Establishing molecular pathology curriculum for pathology trainees and continued medical education: a collaborative work from the Molecular Pathology Study Group of the Korean Society of Pathologists

Background@#The importance of molecular pathology tests has increased during the last decade, and there is a great need for efficient training of molecular pathology for pathology trainees and as continued medical education. @*Methods@#The Molecular Pathology Study Group of the Korean Society of Pathologists appointed a task force composed of experienced molecular pathologists to develop a refined educational curriculum of molecular pathology. A 3-day online educational session was held based on the newly established structure of learning objectives; the audience were asked to score their understanding of 22 selected learning objectives before and after the session to assess the effect of structured education. @*Results@#The structured objectives and goals of molecular pathology was established and posted as a web-based interface which can serve as a knowledge bank of molecular pathology. A total of 201 pathologists participated in the educational session. For all 22 learning objectives, the scores of self-reported understanding increased after educational session by 9.9 points on average (range, 6.6 to 17.0). The most effectively improved items were objectives from next-generation sequencing (NGS) section: ‘NGS library preparation and quality control’ (score increased from 51.8 to 68.8), ‘NGS interpretation of variants and reference database’ (score increased from 54.1 to 68.0), and ‘whole genome, whole exome, and targeted gene sequencing’ (score increased from 58.2 to 71.2). Qualitative responses regarding the adequacy of refined educational curriculum were collected, where favorable comments dominated. @*Conclusions@#Approach toward the education of molecular pathology was refined, which would greatly benefit the future trainees.

Tauroursodeoxycholic Acid Inhibits Nuclear Factor Kappa B Signaling in Gastric Epithelial Cells and Ameliorates Gastric Mucosal Damage in Mice / 대한소화기학회지

Background/Aims@#Previous studies have reported the protective effects of tauroursodeoxycholic acid (TUDCA) on gastric epithelial cells in some animal models, but the precise mechanisms are unclear. This study examined the effects of TUDCA on NF-κB signaling in gastric epithelial cells. Moreover, the protective effects of TUDCA in experimental gastritis models induced by ethanol and NSAID were evaluated and compared with ursodeoxycholic acid (UDCA). @*Methods@#After a pretreatment with TUDCA or UDCA, human gastric epithelial MKN-45 cells were stimulated with tumor necrosis factor (TNF)-α to activate NF-κB signaling. A real-time PCR (RT-PCR) for human interleukin (IL)-1 mRNA was performed. An electrophoretic mobility shift assay (EMSA) and immunoblot analyses were carried out. In murine models, after a pretreatment with TUDCA or UDCA, ethanol and indomethacin were administered via oral gavage. Macroscopic and microscopic assessments were performed to evaluate the preventive effects of TUDCA and UDCA on murine gastritis. @*Results@#A pretreatment with TUDCA downregulated the IL-1α mRNA levels in MKN-45 cells stimulated with TNF-α, as assessed by RT-PCR. As determined using EMSA, a pretreatment with TUDCA reduced the TNF-α-induced NF-κB DNA binding activity. A pretreatment with TUDCA inhibited IκBα phosphorylation induced by TNF-α, as assessed by immunoblot analysis. TUDCA attenuated the ethanol-induced and NSAID-induced gastritis in murine models, as determined macroscopically and microscopically. @*Conclusions@#TUDCA inhibited NF-κB signaling in gastric epithelial cells and ameliorated ethanol- and NSAID-induced gastritis in murine models. These results support the potential of TUDCA for the prevention of gastritis in humans.

