Outcomes in Nonmetastatic Hormone Receptor-Positive HER2-Negative Pure Mucinous Breast Cancer: A Multicenter Cohort Study

BACKGROUND

Although considered a favorable subtype, pure mucinous breast cancer (PMBC) can recur, and evidence for adjuvant therapy is limited. We aimed to compare outcomes of nonmetastatic PMBC with invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) to address these uncertainties.

METHODS

Individual patient-level data from 6 centers on stage I-III hormone receptor-positive and HER2-negative PMBC, IDC, and ILC were used to analyze recurrence-free interval (RFI), recurrence-free survival (RFS), and overall survival (OS), and to identify prognostic factors for PMBC.

RESULTS

Data from 20,684 IDC cases, 1,475 ILC cases, and 943 PMBC cases were used. Median follow-up was 6.6 years. Five-year RFI, RFS, and OS for PMBC were 96.1%, 94.9%, and 98.1%, respectively. On multivariable Cox regression, PMBC demonstrated superior RFI (hazard ratio [HR], 0.59; 95% CI, 0.43-0.80), RFS (HR, 0.70; 95% CI, 0.56-0.89), and OS (HR, 0.71; 95% CI, 0.53-0.96) compared with IDC. ILC showed comparable outcomes to IDC. Fewer than half (48.7%) of recurrences in PMBC were distant, which was a lower rate than for IDC (67.3%) and ILC (80.6%). In contrast to RFI, RFS events were driven more by non-breast cancer deaths in older patients. Significant prognostic factors for RFI among PMBC included positive lymph node(s) (HR, 2.42; 95% CI, 1.08-5.40), radiotherapy (HR, 0.44; 95% CI, 0.23-0.85), and endocrine therapy (HR, 0.25; 95% CI, 0.09-0.70). No differential chemotherapy associations with outcomes were detected across PMBC subgroups by nodal stage, tumor size, and age. A separate SEER database analysis also did not find any association of improved survival with adjuvant chemotherapy in these subgroups.

CONCLUSIONS

Compared with IDC, PMBC demonstrated superior RFI, RFS, and OS. Lymph node negativity, adjuvant radiotherapy, and endocrine therapy were associated with superior RFI. Adjuvant chemotherapy was not associated with better outcomes.

Clinicopathological implications of immunohistochemical expression of TBX21, CXCR3, GATA3, CCR4, and TCF1 in nodal follicular helper T-cell lymphoma and peripheral T-cell lymphoma, not otherwise specified

BACKGROUND

The classification of nodal peripheral T-cell lymphoma (PTCL) has evolved according to histology, cell-of-origin, and genetic alterations. However, the comprehensive expression pattern of follicular helper T-cell (Tfh) markers, T-cell factor-1 (TCF1), and Th1- and Th2-like molecules in nodal PTCL is unclear.

METHODS

Eighty-two cases of nodal PTCL were classified into 53 angioimmunoblastic T-cell lymphomas (AITLs)/nodal T-follicular helper cell lymphoma (nTFHL)-AI, 18 PTCLs-Tfh/nTFHL-not otherwise specified (NOS), and 11 PTCLs-NOS according to the revised 4th/5th World Health Organization classifications. Immunohistochemistry for TCF1, TBX21, CXCR3, GATA3, and CCR4 was performed.

RESULTS

TCF1 was highly expressed in up to 68% of patients with nTFHL but also in 44% of patients with PTCL-NOS (p > .05). CXCR3 expression was higher in AITLs than in non-AITLs (p = .035), whereas GATA3 expression was higher in non-AITL than in AITL (p = .007) and in PTCL-Tfh compared to AITL (p = .010). Of the cases, 70% of AITL, 44% of PTCLTfh/ nTFHL-NOS, and 36% of PTCL-NOS were subclassified as the TBX21 subtype; and 15% of AITL, 38% of PTCL-Tfh/nTFHL-NOS, and 36% of PTCL-NOS were subclassified as the GATA3 subtype. The others were an unclassified subtype. CCR4 expression was associated with poor progression-free survival (PFS) in patients with PTCL-Tfh (p < .001) and nTFHL (p = .023). The GATA3 subtype showed poor overall survival in PTCL-NOS compared to TBX21 (p = .046) and tended to be associated with poor PFS in patients with non-AITL (p = .054).

CONCLUSIONS

The TBX21 subtype was more prevalent than the GATA3 subtype in AITL. The GATA3 subtype was associated with poor prognosis in patients with non-AITL and PTCL-NOS.

Fetal Lung Interstitial Tumor: A Comprehensive Case Study with an Emphasis on Next-Generation Sequencing

Fetal lung interstitial tumor (FLIT), which is characterized by immature interstitial cells resembling the fetal lung parenchyma of 20 to 24 weeks of gestation, is a rare respiratory neoplasm. This study presents the first reported FLIT in Korea. It also aims to refine the diagnostic method of FLIT and increase the accuracy of prognostic assessment by using next-generation sequencing to check for anaplastic lymphoma receptor tyrosine kinase (anaplastic lymphoma kinase) gene rearrangement. Although the initial prognosis for FLIT has been promising since its first report in 2010, certain pathological features are associated with poorer outcomes. Therefore, achieving an accurate diagnosis of FLIT is crucial for avoiding unnecessary treatments beyond surgical resection.

Omission of Breast Surgery in Predicted Pathologic Complete Response after Neoadjuvant Systemic Therapy: A Multicenter, Single-Arm, Non-inferiority Trial

PURPOSE

Advances in chemotherapeutic and targeted agents have increased pathologic complete response (pCR) rates after neoadjuvant systemic therapy (NST). Vacuum-assisted biopsy (VAB) has been suggested to accurately evaluate pCR. This study aims to confirm the non-inferiority of the 5-year disease-free survival of patients who omitted breast surgery when predicted to have a pCR based on breast magnetic resonance imaging (MRI) and VAB after NST, compared with patients with a pCR who had undergone breast surgery in previous studies.

METHODS

The Omission of breast surgery for PredicTed pCR patients wIth MRI and vacuum-assisted bIopsy in breaST cancer after neoadjuvant systemic therapy (OPTIMIST) trial is a prospective, multicenter, single-arm, non-inferiority study enrolling in 17 tertiary care hospitals in the Republic of Korea. Eligible patients must have a clip marker placed in the tumor and meet the MRI criteria suggesting complete clinical response (post-NST MRI size ≤ 1 cm and lesion-to-background signal enhancement ratio ≤ 1.6) after NST. Patients will undergo VAB, and breast surgery will be omitted for those with no residual tumor. Axillary surgery can also be omitted if the patient was clinically node-negative before and after NST and met the stringent criteria of MRI size ≤ 0.5 cm. Survival and efficacy outcomes are evaluated over five years.

DISCUSSION

This study seeks to establish evidence for the safe omission of breast surgery in exceptional responders to NST while minimizing patient burden. The trial will address concerns about potential undertreatment due to false-negative results and recurrence as well as improved patient-reported quality of life issues from the omission of surgery. Successful completion of this trial may reshape clinical practice for certain breast cancer subtypes and lead to a safe and less invasive approach for selected patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05505357. Registered on August 17, 2022. Clinical Research Information Service Identifier: KCT0007638. Registered on July 25, 2022.

Biochemical Profiling of Urine Metabolome in Premature Infants Based on LC-MS Considering Maternal Influence

In this study, Liquid Chromatography-Mass Spectrometry (LC-MS)-based metabolomics profiling was conducted to elucidate the urinary profiles of premature infants during early and late postnatal stages. As a result, we discovered significant excretion of maternal drugs in early-stage infants and identified crucial metabolites like hormones and amino acids. These findings shed light on the maternal impact on neonatal metabolism and underscore the beneficial effects of breastfeeding on the metabolism of essential amino acids in infants. This research not only enhances our understanding of maternal-infant nutritional interactions and their long-term implications for preterm infants but also offers critical insights into the biochemical characteristics and physiological mechanisms of preterm infants, laying a groundwork for future clinical studies focused on neonatal development and health.

Identification of VWA5A as a novel biomarker for inhibiting metastasis in breast cancer by machine-learning based protein prioritization

Distant metastasis is the leading cause of death in breast cancer (BC). The timing of distant metastasis differs according to subtypes of BCs and there is a need for identification of biomarkers for the prediction of early and late metastasis. To identify biomarker candidates whose abundance level can discriminate metastasis types, we performed a high-throughput proteomics assay using tissue samples from BCs with no metastasis, late metastasis, and early metastasis, processed data with machine learning-based feature selection, and found that low VWA5A could be responsible for shorter duration of metastasis-free interval. Low expression of VWA5A gene in METABRIC cohort was associated with poor survival in BCs, especially in hormone receptor (HR)-positive BCs. In-vitro experiments confirmed tumor suppressive effect of VWA5A on BCs in HR+ and triple-negative BC cell lines. We found that expression of VWA5A can be assessed by immunohistochemistry (IHC) on archival tissue samples. Decreasing nuclear expression of VWA5A was significantly associated with advanced T stage and lymphatic invasion in consecutive BCs of all subtypes. We discovered lower expression of VWA5A as the potential biomarker for metastasis-prone BCs, and our results support the clinical utility of VWA5A IHC, as an adjunctive tools for prognostication of BCs.

HER2 amplification level by in situ hybridization predicts survival outcome in advanced HER2-positive breast cancer treated with pertuzumab, trastuzumab, and docetaxel regardless of HER2 IHC results

BACKGROUND

The role of HER2 amplification level in predicting the effectiveness of HER2-directed therapies has been established. However, its association with survival outcomes in advanced HER2-positive breast cancer treated with dual HER2-blockade remains unexplored.

METHODS

This is a single-center retrospective study of patients with advanced HER2-positive breast cancer treated with first-line pertuzumab, trastuzumab, and docetaxel. The primary objective was to ascertain the relationship between treatment outcomes and the level of HER2 amplification by in situ hybridization (ISH).

