IRF1 regulation of ZBP1 links mitochondrial DNA and chondrocyte damage in osteoarthritis.

BACKGROUND: Z-DNA binding protein 1 (ZBP1) is a nucleic acid sensor that is involved in multiple inflammatory diseases, but whether and how it contributes to osteoarthritis (OA) are unclear. METHODS: Cartilage tissues were harvested from patients with OA and a murine model of OA to evaluate ZBP1 expression. Subsequently, the functional role and mechanism of ZBP1 were examined in primary chondrocytes, and the role of ZBP1 in OA was explored in mouse models. RESULTS: We showed the upregulation of ZBP1 in articular cartilage originating from OA patients and mice with OA after destabilization of the medial meniscus (DMM) surgery. Specifically, knockdown of ZBP1 alleviated chondrocyte damage and protected mice from DMM-induced OA. Mechanistically, tumor necrosis factor alpha induced ZBP1 overexpression in an interferon regulatory factor 1 (IRF1)-dependent manner and elicited the activation of ZBP1 via mitochondrial DNA (mtDNA) release and ZBP1 binding. The upregulated and activated ZBP1 could interact with receptor-interacting protein kinase 1 and activate the transforming growth factor-beta-activated kinase 1-NF-κB signaling pathway, which led to chondrocyte inflammation and extracellular matrix degradation. Moreover, inhibition of the mtDNA-IRF1-ZBP1 axis with Cyclosporine A, a blocker of mtDNA release, could delay the progression of DMM-induced OA. CONCLUSIONS: Our data revealed the pathological role of the mtDNA-IRF1-ZBP1 axis in OA chondrocytes, suggesting that inhibition of this axis could be a viable therapeutic approach for OA.

Validation Study of the Newly Proposed Refined Diagnostic Criteria for Malignant Phyllodes Tumor With 136 Borderline and Malignant Phyllodes Tumor Cases.

The World Health Organization (WHO) diagnostic criteria for malignant phyllodes tumor (MPT) may miss a significant number of MPTs with metastatic potential. New refined diagnostic criteria (Refined Criteria) for MPT were recently proposed. The aim of this study is to validate the Refined Criteria. This validation study included 136 borderline (borderline phyllodes tumor [BoPT]) and MPT cases that were not included in the initial study. We evaluated tumor classifications based on both the Refined Criteria and the WHO criteria. The Refined Criteria defines MPT when these criteria are met (1) stromal overgrowth with ≥ 1 feature(s) of marked stromal cellularity, marked stromal cytologic atypia, or ≥10 mitoses per 10 high-power fields (10 mitoses/10 HPFs) or (2) marked stromal cellularity with ≥1 feature(s) of marked stromal cytologic atypia, ≥10 mitoses/10 HPFs or permeative border. The WHO criteria require all 5 morphologic features (stromal overgrowth, permeative border, marked stromal cellularity, marked stromal cytologic atypia, and ≥10 mitoses/10 HPFs) for an MPT diagnosis. Using the Refined Criteria, none of the 61 BoPTs developed metastasis and 40.0% of the 75 MPTs developed metastases; local recurrence was seen in 11.5% BoPTs and 25.3% MPTs. Using the WHO criteria, 9.6% of the 94 BoPTs developed metastases and 50.0% of the 42 MPTs developed metastases; 14.9% of the BoPTs had local recurrence and 28.6% of the MPTs had local recurrence. Nine (30.0%) of the 30 tumors that developed distant metastases were diagnosed as BoPTs by the WHO criteria. When we combined the 75 MPTs from this validation cohort with the 65 MPT cases from the published data using the Refined Criteria, 50 (35.7%) of the 140 MPTs developed metastases, whereas 8 cases with metastases were <5 cm. In the univariate analysis with log-rank test, stromal overgrowth, marked stromal cellularity, marked stromal cytologic atypia, ≥10 mitoses/10 HPFs, presence of heterologous components other than liposarcomatous component, and presence of stromal necrosis were significantly associated with the risk of metastasis (all with P < 0.05). In multivariate analysis with Cox proportional hazard regression, stromal overgrowth and marked stromal cellularity were significantly associated with metastasis (both with P < 0.001). The Refined Criteria are superior to the WHO criteria in predicting the clinical outcomes of BoPTs and MPTs. Using the Refined Criteria, 35.7% of 140 patients with MPT developed metastases, whereas none (0%) of the patients with BoPT developed metastases. Patients with MPT have a high metastatic rate; these patients may benefit from systemic chemotherapy or targeted therapies. In contrast, patients with BoPT may be managed with complete local excision alone without chemotherapy.