An unusual case of microsatellite instability–high/deficient mismatch repair (MSI-H/dMMR) diffuse large B-cell lymphoma revealed by targeted gene sequencing

Microsatellite instability-high/deficient mismatch repair (MSI-H/dMMR) status has been approved as a tissue-agnostic biomarker for immune checkpoint inhibitor therapy in patients with solid tumors. We report the case of an MSI-H/dMMR diffuse large B-cell lymphoma (DLBCL) identified by targeted gene sequencing (TGS). A 90-year-old female who presented with vaginal bleeding and a large mass in the upper vagina was diagnosed with germinal center-B-cell-like DLBCL, which recurred at the uterine cervix at 9 months after chemotherapy. Based on TGS of 121 lymphoma-related genes and the LymphGen algorithm, the tumor was classified genetically as DLBCL of EZB subtype. Mutations in multiple genes, including frequent frameshift mutations, were detected by TGS and further suggested MSI. The MSI-H/dMMR and loss of MLH1 and PMS2 expression were determined in MSI-fragment analysis, MSI real-time polymerase chain reaction, and immunohistochemical tests. This case demonstrates the potential diagnostic and therapeutic utility of lymphoma panel sequencing for DLBCL with MSI-H/dMMR.

Clinical and Genomic Characteristics of Adult Diffuse Midline Glioma / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#The treatment outcomes and genomic profiles of diffuse midline glioma (DMG) in adult patients are rarely characterized. We performed a retrospective study to evaluate the clinicogenomic profiles of adult patients with brain DMG. @*Materials and Methods@#Patients aged ≥ 18 years diagnosed with brain DMG at Seoul National University Hospital were included. The clinicopathological parameters, treatment outcomes, survival, and genomic profiles using 82-gene targeted next-generation sequencing (NGS) were analyzed. The 6-month progression-free survival (PFS6) after radiotherapy and overall survival (OS) were evaluated. @*Results@#Thirty-three patients with H3-mutant brain DMG were identified. The median OS from diagnosis was 21.8 months (95% confidence interval [CI], 13.2 to not available [NA]) and involvement of the ponto-medullary area tended to have poor OS (median OS, 20.4 months [95% CI, 9.3 to NA] vs. 43.6 months [95% CI, 18.2 to NA]; p=0.07). Twenty-four patients (72.7%) received radiotherapy with or without temozolomide. The PFS6 rate was 83.3% (n=20). Patients without progression at 6 months showed significantly prolonged OS compared with those with progression at 6 months (median OS, 24.9 months [95% CI, 20.4 to NA] vs. 10.8 months [95% CI, 4.0 to NA]; p=0.02, respectively). Targeted NGS was performed in 13 patients with DMG, among whom nine (69.2%) harbored concurrent TP53 mutation. Two patients (DMG14 and DMG23) with PIK3CAR38S+E545K and KRASG12A mutations received matched therapies. Patient DMG14 received sirolimus with a PFS of 8.4 months. @*Conclusion@#PFS6 after radiotherapy was associated with prolonged survival in adult patients with DMG. Genome-based matched therapy may be an encouraging approach for progressive adult patients with DMG.

A comparative prognostic performance of definitions of Crohn-like lymphoid reaction in colorectal carcinoma

Background@#The prognostic potential of Crohn-like lymphoid reaction (CLR) in colorectal carcinoma (CRC) has been investigated through the assessment of different criteria. @*Methods@#The prognostic impact of CLR was investigated in 636 CRC patients to compare methods from previously published articles. These methods included CLR measured by number of lymphoid aggregates (LAs) (CLR count), LA size greater than or equal to 1 mm (CLR size), CLR density with a cutoff value of 0.38, and subjective criteria as defined by intense CLR. @*Results@#In univariate survival analysis, CLR-positive CRC as defined by the four aforementioned methods was associated with better overall survival (OS) (hazard ratio [HR], 0.463; 95% confidence interval [CI], 0.305 to 0.702; p <.001; HR, 0.656; 95% CI, 0.411 to 1.046; p=.077; HR, 0.363; 95% CI, 0.197 to 0.669; p=.001; and HR, 0.433; 95% CI, 0.271 to 0.690; p<.001, respectively) and disease-free survival (DFS) (HR, 0.411; 95% CI, 0.304 to 0.639; p<.001; HR, 0.528; 95% CI, 0.340 to 0.821; p=.004; HR, 0.382; 95% CI, 0.226 to 0.645, p=.004; and HR, 0.501; 95% CI, 0.339 to 0.741; p<.001, respectively) than CLR-negative CRC, regardless of criteria with the exception of OS for CLR density. In multivariate analysis, two objective criteria (CLR count and CLR density) and one subjective criterion (intense CLR) for defining CLR were considered independent prognostic factors of OS and DFS in CRC patients. @*Conclusions@#CLR has similar traits regardless of criteria, but CLR-positivity should be defined by objective criteria for better reproducibility and prognostic value.

