspinning (0.2  M_{⊙}, 0.2  M_{⊙}) ultracompact binaries to be less than 1.0×10^{6}  Gpc^{-3}  yr^{-1} and the coalescence rate of a similar distribution of (1.0  M_{⊙}, 1.0  M_{⊙}) ultracompact binaries to be less than 1.9×10^{4}  Gpc^{-3}  yr^{-1} (at 90% confidence). Neither black holes nor neutron stars are expected to form below ∼1  M_{⊙} through conventional stellar evolution, though it has been proposed that similarly low mass black holes could be formed primordially through density fluctuations in the early Universe and contribute to the dark matter density. The interpretation of our constraints in the primordial black hole dark matter paradigm is highly model dependent; however, under a particular primordial black hole binary formation scenario we constrain monochromatic primordial black hole populations of 0.2  M_{⊙} to be less than 33% of the total dark matter density and monochromatic populations of 1.0  M_{⊙} to be less than 5% of the dark matter density. The latter strengthens the presently placed bounds from microlensing surveys of massive compact halo objects (MACHOs) provided by the MACHO and EROS Collaborations.

GW170817: Measurements of Neutron Star Radii and Equation of State

On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were neutron stars that are described by the same equation of state and have spins within the range observed in Galactic binary neutron stars. Our analysis employs two methods: the use of equation-of-state-insensitive relations between various macroscopic properties of the neutron stars and the use of an efficient parametrization of the defining function p(ρ) of the equation of state itself. From the LIGO and Virgo data alone and the first method, we measure the two neutron star radii as R_{1}=10.8_{-1.7}^{+2.0}  km for the heavier star and R_{2}=10.7_{-1.5}^{+2.1}  km for the lighter star at the 90% credible level. If we additionally require that the equation of state supports neutron stars with masses larger than 1.97  M_{⊙} as required from electromagnetic observations and employ the equation-of-state parametrization, we further constrain R_{1}=11.9_{-1.4}^{+1.4}  km and R_{2}=11.9_{-1.4}^{+1.4}  km at the 90% credible level. Finally, we obtain constraints on p(ρ) at supranuclear densities, with pressure at twice nuclear saturation density measured at 3.5_{-1.7}^{+2.7}×10^{34}  dyn cm^{-2} at the 90% level.

Cumulative smoking dose affects the clinical outcomes of EGFR-mutated lung adenocarcinoma patients treated with EGFR-TKIs: a retrospective study

Background

Although lung adenocarcinoma with activating epidermal growth factor receptor (EGFR) mutations is common in never smokers, one-third of the patients are ever-smokers. We aimed to investigate the effect of cumulative smoking dose(CSD) on clinical outcomes, including progression-free survival (PFS) and overall survival (OS), in patients with EGFR-mutated lung adenocarcinoma receiving EGFR-tyrosine kinase inhibitors (TKIs).

Methods

We retrospectively analyzed 142 patients with EGFR-mutation positive advanced or recurrent lung adenocarcinoma who were administered gefitinib, erlotinib, afatinib, and osimertinib. These patients were classified based on their CSD as never smokers, light smokers (≤10 pack-years [PYs]), moderate smokers (11–30 PYs), and heavy smokers (> 30 PYs). PFS and OS were analyzed according to smoking subgroups via Kaplan-Meier curves.

Results

Among the 142 patients, 91 (64.1%), 12 (8.5%), 22 (15.5%), and 17 (12%) were never, light, moderate, and heavy smokers, respectively. CSD was inversely associated with median PFS in a statistically significant dose-dependent manner (11.8 months (mo), 11.0 mo, 7.4 mo, and 3.9 mo; p < 0.001). Statistically significant negative association was observed between CSD and median OS (33.6 mo, 26.3 mo, 20 mo, and 8.9 mo; p < 0.001). In the multivariate analysis adjusted for age, sex, performance status, stage, and timing of EGFR-TKIs, CSD was an independent predictive factor for disease progression (hazard ratio [HR], 4.00; 95% confidence interval [CI], 1.95–8.23; p = 0.012) and OS (HR, 3.9; 95% CI, 1.84–8.28; p < 0.001).