Immunohistochemical Expression of Lymphoid Enhancer-binding Factor 1 in Low-grade Endometrial Stromal Tumors.

Endometrial stromal tumors (ESTs) are uncommon uterine mesenchymal lesions. Nuclear expression of ß-catenin, an indication of activated Wnt/ß-catenin signaling pathway, was described in 50% to 92% of low-grade ESTs, including endometrial stromal nodule and low-grade endometrial stromal sarcoma. Activation of the Wnt/ß-catenin signaling pathway leads to the translocation of ß-catenin into the nucleus and interaction with the T-cell factor/lymphoid enhancer-binding factor-1 (LEF1) family of transcription factors to regulate cell proliferation, differentiation, migration, and survival. Immunohistochemical analysis of ß-catenin and LEF1 was performed in 2 endometrial stromal nodules and 20 low-grade endometrial stromal sarcomas and demonstrated 90.9% and 81.8% positive rates for ß-catenin and LEF1, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of ß-catenin and LEF1 were 90.9% versus 81.8%, 81.0% versus 85.7%, 83.3% versus 85.7%, 89.5% versus 81.8%, respectively, in the diagnosis of low-grade ESTs. There is no statistical significance of the performance of ß-catenin and LEF1 in all ESTs (P = 0.664) or in primary or metastatic/recurrent settings (P = 0.515 and 0.999, respectively). Only 3 smooth muscle tumors showed focal and weak positivity for LEF1. Our results indicate LEF1 can be a useful marker in aiding a diagnosis of low-grade EST and differentiating from smooth muscle tumors alone or in combination with ß-catenin.

Identification of two short peptide motifs from serine/arginine-rich protein ribonucleic acid recognition motif-1 domain acting as splicing regulators.

Background: Serine/arginine-rich (SR) proteins regulate pre-mRNA splicing. However, structurally similar proteins often behave differently in splicing regulation and the underlying mechanisms are largely unknown. Here, using SMN1/2 minigenes we extensively analyzed four SR proteins, SRSF1/5/6/9. Methods: In this study, the effects of these proteins on SMN1/2 exon 7 splicing when tethered at either intron 6 or 7 were evaluated using an MS2-tethering assay. Deletion analysis in four SR proteins and co-overexpression analysis were performed. Results: Splicing outcomes varied among all four SR proteins, SRSF1 and SRSF5 function the same at the two sites, acting as repressor and stimulator, respectively; while SRSF6 and SRSF9 promote exon 7 inclusion at only one site. Further, the key domains of each SR proteins were investigated, which identified a potent inhibitory nonapeptide in the C-terminus of SRSF1/9 ribonucleic acid recognition motif-1 (RRM1) and a potent stimulatory heptapeptide at the N-terminus of SRSF5/6 RRM1. Conclusion: The insight of the four SR proteins and their domains in affecting SMN gene splicing brings a new perspective on the modes of action of SR proteins; and the functional peptides obtained here offers new ideas for developing splice switching-related therapies.

HER2 Intratumoral Heterogeneity in Breast Cancer, an Evolving Concept.

Amplification and/or overexpression of human epidermal growth factor receptor 2 (HER2) in breast cancer is associated with an adverse prognosis. The introduction of anti-HER2 targeted therapy has dramatically improved the clinical outcomes of patients with HER2-positive breast cancer. Unfortunately, a significant number of patients eventually relapse and develop distant metastasis. HER2 intratumoral heterogeneity (ITH) has been reported to be associated with poor prognosis in patients with anti-HER2 targeted therapies and was proposed to be a potential mechanism for anti-HER2 resistance. In this review, we described the current definition, common types of HER2 ITH in breast cancer, the challenge in interpretation of HER2 status in cases showing ITH and the clinical applications of anti-HER2 agents in breast cancer showing heterogeneous HER2 expression. Digital image analysis has emerged as an objective and reproducible scoring method and its role in the assessment of HER2 status with ITH remains to be demonstrated.