Clinical and Genomic Characteristics of Adult Diffuse Midline Glioma / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#The treatment outcomes and genomic profiles of diffuse midline glioma (DMG) in adult patients are rarely characterized. We performed a retrospective study to evaluate the clinicogenomic profiles of adult patients with brain DMG. @*Materials and Methods@#Patients aged ≥ 18 years diagnosed with brain DMG at Seoul National University Hospital were included. The clinicopathological parameters, treatment outcomes, survival, and genomic profiles using 82-gene targeted next-generation sequencing (NGS) were analyzed. The 6-month progression-free survival (PFS6) after radiotherapy and overall survival (OS) were evaluated. @*Results@#Thirty-three patients with H3-mutant brain DMG were identified. The median OS from diagnosis was 21.8 months (95% confidence interval [CI], 13.2 to not available [NA]) and involvement of the ponto-medullary area tended to have poor OS (median OS, 20.4 months [95% CI, 9.3 to NA] vs. 43.6 months [95% CI, 18.2 to NA]; p=0.07). Twenty-four patients (72.7%) received radiotherapy with or without temozolomide. The PFS6 rate was 83.3% (n=20). Patients without progression at 6 months showed significantly prolonged OS compared with those with progression at 6 months (median OS, 24.9 months [95% CI, 20.4 to NA] vs. 10.8 months [95% CI, 4.0 to NA]; p=0.02, respectively). Targeted NGS was performed in 13 patients with DMG, among whom nine (69.2%) harbored concurrent TP53 mutation. Two patients (DMG14 and DMG23) with PIK3CAR38S+E545K and KRASG12A mutations received matched therapies. Patient DMG14 received sirolimus with a PFS of 8.4 months. @*Conclusion@#PFS6 after radiotherapy was associated with prolonged survival in adult patients with DMG. Genome-based matched therapy may be an encouraging approach for progressive adult patients with DMG.

Distribution and malignancy risk of six categories of the pathology reporting system for thyroid core-needle biopsy in 1,216 consecutive thyroid nodules

Purpose@#The purpose of this study was to present the distribution of lesions among the six categories of the pathology reporting system for thyroid core-needle biopsy (CNB), along with the range of malignancy risk of each category based on different diagnostic criteria for benignity in a clinical cohort. @*Methods@#For 1,216 consecutive nodules (≥1 cm) of 1,125 patients who underwent CNB at two hospitals, the diagnostic results based on the six categories of thyroid CNB were analyzed. Patients were divided into three groups according to prior fine-needle aspiration (FNA) status: second-line CNB for nodules where prior FNA yielded nondiagnostic or unsatisfactory results (n=57), second-line CNB for nodules with prior FNA results of atypia/follicular lesion of undetermined significance (AUS/FLUS) (n=303), and first-line CNB (n=856). @*Results@#The proportion of nodules in each CNB category and the range of the malignancy rate for each category was as follows, in order from category I to VI: 1.8%, 23.1%-75.0%; 57.9%, 0.7%-16.7%; 16.0%, 13.2%-46.7%; 8.8%, 53.8%-56.8%; 2.0%, 100%; and 13.5%, 100%. First-line CNB was associated with a higher rate of conclusive diagnoses (category II, IV, or VI) (725 of 856, 84.7%) than second-line CNB with prior nondiagnostic or AUS/FLUS FNA results (241 of 360, 66.9%; P<0.001). @*Conclusion@#The overall distribution of nodules across the six categories of thyroid CNB and the ranges of malignancy risk for those categories were presented in a clinical cohort. First-line CNB tended to produce a higher rate of conclusive results than second-line CNB with prior inconclusive FNA results.