RESULTS

A total of 152 patients were included with a median follow-up duration of 50.0 months. Among the 78 patients who received ISH, a higher HER2/CEP17 ratio correlated significantly with longer PFS (HR 0.50, p = 0.022) and OS (HR 0.28, p = 0.014) when dichotomized by the median. A higher HER2 copy number also correlated significantly with better PFS (HR 0.35, p < 0.001) and OS (HR 0.27, p = 0.009). In multivariate analysis, the HER2/CEP17 ratio was an independent predictive factor for PFS (HR 0.66, p = 0.004) and potentially for OS (HR 0.64, p = 0.054), along with HER2 copy number (PFS HR 0.85, p = 0.004; OS HR 0.84, p = 0.049). Furthermore, the correlation between HER2 amplification level by ISH with PFS and OS was consistent across the HER2 IHC 1+/2+ and 3+ categories.

CONCLUSIONS

This is the first study to report that a higher level of HER2 amplification by ISH is associated with improved PFS and OS in advanced HER2-positive breast cancer treated with dual HER2-blockade. Notably, HER2 amplification level had a predictive role regardless of IHC results. Even in patients with HER2 protein expression of 3+, treatment outcome to HER2-directed therapy was dependent on the level of HER2 gene amplification.

The prognostic value of a combined immune score in tumor and immune cells assessed by immunohistochemistry in triple-negative breast cancer

BACKGROUND

This study aimed to develop a novel combined immune score (CIS)-based model assessing prognosis in triple-negative breast cancer (TNBC).

METHODS

The expression of eight immune markers (PD-1, PD-L1, PD-L2, IDO, TIM3, OX40, OX40L, and H7-H2) was assessed with immunohistochemistry on the tumor cells (TCs) and immune cells (ICs) of 227 TNBC cases, respectively, and subsequently associated with selected clinicopathological parameters and survival. Data retrieved from The Cancer Genome Atlas (TCGA) were further examined to validate our findings.

RESULTS

All immune markers were often expressed in TCs and ICs, except for PD-1 which was not expressed in TCs. In ICs, the expression of all immune markers was positively correlated between one another, except between PD-L1 and OX40, also TIM3 and OX40. In ICs, PD-1, PD-L1, and OX40L positive expression was associated with a longer progression-free survival (PFS; p = 0.040, p = 0.020, and p = 0.020, respectively). In TCs, OX40 positive expression was associated with a shorter PFS (p = 0.025). Subsequently, the TNBC patients were classified into high and low combined immune score groups (CIS-H and CIS-L), based on the expression levels of a selection of biomarkers in TCs (TCIS-H or TCIS-L) and ICs (ICIS-H or ICIS-L). The TCIS-H group was significantly associated with a longer PFS (p < 0.001). Furthermore, the ICIS-H group was additionally associated with a longer PFS (p < 0.001) and overall survival (OS; p = 0.001), at significant levels. In the multivariate analysis, both TCIS-H and ICIS-H groups were identified as independent predictors of favorable PFS (p = 0.012 and p = 0.001, respectively). ICIS-H was also shown to be an independent predictor of favorable OS (p = 0.003). The analysis of the mRNA expression data from TCGA also validated our findings regarding TNBC.

CONCLUSION

Our novel TCIS and ICIS exhibited a significant prognostic value in TNBC. Additional research would be needed to strengthen our findings and identify the most efficient prognostic and predictive biomarkers for TNBC patients.

Artificial intelligence-powered spatial analysis of tumor-infiltrating lymphocytes as a biomarker in locally advanced unresectable thymic epithelial neoplasm: A single-center, retrospective, longitudinal cohort study

BACKGROUND

Thymic epithelial tumors (TET) are rare malignancies and lack well-defined biomarkers for neoadjuvant therapy. This study aimed to evaluate the clinical utility of artificial intelligence (AI)-powered tumor-infiltrating lymphocyte (TIL) analysis in TET.

METHODS

Patients initially diagnosed with unresectable thymoma or thymic carcinoma who underwent neoadjuvant therapy between January 2004 and December 2021 formed our study population. Hematoxylin and eosin-stained sections from the initial biopsy and surgery were analyzed using an AI-powered spatial TIL analyzer. Intratumoral TIL (iTIL) and stromal TIL (sTIL) were quantified and their immune phenotype (IP) was identified.

RESULTS

Thirty-five patients were included in this study. The proportion of patients with partial response to neoadjuvant therapy was higher in the group with nondesert IP in preneoadjuvant biopsy (63.6% vs. 17.6%, p = 0.038). A significant increase in both iTIL (median 22.18/mm2 vs. 340.69/mm2 , p < 0.001) and sTIL (median 175.19/mm2 vs. 531.02/mm2 , p = 0.004) was observed after neoadjuvant therapy. Patients with higher iTIL (>147/mm2 ) exhibited longer disease-free survival (median, 29 months vs. 12 months, p = 0.009) and overall survival (OS) (median, 62 months vs. 45 months, p = 0.002). Patients with higher sTIL (>232.1/mm2 ) exhibited longer OS (median 62 months vs. 30 months, p = 0.021).

CONCLUSIONS

Nondesert IP in initial biopsy was associated with a better response to neoadjuvant therapy. Increased infiltration of both iTIL and sTIL in surgical specimens were associated with longer OS in patients with TET who underwent resection followed by neoadjuvant therapy.

The Early and Late Effects of High-Dose Irradiation on Cardiac Injury in a Rat Model

PURPOSE/OBJECTIVE(S)

Radiation-induced heart disease is a critical concern after radiotherapy (RT) for thoracic and chest wall tumors; however, the biological effects and mechanisms are still unknown. In this study, we investigated dose-responsive functional and pathological changes in rat hearts at 1, 3, and 5 months after high-dose irradiation. Then, we sought to elucidate the underlying mechanisms of myocardial changes induced by high-dose irradiation.

MATERIALS/METHODS

Whole hearts of rats (N = 72) were irradiated with a single fraction of 0 (control), 10, 20, or 30 Gy and allocated into three groups according to the follow-up period after RT: baseline, one, three, and five months. During follow-up periods, rats underwent functional evaluation by electrocardiogram and echocardiography at 4-week intervals. If a rat's body weight decreased by 20% or more, it was considered premature death, and the heart was explanted immediately. Otherwise, all hearts were explanted when each group's follow-up period was completed. Pathological changes of cardiac structures were evaluated using a light microscope after staining with hematoxylin-eosin, Masson's trichrome, α-smooth muscle actin, desmin, and connexin-43.

RESULTS

All rats irradiated with 0 or 10 Gy completed their follow-up periods with continuously increasing body weight. However, among rats irradiated with 20 or 30 Gy, half of the rats died prematurely at 8-10 weeks after RT, and the remainder survived until 20 weeks. In echocardiography, increased wall thickness and E/E' ratio, and decreased end-diastolic volume were observed in 20-30 Gy groups compared to 0-10 Gy groups from 8 weeks after RT. Ejection fraction was preserved in all groups. In pathological review, 20-30 Gy groups demonstrated diffuse inflammation and vacuolization at 4 weeks. Then, at 8 weeks, prominent fibrotic changes and intercalated disc disruptions were observed. Notably, fibrotic changes were somewhat resolved at 20 weeks, but intercalated disc disruptions were not repaired until 20 weeks. The 0 and 10 Gy groups showed no significant changes in both functional and pathological analyses.

CONCLUSION

Rats irradiated with 20 or 30 Gy showed diastolic dysfunction in functional analysis and time-dependent myocardial changes in pathological analysis. Radiation-induced fibrosis might be a "reactive" fibrosis, which could proceed to either a profibrotic course (progressive fibrosis) or an anti-fibrotic course (recovery phase). Further studies are needed to identify whether high-dose irradiation-induced cardiac fibrosis could be reversible.

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.

Longitudinal multi-omics study of palbociclib resistance in HR-positive/HER2-negative metastatic breast cancer

BACKGROUND

Cyclin-dependent kinase 4/6 inhibitor (CDK4/6) therapy plus endocrine therapy (ET) is an effective treatment for patients with hormone receptor-positive/human epidermal receptor 2-negative metastatic breast cancer (HR+/HER2- MBC); however, resistance is common and poorly understood. A comprehensive genomic and transcriptomic analysis of pretreatment and post-treatment tumors from patients receiving palbociclib plus ET was performed to delineate molecular mechanisms of drug resistance.

METHODS

Tissue was collected from 89 patients with HR+/HER2- MBC, including those with recurrent and/or metastatic disease, receiving palbociclib plus an aromatase inhibitor or fulvestrant at Samsung Medical Center and Seoul National University Hospital from 2017 to 2020. Tumor biopsy and blood samples obtained at pretreatment, on-treatment (6 weeks and/or 12 weeks), and post-progression underwent RNA sequencing and whole-exome sequencing. Cox regression analysis was performed to identify the clinical and genomic variables associated with progression-free survival.

RESULTS

Novel markers associated with poor prognosis, including genomic scar features caused by homologous repair deficiency (HRD), estrogen response signatures, and four prognostic clusters with distinct molecular features were identified. Tumors with TP53 mutations co-occurring with a unique HRD-high cluster responded poorly to palbociclib plus ET. Comparisons of paired pre- and post-treatment samples revealed that tumors became enriched in APOBEC mutation signatures, and many switched to aggressive molecular subtypes with estrogen-independent characteristics. We identified frequent genomic alterations upon disease progression in RB1, ESR1, PTEN, and KMT2C.

CONCLUSIONS

We identified novel molecular features associated with poor prognosis and molecular mechanisms that could be targeted to overcome resistance to CKD4/6 plus ET.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03401359. The trial was posted on 18 January 2018 and registered prospectively.