Dissecting amide-I vibrations in histidine dipeptide.

The amide-I vibrational characteristics and conformational preferences of the model compound - histidine dipeptide (Ac-His-NHCH3, HISD) in gas phase and solution have been revealed with the help of ab initio calculations and wavefunction analyses. The Gibbs free energy surfaces (FESs) of solvated HISD were smoothed by solvent effect to exhibit different structural populations concerning various external environments. It was shown that the most stable conformations of HISD in CHCl3 and gas phase are C7eq, while those in DMSO and water are ß and PPII, respectively. Compared with ALAD, the number of accessible conformational states on these FESs was predicted to be reduced due to the steric effect of imidazole group. The two amide-I normal modes of HISD were found to have intrinsically secondary structural dependencies, and be sensitive to surrounding environments. The average amide-Ia frequencies of HISD isomers in these environments were predicted to be almost the same as those of ALAD, while the amide-Ib mean frequencies were estimated to be lower than ALAD due to the intramolecular interactions between the imidazole group and amino-terminal amide unit. The good linear correlations between amide-I frequencies and the atomic electrostatic potentials (ESPs) of amide groups were also found to interpret the solvent-induced amide-I frequency shifts of HISD at the electronic structure level. These results allow us to gain a deep understanding of amide-I vibrations of HISD, and would be helpful for the site-specific conformational monitoring and spectral interpretation of solvated polypeptides.

Artificial intelligence reveals features associated with breast cancer neoadjuvant chemotherapy responses from multi-stain histopathologic images.

Advances in computational algorithms and tools have made the prediction of cancer patient outcomes using computational pathology feasible. However, predicting clinical outcomes from pre-treatment histopathologic images remains a challenging task, limited by the poor understanding of tumor immune micro-environments. In this study, an automatic, accurate, comprehensive, interpretable, and reproducible whole slide image (WSI) feature extraction pipeline known as, IMage-based Pathological REgistration and Segmentation Statistics (IMPRESS), is described. We used both H&E and multiplex IHC (PD-L1, CD8+, and CD163+) images, investigated whether artificial intelligence (AI)-based algorithms using automatic feature extraction methods can predict neoadjuvant chemotherapy (NAC) outcomes in HER2-positive (HER2+) and triple-negative breast cancer (TNBC) patients. Features are derived from tumor immune micro-environment and clinical data and used to train machine learning models to accurately predict the response to NAC in breast cancer patients (HER2+ AUC = 0.8975; TNBC AUC = 0.7674). The results demonstrate that this method outperforms the results trained from features that were manually generated by pathologists. The developed image features and algorithms were further externally validated by independent cohorts, yielding encouraging results, especially for the HER2+ subtype.

Characterization of cardiac involvement in patients with LMNA splice-site mutation-related dilated cardiomyopathy and sudden cardiac death.

Introduction: LMNA splicing mutations occur in 9.1% of cases with cardiac involvement cases, but the phenotype and severity of disease they cause have not yet been systematically studied. The aim of this study was to understand the clinical and pathogenic characteristics of the LMNA splice-site mutation phenotype in patients with LMNA-related dilated cardiomyopathy (DCM) and sudden cardiac death (SCD). Methods and Results: First, we reported a novel family with LMNA-related DCM and SCD, and the clinical characteristics of all current patients with LMNA splicing mutations were further summarized through the ClinVar database. Seventeen families with a total of 134 individuals, containing a total of 15 LMNA splicing mutation sites, were enrolled. A total of 42 subjects (31.3%) had SCD. Compared without with the non-DCM group (n = 56), the patients within the DCM group (n = 78) presented a lower incidence of atrioventricular block (AVB) (p = 0.015) and a higher incidence rates of non-sustained ventricular tachycardia (p = 0.004),) and implantable cardioverter defibrillator (ICD) implantation (p = 0.005). Kaplan‒Meier survival analysis showed that the patients with pacemaker (PM) implantation had a significantly reduced the occurrence of SCD compared to patientswith those without PM implantation (log-rank p < 0.001), while there was no significant difference in ICD implantation between the two groups (log-rank p = 0.73). Second, we identified the family that we reported with a mutation in an LMNA c.513+1 G>A mutation in the reported family, and pathogenic prediction analysis showed that the mutation site was extremely harmful. Next, we conducted gene expression levels and cardiac pathological biopsy studies on the proband of this family. We found that the expression of normal LMNA mRNA from the proband was significantly downregulated in peripheral blood mononuclear cells than incompared with healthy individuals. Finally, we comprehensively summarized the pathological characteristics of LMNA-related DCM, including hypertrophy, atrophy, fibrosis, white blood cell infiltration, intercalated disc remodeling, and downregulation of desmin and connexin 43 (Cx43) expression. Discussion: Above all, Cardiaccardiac involvement in patients with LMNA splice-site mutation presented with a high rate of SCD. Implanting a pacemaker significantly reduced the SCD rate in non-DCM patients with AVB. The pathogenic characterization was not only haveinvolved suppressed the expression of the healthy LMNA allele, but was also associated with abnormal expression and distribution of desmin and Cx43.