Immune landscape and biomarkers for immuno-oncology in colorectal cancers

Recent advances in immuno-oncology have increased understanding of the tumor immune microenvironment (TIME), and clinical trials for immune checkpoint inhibitor treatment have shown remission and/or durable response in certain proportions of patients stratified by predictive biomarkers. The TIME in colorectal cancer (CRC) was initially evaluated several decades ago. The prognostic value of the immune response to tumors, including tumor-infiltrating lymphocytes, peritumoral lymphoid reaction, and Crohn’s-like lymphoid reaction, has been well demonstrated. In this review, we describe the chronology of TIME research and review the up-to-date high-dimensional TIME landscape of CRC. We also summarize the clinical relevance of several biomarkers associated with immunotherapy in CRC, such as microsatellite instability, tumor mutational burden, POLE/POLD mutation, consensus molecular subtype, and programmed death-ligand 1 expression.

Standardized Pathology Report for Colorectal Cancer, 2nd Edition

The first edition of the ‘Standardized Pathology Report for Colorectal Cancer,’ which was developed by the Gastrointestinal Pathology Study Group (GIP) of the Korean Society of Pathologists, was published 13 years ago. Meanwhile, there have been many changes in the pathologic diagnosis of colorectal cancer (CRC), pathologic findings included in the pathology report, and immunohistochemical and molecular pathology required for the diagnosis and treatment of colorectal cancer. In order to reflect these changes, we (GIP) decided to make the second edition of the report. The purpose of this standardized pathology report is to provide a practical protocol for Korean pathologists, which could help diagnose and treat CRC patients. This report consists of “standard data elements” and “conditional data elements.” Basic pathologic findings and parts necessary for prognostication of CRC patients are classified as “standard data elements,” while other prognostic factors and factors related to adjuvant therapy are classified as “conditional data elements” so that each institution could select the contents according to the characteristics of the institution. The Korean version is also provided separately so that Korean pathologists can easily understand and use this report. We hope that this report will be helpful in the daily practice of CRC diagnosis.

Ultrasonographic Indeterminate Lymph Nodes inPreoperative Thyroid Cancer Patients: Malignancy Riskand Ultrasonographic Findings Predictive of Malignancy

Objective@#Proper management of lymph nodes (LNs) with ultrasonographic (US) indeterminate features in thyroid cancerpatients remains elusive. We aimed to evaluate the malignancy risk and US findings predictive of malignancy for USindeterminate LNs in preoperative thyroid cancer patients through node-by-node correlation. @*Materials and Methods@#A total of 348 LNs in 284 thyroid cancer patients, who underwent fine-needle aspiration or coreneedlebiopsy between December 2006 and June 2015, were included. We determined the malignancy risks for US probablybenign, indeterminate, and suspicious categories. For US indeterminate LNs, which had neither echogenic hilum nor hilarvascularity in the absence of any suspicious finding, US findings were compared between benign and metastatic LNs usingMann-Whitney U test and Fisher’s exact test. @*Results@#US imaging diagnoses were probably benign in 20.7% (n = 72) cases, indeterminate in 23.6% (n = 82), andsuspicious in 55.7% (n = 194). Malignancy risk of US indeterminate LNs (19.5% [16/82]) differed from those of the USprobably benign (2.8% [2/72]) (p = 0.002) and US suspicious LNs (78.4% [152/194]) (p < 0.001). Among US indeterminate LNs,there were no significant differences in short, long, and long-to-short diameter (L/S) ratios between benign and metastatic LNs(3.9 vs. 3.8 mm, p = 0.619; 7.3 vs. 7.3 mm, p = 0.590; 1.9 vs. 1.9, p = 0.652). @*Conclusion@#US indeterminate LNs were frequently encountered during preoperative evaluation and had intermediate malignancyrisk. Given the lack of discriminative power of size criteria and L/S ratio, clinical factors such as surgical strategy and nodesize should be considered for proper triage of US indeterminate LNs in thyroid cancer.