Conclusion

CSD is an important predictive and prognostic factor in patients with EGFR-mutated lung adenocarcinoma, and associated smoking-related gene signatures might affect the outcomes.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4691-0) contains supplementary material, which is available to authorized users.

Beyond first-line non-anthracycline-based chemotherapy for extranodal NK/T-cell lymphoma: clinical outcome and current perspectives on salvage therapy for patients after first relapse and progression of disease

Background

Current standard treatment, including non-anthracycline-based chemotherapy and optimal combining of radiotherapy, has dramatically improved outcomes of patients with extranodal natural killer/T-cell lymphoma (ENKTL) during the last decade. This study was conducted to investigate the clinical outcome of ENKTL patients with relapsed or progressive disease after initial current standard therapy.

Patients and methods

We retrospectively reviewed patients diagnosed with ENKTL at six centers in four countries (China, France, Singapore, and South Korea) from 1997 to 2015 and analyzed 179 patients who had relapsed or progressed after initial current standard therapy.

Results

After a median follow-up of 58.6 months (range 27.9-89.2), the median second progression-free survival (PFS) was 4.1 months [95% confidence interval (CI) 3.04-5.16] and overall survival (OS) was 6.4 months (95% CI 4.36-8.51). Multivariate Cox-regression analysis revealed that elevated lactate dehydrogenase, multiple extranodal sites (≥2), and presence of B symptoms were associated with inferior OS (P < 0.05). OS and PFS were significantly different according to both prognostic index of natural killer lymphoma (PINK) and PINK-E (Epstein-Barr virus) models. Salvage chemotherapy with l-asparaginase (l-Asp)-based regimens showed a significantly better clinical benefit to response rate and PFS, although it did not lead to OS improvement. First use of l-Asp in the salvage setting and l-Asp rechallenge at least 6 months after initial treatment were the best candidates for salvage l-Asp containing chemotherapy.

Conclusions

Most patients with relapsed or refractory ENKTL had poor prognosis with short survival. Further studies are warranted to determine the optimal treatment of patients with relapsed or refractory ENKTL.

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω_{0}^{T}<5.58×10^{-8}, Ω_{0}^{V}<6.35×10^{-8}, and Ω_{0}^{S}<1.08×10^{-7} at a reference frequency f_{0}=25  Hz.

GW170817: Implications for the Stochastic Gravitational-Wave Background from Compact Binary Coalescences

The LIGO Scientific and Virgo Collaborations have announced the event GW170817, the first detection of gravitational waves from the coalescence of two neutron stars. The merger rate of binary neutron stars estimated from this event suggests that distant, unresolvable binary neutron stars create a significant astrophysical stochastic gravitational-wave background. The binary neutron star component will add to the contribution from binary black holes, increasing the amplitude of the total astrophysical background relative to previous expectations. In the Advanced LIGO-Virgo frequency band most sensitive to stochastic backgrounds (near 25 Hz), we predict a total astrophysical background with amplitude Ω_{GW}(f=25  Hz)=1.8_{-1.3}^{+2.7}×10^{-9} with 90% confidence, compared with Ω_{GW}(f=25  Hz)=1.1_{-0.7}^{+1.2}×10^{-9} from binary black holes alone. Assuming the most probable rate for compact binary mergers, we find that the total background may be detectable with a signal-to-noise-ratio of 3 after 40 months of total observation time, based on the expected timeline for Advanced LIGO and Virgo to reach their design sensitivity.