Update on prognostic and predictive biomarkers of breast cancer.

Breast cancer represents a heterogeneous group of human cancer at both histological and molecular levels. Estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) are the most commonly used biomarkers in clinical practice for making treatment plans for breast cancer patients by oncologists. Recently, PD-L1 testing plays an important role for immunotherapy for triple-negative breast cancer. With the increased understanding of the molecular characterization of breast cancer and the emergence of novel targeted therapies, more potential biomarkers are needed for the development of more personalized treatments. In this review, we summarized several main prognostic and predictive biomarkers in breast cancer at genomic, transcriptomic and proteomic levels, including hormone receptors, HER2, Ki67, multiple gene expression assays, PD-L1 testing, mismatch repair deficiency/microsatellite instability, tumor mutational burden, PIK3CA, ESR1 andNTRK and briefly introduced the roles of digital imaging analysis in breast biomarker evaluation.

Female Adnexal Tumor of Probable Wolffian Origin.

CONTEXT.­: Female adnexal tumor of probable Wolffian origin (FATWO) often is a diagnostic challenge given its rarity, histologic heterogeneity, and lack of specific immunoprofile. OBJECTIVE.­: To further understand the clinicopathologic and immunohistochemical features of this rare entity. DESIGN.­: We studied the clinical, morphologic, and immunohistochemical features of a cohort of 11 FATWO cases from our institute. RESULTS.­: Patients' age ranged from 25 to 76 years (mean, 55 years). Tumor size ranged from 0.5 to 18 cm (mean, 2.7 cm). Histopathologically, most tumors presented with low-grade cytologic features with low mitotic activity and lack of necrosis. Three main growth patterns were appreciated: solid, tubular, and sievelike patterns. Higher-grade nuclear atypia, increased mitotic activity, and focal necrosis were seen in 2 cases. These 2 cases were clinically considered malignant FATWO mainly because of their extra-adnexal involvement. Immunohistochemical studies found that tumor cells were positive for CD10 (11 of 11, 100%), AE1/3 (8 of 8, 100%), CAM 5.2 (4 of 5, 80%), and cytokeratin 7 (CK7; 7 of 10, 70%), and focally positive for calretinin (4 of 10, 40%), inhibin (4 of 10, 40%), epithelial membrane antigen (EMA; 3 of 9, 33%), and steroidogenic factor-1 (SF-1; 2 of 8, 25%). Lack of immunoreactivity to PAX8 and GATA3 in almost all cases indicates that FATWO is different from the tumors derived from the Müllerian or mesonephric origins. All patients with available follow-up had favorable prognosis. CONCLUSION.­: The broad spectrum of clinical presentation, various morphologic features, and overlapping immunophenotype suggest that FATWO is a diagnosis of exclusion until it is further defined at the molecular and immunohistochemical levels.

Homeodomain protein Six4 prevents the generation of supernumerary Drosophila type II neuroblasts and premature differentiation of intermediate neural progenitors.

In order to boost the number and diversity of neurons generated from neural stem cells, intermediate neural progenitors (INPs) need to maintain their homeostasis by avoiding both dedifferentiation and premature differentiation. Elucidating how INPs maintain homeostasis is critical for understanding the generation of brain complexity and various neurological diseases resulting from defects in INP development. Here we report that Six4 expressed in Drosophila type II neuroblast (NB) lineages prevents the generation of supernumerary type II NBs and premature differentiation of INPs. We show that loss of Six4 leads to supernumerary type II NBs likely due to dedifferentiation of immature INPs (imINPs). We provide data to further demonstrate that Six4 inhibits the expression and activity of PntP1 in imINPs in part by forming a trimeric complex with Earmuff and PntP1. Furthermore, knockdown of Six4 exacerbates the loss of INPs resulting from the loss of PntP1 by enhancing ectopic Prospero expression in imINPs, suggesting that Six4 is also required for preventing premature differentiation of INPs. Taken together, our work identified a novel transcription factor that likely plays important roles in maintaining INP homeostasis.