Historical Review and Future of Cardiac Xenotransplantation

Along with the development of immunosuppressive drugs, major advances on xenotransplantation were achieved by understanding the immunobiology of xenograft rejection. Most importantly, three predominant carbohydrate antigens on porcine endothelial cells were key elements provoking hyperacute rejection: α1,3-galactose, SDa blood group antigen, and N-glycolylneuraminic acid. Preformed antibodies binding to the porcine major xenoantigen causes complement activation and endothelial cell activation, leading to xenograft injury and intravascular thrombosis. Recent advances in genetic engineering enabled knock-outs of these major xenoantigens, thus producing xenografts with less hyperacute rejection rates. Another milestone in the history of xenotransplantation was the development of co-stimulation blockaded strategy. Unlike allotransplantation, xenotransplantation requires blockade of CD40-CD40L pathway to prevent T-cell dependent B-cell activation and antibody production. In 2010s, advanced genetic engineering of xenograft by inducing the expression of multiple human transgenes became available. So-called 'multi-gene' xenografts expressing human transgenes such as thrombomodulin and endothelial protein C receptor were introduced, which resulted in the reduction of thrombotic events and improvement of xenograft survival. Still, there are many limitations to clinical translation of cardiac xenotransplantation. Along with technical challenges, zoonotic infection and physiological discordances are major obstacles. Social barriers including healthcare costs also need to be addressed. Although there are several remaining obstacles to overcome, xenotransplantation would surely become the novel option for millions of patients with end-stage heart failure who have limited options to traditional therapeutics.

Abstract 2467: Novel biomarkers of metastasis-prone breast cancer revealed by high-throughput proteomics assay

Relatively high cost of gene expression-based prognostic tools in breast cancer (BC) hinders the public accessibility. Therefore, there is a need for development of robust prognostic biomarker for prediction of early and late metastasis. We designed high-throughput proteomics assay to compare protein expression profiles of BC with no metastasis (NM), late metastasis (LM), and early metastasis (M) on 29 patients with BC at Seoul National University Hospital (SNUH). We defined the LM as the development of metastasis after 5 years from the diagnosis. Mass spectrometry (MS) data were collected in data-dependent acquisition (DDA) mode and quantified by Perseus (version 1.5.8.5). ANOVA was used to determine differentially expressed proteins (DEP). Mutual information-based feature selection was used to pick features for metastasis. We used METABRIC dataset to validate prognostic significance. Cell migration and invasion assays were further performed using TNBC cell line after transfecting the cells with siRNA. Mean metastasis free survival time was 8.4 years with LM, and 1.6 years in the patients in M group. A total of 9,455 proteins were identified across the discovery set, and 6,639 proteins were quantified with label-free quantification intensities. 830 proteins were found to be differentially expressed among the groups with an FDR-adjusted p-value &lt; 0.05. Mutual information selected TUBB as the most highly expressed in M group (median, 36.4), least in NM group (median, 36.0), and intermediate in LM groups (median, 36.1). The expression of VWA5A sequentially decreased from NM group (median, 29.6), LM group (median, 29.2), and M group (median, 28.2). In METABRIC cohort, we found that high TUBB expression is strong, significant poor prognostic factor for DFS in all cases with BC (p &lt; 0.0001), ER+ subgroup (p = 0.0001), HER2+ subgroup (p = 0.0085), but not in TNBC (p = 0.1017). In similar manner, lower expression of VWA5A was significantly correlated with shorter DFS in all (p = 0.0003) and ER+ subtype (p &lt; 0.0001), but not in HER2+ and TNBC subsets (p = 0.1350 and 0.2314, respectively). Discrepant prognostic significance of two candidate biomarkers in certain subtypes of BCs indicate that these molecules may behave differently according to intrinsic subtypes. Therefore, we performed functional experiments using TNBC cell lines. siRNA induced silencing of TUBB in MDA-MB-231 and Hs378T resulted in significantly decreased invasion and migration, while siVWA5A transfected BT20 and HCC70 showed stronger propensity toward invasion and migration. Though impacts on survival were not ascertained, our proteomics and in vitro analyses suggest TUBB and VWA5A as the feasible biomarkers representing the biological aggressiveness of BCs including TNBCs. Further investigations on TUBB and VWA5A are warranted to gather deeper understandings how these two molecules results in different biological behaviors of BCs.

Citation Format: Jiwon Koh, Dabin Jeong, Dohyun Han, Sohyeon Yang, Sun Kim, Han Suk Ryu. Novel biomarkers of metastasis-prone breast cancer revealed by high-throughput proteomics assay [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2467.

Abstract 5951: The correlation between single nucleotide polymorphism of chemokine receptor and ligand and infiltrating immune cells on tumor microenvironment of gastric cancer

Objective: Chemokines play roles in many normal biological processes, such as hematopoietic cell genesis and leukocyte migration and homing. Chemokines could be responsible for eliciting local accumulation of immune cells within tumor microenvironment. In this study, we examine if genetic variations in chemokine receptor and ligand are associated with infiltrations of immune cells on tumor microenvironment in gastric cancer.

Methods: In 356 gastric cancer patients who received curative surgery followed by adjuvant chemotherapy, total 105 single nucleotide polymorphisms (SNP) in a chemokine ligand and chemokine receptor locus within 16 genes (CXCR4, CXCR2, CXCR1, CX3CR1, CCR8, CCR9, CCR3, CCR2, CCR5, CCRL2, CCR6, CXCR5, CCR6, CXCR6, CCR7, DARC) were genotyped from peripheral blood sample. Total 11 immune markers such as CD3, CD4, CD8, FOXp3, CD68, CD163, L-selectin, i-NOS, ADMA17, Arginase, CD45RO were analyzed for deposition of immune cells according to SNP of chemokine receptor and ligand. Levels of immunohistochemistry staining were quantified by Image Analysis Toolbox and density of immune cells infiltration was calculated.

Results: 32 SNP locus of 8 genes (such as CXCR1, CXCR2, CCR3, CCR2, CCR5, CCRL2, CCR6. CXCR5) were selected using 25% cut-off value of minor allele frequency (MAF). Among 8 genes, CCR5 was the most relevant gene for immune cell infiltration on tumor microenvironment. Intron1-2545G&gt;A (rs1799987) were associated with increased accumulation of CD3+, CD68+ and FOXp3+ cells compared to recessive carriers of the common allele. In CCR5 SNP that contained the common alleles of intron1-2549 G&gt;T (rs2734648) and exon2A-2081 A&gt;G (rs1800023), CD3+, CD4+, CD8+ and FOXp3+ cells were infiltrated more than minor alleles.

Conclusions: The associations between infiltration of immune cells and SNP of chemokine receptor and ligand in gastric cancer were shown. Particularly, CCR5 SNP may be most relevant for correlation with infiltration of immune cells on tumor microenvironment.

Citation Format: Sunjoo Yoon, Ju Hyun Lee, Minsu Kang, Hyeon Jeong Oh, Jiwon Koh, Hye Seung Lee, So Hyun Kang, Young Suk Park, Keun-Wook Lee, Jin Won Kim. The correlation between single nucleotide polymorphism of chemokine receptor and ligand and infiltrating immune cells on tumor microenvironment of gastric cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5951.

Abstract P3-05-36: Prognostic factors in non-metastatic hormone receptor-positive HER2-negative mucinous breast cancer: an international multicentre cohort study

Background: Mucinous carcinoma is the third most common histological subtype of breast cancer after ductal and lobular carcinomas, accounting for approximately 3% of invasive breast cancers. Although considered a favourable subtype with de-escalation of treatment recommended in the National Comprehensive Cancer Network guidelines, recurrence can occur and supporting data is limited. We thus examined prognostic factors of pure mucinous breast cancer (PMBC) in an international multicentre cohort study. Methods: Patients diagnosed between January 2000 to December 2015 with hormone receptor-positive HER2-negative stage I to III PMBC, invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) at 6 centers in Singapore, Taiwan, Korea and Japan were evaluated. Cox proportional hazards regression analyses were used to compare relapse-free survival (RFS), distant relapse-free survival (DRFS) and overall survival (OS) by histological subtypes, and to identify prognostic factors for PMBC. Results: Of 23,105 women eligible for analysis, 20,684 had IDC, 1,475 had ILC and 946 had PMBC. The median follow-up was 6.6 years; 5-year RFS, DRFS and OS for PMBC were 94.6%, 96.5% and 98.1% respectively. On multivariable cox regression analyses, PMBC demonstrated superior RFS (hazard ratio [HR] = 0.70, 95% CI: 0.56 - 0.88), DRFS (HR = 0.69, 95% CI: 0.53 - 0.89) and OS (HR = 0.70, 95% CI: 0.52 - 0.93) compared to IDC, while ILC had comparable survival outcomes as IDC. When restricted to only PMBC, significant independent prognostic factors for RFS included ethnicity (vs Chinese, “Others” [non-Chinese/Japanese/Korean, mainly Malay and Indian]: HR = 2.62, 95% CI 1.23 – 5.57), older age (vs &lt; 40 years, &gt;70 years: HR = 3.53, 95% CI 1.67 – 7.46), tumor size (vs T1, T3-4: HR = 2.79, 95% CI 1.45 – 5.37), positive lymph nodes (HR = 2.04, 95% CI: 1.10 – 3.77), use of radiotherapy (HR = 0.54, 95% CI 0.33 – 0.91) and endocrine therapy (HR = 0.31, 95% CI 0.12 – 0.77). On further analysis, the inferior RFS, DRFS and OS in older patients (&gt;70 years) were driven largely by non-breast cancer deaths rather than relapses. Use of endocrine therapy was also associated with superior DRFS (HR = 0.26, 95% CI 0.09 – 0.73) but not OS. In a subgroup analysis, use of chemotherapy was associated with improved DRFS (HR = 0.25, 95% CI 0.08 – 0.82) and OS (HR = 0.07, 95% CI 0.01 – 0.37) with a trend in RFS (HR = 0.41, 95% CI 0.14 – 1.24) for lymph node-positive PMBC; no differences in outcomes were observed for the lymph node-negative subgroup. Conclusions: Larger tumor size, lymph node positivity and ethnicity were significant factors for RFS in PMBC. Use of endocrine therapy was associated with superior RFS and DRFS, while chemotherapy was associated with better DRFS and OS for lymph-node positive PMBC.

Citation Format: Ryan Tan, Whee Sze Ong, Kyung-Hun Lee, Seri Park, Jabed Iqbal, Yeon Hee Park, Jeong-Eon Lee, Jong Han Yu, Ching-Hung Lin, Yen-Shen Lu, Makiko Ono, Takayuki Ueno, Yoichi Naito, Tatsuya Onishi, Geok hoon Lim, Su-Ming Tan, Han-Byoel Lee, Jiwon Koh, Han Suk Ryu, Wonshik Han, Veronique Kiak Mien Tan, Fuh-Yong Wong, Seock-Ah Im, Puay Hoon Tan, Yoon-Sim Yap. Prognostic factors in non-metastatic hormone receptor-positive HER2-negative mucinous breast cancer: an international multicentre cohort study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-05-36.

