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.

Correlation Between Programmed Death Receptor-1 Expression in Tumor-Infiltrating Lymphocytes and Programmed Death Ligand-1 Expression in Non-Small Cell Lung Carcinoma.

CONTEXT.­: The interaction between programmed death ligand-1 (PD-L1) and programmed death receptor-1 (PD-1) on activated T cells sends an inhibitory signal that dampens the immune response. Tumors can express PD-L1 and evade the immune system. In advanced non-small cell lung carcinoma, expression of PD-1 in tumor-infiltrating lymphocytes (TILs) correlates with PD-L1 expression in tumor cells (TCs). However, this relationship has not been thoroughly explored in early disease. OBJECTIVE.­: To investigate the correlation of PD-1 and PD-L1 in non-small cell lung carcinoma tumor samples, with emphasis on stage I disease. DESIGN.­: Whole tissue sections from non-small cell lung carcinoma tumors were retrospectively evaluated by immunohistochemistry for PD-1 and PD-L1 expression. The scoring was based on the percentage of cells positive for PD-1 in TILs and PD-L1 in TCs and tumor-infiltrating immune cells (ICs). RESULTS.­: Expression of PD-1 in TILs was observed in 147 of 161 non-small cell lung carcinoma cases (91%). The majority of cases negative for PD-1 also lacked PD-L1 in TCs. The 68 cases with highest PD-1 expression in TILs included 33 (49%) with expression of PD-L1 in TCs and ICs. Strong correlations were observed in patients with elevated PD-1 expression in TILs and PD-L1 in TCs ( P = .01) and ICs ( P = .003). Expression of PD-1 also correlated with increased PD-L1 in TCs and ICs when the 2 were grouped together ( P < .001). Finally, stage I patients with negative PD-1 and PD-L1 expression showed trends toward increased disease-specific survival. CONCLUSIONS.­: Expression of PD-1 in TILs correlates with PD-L1 expression in both TCs and ICs. Furthermore, negative expression of PD-1 and PD-L1 suggest trends toward disease-specific survival, even in early disease stages.

Programmed Death Ligand-1 (PD-L1) Expression in Either Tumor Cells or Tumor-Infiltrating Immune Cells Correlates With Solid and High-Grade Lung Adenocarcinomas.

CONTEXT: - Programmed death ligand-1 (PD-L1) expression in non-small cell lung carcinoma (NSCLC) is heterogeneous and known to be underestimated on small biopsies. Correlation of PD-L1 expression with clinicopathologic features may provide additional useful information. To our knowledge, the clinicopathologic features of NSCLC have not been reported for subsets defined by PD-L1 expression in either tumor cells or tumor-infiltrating immune cells. OBJECTIVE: - To investigate the clinicopathologic characteristics of NSCLC subsets defined by PD-L1 expression in either tumor cells or tumor-infiltrating immune cells. DESIGN: - PD-L1 immunohistochemistry with the SP142 clone was performed on whole-tissue sections and given semiquantitative scores (0/1/2/3) according to percent of PD-L1+ tumor cells (TCs) and percent tumor area with PD-L1+ tumor-infiltrating immune cells (ICs). RESULTS: - Adenocarcinoma cases that were scored either TC 1/2/3 or IC 1/2/3 included most (22 of 34; 65%) high-histologic grade cases and most (25 of 36; 69%) solid subtype cases. Compared with the adenocarcinoma TC 0 and IC 0 subset, the TC 1/2/3 or IC 1/2/3 subset correlated with higher histologic grade (P = .005, χ2 test for trend) and solid subtype (P < .001, Fisher exact test). Compared with the adenocarcinoma TC 0/1 or IC 0/1 subset, the TC 2/3 or IC 2/3 subset correlated with higher histologic grade (P = .002, χ2 test for trend), solid subtype (P < .001, Fisher exact test), and higher smoking pack-years (P = .01, Mann-Whitney test). CONCLUSIONS: - Lung adenocarcinoma subsets defined by PD-L1 expression in either tumor cells or tumor-infiltrating immune cells correlated with high histologic grade, solid subtype, and high smoking pack-years.

Next-Generation Sequencing of a Cohort of Pulmonary Large Cell Carcinomas Reclassified by World Health Organization 2015 Criteria.

CONTEXT: The classification of pulmonary large cell carcinoma has undergone a major revision with the recent World Health Organization (WHO) 2015 Classification. Many large cell carcinomas are now reassigned to either adenocarcinoma with solid pattern or nonkeratinizing squamous cell carcinoma based on immunopositivity for adenocarcinoma markers or squamous cell carcinoma markers, respectively. Large cell carcinomas that are negative for adenocarcinoma and squamous cell carcinoma immunomarkers are now classified as large cell carcinoma with null immunohistochemical features (LCC-N). Although a few studies investigated the mutation profile of large cell carcinomas grouped by immunostain profile before the publication of the new WHO classification, investigation of tumors previously diagnosed as large cell carcinoma and reclassified according to the 2015 WHO classification has not, to our knowledge, been reported. OBJECTIVE: To determine the mutation profiles of pulmonary large cell carcinomas reclassified by WHO 2015 criteria. DESIGN: Archival cases of non-small cell lung carcinoma with large cell carcinoma morphology (n = 17) were reclassified according to 2015 WHO criteria. To determine mutation profile, we employed Ion Torrent (Life Technologies, Carlsbad, California)-based next-generation sequencing (50 genes; more than 2800 mutations) in addition to real-time quantitative reverse transcription polymerase chain reaction for ALK translocation detection. RESULTS: Two of 17 cases (12%) were reclassified as LCC-N, and both had mutations-BRAF D594N in one case and KRAS G12C in the other case. Seven of 17 cases (41%) were reclassified in the adenocarcinoma with solid pattern group, which showed one KRAS G12C and one EGFR E709K + G719C double mutation in addition to mutations in TP53. Eight of 17 cases (47%) were reclassified in the nonkeratinizing squamous cell carcinoma group, which showed mutations in PIK3CA, CDKN2A, and TP53. No ALK translocations or amplifications were detected. CONCLUSIONS: The adenocarcinoma with solid pattern group showed mutations typical of adenocarcinoma, whereas the nonkeratinizing squamous cell carcinoma group showed mutations typical of squamous cell carcinoma. Both LCC-N cases had mutations associated with adenocarcinoma, supporting the hypothesis that LCC-N is related to adenocarcinoma.

