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.

Interpathologist Diagnostic Agreement for Non-Small Cell Lung Carcinomas Using Current and Recent Classifications

CONTEXT.—

Measurement of interpathologist diagnostic agreement (IPDA) should allow pathologists to improve current diagnostic criteria and disease classifications.

OBJECTIVES.—

To determine how IPDA for pathologists' diagnoses of non-small cell lung carcinoma (NSCLC) is affected by the addition of a set of mucin and immunohistochemical (IHC) stains to hematoxylin-eosin (H&E) alone, by recent NSCLC reclassifications, by simplification of these classifications, and by pathologists' practice location, pulmonary pathology expertise, practice duration, and lung carcinoma case exposure.

DESIGN.—

We used a Web-based survey to present core images of 54 NSCLC cases to 22 practicing pathologists for diagnosis, initially as H&E only, then as H&E plus mucin and 4 IHC stains. Each case was diagnosed according to published 2004, 2011, and 2015 NSCLC classifications. Cohen's kappa was calculated for the 231 pathologist pairs as a measure of IPDA.

RESULTS.—

Twenty-two pathologists diagnosed 54 NSCLC cases by using 4 published classifications. IPDA is significantly higher for H&E/mucin/IHC diagnoses than for H&E-only diagnoses. IPDA for H&E/mucin/IHC diagnoses is highest with the 2015 classification. IPDA is estimated higher after collapse of stated diagnoses into subhead or dichotomized classes. IPDA for H&E/mucin/IHC diagnoses with the 2015 World Health Organization classification is similar for community and academic pathologists, and is higher when pathologists have pulmonary pathology expertise, have more than 6 years of practice experience, or diagnose more than 100 new lung carcinoma cases per year.

CONCLUSIONS.—

Higher IPDA is associated with use of mucin and IHC stains, with the 2015 NSCLC classification, and with pathologists' pulmonary pathology expertise, practice duration, and frequency of lung carcinoma cases.

Evaluation of Immune Reaction and PD-L1 Expression Using Multiplex Immunohistochemistry in HER2-Positive Breast Cancer: The Association With Response to Anti-HER2 Neoadjuvant Therapy

BACKGROUND

Immune reaction with tumor-infiltrating lymphocytes (TILs) has been extensively investigated in breast cancer. Programmed cell death 1 and its ligand (PD-L1) are key physiologic suppressors of cytotoxic immune reaction. However, the combination of TILs with PD-L1 expression has not been well studied in breast cancer.

PATIENTS AND METHODS

A multi-color immunohistochemical multiplex assay simultaneously detecting PD-L1, CD8, and CD163 was performed on biopsy whole sections from 123 HER2-positive (HER2⁺) breast cancers, including 64 treated with anti-HER2 neoadjuvant therapy and subsequent resection.

RESULTS

PD-L1 expression was identified in 88 cases (72%) including 21 (17%) in tumor cells and 67 (55%) in immune cells. PD-L1 expression was positively associated with high Nottingham grade, high nuclear grade, and a high level of CD8⁺ and CD163⁺ cells. Among the 64 patients who received neoadjuvant therapy, 39 had pathologic complete remission (pCR) and 25 had incomplete response. Multivariate analysis showed progesterone receptor negativity, HER2/chromosome 17 centromere (CEN17) ratio and intratumoral CD8⁺ cells were significantly associated with pCR. Furthermore, all patients with intratumoral CD8⁺ cells but no PD-L1 expression achieved pCR.

CONCLUSION

Our data have shown that examination of intratumoral CD8⁺ cells together with PD-L1 expression proves useful in predicting response to anti-HER2 targeted therapy in patients with HER2⁺ breast cancer.

A novel highly differentially expressed gene in wheat endosperm associated with bread quality

Analysis of gene expression in developing wheat seeds was used to identify a gene, wheat bread making (wbm), with highly differential expression (~1000 fold) in the starchy endosperm of genotypes varying in bread making quality. Several alleles differing in the 5’-upstream region (promoter) of this gene were identified, with one present only in genotypes with high levels of wbm expression. RNA-Seq analysis revealed low or no wbm expression in most genotypes but high expression (0.2-0.4% of total gene expression) in genotypes that had good bread loaf volume. The wbm gene is predicted to encode a mature protein of 48 amino acids (including four cysteine residues) not previously identified in association with wheat quality, possibly because of its small size and low frequency in the wheat gene pool. Genotypes with high wbm expression all had good bread making quality but not always good physical dough qualities. The predicted protein was sulphur rich suggesting the possibility of a contribution to bread loaf volume by supporting the crossing linking of proteins in gluten. Improved understanding of the molecular basis of differences in bread making quality may allow more rapid development of high performing genotypes with acceptable end-use properties and facilitate increased wheat production.

