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.

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.

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.

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.

BRAF-Mutated Colorectal Cancer Exhibits Distinct Clinicopathological Features from Wild-Type BRAF-Expressing Cancer Independent of the Microsatellite Instability Status.

In patients with colorectal cancer (CRC), the BRAF V600E mutation has been reported to be associated with several clinicopathological features and poor survival. However, the prognostic implications of BRAF V600E mutation and the associated clinicopathological characteristics in CRCs remain controversial. Therefore, we reviewed various clinicopathological features, including BRAF status, in 349 primary CRCs and analyzed the relationship between BRAF status and various clinicopathological factors, including overall survival. Similar to previous studies conducted in Eastern countries, the incidence of the BRAF V600E mutation in the current study was relatively low (5.7%). BRAF-mutated CRC exhibits distinct clinicopathological features from wild-type BRAF-expressing cancer independent of the microsatellite instability (MSI) status. This mutation was significantly associated with a proximal tumor location (P = 0.002); mucinous, signet ring cell, and serrated tumor components (P < 0.001, P = 0.003, and P = 0.008, respectively); lymphovascular invasion (P = 0.004); a peritumoral lymphoid reaction (P = 0.009); tumor budding (P = 0.046); and peritoneal seeding (P = 0.012). In conclusion, the incidence of the BRAF V600E mutation was relatively low in this study. BRAF-mutated CRCs exhibited some clinicopathological features which were also frequently observed in MSI-H CRCs, such as a proximal location; mucinous, signet ring cell, and serrated components; and marked peritumoral lymphoid reactions.

Nobiletin Inhibits Angiogenesis by Regulating Src/FAK/STAT3-Mediated Signaling through PXN in ER⁺ Breast Cancer Cells.

Tumor angiogenesis is one of the major hallmarks of tumor progression. Nobiletin is a natural flavonoid isolated from citrus peel that has anti-angiogenic activity. Steroid receptor coactivator (Src) is an intracellular tyrosine kinase so that focal adhesion kinase (FAK) binds to Src to play a role in tumor angiogenesis. Signal transducer and activator of transcription 3 (STAT3) is a marker for tumor angiogenesis which interacts with Src. Paxillin (PXN) acts as a downstream target for both FAK and STAT3. The main goal of this study was to assess inhibition of tumor angiogenesis by nobiletin in estrogen receptor positive (ER⁺) breast cancer cells via Src, FAK, and STAT3-mediated signaling through PXN. Treatment with nobiletin in MCF-7 and T47D breast cancer cells inhibited angiogenesis markers, based on western blotting and RT-PCR. Validation of in vitro angiogenesis in the human umbilical vein endothelial cells (HUVEC) endothelial cell line proved the anti-angiogenic activity of nobiletin. Electrophoretic mobility shift assay and the ChIP assay showed that nobiletin inhibits STAT3/DNA binding activity and STAT3 binding to a novel binding site of the PXN gene promoter. We also investigated the migration and invasive ability of nobiletin in ER⁺ cells. Nobiletin inhibited tumor angiogenesis by regulating Src, FAK, and STAT3 signaling through PXN in ER⁺ breast cancer cells.

Diagnostic Limitation of Fine-Needle Aspiration (FNA) on Indeterminate Thyroid Nodules Can Be Partially Overcome by Preoperative Molecular Analysis: Assessment of RET/PTC1 Rearrangement in BRAF and RAS Wild-Type Routine Air-Dried FNA Specimens.