Distinct and overlapping features of nodal peripheral T-cell lymphomas exhibiting a follicular helper T-cell phenotype: a multicenter study emphasizing the clinicopathological significance of follicular helper T-cell marker expression

Nodal peripheral T-cell lymphoma (PTCL) is a heterogeneous category including angioimmunoblastic T-cell lymphoma (AITL), PTCL of follicular helper T-cell (Tfh) phenotype (PTCL-Tfh), and PTCL, not otherwise specified (PTCL-NOS). We explored Tfh marker profiles in nodal PTCL. Nodal PTCLs (n = 129) were reclassified into AITL (58%; 75/129), PTCL-Tfh (26%; 34/129), and PTCL-NOS (16%; 20/129). Histologically, clear cell clusters, high endothelial venules, follicular dendritic cell proliferation, EBV+ cells, and Hodgkin-Reed-Sternberg (HRS)-like cells were more common in AITL than PTCL-Tfh (HRS-like cells, P = .005; otherwise, P < .001) and PTCL-NOS (HRS-like cells, P = .028; otherwise, P < .001). PTCL-NOS had a higher Ki-67 index than AITL (P = .001) and PTCL-Tfh (P = .002). Clinically, AITL had frequent B symptoms (versus PTCL-Tfh, P = .010), while PTCL-NOS exhibited low stage (versus AITL + PTCL-Tfh, P = .036). Positive Tfh markers were greater in AITL (3.5 ± 1.1) than PTCL-Tfh (2.9 ± 0.9; P = .006) and PTCL-NOS (0.5 ± 0.5; P < .001). Tfh markers showed close correlations among them and AITL-defining histology. By clustering analysis, AITL and PTCL-NOS were relatively exclusively clustered, while PTCL-Tfh overlapped with them. Survival was not different among the PTCL entities. By Cox regression, sex and ECOG performance status (PS) independently predicted shorter progression-free survival in the whole cohort (male, P = .001, HR = 2.5; PS ≥ 2, P = .010, HR = 1.9) and in 'Tfh-lymphomas' (ie, AITL + PTCL-Tfh) (male, P = .001, HR = 2.6; PS ≥ 2, P = .016, HR = 2.1), while only PS predicted shorter overall survival (OS) in the whole cohort (P = .012, HR = 2.7) and in 'Tfh-lymphomas' (P = .001; HR = 3.2). ICOS predicted favorable OS in 'Tfh-lymphomas' (log-rank; P = .016). Despite the overlapping features, nodal PTCL entities could be characterized by Tfh markers revealing clinicopathologic implications.

Feasibility and safety of a novel 3D-printed biodegradable biliary stent in an in vivo porcine model: a preliminary study

To assess the feasibility and safety of a novel 3D-printed biodegradable biliary stent using polycaprolactone (PCL) in an in vivo porcine model. In this animal study using domestic pigs, biodegradable radiopaque biliary stents made of polycaprolactone (PCL) and barium sulfate were produced using 3D printing and surgically inserted into the common bile duct (CBD) of pigs (stent group, n = 12). Another five pigs were allocated to the control group that only underwent resection and anastomosis of the CBD without stent insertion. To check the position and status of the stents and stent-related complications, follow-up computed tomography (CT) was performed every month. The pigs were sacrificed 1 or 3 months after surgery, and their excised CBD specimens were examined at both the macroscopic and microscopic levels. Three pigs (one in the stent group and two in the control group) died within one day after surgery and were excluded from further analysis; the remaining 11 in the stent group and 3 in the control group survived the scheduled follow-up period (1 month, 5 and 1; and 3 months, 6 and 2 in stent and control groups, respectively). In all pigs, no clinical symptoms or radiologic evidence of biliary complications was observed. In the stent group (n = 11), stent migration (n = 1 at 3 months; n = 2 at 1 month) and stent fracture (n = 3 at 2 months) were detected on CT scans. Macroscopic evaluation of the stent indicated no significant change at 1 month (n = 3) or fragmentation with discoloration at 3 months (n = 5). On microscopic examination of CBD specimens, the tissue inflammation score was significantly higher in the stent group than in the control group (mean ± standard deviation (SD), 5.63 ± 2.07 vs. 2.00 ± 1.73; P = 0.039) and thickness of fibrosis of the CBD wall was significantly higher than that of the control group (0.46 ± 0.12 mm vs. 0.21 ± 0.05 mm; P = 0.012). Despite mild bile duct inflammation and fibrosis, 3D-printed biodegradable biliary stents showed good feasibility and safety in porcine bile ducts, suggesting their potential for use in the prevention of postoperative biliary strictures.

Lymphoproliferative disorder involving body fluid: diagnostic approaches and roles of ancillary studies

Lymphocyte-rich effusions represent benign reactive process or neoplastic condition. Involvement of lymphoproliferative disease in body cavity is not uncommon, and it often causes diagnostic challenge. In this review, we suggest a practical diagnostic approach toward lymphocyte-rich effusions, share representative cases, and discuss the utility of ancillary tests. Cytomorphologic features favoring neoplastic condition include high cellularity, cellular atypia/pleomorphism, monomorphic cell population, and frequent apoptosis, whereas lack of atypia, polymorphic cell population, and predominance of small T cells usually represent benign reactive process. Involvement of non-hematolymphoid malignant cells in body fluid should be ruled out first, followed by categorization of the samples into either small/medium-sized cell dominant or large-sized cell dominant fluid. Small/medium-sized cell dominant effusions require ancillary tests when either cellular atypia or history/clinical suspicion of lymphoproliferative disease is present. Large-sized cell dominant effusions usually suggest neoplastic condition, however, in the settings of initial presentation or low overall cellularity, ancillary studies are helpful for more clarification. Ancillary tests including immunocytochemistry, in situ hybridization, clonality test, and next-generation sequencing can be performed using cytologic preparations. Throughout the diagnostic process, proper review of clinical history, cytomorphologic examination, and application of adequate ancillary tests are key elements for successful diagnosis.

Clinicopathologic and Genetic Features of Primary T-cell Lymphomas of the Central Nervous System: An Analysis of 11 Cases Using Targeted Gene Sequencing

Primary central nervous system lymphoma (PCNSL) of peripheral T-cell lineage (T-PCNSL) is rare, and its genetic and clinicopathologic features remain unclear. Here, we present 11 cases of T-PCNSL in immunocompetent individuals from a single institute, focusing on their genetic alterations. Seven cases were subject to targeted panel sequencing covering 120 lymphoma-related genes. Nine of the eleven cases were classified as peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), of which one was of γδT-cell lineage. There was one case of anaplastic lymphoma kinase-positive anaplastic large cell lymphoma and another of extranodal natural killer (NK)/T-cell lymphoma (ENKTL) of αβT-cell lineage. The male to female ratio was 7 : 4 and the age ranged from 3 to 75 years (median, 61 y). Most patients presented with neurological deficits (n=10) and showed multifocal lesions (n=9) and deep brain structure involvement (n=9). Tumor cells were mostly small-to-medium, and T-cell monoclonality was detected in all nine evaluated cases. PTCL-NOS was CD4-positive (n=4), CD8-positive (n=3), mixed CD4-positive and CD8-positive (n=1), or CD4/CD8-double-negative (n=1, γδT-cell type). Cytotoxic molecule expression was observed in 4 (67%) of the 6 evaluated cases. Pathogenic alterations were found in 4 patients: one PTCL-NOS case had a frameshift mutation in KMT2C, another PTCL-NOS case harbored a truncating mutation in TET2, and another (γδT-cell-PTCL-NOS) harbored NRAS G12S and JAK3 M511I mutations, and homozygous deletions of CDKN2A and CDKN2B. The ENKTL (αβT-cell lineage) case harbored mutations in genes ARID1B, FAS, TP53, BCOR, KMT2C, POT1, and PRDM1. In conclusion, most of the T-PCNSL were PTCL-NOS, but sporadic cases of other subtypes including γδT-cell lymphoma, anaplastic lymphoma kinase-positive anaplastic large cell lymphoma, and ENKTL were also encountered. Immunophenotypic analysis, clonality test, and targeted gene sequencing along with clinicoradiologic evaluation, may be helpful for establishing the diagnosis of T-PCNSL. Moreover, this study demonstrates genetic alterations with potential diagnostic and therapeutic utility in T-PCNSL.

Nicotinamide (niacin) supplement increases lipid metabolism and ROS‐induced energy disruption in triple‐negative breast cancer: potential for drug repositioning as an anti‐tumor agent

Metabolic dysregulation is an important hallmark of cancer. Nicotinamide (NAM), a water‐soluble amide form of niacin (vitamin B3), is currently available as a supplement for maintaining general physiologic functions. NAM is a crucial regulator of mitochondrial metabolism and redox reactions. In this study, we aimed to identify the mechanistic link between NAM‐induced metabolic regulation and the therapeutic efficacy of NAM in triple‐negative breast cancer (TNBC). The combined analysis using multiomics systems biology showed that NAM decreased mitochondrial membrane potential and ATP production, but increased the activities of reverse electron transport (RET), fatty acid β‐oxidation and glycerophospholipid/sphingolipid metabolic pathways in TNBC, collectively leading to an increase in the levels of reactive oxygen species (ROS). The increased ROS levels triggered apoptosis and suppressed tumour growth and metastasis of TNBC in both human organoids and xenograft mouse models. Our results showed that NAM treatment leads to cancer cell death in TNBC via mitochondrial dysfunction and activation of ROS by bifurcating metabolic pathways (RET and lipid metabolism); this provides insights into the repositioning of NAM supplement as a next‐generation anti‐metabolic agent for TNBC treatment.