Deciphering the structural preference encoded in amide-I vibrations of lysine dipeptide in gas phase and in aqueous solution.

Protein's biological function is critically associated with its structural feature, which is encoded in its amino acid sequence. For evaluation of conformational fluctuation and folding mechanism, DFT calculations were performed on the model compound - lysine dipeptide (LYSD) in gas phase to demonstrate the correlation between amide-I vibrations and secondary structure. Molecular dynamics simulations were carried out for the structural dynamics of LYSD in aqueous solution. The results show that LYSD tends form C7eq, C5, ß, PPII and α conformations in the gas phase and primarily presented PPII and α conformations in aqueous solution. The obtained amide-I vibrational frequencies of LYSD conformers were assigned, thus build the correlations between amide-I probes and secondary structure of LYSD. These results provide theoretical insights into the structural feature of LYSD through amide-I vibrations, and would shed light on site specific structural prediction of polypeptides.

ADORA1-driven brain-sympathetic neuro-adipose connections control body weight and adipose lipid metabolism.

It is essential to elucidate brain-adipocyte interactions in order to tackle obesity and its comorbidities, as the precise control of brain-adipose tissue cross-talk is crucial for energy and glucose homeostasis. Recent studies show that in the peripheral adipose tissue, adenosine induces adipogenesis through peripheral adenosine A1 receptor (pADORA1) signaling; however, it remains unclear whether systemic and adipose tissue metabolism would also be under the control of central (c) ADORA1 signaling. Here, we use tissue-specific pharmacology and metabolic tools to clarify the roles of cADORA1 signaling in energy and adipocyte physiology. We found that cADORA1 signaling reduces body weight while also inducing adipose tissue lipolysis. cADORA1 signaling also increases adipose tissue sympathetic norepinephrine content. In contrast, pADORA1 signaling facilitates a high-fat diet-induced obesity (DIO). We propose here a novel mechanism in which cADORA1 and pADORA1 signaling hinder and aggravate DIO, respectively.

Features, Outcomes, and Management Strategies of Male Breast Cancer: A Single Institution Comparison to Well-Matched Female Controls.

OBJECTIVE: The primary objective of this study was to delineate differences in management, overall and distant disease-free survival in males diagnosed with breast cancer and treated at The Ohio State University Comprehensive Cancer Center as compared to comprehensively matched female subjects. Secondary objectives included assessment of clinical and histopathologic features and recurrence score, as measured by Oncotype DX and the modified Magee equation #2. MATERIALS AND METHODS: This single institution retrospective study compared male and comprehensively matched female patients (1:2) with stage I-III breast cancer between 1994 and 2014. Recurrence risk was estimated using a modified Magee equation. Overall survival and distant disease-free survival were estimated and compared using Kaplan-Meier and Log-rank methods. RESULTS: Forty-five male breast cancer patients were included (stage I: 26.7%; stage II: 53.3%; stage III: 20.0%; hormone receptor positive: 97.8%; human epidermal growth factor receptor 2 negative: 84.4%) with a median age of 63.8 (43.0-79.4) years at diagnosis. Intermediate and low recurrence scores were most common in male and female patients respectively; mean score was similar between groups (20.3 vs. 19.8). The proportion of male breast cancer patients treated with adjuvant chemotherapy and post-mastectomy radiation was lower compared to female patients (42.2% vs. 65.3%, p=0.013; 22.7% vs. 44.4%, p=0.030, respectively). Overall survival and distant disease-free survival between male and female patients were similar. CONCLUSION: Male breast cancer patient outcomes were similar compared to well-matched female patients suggesting that breast cancer specific factors are more prognostic than gender.

Cytology and curetting diagnosis of endocervical adenocarcinoma.