The utility of BRAF V600E mutation-specific antibody VE1 for the diagnosis of hairy cell leukemia

OBJECTIVES

BRAF V600E mutation is characteristic of hairy cell leukemia (HCL). A V600E mutation-specific antibody, VE1, has been recently developed. We studied the diagnostic utility of this antibody in HCL and compared it with other B-cell neoplasms.

METHODS

VE1 activity was assessed using immunohistochemistry in 90 mature B-cell neoplasms, including HCL (n = 17), HCL variant (n = 6), chronic lymphocytic leukemia (CLL) (n = 20), and 47 other B-cell lymphomas. Most (87/90) specimens were formalin-fixed, paraffin-embedded bone marrow (BM) biopsy specimens decalcified in either hydrochloric acid or formic acid.

RESULTS

VE1 was positive in 15 (88%) cases of HCL and two (10%) cases of CLL and was negative in all other tumors assessed. The VE1-positive HCL cases showed uniform staining in all tumor cells, but intensity was variable. The two VE1-negative HCL cases had BRAF V600 mutations proven by molecular analysis. The two CLL cases positive with VE1 showed an atypical staining pattern with expression in a minority of lymphoma cells. Immunohistochemistry using the VE1 antibody had a sensitivity of 88% and a specificity of 97% for HCL.

CONCLUSIONS

VE1 immunohistochemistry is a useful and convenient surrogate for detecting BRAF V600E mutation in BM biopsy specimens decalcified with hydrochloric or formic acid-based solutions.

Varying chromosome composition of 56-chromosome wheat x Thinopyrum intermedium partial amphiploids

Thinopyrum intermedium (2n = 42) is a source of many potentially useful genes for wheat improvement. Many partial amphiploids have been produced between Th. intermedium and Triticum aestivum that are fertile and stable. These partial amphiploids all have 56 chromosomes, including seven pairs of chromosomes from Th. intermedium. To explore the genomic composition of these lines, meiotic analysis was conducted on 32 hybrid combinations between eight different partial amphiploids. All but two of the chosen parents were distinguishable on the basis of perenniality, head morphology, and reactions to leaf, stripe, and stem rusts and to barley yellow dwarf virus. Chromosome pairing in the hybrids clearly indicated that all but two of the partial amphiploids differed in their composition of Thinopyrum chromosomes. The differences varied from one to five chromosomes. This confirms molecular evidence that the extra genome of the octoploid partial amphiploids is a variable synthetic genome combining chromosomes of the three Thinopyrum genomes E, J, and X. Though the extra synthetic genomes vary widely between different octoploids, they are nevertheless stable once formed. It is argued that the failure to establish these octoploid amphiploids as a new crop is a consequence of their differing chromosome complements, which makes it impractical to interbreed them.

The use of cell culture for subchromosomal introgressions of barley yellow dwarf virus resistance from Thinopyrum intermedium to wheat

Barley yellow dwarf virus (BYDV) resistance has been transferred to wheat from a group 7 chromosome of Thinopyrum (Agropyron) intermedium. The source of the resistance gene was the L1 disomic addition line, which carries the 7Ai-1 chromosome. The resistance locus is on the long arm of this chromosome. BYDV resistant recombinant lines were identified after three or more generations of selection against a group 7 Th. intermedium short arm marker (red coleoptile) and selection for the presence of BYDV resistance. One recombinant line produced by ph. mutant induced homoeologous pairing and 14 recombinant lines induced by cell culture have been identified. Resistance in seven of the cell culture induced recombinants has been inherited via pollen according to Mendelian segregation ratios for up to eight generations. Meiotic analysis of heterozygotes indicates that the alien chromatin in the cell culture induced recombinants is small enough to allow regular meiotic behaviour. The ph-induced recombinant was less regular in meiosis. A probe, pEleAcc2, originally isolated from Th. elongatum and that hybridizes to dispersed repeated DNA sequences, was utilised to detect Th. intermedium chromatin, which confers resistance to BYDV, in wheat backgrounds. Quantification of these hybridization signals indicated that the translocations involved a portion of alien chromatin that was smaller than the complete long arm of 7Ai-1. Restriction fragment length polymorphism analysis confirmed the loss of the short arm of 7Ai-1 and indicated the retention of segments of the long arm of 7Ai-1. Two 7Ai-1L DNA markers always assorted with the BYDV resistance. A third 7Ai-IL DNA marker was also present in seven of eight recombinants. In all recombinants except TC7, the 7Ai-1L markers replaced the 7DL markers. None of the wheat group 7 markers was missing from TC7. It is concluded that all the resistant lines are the result of recombination with wheat chromosome 7D, except line TC7, which is the result of recombination with an unidentified nongroup 7 chromosome.