Abstract PD15-08: Window of opportunity trial of neoadjuvant olaparib and durvalumab for triple negative or low ER-positive breast cancer

Background PARP inhibitors have proven efficacy in breast cancer patients with germline BRCA1 or BRCA2 mutations (gBRCAmt) but also have potential to be effective in cancers with defects in homologous recombination (HR) DNA repair. Moreover, synergy between PARP inhibition and immune checkpoint blockade is expected based on increased mutation burden, neoantigen expression, and immunogenic cell death. Triple negative breast cancer (TNBC) or low estrogen receptor (ER)-positive breast cancers may have diverse defects in HR repair. Methods This is a window of opportunity, serial biopsy trial of olaparib and durvalumab before standard neoadjuvant chemotherapy for TNBC or low ER+ breast cancer (NCT03594396). Patients had clinical stage II/III TNBC or low ER+ HER2- breast cancers where ER was expressed in 10% or lower in tumor cells. Olaparib 300mg bid was given for 4 weeks without rest. One dose of durvalumab 1500mg was given on day 15. Study tumor biopsy and blood sample were taken before the study treatment, after 2 weeks of olaparib before durvalumab, and 2 weeks after durvalumab at the completion of 4 weeks of olaparib. FDG-PET/MRI was taken at baseline, after 2 weeks, after 4 weeks of study treatment, and computed tomography (CT) scan at baseline and after 4 weeks. After the study treatment, standard neoadjuvant chemotherapy with 4 cycles of doxorubicin+cyclophosphamide followed by 4 cycles of docetaxel was given. Primary endpoint was the changes of tumor biology detected by serial tumor biopsy. Secondary endpoints were pathological complete response (pCR) rate, response rate, prediction of early metabolic response by functional HR status, and safety. Functional HR deficiency was assessed by counting RAD51 foci as a marker for HR repair in the baseline tumor tissues before and after 30Gy irradiation to induce DNA damage. Results Fifty-four female patients were enrolled (median age 40 years, range 24-68). ER was negative (TNBC) in 43 patients and low-positive in 11 patients. Clinical stage was II in 25 patients and III in 29 patients, and axillary lymph node involvement was in 47 patients. gBRCAmt was assessed in 53 patients and 16 (30.1%) harbored pathogenic mutations. Functional HR status as measured by RAD51 foci formation was deficient in 27 (50%) patients and proficient in 27 (50%) patients. Functional HR deficiency was related with early metabolic response by FDG-PET after 2 weeks of olaparib (response in 17/27 HR-deficient tumors [63.0%] vs. 7/27 HR-proficient tumors [25.9%]; p=.006). After 4 weeks of olaparib and durvalumab, HR-deficiency was still related to metabolic response (23/27 vs. 17/27, respectively; p=.062) but HR-proficient tumors also showed metabolic decline. Moreover, HR deficiency was also related with RECIST response measured by CT after 4 weeks (17/27 vs. 9/27; p=.029). As of June 2021, 40 patients completed the neoadjuvant treatment and surgery; among those, 30 achieved pCR (pCR rate 75%). Among 13 patients with gBRCAmt who underwent surgery, 11 achieved pCR (84.6%). Updated results on pCR will be presented. Conclusions Olaparib and durvalumab followed by standard neoadjuvant chemotherapy shows very high pCR rate in TNBC or low ER+ stage II/III breast cancer. Functional HR status as measured by RAD51 foci formation was predictive of early metabolic response to olaparib. Genomic and transcriptomic analyses are underway in the samples before, during, and after olaparib and durvalumab.

Citation Format: Seock-Ah Im, Kyung-Hun Lee, Ahrum Min, Daewon Lee, Tae Yong Kim, Han Suk Ryu, Jiwon Koh, Gi-Jeong Cheon, Yoon-Jung Shin, Yujin Kim, Hyeong-Gon Moon, Wonshik Han, Han-Byoel Lee, Morgan Diolaiti, David Quigley, Alan Ashworth, Nariya Cho. Window of opportunity trial of neoadjuvant olaparib and durvalumab for triple negative or low ER-positive breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD15-08.

Abstract PD2-08: Serial genomic profiling reveals molecular mechanisms of breast cancer resistance to palbociclib

CDK4/6 inhibitors such as palbociclib in combination with endocrine therapy (ET) have remarkablyimproved the outcome of patients with ER+/HER2- metastatic breast cancer (MBC). However, manypatients are intrinsically resistant to CDK4/6i therapy, and those who respond eventually acquireresistance. Although high baseline CCNE1 expression and rare alterations in RB1 and FAT1 geneshave been shown to be associated with CDK4/6i resistance, the molecular mechanisms of CDK4/6iresistance are complex and remain poorly understood. To better understand and overcome CDK4/6iresistance, we performed multi-omics profiling of paired tumor biopsies from ER+/HER2- MBCpatients treated with palbociclib combined with ET. Tumor biopsies taken at pre-treatment, on-treatment, and progressive disease (PD) from 71 patients were profiled using whole-exomesequencing (WES), whole-transcriptome sequencing (RNA-Seq) and IHC analysis. Ourcomprehensive analysis identified several tumor intrinsic molecular markers associated with worsePFS, including the Luminal B subtype (p=0.012, HR=2.593), BRCA1/2 pathogenic mutation (p=0.012,HR=2.67) and mutation signatures linked to APOBEC enzymatic activity (p=0.002, HR=3.19).Conversely, the estrogen response signature (p=0.006, HR=0.43) was associated with favorableprognosis. Unsupervised analysis revealed a cluster of tumors enriched in homologousrecombination deficiency (HRD) linked genomic scars that was associated with poor prognosis(p=0.005, HR=2.49). Of note, these HRD-high tumors responded even more poorly to treatment whenco-occurring with TP53 somatic mutations. Integrative analysis further identified three poorprognosis clusters (IC2-4) enriched in Luminal B, proliferative and HRD features when compared tothe favorable prognosis cluster (IC1).Comparing baseline vs. PD samples, we observed a pattern of post-treatment enrichment for the poorprognosis markers. In addition, breast cancer-associated genes such as BRCA1/2, TP53 and PTENharbored a higher prevalence of genomic alterations including somatic mutation, amplification,. deletion and gene fusion at PD. Cell cycle gene expression and signatures also markedly increased atPD compared to baseline whereas estrogen response signatures decreased. Upon diseaseprogression, tumors had frequently switched to molecular subtypes with aggressive and estrogenindependent characteristics, demonstrating high plasticity in response to CDK4/6i and ET treatment.These patterns of acquired resistance were validated by IHC analysis of cyclins E1 and E2, Ki67 andpRb. To investigate the genomic alterations responsible for acquired resistance, we compared 21paired baseline and PD samples. We observed that PD-specific RB1 loss-of-function events occurredwith higher prevalence than previously reported, underscoring a major role of cell cycle de-regulation in conferring resistance to CDK4/6 inhibition. In this prospective longitudinal multi-omicsstudy, we identified novel candidate biomarkers that can be used to improve prediction of responseto CDK4/6i. In addition, we derived new insights into the molecular mechanisms of drug resistanceto palbociclib plus ET that will help guide therapeutic strategies and drug development inHR+/HER2− MBC.

Citation Format: Zhengyan Kan, Seock-Ah Im, Kyunghee Park, Ji Wen, Kyung-Hun Lee, Yoon-La Choi, Won-Chul Lee, Ahrum Min, Vinicius Bonato, Seri Park, Sripad Ram, Dae-Won Lee, Ji-Yeon Kim, Su Kyeong Lee, Won-Woo Lee, Jisook Lee, Miso Kim, Scott L. Weinrich, Han Suk Ryu, Tae Yong Kim, Stephen Dann, Diane Fernandez, Jiwon Koh, Song Yi Park, Shibing Deng, Eric Powell, Rupesh Kanchi Ravi, Jadwiga Bienkowska, Paul A. Rejto, Woong-Yang Park, Yeon Hee Park. Serial genomic profiling reveals molecular mechanisms of breast cancer resistance to palbociclib [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD2-08.

Prognostic significance of natural killer cell-associated markers in gastric cancer: quantitative analysis using multiplex immunohistochemistry

Background

Natural killer (NK) cells mediate the anti-tumoral immune response as an important component of innate immunity. The aim of this study was to investigate the prognostic significance and functional implication of NK cell-associated surface receptors in gastric cancer (GC) by using multiplex immunohistochemistry (mIHC).

Methods

We performed an mIHC on tissue microarray slides, including 55 GC tissue samples. A total of 11 antibodies including CD57, NKG2A, CD16, HLA-E, CD3, CD20, CD45, CD68, CK, SMA, and ki-67 were used. CD45 + CD3-CD57 + cells were considered as CD57 + NK cells.

Results

Among CD45 + immune cells, the proportion of CD57 + NK cell was the lowest (3.8%), whereas that of CD57 + and CD57- T cells (65.5%) was the highest, followed by macrophages (25.4%), and B cells (5.3%). CD57 + NK cells constituted 20% of CD45 + CD57 + immune cells while the remaining 80% were CD57 + T cells. The expression of HLA-E in tumor cells correlated with that in tumoral T cells, B cells, and macrophages, but not CD57 + NK cells. The higher density of tumoral CD57 + NK cells and tumoral CD57 + NKG2A + NK cells was associated with inferior survival.

Conclusions

Although the number of CD57 + NK cells was lower than that of other immune cells, CD57 + NK cells and CD57 + NKG2A + NK cells were significantly associated with poor outcomes, suggesting that NK cell subsets play a critical role in GC progression. NK cells and their inhibitory receptor, NKG2A, may be potential targets in GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03203-8.

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.

Clinicopathologic implication of PD-L1 gene alteration in primary adrenal diffuse large B cell lymphoma

Background

Primary adrenal (PA) diffuse large B cell lymphoma (DLBCL) was previously reported as an aggressive subset of DLBCL, but its genetic features were not sufficiently characterized. From our previous study of DLBCL with programmed death-ligand 1 (PD-L1) gene alterations, we focused on PD-L1 gene alterations in PA-DLBCL with clinicopathologic implications.

Methods

We performed fluorescence in situ hybridization for PD-L1 gene translocation and amplification in PA-DLBCL (n = 18) and comparatively analyzed clinicopathologic characteristics with systemic non-adrenal (NA)-DLBCL (n = 90).