INTRODUCTION: Papanicolaou testing is effective in identifying squamous intraepithelial lesions of the cervix. Endocervical adenocarcinoma (EAC) and adenocarcinoma in situ (AIS) are far less commonly identified. Endocervical curettings (ECCs) are usually obtained after colposcopic biopsy, sample the endocervical canal, and aid in the detection of endocervical glandular lesions. Here, we examine the utility of Papanicolaou testing and endocervical curetting for detecting AIS and EAC. MATERIALS AND METHODS: Cases from 2007 to 2019 with a histologically confirmed diagnosis of AIS and EAC were identified and the clinical data and diagnostic material, including the cytology and surgical specimens, obtained. RESULTS: A total of 108 cases of AIS and EAC were identified, Papanicolaou tests were performed in 97 of these cases, and ECC in 87. AIS or EAC were detected in 46.4% of Papanicolaou tests; 41.4% of ECC showed AIS or EAC. A total of 92.7% of cases were positive for high-risk human papillomavirus (HPV) and concurrent squamous intraepithelial lesion was present in 53.3% of cases. AIS or EAC were more commonly identified in cases without concurrent squamous intraepithelial lesions. CONCLUSIONS: Papanicolaou testing and endocervical curettings have a low detection rate for AIS and EAC. The majority of AIS and EAC cases test positive for high-risk HPV. Papanicolaou test and ECC show different detection rates and are complementary tools in patients with AIS and EAC. In some settings, an ECC can increase the diagnostic sensitivity and specificity of the pathologic diagnosis.

Paraganglioma-like medullary thyroid carcinoma: A case report and literature review.

Medullary thyroid carcinoma (MTC) accounts for 3%-5% of all thyroid malignancies. Most MTC can be diagnosed by their typical cytologic and histologic morphology and immunohistochemical features. However, some rare variants of MTC may pose diagnostic difficulties on both cytology and histology. Paraganglioma-like MTC (PLMTC) is a rare, but widely recognized variant of MTC. PLMTC is known to share morphological and architectural similarities with paraganglioma, hyalinizing trabecular tumor, and carcinomas of thyroid follicular cell origin, such as follicular carcinoma and follicular variant of papillary thyroid carcinoma. The combination of clinicopathologic features and a battery of immunohistochemical markers is essential for making a correct diagnosis. Herein, we report one case of PLMTC with both cytologic and histologic features and review the clinicopathologic features of previously reported cases.

Endometrial Polyp of the Placental Fetal Membranes: Report of a Case.

Endometrial polyps embedded in the fetal membranes have only rarely been described. A review of the English literature showed only one abstract describing this occurrence and to the best of our knowledge, there have been no other publications of this entity. Herein we present a case of a 37-yr-old woman with a history prior abortion and complicated pregnancy (type 2 diabetes mellitus and preeclampsia) who delivered by cesarean section. Although the placenta did not show hypertensive vasculopathic changes or other pathologic findings, an endometrial polyp embedded within the fetal membranes was present. Recognition of this rarely reported entity is important in order to avoid confusion with a significant neoplastic process.

Primary tumor types and origins in positive abdominopelvic washing cytology, a single institution experience.

INTRODUCTION: Abdominopelvic washing cytology is a common specimen evaluated for ovarian, fallopian tubal, and peritoneal cancer staging or other nongynecologic malignancies presented as metastases. We reviewed our experience in diagnosing abdominopelvic washing specimens and assessing the primary tumor types and origins of the positive abdominopelvic washings. MATERIALS AND METHODS: A pathology archive database search was performed for abdominopelvic washing specimens from 2007 to 2018. The corresponding cytologic diagnoses, results of ancillary studies, clinical histories, and surgical follow-up were reviewed. The primary sites were determined based on the synoptic reports, when available. RESULTS: A total of 5.8% (350 of 6023) of cases were positive for malignancy or neoplasm. Additionally, 1.3% (78 of 6023) were diagnosed as atypical cells. Of the 350 positive cases, 93.4% were müllerian tumors. The frequency of primary sites for müllerian tumors in descending order were: ovary, uterus, fallopian tube, peritoneum, and uncertain müllerian sites. The common ovarian tumors identified in pelvic washing in descending order were: high-grade serous carcinoma, serous borderline tumor, clear cell carcinoma, low-grade serous carcinoma, and endometrioid carcinoma. Gastrointestinal, breast, bladder, and lymphoma primaries were the 23 nongynecologic tumors identified in pelvic washings. CONCLUSIONS: Positive findings in abdominopelvic washing cytology is rare. The majority of the positive cases were from müllerian origins, with ovary and uterus as the most common sites. Endometrial adenocarcinoma, endometrioid type and ovarian high-grade serous carcinoma were the most common tumor types. Knowing prior history of malignancy, morphologic comparison with concurrent surgical cases, and performing ancillary studies are keys to improve diagnostic accuracy of abdominopelvic washings.