Validation of interobserver agreement in lung cancer assessment: hematoxylin-eosin diagnostic reproducibility for non-small cell lung cancer: the 2004 World Health Organization classification and therapeutically relevant subsets

CONTEXT

Precise subtype diagnosis of non-small cell lung carcinoma is increasingly relevant, based on the availability of subtype-specific therapies, such as bevacizumab and pemetrexed, and based on the subtype-specific prevalence of activating epidermal growth factor receptor mutations.

OBJECTIVES

To establish a baseline measure of interobserver reproducibility for non-small cell lung carcinoma diagnoses with hematoxylin-eosin for the current 2004 World Health Organization classification, to estimate interobserver reproducibility for the therapeutically relevant squamous/nonsquamous subsets, and to examine characteristics that improve interobserver reproducibility.

DESIGN

Primary, resected lung cancer specimens were converted to digital (virtual) slides. Based on a single hematoxylin-eosin virtual slide, pathologists were asked to assign a diagnosis using the 2004 World Health Organization classification. Kappa statistics were calculated for each pathologist-pair for each slide and were summarized by classification scheme, pulmonary pathology expertise, diagnostic confidence, and neoplastic grade.

RESULTS

The 12 pulmonary pathology experts and the 12 community pathologists each independently diagnosed 48 to 96 single hematoxylin-eosin digital slides derived from 96 cases of non-small cell lung carcinoma resection. Overall agreement improved with simplification from the comprehensive 44 World Health Organization diagnoses (κ  =  0.25) to their 10 major header subtypes (κ  =  0.48) and improved again with simplification into the therapeutically relevant squamous/nonsquamous dichotomy (κ  =  0.55). Multivariate analysis showed that higher diagnostic agreement was associated with better differentiation, better slide quality, higher diagnostic confidence, similar years of pathology experience, and pulmonary pathology expertise.

CONCLUSIONS

These data define the baseline diagnostic agreement for hematoxylin-eosin diagnosis of non-small cell lung carcinoma, allowing future studies to test for improved diagnostic agreement with reflex ancillary tests.

Co-occurrence of Langerhans cell histiocytosis and Rosai-Dorfman disease: possible relationship of two histiocytic disorders in rare cases

Rosai-Dorfman disease and Langerhans cell histiocytosis are both disorders of accessory immune cells. Two cases have been previously reported of concurrent Langerhans cell histiocytosis and Rosai-Dorfman disease. In this report, we characterize the findings and selected molecular studies in nine additional cases. Histology was reviewed. Immunohistochemical stains were performed on all cases in which slides or blocks were available. A combination of CD1a, S-100, CD3, CD20, langerin, CD68, CD163, CD21, CD35 and CD123 immunohistochemical stains were performed. High-resolution array comparative genomic hybridization was performed on six samples from five cases. In these cases, seven were female and two male, with an average age of 25 years (15 months-59 years). A majority of the cases were identified in lymph node. Areas of Langerhans cell histiocytosis had a typical appearance with the existence of bland 'coffee-bean' nuclei, clear cytoplasm and associated eosinophils. The immunophenotype was typical, including expression of CD1a, S100, CD68 and langerin. In areas of Rosai-Dorfman disease, there was emperipolesis seen in all cases. Cells were intermediate-large in size with large round nuclei and ample clear or pale cytoplasm. The lesional cells were positive for S100, CD68, CD163, without expression of langerin or CD1a. Array comparative genomic hybridization showed gains and/or losses in four of the six samples. One case showed no gains or losses and one additional case showed gains and losses in the Langerhans cell histiocytosis, while no abnormalities were discovered in the Rosai-Dorfman disease component. These findings are comparable to those seen in previous studies of Langerhans cell histiocytosis. We report the clinical and pathologic findings of the combination of Langerhans cell histiocytosis and Rosai-Dorfman disease. Furthermore, we suggest on the basis of evidence from our cases that, when simultaneous, the two entities may be pathophysiologically related.