Frequent somatic TERT promoter mutations and CTNNB1 mutations in hepatocellular carcinoma

Genetic alterations of TERT and CTNNB1 have been documented in hepatocellular carcinoma. TERT promoter mutations are the earliest genetic events in the multistep process of hepatocarcinogenesis related to cirrhosis. However, analyses of TERT promoter and CTNNB1 mutations in hepatocellular carcinoma tumor samples have not been performed in the Korean population, where hepatitis B virus-related hepatocellular carcinoma is prevalent. In order to identify the role of TERT promoter and CTNNB1 mutations in the hepatocarcinogenesis and pathogenesis of recurrent hepatocellular carcinoma, we performed the sequence analyses in 140 hepatocellular nodules (including 107 hepatocellular carcinomas), and 8 pairs of matched primary and relapsed hepatocellular carcinomas. TERT promoter and CTNNB1 mutations were only observed in hepatocellular carcinomas but not in precursor lesions. Of 109 patients with hepatocellular carcinoma, 41 (39.0%) and 15 (14.6%) harbored TERT and CTNNB1 mutations, respectively. TERT promotermutations were significantly more frequent in hepatocellular carcinomas related to hepatitis C virus infection (5/6; 83.3%) compared to tumors of other etiologies (P = 0.001). In two cases, discordance in TERT promoter mutation status was observed between the primary and the corresponding recurrent hepatocellular carcinoma. The two patients with discordant cases had early relapses. In conclusion, we identified TERT promoter and CTNNB1 mutations as the most frequent somatic genetic alterations observed in hepatocellular carcinoma, indicating its pivotal role in hepatocarcinogenesis. Furthermore, we suggest the possibility of intratumoral genetic heterogeneity of TERT promoter mutations in hepatocellular carcinoma as indicated by the discordance in TERT promoter mutations between primary and corresponding recurrent hepatocellular carcinoma.

First Search for Nontensorial Gravitational Waves from Known Pulsars

We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper limits for scalar and vector strains, finding values comparable in magnitude to previously published limits for tensor strain. Our results may be translated into constraints on specific alternative theories of gravity.

GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral

On August 17, 2017 at 12∶41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per 8.0×10^{4}  years. We infer the component masses of the binary to be between 0.86 and 2.26  M_{⊙}, in agreement with masses of known neutron stars. Restricting the component spins to the range inferred in binary neutron stars, we find the component masses to be in the range 1.17-1.60  M_{⊙}, with the total mass of the system 2.74_{-0.01}^{+0.04}M_{⊙}. The source was localized within a sky region of 28  deg^{2} (90% probability) and had a luminosity distance of 40_{-14}^{+8}  Mpc, the closest and most precisely localized gravitational-wave signal yet. The association with the γ-ray burst GRB 170817A, detected by Fermi-GBM 1.7 s after the coalescence, corroborates the hypothesis of a neutron star merger and provides the first direct evidence of a link between these mergers and short γ-ray bursts. Subsequent identification of transient counterparts across the electromagnetic spectrum in the same location further supports the interpretation of this event as a neutron star merger. This unprecedented joint gravitational and electromagnetic observation provides insight into astrophysics, dense matter, gravitation, and cosmology.

GW170814: A Three-Detector Observation of Gravitational Waves from a Binary Black Hole Coalescence

On August 14, 2017 at 10∶30:43 UTC, the Advanced Virgo detector and the two Advanced LIGO detectors coherently observed a transient gravitational-wave signal produced by the coalescence of two stellar mass black holes, with a false-alarm rate of ≲1 in 27 000 years. The signal was observed with a three-detector network matched-filter signal-to-noise ratio of 18. The inferred masses of the initial black holes are 30.5_{-3.0}^{+5.7}M_{⊙} and 25.3_{-4.2}^{+2.8}M_{⊙} (at the 90% credible level). The luminosity distance of the source is 540_{-210}^{+130}  Mpc, corresponding to a redshift of z=0.11_{-0.04}^{+0.03}. A network of three detectors improves the sky localization of the source, reducing the area of the 90% credible region from 1160   deg^{2} using only the two LIGO detectors to 60  deg^{2} using all three detectors. For the first time, we can test the nature of gravitational-wave polarizations from the antenna response of the LIGO-Virgo network, thus enabling a new class of phenomenological tests of gravity.