Results

PA-DLBCL harbored distinctive features (vs. NA-DLBCL), including high international prognostic index score (3–5) (72% [13/18] vs. 38% [34/90], p = .007), poor Eastern Cooperative Oncology Group performance score (≥ 2) (47% [7/15] vs. 11% [10/90], p = .003), elevated serum lactate dehydrogenase (LDH) (78% [14/18] vs. 51% [44/87], p = .035) and MUM1 expression (87% [13/15] vs. 60% [54/90], p = .047). Moreover, PA-DLBCL showed frequent PD-L1 gene alterations (vs. NA-DLBCL) (39% [7/18] vs. 6% [5/86], p = .001), including translocation (22% [4/18] vs. 3% [3/87], p = .016) and amplification (17% [3/18] vs. 2% [2/87], p = .034). Within the PA-DLBCL group, PD-L1 gene–altered cases (vs. non-altered cases) tended to have B symptoms (p = .145) and elevated LDH (p = .119) but less frequent bulky disease (≥ 10 cm) (p = .119). In the survival analysis, PA-DLBCL had a poor prognosis for overall survival (OS) and progression-free survival (PFS) (vs. NA-DLBCL; p = .014 and p = .004). Within the PA-DLBCL group, PD-L1 translocation was associated with shorter OS and PFS (p < .001 and p = .012).

Conclusions

PA-DLBCL is a clinically aggressive and distinct subset of DLBCL with frequent PD-L1 gene alterations. PD-L1 gene translocation was associated with poor prognosis in PA-DLBCL.

Expression of the immune checkpoint receptors PD-1, LAG3, and TIM3 in the immune context of stage II and III gastric cancer by using single and chromogenic multiplex immunohistochemistry

We sought to determine the clinicopathological significance of PD-1, LAG3, and TIM3 in gastric cancer (GC) by examining their expression and immune context. Immunohistochemistry (IHC) for PD-1, TIM3, LAG3, and tumor-infiltrating immune cell (TIIC) markers was performed in 385 stage II/III GCs. Epstein-Barr virus (EBV) and microsatellite stability (MSI) testing were performed for molecular classification. Chromogenic multiplex IHC (mIHC) for PD1, TIM3, LAG3, CD3, CD8, FOXP3, CD68, and cytokeratin was performed in 58 of the total samples. PD-1, LAG3, and TIM3 expression in TIICs was observed in 91 (23.6%), 193 (50.1%), and 257 (66.8%) GCs by single IHC, respectively. The expression was associated with EBV⁺ and MSI-H molecular subtypes (p ≤ 0.001). A positive expression of LAG3 in the invasive margin of the tumor was associated with better prognosis in univariate (p = .020) and multivariate (p = .026) survival analyses. The expression of different immune checkpoint receptors (ICRs) was significantly positively correlated. Dual or triple ICR expression was more frequent in high PD-1 and TIM3 density groups than in low-density groups by mIHC (all p ≤ 0.05). ICRs were mainly expressed in CD3⁺CD8⁺ and CD3⁺CD8⁻ T cells. Fifty-eight GCs were classified into three groups by clustering analysis based on mIHC, and the group with the highest ICR expression in TIICs showed significantly better outcomes in progression-free survival (p = .020). In GC, PD-1, LAG3, and TIM3 expression is positively correlated and associated with better prognosis. Our study provides information for the application of effective immune checkpoint inhibitors against GC.

Marked differences in local bone remodelling in response to different marrow stimulation techniques in a large animal

Marrow stimulation, including subchondral drilling and microfracture, is the most commonly performed cartilage repair strategy, whereby the subchondral bone plate is perforated to release marrow-derived cells into a cartilage defect to initiate repair. Novel scaffolds and therapeutics are being designed to enhance and extend the positive short-term outcomes of this marrow stimulation. However, the translation of these newer treatments is hindered by bony abnormalities, including bone resorption, intralesional osteophytes, and bone cysts, that can arise after marrow stimulation. In this study, three different marrow stimulation approaches - microfracture, subchondral drilling and needle-puncture - were evaluated in a translationally relevant large-animal model, the Yucatan minipig. The objective of the study was to determine which method of marrow access (malleted awl, drilled Kirschner wire or spring-loaded needle) best preserved the underlying subchondral bone. Fluorochrome labels were injected at the time of surgery and 2 weeks post-surgery to capture bone remodelling over the first 4 weeks. Comprehensive outcome measures included cartilage indentation testing, histological grading, microcomputed tomography and fluorochrome imaging. Findings indicated that needle-puncture devices best preserved the underlying subchondral bone relative to other marrow access approaches. This may relate to the degree of bony compaction occurring with marrow access, as the Kirschner wire approach, which consolidated bone the most, induced the most significant bone damage with marrow stimulation. This study provided basic scientific evidence in support of updated marrow stimulation techniques for preclinical and clinical practice.

153 Age and the Extent of Chest Radiographic Findings in Hospitalized Patients with COVID 19

Introduction

Since the emergence of COVID 19 in December 2019, its clinical and radiological features are still being discovered and their prognostic implications evaluated. Chest X-ray (CXR) typically shows patchy or diffuse asymmetric airspace opacities. Regardless of the different classifications of radiological findings that have been used, it is becoming clear that multi-lobar changes in the lungs are associated with poorer outcomes than single lobar involvement or minimal/no radiological abnormalities.

Aim: To assess the correlation of age with the extent of CXR findings in hospitalized COVID 19 patients.

Methods

A retrospective, cross-sectional analysis was carried out on inpatients with RT-PCR confirmed COVID 19. Chest X-ray findings were classified as minimal/no radiological changes, single lobar opacification and multi-lobar changes (involving 2 or more lobes and/or ARDS changes). SPSS 26 software was used for statistical analysis. Spearman’s correlation and linear regression were used to assess correlation.

Results

211 patients were included in the analysis; 124 males and 87 females. Mean age of the patients was 72.4 years; SD +/−16.15. There was significant positive correlation between age and degree and extent of radiological changes in all patients (r = 0.367; p &lt; 0.01). This correlation persisted even when broken down by gender (r = 0.448; p &lt; 0.01) for males and (r = 0.322; p &lt; 0.01) for females. Discussion: Older age has been repeatedly reported as a risk factor for poor prognosis in COVID 19. The main findings of COVID-19 on CXR are those of atypical or organizing pneumonia. Older people tend to have more extensive involvement of the lungs. There could be many explanations for the CXR correlation with age including the diminished cardiovascular reserve with ageing, the accumulation of comorbidities and decreased or abnormal immune response.

Conclusion

Age significantly correlate with the extent of chest radiographic findings in inpatients with COVID 19.

A case of concomitant EGFR/ALK alteration against a mutated EGFR background in early-stage lung adenocarcinoma

Rare cases of lung adenocarcinoma (LUAD) with concomitant epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) translocation have been reported. However, their clonal and evolutional relationship remains unclear. We report a case of early-stage EGFR-mutated LUAD with a focal concomitant EGFR/ALK alteration. A 63-year-old male underwent lobectomy to remove a 1.9-cm-sized lung nodule, which was diagnosed with EGFR-mutated LUAD. ALK immunohistochemistry (IHC) showed focal positivity within the part of the tumor characterized by lepidic pattern, also confirmed by fluorescence in-situ hybridization (FISH). Targeted next-generation sequencing was performed separately on the ALK IHC/FISH-positive and -negative areas. EGFR L833V/L858R mutations were detected in both areas, whereas EML4 (echinoderm microtubule-associated protein-like 4)-ALK translocations was confirmed only in the ALK IHC/FISH-positive area, suggesting the divergence of an EGFR/ALK co-altered subclone from the original EGFR-mutant clone. Our study suggests that concurrent alterations of EGFR and ALK can arise via divergent tumor evolution, even in the relatively early phases of tumorigenesis.

Tryptophanyl-tRNA Synthetase Sensitizes Hormone Receptor-Positive Breast Cancer to Docetaxel-Based Chemotherapy

Purpose

A relatively low response to chemotherapy has been reported for hormone receptor (HR)-positive breast cancer. In this study, we investigated the role of tryptophanyl-transfer RNA synthetase (WARS) in the chemotherapeutic response of HR-positive breast cancer.

Methods

Pre-chemotherapeutic needle biopsy samples of 45 HR-positive breast cancer patients undergoing the same chemotherapeutic regimen were subjected to immunohistochemistry. To investigate the biological functions of WARS in HR-positive breast cancer, we conducted cell viability assay, flow cytometry analysis, caspase activity assay, Quantitative real-time polymerase chain reaction, and western blotting using WARS gene-modulated HR-positive breast cancer cells (T47D, ZR-75-1, and MCF7).

Results

WARS overexpression in HR-positive breast cancer patients showed a significant correlation with favorable chemotherapy response. Downregulation of WARS increased cell viability following docetaxel treatment in tumor cell lines. On the other hand, WARS overexpression sensitized the therapeutic response to docetaxel. Additionally, downregulation of WARS caused a decrease in the number of apoptotic cell populations by docetaxel. Poly (ADP-ribose) polymerase cleavage and caspase 3/7 activity were increased in docetaxel-treated tumor cells with WARS overexpression.

Conclusion

Our results suggest that WARS might be a potential predictor for chemotherapy response in patients with HR-positive breast cancer as well as a novel molecular target to improve chemosensitivity.

Immunophenotypic Landscape and Prognosis of Diffuse Large B-Cell Lymphoma with MYC/BCL2 Double Expression: An Analysis of A Prospectively Immunoprofiled Cohort

Simple Summary

Diffuse large B-cell lymphoma (DLBCL) with MYC/BCL2 double-expression (DE), a recently proposed poor prognostic group, can be easily identified by immunohistochemistry in routine clinical practice. However, clinical outcomes of DE-DLBCL patients vary immensely after R-CHOP immunochemotherapy and prognostic impact of MYC/BCL2-DE was conflicting according to the cell-of-origin, i.e., between germinal center-B-cell (GCB)- and non-GCB-DLBCLs. This implies the heterogeneity within DE-DLBCLs and emphasizes a need for proper risk stratification to select the patients who require more intensive therapy. By analyzing a prospectively immunoprofiled cohort of consecutively diagnosed DLBCL patients, we confirmed the poor prognostic value of MYC/BCL2-DE in DLBCL patients treated with R-CHOP irrespective of the cell-of-origin and international prognostic index. DE-DLBCLs with a concurrent risk factor, especially, elevated serum lactate dehydrogenase (LDH), had the worst survival and DE-DLBCL patients with normal LDH had clinical outcomes similar to those of non-DE-DLBCL patients. Risk stratification of DE-DLBCL based on serum LDH may guide clinical decision-making for DE-DLBCL patients.