Prognostic Value of the Alcoholic Hepatitis Histologic Score in Korean Patients with Biopsy-Proven Alcoholic Hepatitis

Background/Aims@#The alcoholic hepatitis histologic score (AHHS) is a recently developed clinical model for predicting short-term mortality in Caucasian patients with alcoholic hepatitis (AH). The AHHS has not been extensively validated in other ethnic populations. This study validated the AHHS in a Korean patient cohort. @*Methods@#We conducted a pro-spective cohort study of hospitalized Korean patients with AH between January 2010 and August 2017. Histopatho-logical findings were assessed to determine the AHHS in all study subjects. Histopathological risk factors were examined by Cox regression analysis to predict overall survival (OS).Kaplan-Meier curves were plotted to assess the diagnostic performance of the AHHS. @*Results@#We recruited a total of 107 patients with biopsy-proven AH. None of the individual AHHS components were associated with 3-month mortality.However, the bilirubinostasis type and fibrosis severity were significantly associated with AH mortality beyond 6 months (all p<0.05, except fibrosis severity for 6-month mortality) and OS (all p<0.05). The modified AHHS classification as a binary variable (<5 vs ≥5) was also associated with OS (haz-ard ratio, 2.88; 95% confidence interval [CI], 1.50 to 5.56;p=0.002), and had higher predictive performance for OS (concordance index [C-index], 0.634; 95% CI, 0.561 to 0.707) than the original AHHS classification (mild vs moderate vs severe: C-index, 0.577; 95% CI, 0.498 to 0.656). This differ-ence was statistically significant (p=0.045). @*Conclusions@#In this prospective Korean AH cohort, the modified AHHS was significantly associated with OS. Therefore, the AHHS might be a useful histological prognosticator for long-term progno-sis in patients with nonsevere AH.

Fibroblast Growth Factor Receptor 1 (FGFR1) Amplification Detected by Droplet Digital Polymerase Chain Reaction (ddPCR) Is a Prognostic Factor in Colorectal Cancers / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#The purpose of this study was to reveal the clinicopathological characteristics and prognostic implications associated with fibroblast growth factor receptor 1 (FGFR1) amplification in colorectal cancers (CRCs). @*Materials and Methods@#We measured the copy number of FGFR1 by droplet digital polymerase chain reaction (ddPCR), and analyzed the FGFR1 expression by immunohistochemistry, in 764 surgically resected CRCs (SNUH2007 dataset, 384 CRCs; SNUH Folfox dataset, 380 CRCs). @*Results@#CRCs with ≥ 3.3 copies of the FGFR1 gene were classified as FGFR1 amplified. FGFR1 amplification was found in 10 of the 384 CRCs (2.6%) in the SNUH2007 dataset, and in 28 of the 380 CRCs (7.4%) in the SNUH Folfox dataset. In the SNUH2007 dataset, there was no association between the FGFR1 copy number status and sex, gross appearance, stage, or differentiation. High FGFR1 expression was associated with female sex and KRAS mutation. At the molecular level, FGFR1 amplification was mutually exclusive with BRAF mutation, microsatellite instability, and MLH1 methylation, in both SNUH2007 and SNUH Folfox datasets. Survival analysis revealed that FGFR1 amplification was associated with significantly worse clinical outcome compared with no FGFR1 amplification, in both SNUH2007 and SNUH Folfox datasets. Within the SNUH2007 dataset, CRC patients with high FGFR1 expression had an inferior progression-free survival compared with those with low FGFR1 expression. The FGFR inhibitor, PD173074, repressed the proliferation of a CRC cell line overexpressing FGFR1, but not of cells with FGFR1 amplification. @*Conclusion@#FGFR1 amplification measured by ddPCR can be a prognostic indicator of poor clinical outcome in patients with CRCs.