Molecular markers are helpful diagnostic tools, particularly for cytologically indeterminate thyroid nodules. Preoperative RET/PTC1 rearrangement analysis in BRAF and RAS wild-type indeterminate thyroid nodules would permit the formulation of an unambiguous surgical plan. Cycle threshold values according to the cell count for detection of the RET/PTC1 rearrangement by real-time reverse transcription-polymerase chain reaction (RT-PCR) using fresh and routine air-dried TPC1 cells were evaluated. The correlation of RET/PTC1 rearrangement between fine-needle aspiration (FNA) and paired formalin-fixed paraffin-embedded (FFPE) specimens was analyzed. RET/PTC1 rearrangements of 76 resected BRAF and RAS wild-type classical PTCs were also analyzed. Results of RT-PCR and the Nanostring were compared. When 100 fresh and air-dried TPC1 cells were used, expression of RET/PTC1 rearrangement was detectable after 35 and 33 PCR cycles, respectively. The results of RET/PTC1 rearrangement in 10 FNA and paired FFPE papillary thyroid carcinoma (PTC) specimens showed complete correlation. Twenty-nine (38.2%) of 76 BRAF and RAS wild-type classical PTCs had RET/PTC1 rearrangement. Comparison of RET/PTC1 rearrangement analysis between RT-PCR and the Nanostring showed moderate agreement with a κ value of 0.56 (p = 0.002). The RET/PTC1 rearrangement analysis by RT-PCR using routine air-dried FNA specimen was confirmed to be technically applicable. A significant proportion (38.2%) of the BRAF and RAS wild-type PTCs harbored RET/PTC1 rearrangements.

Ectopic overexpression of Nanog induces tumorigenesis in non-tumorous fibroblasts.

Key regulatory genes in pluripotent stem cells are of interest not only as reprogramming factors but also as regulators driving tumorigenesis. Nanog is a transcription factor involved in the maintenance of embryonic stem cells and is one of the reprogramming factors along with Oct4, Sox2, and Lin28. Nanog expression has been detected in different types of tumors, and its expression is a poor prognosis for cancer patients. However, there is no clear evidence that Nanog is functionally involved in tumorigenesis. In this study, we induced overexpression of Nanog in mouse embryonic fibroblast cells and subsequently assessed their morphological changes, proliferation rate, and tumor formation ability. We found that Nanog overexpression induced immortalization of mouse embryonic fibroblast cells (MEFs) and increased their proliferation rate in vitro. We also found that formation of tumors after subcutaneous injection of retroviral-Nanog infected MEFs (N-MEFs) into athymic mouse. Cancer-related genes such as Bmi1 were expressed at high levels in N-MEFs. Hence, our results demonstrate that Nanog is able to transform normal somatic cells into tumor cells.

Switched integration amplifier-based photocurrent meter for accurate spectral responsivity measurement of photometers.

This work introduces a switched integration amplifier (SIA)-based photocurrent meter for femtoampere (fA)-level current measurement, which enables us to measure a 107 dynamic range of spectral responsivity of photometers even with a common lamp-based monochromatic light source. We described design considerations and practices about operational amplifiers (op-amps), switches, readout methods, etc., to compose a stable SIA of low offset current in terms of leakage current and gain peaking in detail. According to the design, we made six SIAs of different integration capacitance and different op-amps and evaluated their offset currents. They showed an offset current of (1.5-85) fA with a slow variation of (0.5-10) fA for an hour under opened input. Applying a detector to the SIA input, the offset current and its variation were increased and the SIA readout became noisier due to finite shunt resistance and nonzero shunt capacitance of the detector. One of the SIAs with 10 pF nominal capacitance was calibrated using a calibrated current source at the current level of 10 nA to 1 fA and at the integration time of 2 to 65,536 ms. As a result, we obtained a calibration formula for integration capacitance as a function of integration time rather than a single capacitance value because the SIA readout showed a distinct dependence on integration time at a given current level. Finally, we applied it to spectral responsivity measurement of a photometer. It is demonstrated that the home-made SIA of 10 pF was capable of measuring a 107 dynamic range of spectral responsivity of a photometer.

Detection of EGFR and KRAS Mutation by Pyrosequencing Analysis in Cytologic Samples of Non-Small Cell Lung Cancer.