Altered aquaporin 9 expression and localization in human hepatocellular carcinoma

BACKGROUND

In addition to the biochemical components secreted in bile, aquaporin (AQP) water channels exist in hepatocyte membranes to form conduits for water movement between the sinusoid and the bile canaliculus. The aim of the current study was to analyse AQP 9 expression and localization in human hepatocellular carcinoma (HCC) and non-tumourigenic liver (NTL) tissue from patients undergoing hepatic resection.

METHODS

Archived tissue from 17 patients was sectioned and analysis performed using an antibody raised against AQP 9. Slides were blind-scored to determine AQP 9 distribution within HCC and NTL tissue.

RESULTS

Aquaporin 9 was predominantly expressed in the membranes of hepatocytes and demonstrated zonal distribution relative to hepatic sinusoid structure in normal liver. In HCC arising in the absence of cirrhosis AQP 9 remained membrane-localized with zonal distribution in the majority of NTL. By contrast, AQP 9 expression was significantly decreased in the HCC mass vs. pair-matched NTL. In HCC in the presence of cirrhosis, NTL was characterized by extensive AQP 9 staining in the membrane in the absence of zonal distribution and AQP 9 staining in NTL was significantly greater than that observed in the tumour mass.

CONCLUSIONS

These data demonstrate that human HCC is characterized by altered AQP 9 expression and AQP 9 localization in the NTL mass is dependent on underlying liver pathology. Given the central role of AQPs in normal liver function and the potential role of AQPs during transformation and progression, these data may prove valuable in future diagnostic and/or therapeutic strategies.

Castleman disease of the hyaline-vascular type confined to the kidney

The case is a 38-year-old man in whom a solitary subcapsular left renal cortical mass was successfully resected. Comorbidities included a benign epididymal cyst and a history of nephrolithiasis. Computed tomographic imaging demonstrated a 1.8-cm enhancing mass in the anterior midregion of the kidney. An open partial nephrectomy was performed, and histopathologic examination established a diagnosis of the hyaline-vascular type of Castleman disease (CD). The patient had an uneventful postoperative course and has experienced no local or metastatic recurrence in the 10 months since surgery. CD localized in the kidney is an exceptionally rare occurrence but should be included in the complete differential diagnosis of solitary renal cortical mass lesions.

Gastrointestinal lymphoproliferative disorders

Malignant lymphomas can be first detected in some patients in endoscopic biopsies of the gastrointestinal (GI) tract. However, their recognition and accurate classification often pose problems for the pathologist for several reasons. First, the small sampling size limits pattern recognition and the number of ancillary studies which can be performed. Second, the immune system of the GI tract is capable of intense hyperplastic responses which may mimic lymphoma. Third, in a fashion similar to cutaneous lesions, those in the alimentary tract may be visualized and biopsied at a very early phase in their development when differentiation into neoplasia may be incomplete. Some forms of immune response actually pass through a poorly defined transition into lymphoma. Examples of such 'dysplasia' of the gut immune system include Helicobacter gastritis, coeliac disease and multicentric lymphoid hyperplasia associated with underlying immunodeficiency. With ever increasing endoscopic scrutiny of the gut by gastroenterologists, it is not surprising that the frequency of these indeterminate cases seems to be growing. In combination with careful clinical correlation and conventional microscopic analysis, selective immunohistochemical studies currently constitute the most powerful ancillary method in the pathologist's effort to recognize and classify GI lymphomas accurately.

Ki67 staining pattern as a diagnostic tool in the evaluation of lymphoproliferative disorders

AIMS

To evaluate a group of lymphoid proliferations using only Ki67-stained slides to determine the value of the pattern of proliferating cells in diagnosis. Ki67 immunohistochemistry allows evaluation of the distribution of proliferating cells in addition to simply determining the proliferation rate of cells.

METHODS AND RESULTS

Three observers, using a Ki67-stained slide only, studied 149 cases from five diagnostic groupings: follicular hyperplasia, mixed pattern hyperplasia, localized Castleman's disease, follicular lymphoma and marginal zone lymphoma. The sensitivity for benign lesions varied from 94% to 97% among the three observers. Follicular lymphomas were recognized as neoplastic with a sensitivity of 96% and 100% by two of the observers. Marginal zone lymphoma was recognized as neoplastic in 67-73% of cases.

CONCLUSIONS

The Ki67 stain alone is a powerful tool for distinguishing benign from malignant proliferations within the selected groups. Nuances and pitfalls in the interpretation of Ki67 staining pattern are discussed.