Abstract

Diffuse large B-cell lymphoma (DLBCL) patients with MYC/BCL2 double expression (DE) show poor prognosis and their clinical outcomes after R-CHOP therapy vary immensely. We investigated the prognostic value of DE in aggressive B-cell lymphoma patients (n = 461), including those with DLBCL (n = 417) and high-grade B-cell lymphoma (HGBL; n = 44), in a prospectively immunoprofiled cohort. DE was observed in 27.8% of DLBCLs and 43.2% of HGBLs (p = 0.058). DE-DLBCL patients were older (p = 0.040) and more frequently exhibited elevated serum LDH levels (p = 0.002), higher international prognostic index (IPI; p = 0.042), non-germinal-center B-cell phenotype (p < 0.001), and poor response to therapy (p = 0.042) compared to non-DE-DLBCL patients. In R-CHOP-treated DLBCL patients, DE status predicted poor PFS and OS independently of IPI (p < 0.001 for both). Additionally, in DE-DLBCL patients, older age (>60 years; p = 0.017), involvement of ≥2 extranodal sites (p = 0.021), bone marrow involvement (p = 0.001), high IPI (p = 0.017), CD10 expression (p = 0.006), poor performance status (p = 0.028), and elevated LDH levels (p < 0.001) were significantly associated with poor OS. Notably, DE-DLBCL patients with normal LDH levels exhibited similar PFS and OS to those of patients with non-DE-DLBCL. Our findings suggest that MYC/BCL2 DE predicts poor prognosis in DLBCL. Risk stratification of DE-DLBCL patients based on LDH levels may guide clinical decision-making for DE-DLBCL patients.

Abstract PO-34: Subcutaneous panniculitis-like T-cell lymphoma with HAVCR2 mutation shows unique clinicopathologic features and gene expression profile

Recent studies identified germline HAVCR2 (TIM-3) mutations as the specific genetic predisposition to subcutaneous panniculitis-like T-cell lymphoma (SPTCL). However, distinction between HAVCR2-mutated and HAVCR2-wildtype SPTCLs remains elusive. We studied the prevalence of HAVCR2 mutation in a nation-wide cohort of SPTCL and investigated clinical and molecular distinction between HAVCR2-mutated and HAVCR2-wild-type SPTCLs. A multicenter nationwide cohort of 53 SPTCL cases was established; patients were diagnosed at seven Korean institutions between 2003 and 2020. Histologic features were reviewed by experienced hematopathologists and clinical features were retrospectively reviewed. Whole-exome sequencing (WES) and RNA-seq were performed using formalin-fixed, paraffin-embedded (FFPE) samples of 8 patients diagnosed in Seoul National University Hospital (SNUH), with matched non-neoplastic tissue samples from two patients. Direct sequencing of HAVCR2 exon 2 was successfully carried out using FFPE samples from 33 of the remaining 45 patients. Among 41 patients with available HAVCR2 mutation status, 28 (68.3%) were women, and the median age at diagnosis was 30 years (range 11–74). Ten patients (10/40; 25.0%) suffered hemophagocytic syndrome (HPS) or HPS-like systemic illness during the clinical course, and 14 patients (14/40; 35.0%) progressed during the follow-up. Six patients (6/41; 14.6%) died of disease progression or HPS. We found 18 patients (18/41; 43.9%) with HAVCR2 mutation; 15 patients harbored biallelic HAVCR2 Y82C mutation and 3 patients were noted for heterozygous HAVCR2 Y82C mutation. HAVCR2-mutated SPTCLs occurred in younger patients (median age 26.5 versus 37; Mann-Whitney p-value = 0.003), and were more often complicated by HPS or HPS-like systemic illness (10/18 versus 0/22; Fisher's exact p-value &lt; 0.001), compared to HAVCR2-wild-type SPTCLs. Survival analysis using log-rank test revealed that HAVCR2-mutated SPTCLs had shorter progression-free survival, though statistical significance was not achieved (p-value = 0.081) WES results did not show recurrent genetic alteration other than HAVCR2 Y82C in 4 out of 8 patients. Mutations in genes involved in T/NK cell-associated inflammation (PVRL1, PVRL2, TICAM1, GZMA), epigenetic modification (BAZ2A, KMT2C, KMT2D, SETD1A), JAK-STAT signaling (IFNL2, PIAS3), and NF-kB pathway (PDCD11) were observed in individual cases. Gene set enrichment analyses (GSEA) using RNA-seq results showed significant enrichment of pathways involving TNF-alpha signaling via NF-kB (FDR q-value = 0.008), hypoxia (FDR q-value = 0.009), IL6-JAK-STAT3 signaling (FDR q-value = 0.026), apoptosis (FDR q-value = 0.121), and MTORC1 signaling (FDR q-value = 0.188) in HAVCR2-mutated SPTCLs. HAVCR2 Y82C hotspot mutation frequently occurs in Korean patients with SPTCL, which was characterized by unique clinicopathologic features. SPTCL with HAVCR2 Y82C was enriched with distinct cellular pathways, which remains to be further validated.

Citation Format: Jiwon Koh, Insoon Jang, Seungchan Mun, Cheol Lee, Hee-Jung Cha, Young Ha Oh, Jin Man Kim, Young Hyeh Ko, Jae Ho Han, Heounjeong Go, Jooryung Huh, Kwangsoo Kim, Yoon Kyung Jeon. Subcutaneous panniculitis-like T-cell lymphoma with HAVCR2 mutation shows unique clinicopathologic features and gene expression profile [abstract]. In: Proceedings of the AACR Virtual Meeting: Advances in Malignant Lymphoma; 2020 Aug 17-19. Philadelphia (PA): AACR; Blood Cancer Discov 2020;1(3_Suppl):Abstract nr PO-34.

Comprehensive genetic features of gastric mixed adenoneuroendocrine carcinomas and pure neuroendocrine carcinomas

We aimed to determine the pathogenesis of gastric mixed adenoneuroendocrine carcinoma (MANEC) and pure neuroendocrine carcinoma (NEC), which is largely unknown. Targeted DNA sequencing was performed on 34 tumor samples from 21 patients - 13 adenocarcinoma (ADC)/NEC components from MANECs and eight pure NECs - and 21 matched non-neoplastic gastric tissues. Mutational profiles of MANECs/NECs were compared with those of other tumors using public databases. The majority (64.1%; 59/92) of mutations in MANEC were shared by both ADC and NEC components. TP53 was the most commonly mutated gene in MANEC (69.2%, 9/13) and pure NEC (87.5%, 8/9). All TP53 mutations in MANEC were pathogenic mutations and were shared by both ADC and NEC components. A subset of TP53^WT MANECs had a microsatellite-unstable phenotype or amplifications in various oncogenes including ERBB2 and NMYC, and the only TP53^WT pure NEC harbored MYC amplification. Compared to NEC in other organs, NECs arising from the stomach had unique features including less frequent RB1 mutations. Differentially altered genes of MANEC ADC components were significantly associated with receptor tyrosine kinase signaling pathways, while differentially altered genes of MANEC NEC components were significantly associated with the NOTCH signaling pathway. Our data provide evidence suggesting a possible clonal origin of ADC and NEC components of MANEC, and we found that gastric MANECs and pure NECs are distinct entities with unique mutational profiles and underlying protein networks. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Immunoscore is a strong predictor of survival in the prognosis of stage II/III gastric cancer patients following 5-FU-based adjuvant chemotherapy

The prognostic impact of Immunoscore (IS) in gastric cancer (GC) patients treated with adjuvant chemotherapy remains unelucidated. We evaluated the CD3 + , CD8 + , and Foxp3 + T-lymphocyte densities in tumor centers and invasive margin regions of 389 patients with surgically resected stage II/III GC who received 5-FU-based adjuvant chemotherapy and investigated the impact of IS on survival. In univariate analysis, high CD3 + , CD8 + , and Foxp3 + T-lymphocyte densities in the invasive margin were correlated with better prognosis (all P < 0.05). Patients with high IS had significantly longer disease-free survival (DFS; P < 0.001) and overall survival (OS; P < 0.001). In multivariate analysis, IS demonstrated a powerful prognostic impact on patient outcome [DFS, hazard ratio (HR) = 0.465; 95% confidence interval (CI), 0.306-0.707, P < 0.001; OS, HR = 0.478; 95% CI, 0.308-0.743, P = 0.001]. Additionally, although all EBV-positive cases had high IS, IS was similar in both microsatellite instability (MSI)-high and microsatellite stable (MSS)/MSI-low groups (83.3% and 80.5%, respectively). Subgroup analysis according to MSI status revealed that high IS patients had significant DFS and OS benefits in both MSS/MSI-low (DFS, HR = 0.527, 95% CI, 0.341-0.816, P = 0.004; OS, HR = 0.528, 95% CI, 0.334-0.837, P = 0.007) and MSI-high (DFS, HR = 0.166, 95% CI, 0.033-0.826, P = 0.028; OS, HR = 0.177, 95% CI, 0.036-0.883, P = 0.035) groups. Thus, the assessment of immune cell infiltration based on IS may provide a strong indicator of survival in stage II/III GC patients with curative resection following 5-FU-based adjuvant chemotherapy.

Prediction of TP53 mutations by p53 immunohistochemistry and their prognostic significance in gastric cancer

Background

Recently, molecular classifications of gastric cancer (GC) have been proposed that include TP53 mutations and their functional activity. We aimed to demonstrate the correlation between p53 immunohistochemistry (IHC) and TP53 mutations as well as their clinicopathological significance in GC.