EGFR and KRAS mutations are two of the most common mutations that are present in lung cancer. Screening and detecting these mutations are of issue these days, and many different methods and tissue samples are currently used to effectively detect these two mutations. In this study, we aimed to evaluate the testing for EGFR and KRAS mutations by pyrosequencing method, and compared the yield of cytology versus histology specimens in a consecutive series of patients with lung cancer. We retrospectively reviewed EGFR and KRAS mutation results of 399 (patients with EGFR mutation test) and 323 patients (patients with KRAS mutation test) diagnosed with lung cancer in Konkuk University Medical Center from 2008 to 2014. Among them, 60 patients had received both EGFR and KRAS mutation studies. We compared the detection rate of EGFR and KRAS tests in cytology, biopsy, and resection specimens. EGFR and KRAS mutations were detected in 29.8% and 8.7% of total patients, and the positive mutation results of EGFR and KRAS were mutually exclusive. The detection rate of EGFR mutation in cytology was higher than non-cytology (biopsy or resection) materials (cytology: 48.5%, non-cytology: 26.1%), and the detection rate of KRAS mutation in cytology specimens was comparable to non-cytology specimens (cytology: 8.3%, non-cytology: 8.7%). We suggest that cytology specimens are good alternatives that can readily substitute tissue samples for testing both EGFR and KRAS mutations. Moreover, pyrosequencing method is highly sensitive in detecting EGFR and KRAS mutations in lung cancer patients.

The combination of methylsulfonylmethane and tamoxifen inhibits the Jak2/STAT5b pathway and synergistically inhibits tumor growth and metastasis in ER-positive breast cancer xenografts.

BACKGROUND: Combination therapy, which reduces the dosage intensity of the individual drugs while increasing their efficacy, is not a novel approach for the treatment of cancer. Methylsulfonylmethane (MSM) is an organic sulfur compound shown to act against tumor cells. Tamoxifen is a commercially available therapeutic agent for breast malignancies. METHODS: In the current study, we analyzed the combinatorial effect of MSM and tamoxifen on the suppression of ER-positive breast cancer xenograft growth and metastasis. Additionally, we also validated the molecular targets by which the drug combination regulated tumor growth and metastasis. RESULTS: We observed that the combination of MSM and tamoxifen regulated cell viability and migration in vitro. The intragastric administration of MSM and subcutaneous implantation of tamoxifen tablets led to tumor growth suppression and inhibition of the Janus kinase 2 (Jak2)/signal transducer and activator of transcription 5b (STAT5b) pathway. Our study also assessed the regulation of signaling molecules implicated in the growth, progression, differentiation, and migration of cancer cells, such as Jak2, STAT5b, insulin-like growth factor-1Rß, and their phosphorylation status. CONCLUSIONS: Study results indicated that this combination therapy inhibited tumor growth and metastasis. Therefore, this drug combination may have a synergistic and powerful anticancer effect against breast cancer.

Pathological Substratum for a Case of Fulminant Myocarditis Treated with Extracorporeal Membrane Oxygenation and Subsequent Heart Transplantation.

Fulminant myocarditis has been defined as the clinical manifestation of cardiac inflammation with rapid-onset heart failure and cardiogenic shock. We report on the case of a 23-yr-old woman with pathology-proven fulminant lymphocytic myocarditis presenting shock with elevated cardiac troponin I and ST segments in V1-2, following sustained ventricular tachycardia and a complete atrioventricular block. About 55 min of intensive cardio-pulmonary resuscitation, with extracorporeal membrane oxygenation support, bridged the patient to orthotopic heart transplantation. The explanted heart revealed diffuse lymphocytic infiltration and myocyte necrosis in all four cardiac chamber walls. Aggressive mechanical circulatory support may be an essential bridge for recovery or even transplantation in patients with fulminant myocarditis with shock.

Imaging mass spectrometry in papillary thyroid carcinoma for the identification and validation of biomarker proteins.

Direct tissue imaging mass spectrometry (IMS) by matrix-assisted laser desorption ionization and time-of-flight (MALDI-TOF) mass spectrometry has become increasingly important in biology and medicine, because this technology can detect the relative abundance and spatial distribution of interesting proteins in tissues. Five thyroid cancer samples, along with normal tissue, were sliced and transferred onto conductive glass slides. After laser scanning by MALDI-TOF equipped with a smart beam laser, images were created for individual masses and proteins were classified at 200-µm spatial resolution. Based on the spatial distribution, region-specific proteins on a tumor lesion could be identified by protein extraction from tumor tissue and analysis using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Using all the spectral data at each spot, various intensities of a specific peak were detected in the tumor and normal regions of the thyroid. Differences in the molecular weights of expressed proteins between tumor and normal regions were analyzed using unsupervised and supervised clustering. To verify the presence of discovered proteins through IMS, we identified ribosomal protein P2, which is specific for cancer. We have demonstrated the feasibility of IMS as a useful tool for the analysis of tissue sections, and identified the tumor-specific protein ribosomal protein P2.