Clinicopathological Characterization and Prognostic Implication of SMAD4 Expression in Colorectal Carcinoma

BACKGROUND: SMAD family member 4 (SMAD4) has gained attention as a promising prognostic factor of colorectal cancer (CRC) as well as a key molecule to understand the tumorigenesis and progression of CRC. METHODS: We retrospectively analyzed 1,281 CRC cases immunohistochemically for their expression status of SMAD4, and correlated this status with clinicopathologic and molecular features of CRCs. RESULTS: A loss of nuclear SMAD4 was significantly associated with frequent lymphovascular and perineural invasion, tumor budding, fewer tumor-infiltrating lymphocytes, higher pT and pN category, and frequent distant metastasis. In contrast, tumors overexpressing SMAD4 showed a significant association with sporadic microsatellite instability. After adjustment for TNM stage, tumor differentiation, adjuvant chemotherapy, and lymphovascular invasion, the loss of SMAD4 was found to be an independent prognostic factor for worse 5-year progression-free survival (hazard ratio [HR], 1.27; 95% confidence interval [CI], 1.01 to 1.60; p=.042) and 7-year cancer-specific survival (HR, 1.45; 95% CI, 1.06 to 1.99; p=.022). CONCLUSIONS: We confirmed the value of determining the loss of SMAD4 immunohistochemically as an independent prognostic factor for CRC in general. In addition, we identified some histologic and molecular features that might be clues to elucidate the role of SMAD4 in colorectal tumorigenesis and progression.

Prognostic Impact of Fusobacterium nucleatum Depends on Combined Tumor Location and Microsatellite Instability Status in Stage II/III Colorectal Cancers Treated with Adjuvant Chemotherapy

BACKGROUND: This study aimed to investigate the prognostic impact of intratumoral Fusobacterium nucleatum in colorectal cancer (CRC) treated with adjuvant chemotherapy. METHODS: F. nucleatum DNA was quantitatively measured in a total of 593 CRC tissues retrospectively collected from surgically resected specimens of stage III or high-risk stage II CRC patients who had received curative surgery and subsequent oxaliplatin-based adjuvant chemotherapy (either FOLFOXor CAPOX). Each case was classified into one of the three categories: F. nucleatum–high, –low, or –negative. RESULTS: No significant differences in survival were observed between the F.nucleatum–high and –low/negative groups in the 593 CRCs (p = .671). Subgroup analyses according to tumor location demonstrated that disease-free survival was significantly better in F.nucleatum–high than in –low/negative patients with non-sigmoid colon cancer (including cecal, ascending, transverse, and descending colon cancers; n = 219; log-rank p = .026). In multivariate analysis, F. nucleatum was determined to be an independent prognostic factor in non-sigmoid colon cancers (hazard ratio, 0.42; 95% confidence interval, 0.18 to 0.97; p = .043). Furthermore, the favorable prognostic effect of F. nucleatum–high was observed only in a non-microsatellite instability-high (non-MSI-high) subset of non-sigmoid colon cancers (log-rank p = 0.014), but not in a MSI-high subset (log-rank p = 0.844), suggesting that the combined status of tumor location and MSI may be a critical factor for different prognostic impacts of F. nucleatum in CRCs treated with adjuvant chemotherapy. CONCLUSIONS: Intratumoral F. nucleatum load is a potential prognostic factor in a non-MSI-high/non-sigmoid/non-rectal cancer subset of stage II/III CRCs treated with oxaliplatin-based adjuvant chemotherapy.