Methods

Deep targeted sequencing was performed using surgical or biopsy specimens from 120 patients with GC. IHC for p53 was performed and interpreted as strong, weak, or negative expression. In 18 cases (15.0%) with discrepant TP53 mutation and p53 IHC results, p53 IHC was repeated.

Results

Strong expression of p53 was associated with TP53 missense mutations, negative expression with other types of mutations, and weak expression with wild-type TP53 (p<.001). The sensitivity for each category was 90.9%, 79.0%, and 80.9%, and the specificity was 95.4%, 88.1%, and 92.3%, respectively. The TNM stage at initial diagnosis exhibited a significant correlation with both TP53 mutation type (p=.004) and p53 expression status (p=.029). The Kaplan-Meier survival analysis for 109 stage II and III GC cases showed that patients with TP53 missense mutations had worse overall survival than those in the wild-type and other mutation groups (p=.028). Strong expression of p53 was also associated with worse overall survival in comparison to negative and weak expression (p=.035).

Conclusions

Results of IHC of the p53 protein may be used as a simple surrogate marker of TP53 mutations. However, negative expression of p53 and other types of mutations of TP53 should be carefully interpreted because of its lower sensitivity and different prognostic implications.

Discovery of Novel Recurrent Mutations and Clinically Meaningful Subgroups in Nodal Marginal Zone Lymphoma

Nodal marginal zone lymphoma (NMZL) is a rare B-cell neoplasm, the genetic and transcriptomic landscape of which are unclear. Using high-throughput sequencing for whole-exome and transcriptome, we investigated the genetic characteristics of NMZL in a discovery cohort (n = 8) and validated their features in an extended cohort (n = 30). Novel mutations in NFKBIE and ITPR2 were found in 7.9% (3/38) and 13.9% (5/36), respectively, suggesting roles for the NF-κB pathway and B-cell-receptor-mediated calcium signaling pathway in the pathogenesis of NMZL. RNA-seq showed that NMZLs were characterized by an aberrant marginal zone differentiation, associated with an altered IRF4-NOTCH2 axis and the enrichment of various oncogenic pathways. Based on gene expression profile, two subgroups were identified. Compared with subgroup 1, subgroup 2 showed the following: the significant enrichment of cell cycle-associated and MYC-signaling pathways, a more diverse repertoire of upstream regulators, and higher Ki-67 proliferation indices. We designated two subgroups according to Ki-67 labeling, and subgroup 2 was significantly associated with a shorter progression-free survival (p = 0.014), a greater proportion of large cells (p = 0.009), and higher MYC expression (p = 0.026). We suggest that NMZL has unique features and, in this study, we provide information as to the heterogeneity of this enigmatic entity.

Clinicopathological features of programmed cell death-1 and programmed cell death-ligand-1 expression in the tumor cells and tumor microenvironment of angioimmunoblastic T cell lymphoma and peripheral T cell lymphoma not otherwise specified

The expression patterns of programmed cell death-1 (PD-1) and programmed cell death-ligand-1 (PD-L1) and their clinicopathological implications were investigated in peripheral T cell lymphoma (PTCL) including angioimmunoblastic T cell lymphoma (AITL) and PTCL-not otherwise specified (PTCL-NOS). PTCL-NOS was further classified into nodal PTCL with follicular helper T cell (Tfh) phenotype ("PTCL-Tfh_new") and "PTCL-NOS_new". PD-1 and PD-L1 expression on tumor cells and reactive immune cells was evaluated using immunohistochemistry. PD-1 and PD-L1 expression on tumor cells (PD-1^T and PD-L1^T, respectively) was interpreted as positive when more than 5% of tumor cells expressed PD-1 or PD-L1. For PD-1 and PD-L1 on tumor cells and/or reactive immune cells (PD-1^T + IC and PD-L1^T + IC, respectively), a cutoff of 10% of cells was used. PD-1^T, PD-L1^T, and PD-L1^T + IC expressions tended to be higher in AITLs than in PTCLs-NOS. PD-1^T, PD-1^T + IC, PD-L1^T, and PD-L1^T + IC expressions tended to be higher in PTCLs with Tfh phenotype including AITLs and "PTCL-Tfh_new" than in PTCLs without Tfh phenotype. The serum LDH level was significantly elevated in patients with PTCL positive for PD-L1^T (P = 0.006) and PD-L1^T + IC (P < 0.001). Patients with PTCL who were positive for combined expression of PD-1^T/PD-L1^T + IC presented at older ages (P = 0.010), nodal diseases (P = 0.001), higher IPI (P = 0.060), and elevated LDH (P = 0.030). Combined PD-1^T/PD-L1^T + IC positivity was related to shorter overall survival in patients with AITL (P = 0.051). Combined PD-1^T/PD-L1^T + IC positivity was a significant poor prognostic factor in patients with stage IV AITL, independent of B symptoms and performance status (HR = 6.282 [CI, 1.655-23.844], P = 0.007). In summary, the PD-1/PD-L1 pathway could be a potential prognostic and therapeutic biomarker for PTCL.

A case of MOG encephalomyelitis with T- cell lymphoma

BACKGROUND

Myelin oligodendrocyte glycoprotein immunoglobulin-G (IgG)-associated encephalomyelitis (MOG-EM) is a distinct inflammatory demyelinating disease. We present an unusual MOG-EM cases with concomitant T-cell lymphoma.

CASE REPORT

A 38-year-old Caucasian male presented with bilateral optic neuritis and multifocal transverse myelitis. He tested positive for MOG-IgG1 and his neurologic symptoms improved with high dose steroid treatment. Six months after his first MOG-EM symptoms, he developed ulcerative skin lesions on his leg and was diagnosed with primary cutaneous γδ T-cell lymphoma. The immunohistochemistry study, performed on his cancer tissue, was negative for MOG.

CONCLUSION

Diagnosis of MOG-EM can be considered in patients with concomitant hematologic malignancy, which might be associated with the dysregulated adaptive immunity rather than the direct presentation of the onconeural antigen by cancer. Further studies need to be conducted for the risks and incidence of malignancy in a larger cohort of MOG-EM.

Morphologic variant of follicular lymphoma reminiscent of hyaline-vascular Castleman disease

Follicular lymphoma (FL) with hyaline-vascular Castleman disease (FL-HVCD)-like features is a rare morphologic variant, with fewer than 20 cases in the literature. Herein, we report a case of FL-HVCD in a 37-year-old female who presented with isolated neck lymph node enlargement. The excised lymph node showed features reminiscent of HVCD, including regressed germinal centers (GCs) surrounded by onion skin-like mantle zones, lollipop lesions composed of hyalinized blood vessels penetrating into regressed GCs, and hyalinized interfollicular stroma. In addition, focal areas of abnormally conglomerated GCs composed of homogeneous, small centrocytes with strong BCL2, CD10, and BCL6 expression were observed, indicating partial involvement of the FL. Several other lymphoid follicles showed features of in situ follicular neoplasia. Based on the observations, a diagnosis of FL-HVCD was made. Although FLHVCD is very rare, the possibility of this variant should be considered in cases resembling CD. Identification of abnormal, neoplastic follicles and ancillary immunostaining are helpful for proper diagnosis.

PD-L1 Testing in Gastric Cancer by the Combined Positive Score of the 22C3 PharmDx and SP263 Assay with Clinically Relevant Cut-offs

Purpose

We provide a comparison between 22C3 pharmDx and SP263 assay, for evaluating programmed death ligand 1 (PD-L1) expression in advanced gastric cancer (GC) patients.

Materials and Methods

The PD-L1 immunohistochemistry by 22C3 pharmDx and SP263 assays was performed in the center of the tumor (CT) and invasive margin (IM) in 379 GC tissues using tissue microarrays and interpreted as combined positive score (CPS) and tumor proportion score (TPS). Of the total samples, 55 samples were independently reviewed by five pathologists.

Results

The two assays showed a high correlation in both the CPS and TPS. At a CPS ≥ 1 cut-off, 219 (57.8%) and 231 (60.9%) GCs were positive for PD-L1 with the 22C3 and SP263 assays, and at ≥ 10 cut-off, 37 (9.8%) and 36 (9.5%) GCs were positive, respectively. The overall percent agreement (OPA) was greater than 90% with CPS ≥ 1 and ≥ 10 cut-offs, and TPS ≥ 1% and ≥ 10% cut-offs. There was higher OPA between the two assays with a CPS cut-off ≥ 10 (99.2%) than ≥ 1 (94.7%). The percent agreement between the CT and IM was higher with a CPS cut-off ≥ 10 (92.9%) than ≥ 1 (77.6%). Patient with positive expression at CPS ≥ 5 cut-off had a significantly better outcomes in both assays. Interobserver variability among five pathologists was higher than the assay variability.

Conclusion

Two assays for PD-L1 expression in GC showed high agreement. These results provide guidance for selecting eligible patients with GC for pembrolizumab treatment.

High-Throughput Multiplex Immunohistochemical Imaging of the Tumor and Its Microenvironment

PURPOSE

The aim of this study was to develop a formalin-fixed paraffin-embedded (FFPE) tissue based multiplex immunochemistry (mIHC) method for high-throughput comprehensive tissue imaging and demonstrate its feasibility, validity, and usefulness.

MATERIALS AND METHODS

The mIHC protocol was developed and tested on tissue microarray slides made from archived gastric cancer (GC) tissue samples. On a single FFPE slide, cyclic immunochemistry for multiple markers of immune cells and cytokeratin for tumor cells was performed; hematoxylin staining was used for demarcation of nuclei. Whole slides were digitally scanned after each cycle. For interpretation of mIHC results, we performed computer-assisted image analysis using publicly available software.

RESULTS

Using mIHC, we were able to characterize the tumor microenvironment (TME) of GCs with accurate visualization of various immune cells harboring complex immunophenotypes. Spatial information regarding intratumoral and peritumoral TME could be demonstrated by digital segmentation of image guided by cytokeratin staining results. We further extended the application of mIHC by showing that subcellular localization of molecules can be achieved by image analysis of mIHC results.

CONCLUSION

We developed a robust method for high-throughput multiplex imaging of FFPE tissue slides. The feasibility and adaptability of mIHC suggest that it is an efficient method for in situ single-cell characterization and analysis.