Primary ductal adenocarcinoma of the lacrimal gland, associated with abundant intracytoplasmic lumens containing some eosinophilic hyaline globules: cytological, histological and ultrastructural findings.

A primary ductal adenocarcinoma (PDA) of the lacrimal gland is a rare distinct subtype of an epithelial tumor arising in the lacrimal gland. PDA is the counterpart of salivary duct carcinoma (SDC) resembling an invasive ductal carcinoma (IDC) of the breast. In our case, PDA revealed histopathological and immunohistochemical results corresponding to SDC. Interestingly, the tumor cells showed intracytoplasmic vacuoles containing dense eosinophilic hyaline globules at light microscopy. Ultrastructurally, the tumor cells exhibited microvilli-lined intracytoplasmic lumen containing homogenous electron-dense secretory products. A previous study demonstrated that numerous intracytoplasmic lumens of tumor cells are favored breast malignant tumor, similar to the histopathology of PDA, rather than benign lesion. This characteristic finding may be meaningful to diagnose high grade epithelial tumors including PDA.

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.

Clinical practice recommendations for the use of next-generation sequencing in patients with solid cancer: a joint report from KSMO and KSP.

In recent years, next-generation sequencing (NGS)-based genetic testing has become crucial in cancer care. While its primary objective is to identify actionable genetic alterations to guide treatment decisions, its scope has broadened to encompass aiding in pathological diagnosis and exploring resistance mechanisms. With the ongoing expansion in NGS application and reliance, a compelling necessity arises for expert consensus on its application in solid cancers. To address this demand, the forthcoming recommendations not only provide pragmatic guidance for the clinical use of NGS but also systematically classify actionable genes based on specific cancer types. Additionally, these recommendations will incorporate expert perspectives on crucial biomarkers, ensuring informed decisions regarding circulating tumor DNA panel testing.

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 in patients with human epidermal growth factor receptor 2 (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 25 institutions included in this study. Of these patients, 40.7% (range, 6.0% to 76.3%) were classified as HER2-zero, 41.7% (range, 10.5% to 69.1%) as HER2-low, and 17.5% (range, 6.7% to 34.0%) as HER2-positive. HER2-low tumors were associated with positive estrogen receptor and progesterone receptor statuses (p < 0.001 and p < 0.001, respectively). Antigen retrieval times (≥ 36 minutes vs. < 36 minutes) and antibody incubation times (≥ 12 minutes vs. < 12 minutes) 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 and subsequent resection specimen HER2 statuses were observed in 24.1% (787/3,259) 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.

Genetic alteration and immunohistochemical staining patterns of ovarian high-grade serous adenocarcinoma with special emphasis on p53 immnnostaining pattern.

We evaluated p53, KRAS, BRAF and CTNNB1 mutation and p53, WT1, p16 and beta-catenin expression in 31 ovarian high-grade serous adenocarcinoma. Twenty-five (80.6%) tumors contained functional mutations of p53; three frameshift, four nonsense and 19 missense mutations. None of the tumors showed KRAS, BRAF or CTNNB1 mutation. In all 18 tumors with missense mutations, ≥60% of tumor cells were strongly positive for p53 immunostaining whereas all tumors with frameshift or nonsense mutations were completely negative. Missense mutation was correlated with diffuse and strong imunoreaction and frameshift/nonsense mutation was correlated with completely negative immunoreaction (P = 0.000). Tumors with wild-type p53 revealed a wide range of immunostaining patterns. In 27 (87.1%) and 18 (58.1%) tumors, ≥50% of tumor cells were moderate to strongly positive for WT1 and p16, respectively. A considerable intratumoral heterogeneity for p16 expression was present. None of the tumors demonstrated nuclear beta-catenin expression. p53 mutations appear to be a powerful molecular marker for ovarian high-grade serous adenocarcinoma. Using p53 with an appropriate interpretation criteria together with WT1, p16 and beta-catenin, most of the high-grade serous adenocarcinoma could be distinguished from other ovarian tumors.

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.