Primary Peripheral Gamma Delta T-Cell Lymphoma of the Central Nervous System: Report of a Case Involving the Intramedullary Spinal Cord and Presenting with Myelopathy

Primary central nervous system lymphoma of T-cell origin (T-PCNSL) is rare, and its clinicopathological features remain unclear. Peripheral T-cell lymphoma of γδ T-cell origin is an aggressive lymphoma mainly involving extranodal sites. Here, we report a case of γδ T-PCNSL involving the intramedullary spinal cord and presenting with paraplegia. A 75-year-old Korean woman visited the hospital complaining of back pain and lower extremity weakness. Magnetic resonance imaging revealed multifocal enhancing intramedullary nodular lesions in the thoracic and lumbar spinal cord. An enhancing nodular lesion was observed in the periventricular white matter of the lateral ventricle in the brain. There were no other abnormalities in systemic organs or skin. Laminectomy and tumor removal were performed. The tumor consisted of monomorphic, medium-to-large atypical lymphocytes with pale-to-eosinophilic cytoplasm. Immunohistochemically, the tumor cells were CD3(+), TCRβF1(-), TCRγ(+), CD30(-), CD4(-), CD8(-), CD56(+), TIA1(+), granzyme B(+), and CD103(+). Epstein-Barr virus in situ was negative. This case represents a unique T-PCNSL of γδ T-cell origin involving the spinal cord.

Recent Advancement of the Molecular Diagnosis in Pediatric Brain Tumor

Recent discoveries of brain tumor-related genes and fast advances in genomic testing technologies have led to the era of molecular diagnosis of brain tumor. Molecular profiling of brain tumor became the significant step in the diagnosis, the prediction of prognosis and the treatment of brain tumor. Because traditional molecular testing methods have limitations in time and cost for multiple gene tests, next-generation sequencing technologies are rapidly introduced into clinical practice. Targeted sequencing panels using these technologies have been developed for brain tumors. In this article, focused on pediatric brain tumor, key discoveries of brain tumor-related genes are reviewed and cancer panels used in the molecular profiling of brain tumor are discussed.

Recent Advancement of the Molecular Diagnosis in Pediatric Brain Tumor

Recent discoveries of brain tumor-related genes and fast advances in genomic testing technologies have led to the era of molecular diagnosis of brain tumor. Molecular profiling of brain tumor became the significant step in the diagnosis, the prediction of prognosis and the treatment of brain tumor. Because traditional molecular testing methods have limitations in time and cost for multiple gene tests, next-generation sequencing technologies are rapidly introduced into clinical practice. Targeted sequencing panels using these technologies have been developed for brain tumors. In this article, focused on pediatric brain tumor, key discoveries of brain tumor-related genes are reviewed and cancer panels used in the molecular profiling of brain tumor are discussed.

Multiplicity of Advanced T Category–Tumors Is a Risk Factor for Survival in Patients with Colorectal Carcinoma

BACKGROUND: Previous studies on synchronous colorectal carcinoma (SCRC) have reported inconsistent results about its clinicopathologic and molecular features and prognostic significance. METHODS: Forty-six patients with multiple advanced tumors (T2 or higher category) who did not receive neoadjuvant chemotherapy and/or radiotherapy and who are not associated with familial adenomatous polyposis were selected and 99 tumors from them were subjected to clinicopathologic and molecular analysis. Ninety-two cases of solitary colorectal carcinoma (CRC) were selected as a control considering the distributions of types of surgeries performed on patients with SCRC and T categories of individual tumors from SCRC. RESULTS: SCRC with multiple advanced tumors was significantly associated with more frequent nodal metastasis (p = .003) and distant metastasis (p = .001) than solitary CRC. KRAS mutation, microsatellite instability, and CpG island methylator phenotype statuses were not different between SCRC and solitary CRC groups. In univariate survival analysis, overall and recurrence-free survival were significantly lower in patients with SCRC than in patients with solitary CRC, even after adjusting for the extensiveness of surgical procedure, adjuvant chemotherapy, or staging. Multivariate Cox regression analysis revealed that tumor multiplicity was an independent prognostic factor for overall survival (hazard ratio, 4.618; 95% confidence interval, 2.126 to 10.030; p < .001), but not for recurrence-free survival (p = .151). CONCLUSIONS: Findings suggested that multiplicity of advanced T category–tumors might be associated with an increased risk of nodal metastasis and a risk factor for poor survival, which raises a concern about the guideline of American Joint Committee on Cancer's tumor-node-metastasis staging that T staging of an index tumor determines T staging of SCRC.