Folate Receptor α Expression Level Correlates With Histologic Grade in Lung Adenocarcinoma.

CONTEXT: -Folate receptor α (FRA) is a glycosylphosphatidylinositol-anchored high-affinity folate receptor that localizes to the apical surface of epithelia when it is expressed in normal tissue. Unlike normal tissues, FRA may localize to the basolateral side in tumors. These features make FRA an attractive drug target, and several FRA-targeted drugs have been developed and are in phases of clinical testing. Folate receptor α protein expression shows intertumoral variability that may correlate with response to therapy and to clinicopathologic parameters. Using immunohistochemistry, a recent study of breast carcinomas found FRA protein expression was associated with triple-negative status and high histologic grade in breast cancer. Although a prior study of lung adenocarcinomas found the expression level of the gene encoding FRA, FOLR1, was significantly increased in low-histologic-grade tumors compared to high-histologic-grade tumors, the relationship between FRA protein expression and histologic grade has not been reported for lung adenocarcinomas. OBJECTIVE: -To investigate the relationship between FRA protein expression level and clinicopathologic parameters in lung adenocarcinomas, including histologic grade, by performing immunohistochemistry for FRA on a cohort of non-small cell lung carcinomas. DESIGN: -High-density tissue microarrays constructed from 188 non-small cell lung carcinomas and used in prior studies were immunostained with FRA-specific antibody clone 26B3. Folate receptor α membranous staining intensity was given a semiquantitative score from 0 to 3+ for triplicate cores of tumor and averaged for each tumor. An average semiquantitative score from 0 to 1.4 was considered low expression, and an average semiquantitative score greater than 1.4 was considered high expression. RESULTS: -The majority (60 of 78; 77%) of lung adenocarcinomas and a minority (4 of 41; 10%) of lung squamous cell carcinomas were positive for FRA. Folate receptor α expression in lung adenocarcinomas compared with squamous cell carcinomas was statistically different (P < .001, χ(2) test). In lung adenocarcinomas, FRA expression level correlated with histologic grade (P = .005, χ(2) test for trend), but no other clinicopathologic parameter. The majority (23 of 27; 85%) of grade 1 adenocarcinomas had high FRA protein expression, whereas approximately half of grade 2 (10 of 19; 53%) and grade 3 (12 of 25; 48%) adenocarcinomas had high FRA protein expression. Out of adenocarcinomas with lepidic growth pattern, 16 of 20 (80%) showed high FRA protein expression. Out of adenocarcinomas with solid growth pattern, 2 of 6 (33%) showed high FRA protein expression. In lung adenocarcinomas, FRA expression level did not correlate with thyroid transcription factor 1, napsin A, or survival. CONCLUSIONS: -Folate receptor α protein was expressed in the majority of lung adenocarcinomas and a minority of lung squamous cell carcinomas. Folate receptor α protein expression correlated with histologic grade for lung adenocarcinomas, and the greatest difference was observed between grade 1 and grade 3. Our results indicate that poorly differentiated adenocarcinomas or focuses of poor differentiation in a heterogeneous tumor may lack FRA protein expression and be more likely to be resistant to FRA-targeting drugs.

The Toll-like receptor 4 agonist monophosphoryl lipid a augments innate host resistance to systemic bacterial infection.

Monophosphoryl lipid A (MPLA) is a Toll-like receptor 4 (TLR4) agonist that is currently used as a vaccine adjuvant in humans. In this study, we evaluated the effect of MPLA treatment on the innate immune response to systemic bacterial infections in mice. Mice treated with MPLA after burn injury showed improved survival and less local and systemic dissemination of bacteria in a model of Pseudomonas aeruginosa burn wound infection. Prophylactic treatment with MPLA significantly enhanced bacterial clearance at the site of infection and reduced systemic dissemination of bacteria despite causing attenuation of proinflammatory cytokine production during acute intra-abdominal infection caused by cecal ligation and puncture. Administration of MPLA at 1 h after CLP also improved bacterial clearance but did not alter cytokine production. MPLA treatment increased the numbers of granulocytes, double-positive myeloid cells, and macrophages at sites of infection and increased the percentage and total numbers of myeloid cells mediating phagocytosis of bacteria. Depletion of Ly6G(+) neutrophils, but not macrophages, eliminated the ability of MPLA treatment to improve bacterial clearance. The immunomodulatory effects of MPLA were absent in TLR4-deficient mice. In conclusion, these studies show that MPLA treatment significantly augments the innate immune response to bacterial infection by enhancing bacterial clearance despite the attenuation of proinflammatory cytokine production. The enhanced bacterial clearance is mediated, in part, by increased numbers of myeloid cells with effective phagocytic functions at sites of infection and is TLR4 dependent.