PD-L1 and CD8 are associated with deficient mismatch repair status in triple-negative and HER2-positive breast cancers.

Triple-negative and HER2-positive breast cancers (BCs) are more aggressive than hormone receptor-positive/HER2-negative BCs and show higher levels of tumor-infiltrating lymphocytes (TILs) and PD-L1 expression. Recently, US Food and Drug Administration approved anti-PD-L1 immunotherapy for solid tumors with deficient mismatch repair (MMR). In this study, we aimed to examine the prevalence of deficient MMR and its association with checkpoint immune markers in BCs. Immunohistochemistries (IHCs) with anti-MMR proteins (MLH1, PMS2, MSH2 and MSH6) and multiplex IHCs with anti-PD-L1, anti-CD8 or anti-CD163 were performed on tissue microarrays (TMAs) with 101 triple-negative BCs (TNBC) and 197 HER2-positive BCs. Additional IHCs for MMR proteins were also performed on whole-tissue sections from selected cases. Thirteen cases (4.4%) showed complete loss of MMR protein on TMAs, including 7 TNBCs (6.9%) and 6 HER2-positive BCs. On whole-tissue sections, only one of 13 cases showed complete loss of MMR proteins, while the other 12 cases showed partial loss. PD-L1 expression was identified in 37% of cases and was significantly higher in TNBCs than in HER2-positive BCs (71% versus 19%). Furthermore, BCs with complete/partial loss of MMR demonstrated significantly more PD-L1 and CD8 expressions than BCs with preserved MMR proteins. Although complete loss of MMR proteins exists in an extremely low frequency, partial loss is not uncommon in BCs. The association of partial loss of MMR proteins with increased PD-L1 and CD8 expression suggests a potential use of MMR testing as a screening method for anti-PD-L1 immunotherapy in BCs.

PD-L1 expression and CD8-positive T cells are associated with favorable survival in HER2-positive invasive breast cancer.

Programmed cell death 1 (PD-1) and its ligand (PD-L1) are key physiologic suppressors of the cytotoxic immune reaction. However, to date, the combination of PD1/PD-L1 expression and tumor-infiltrating lymphocytes (TILs) and antigen-presenting cells has been only minimally reported in breast carcinoma, in particular in relation to HER2-positive cases. The goal of this study was to evaluate both cellular tumoral immune reaction and PD-L1/PD1 distribution in HER2-positive cases, as well as any associations with clinical outcome using conventional chemotherapy combined with HER2 blocking. Multicolor immunohistochemical multiplex assays simultaneously demonstrating PD1, PD-L1, and CD8 or PD-L1, CD3, and CD163 were performed on tissue microarrays (TMA) representing 216 pretreatment cases of HER2-positive invasive breast carcinoma. PD-L1 expression was identified in 38 cases (18%), including 12 cases (6%) with PD-L1 labeling of tumor cells and 26 cases (12%) with PD-L1 labeling of immune cells only. Ten of 12 cases with PD-L1 staining of tumor cells showed staining of associated immune cells as well. With this assay method, PD1 was detectable in many fewer cases (6 cases or 3%). PD-L1 expression was positively associated with high Nottingham grade, negative ER and PR, the absence of lymph node metastasis, and high levels of CD8+ cells. The overall survival by univariate analysis was positively associated with lower tumor stage, the absence of lymph node metastasis, PD-L1 expression, and high levels of CD8+ cells. Therefore, our data suggest cytotoxic immune reaction mediated by CD8-positive T cells and PD-L1 expression may predict a better outcome in patients with HER2-positive breast carcinoma managed with conventional chemotherapy and HER2-blocking therapy. These findings recommend clinical trials utilizing checkpoint blocking immunotherapy in some form for HER2-positive breast cancer.