Prognostic Significance of EPHB2 Expression in Colorectal Cancer Progression

BACKGROUND: A receptor tyrosine kinase for ephrin ligands, EPHB2, is expressed in normal colorectal tissues and colorectal cancers (CRCs). The aim of this study was to investigate EPHB2 expression over CRC progression and determine its prognostic significance in CRC. METHODS: To measure EPHB2 mRNA and protein expression, real-time polymerase chain reaction and immunohistochemistry were performed in 32 fresh-frozen and 567 formalin-fixed paraffin-embedded CRC samples, respectively. We further investigated clinicopathological features and overall and recurrence-free survival according to EPHB2 protein expression. RESULTS: The EPHB2 level was upregulated in CRC samples compared to non-cancerous tissue in most samples and showed a strong positive correlation with AXIN2. Notably, CD44 had a positive association with both mRNA and protein levels of EPHB2. Immunohistochemical analysis revealed no difference in EPHB2 expression between adenoma and carcinoma areas. Although EPHB2 expression was slightly lower in invasive fronts compared to surface area (p < .05), there was no difference between superficial and metastatic areas. EPHB2 positivity was associated with lymphatic (p < .001) and venous (p = .001) invasion, TNM stage (p < .001), and microsatellite instability (p = .036). Kaplan–Meier analysis demonstrated that CRC patients with EPHB2 positivity showed better clinical outcomes in both overall (p = .049) and recurrence-free survival (p = .015). However, multivariate analysis failed to show that EPHB2 is an independent prognostic marker in CRCs (hazard ratio, 0.692; p = .692). CONCLUSIONS: Our results suggest that EPHB2 is overexpressed in a subset of CRCs and is a significant prognostic marker.

Molecular Testing for Gastrointestinal Cancer

With recent advances in molecular diagnostic methods and targeted cancer therapies, several molecular tests have been recommended for gastric cancer (GC) and colorectal cancer (CRC). Microsatellite instability analysis of gastrointestinal cancers is performed to screen for Lynch syndrome, predict favorable prognosis, and screen patients for immunotherapy. The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor has been approved in metastatic CRCs with wildtype RAS (KRAS and NRAS exon 2–4). A BRAF mutation is required for predicting poor prognosis. Additionally, amplification of human epidermal growth factor receptor 2 (HER2) and MET is also associated with resistance to EGFR inhibitor in metastatic CRC patients. The BRAF V600E mutation is found in sporadic microsatellite unstable CRCs, and thus is helpful for ruling out Lynch syndrome. In addition, the KRAS mutation is a prognostic biomarker and the PIK3CA mutation is a molecular biomarker predicting response to phosphoinositide 3-kinase/AKT/mammalian target of rapamycin inhibitors and response to aspirin therapy in CRC patients. Additionally, HER2 testing should be performed in all recurrent or metastatic GCs. If the results of HER2 immunohistochemistry are equivocal, HER2 silver or fluorescence in situ hybridization testing are essential for confirmative determination of HER2 status. Epstein-Barr virus–positive GCs have distinct characteristics, including heavy lymphoid stroma, hypermethylation phenotype, and high expression of immune modulators. Recent advances in next-generation sequencing technologies enable us to examine various genetic alterations using a single test. Pathologists play a crucial role in ensuring reliable molecular testing and they should also take an integral role between molecular laboratories and clinicians.