Protein correlates of molecular alterations in lung adenocarcinoma: Immunohistochemistry as a surrogate for molecular analysis

Immunohistochemistry of Lung Cancer Biomarkers

Immunohistochemical (IHC) staining represents a comparatively inexpensive testing method that is attractive as a potential alternative to molecular sequencing methods or fluorescence in situ hybridization for pulmonary biomarker testing. While a variety of IHC tests directed at actionable genetic alterations have been developed and evaluated since the advent of targeted therapy, specific antibody clones for anaplastic lymphoma kinase, ROS-1, and potentially neurotrophic tropmyosin receptor kinase have been the primary antibodies that provide sufficiently robust results to be utilized as either a primary testing or screening method to direct targeted therapy. Antibodies for a variety of other targets such as epidermal growth factor receptors, for example, have lacked sufficient sensitivity and specificity to cover the range of mutations that may occur and are generally not recommended in lieu of molecular testing with the exception of limited resource settings. IHC is also used as a predictive marker for response to immunotherapy through evaluation of programmed death ligand 1 expression. In addition, multiple antibody-drug conjugates (ADCs) are under investigation, designed to deliver drugs directly to tumor cells through binding to specific target antigens. Some ADCs have already received accelerated FDA approval, and IHC was incorporated in many clinical trials evaluating ADC efficacy. As such, it is anticipated that ADCs may have a companion diagnostic IHC to guide patient selection.

LKB-1 Expression and High-Risk Histopathology are Independent Prognostic Factors for Patients with Oral Cavity Carcinoma

BACKGROUND

The expression of liver kinase B1 (LKB-1) has been associated with prognosis in squamous cell carcinoma of the oral cavity (SCCOC). This study aimed to define the prognostic role of LKB-1 expression for patients with SCCOC and the suitability of its integration into a multivariate prognostic model.

METHODS

A retrospective cohort study of patients with SCCOC was conducted in a cancer center. Expression of LKB-1 was evaluated by immunohistochemistry, and multivariate analysis defined prognostic factors associated with recurrence, recurrence-free survival (RFS), and overall survival (OS). The logistic regression model was used to construct a predictive computer software program.

RESULTS

Of the 201 patients in this study, 104 (51.7%) experienced recurrence of their disease. Lower expression of LKB-1, high-risk histopathology, and advanced tumor-node-metastasis (TNM) stages were independent factors via multivariate analysis associated with the increased recurrence risk, poor RFS, and poor OS. If lack of LKB-1 expression is considered the reference category, the factors independently associated with recurrence were low (odds ratio [OR], 0.157; 95% confidence interval [CI], 0.044-0.557), intermediate (OR, 0.073; 95% CI, 0.017-0.319), and intense (OR, 0.047; 95% CI, 0.007-0.304) expression of LKB-1. This model permitted construction of a computer software program capable of prediction with receiver operating characteristic analysis (area under the curve, 0.925) and led to the definition of five prognostic groups with a biologic gradient.

CONCLUSION

These results suggest that LKB-1 expression in patients with SCCOC is of robust prognostic value and complements the TNM staging system. The proposed model requires external validation in prospective observational studies.

Round Robin Evaluation of MET Protein Expression in Lung Adenocarcinomas Improves Interobserver Concordance

Overexpression of the mesenchymal-epithelial transition (MET) receptor, a receptor tyrosine kinase, can propel the growth of cancer cells and portends poor prognoses for patients with lung cancer. Evaluation of MET by immunohistochemistry is challenging, with MET protein overexpression varying from 20% to 80% between lung cancer cohorts. Clinical trials using MET protein expression to select patients have also reported a wide range of positivity rates and outcomes.

AHNAK2 Is Associated with Poor Prognosis and Cell Migration in Lung Adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD), as the main subtype of lung cancer, is one of the common causes of cancer-related deaths worldwide. The AHNAK family is correlated with cell structure and migration, cardiac calcium channel signaling, and tumor metastasis. Previous studies showed AHNAK2 could promote tumor progression and cell migration in melanoma and renal clear cell carcinoma. However, the role of AHNAK2 in LUAD remains unknown.

METHODS

We examined the levels of AHNAK2 in pathological specimens and the database of Clinical Proteomic Tumor Analysis Consortium-Lung adenocarcinoma (CPTAC-LUAD), The Cancer Genome Atlas-Lung Adenocarcinoma (TCGA-LUAD), Gene Expression Omnibus dataset (GSE72094, GSE26939), and The Genotype-Tissue Expression (GTEx) of lung tissue samples. Univariate Cox regression, multivariate Cox regression, and Kaplan-Meier survival analysis were performed to reveal the relationship between AHNAK2 and prognosis. A nomogram was constructed to predict 2- or 3-year overall survival and validated via calibration curves, receiver operating characteristic (ROC) analysis, and decision curve analysis (DCA). Furthermore, Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to explore the functional role of AHNAK2 in lung adenocarcinoma. Finally, by transfecting siRNA, we examined the regulatory effect of AHNAK2 on cell migration.

RESULTS

The expression of AHNAK2 was upregulated in tumor samples and correlated with poor prognosis in LUAD patients. Nomogram with AHNAK2 and clinical parameters showed a good prediction in overall survival (OS), especially the 2-year OS. In addition, functional analyses and wound healing assay suggested that AHNAK2 might be involved in the regulation of migration in LUAD.

CONCLUSION

In summary, our study showed that AHNAK2 might be a novel biomarker in LUAD and revealed the potential mechanism of AHNAK2 in LUAD progression which could provide new insights for target therapy.

Usefulness of complementary next-generation sequencing and quantitative immunohistochemistry panels for predicting brain metastases and selecting treatment outcomes of non-small cell lung cancer

To demonstrate the usefulness of complementary next-generation sequencing (NGS) and immunohistochemistry (IHC) counting, we analyzed 196 patients with non-small cell lung cancer who underwent surgical resection and adjuvant chemotherapy. Formalin-fixed, paraffin-embedded samples of adenocarcinoma (ADC), squamous cell carcinoma, and large cell carcinoma were used to prepare tissue microarrays and were examined by protein H-score IHC image analysis and NGS for oncogenes and proto-oncogenes and genes of tumor suppressors, immune checkpoints, epithelial-mesenchymal transition factors, tyrosine kinase receptors, and vascular endothelial growth factors. In patients with brain metastases, primary tumors expressed lower PIK3CA protein levels. Overexpression of p53 and a higher PD-L1 protein H-score were detected in patients who underwent surgical treatment followed by chemotherapy as compared with those who underwent only surgical treatment The absence of brain metastases was associated with wild-type sequences of genes EGFR, CD267, CTLA-4, and ZEB1. The combination of protein overexpression according to IHC and mutation according to NGS was rare (ie, represented by a very low percentage of concordant cases), except for p53 and vascular endothelial growth factor. Our data suggest that protein levels detected by IHC may be a useful complementary tool when mutations are not detected by NGS and also support the idea to expand this approach beyond ADC to include squamous cell carcinoma and even large cell carcinoma, particularly for patients with unusual clinical characteristics. Conversely, well-pronounced immunogenotypic features seemed to predict the clinical outcome after univariate and multivariate analyses. Patients with a solid ADC subtype and mutated genes EGFR, CTLA4, PDCD1LG2, or ZEB1 complemented with PD-L1 or p53 protein lower expression that only underwent surgical treatment who develop brain metastases may have the worst prognosis.

Lung cancer samples preserved in liquid medium: One step beyond cytology

Lung cancer is one of the most common cancer types in men and women worldwide with a high mortality rate. World Health Organization (WHO) classification has accepted biopsy as the primary sample for lung cancer diagnosis, pathological classification and molecular testing for management of patients, yet, the use of alternative sampling procedures is highly encouraged. Bronchial cytological samples require a less invasive collection technique and may be suitable for pathological and molecular analysis and storage in liquid medium. Furthermore, the molecular analysis of bronchial cytological samples allows the detection of molecular biomarkers, which may be useful for the selection of molecular targeted therapies. Thus, the purpose of this review is to describe the usefulness of bronchial cytological samples preserved in liquid medium from lung cancer patients for pathological diagnosis and molecular investigation.

Considerations for standardizing predictive molecular pathology for cancer prognosis

INTRODUCTION

Molecular tests that were once ancillary to the core business of cyto-histopathology are becoming the most relevant workload in pathology departments after histopathology/cytopathology and before autopsies. This has resulted from innovations in molecular biology techniques, which have developed at an incredibly fast pace. Areas covered: Most of the current widely used techniques in molecular pathology such as FISH, direct sequencing, pyrosequencing, and allele-specific PCR will be replaced by massive parallel sequencing that will not be considered next generation, but rather, will be considered to be current generation sequencing. The pre-analytical steps of molecular techniques such as DNA extraction or sample preparation will be largely automated. Moreover, all the molecular pathology instruments will be part of an integrated workflow that traces the sample from extraction to the analytical steps until the results are reported; these steps will be guided by expert laboratory information systems. In situ hybridization and immunohistochemistry for quantification will be largely digitalized as much as histology will be mostly digitalized rather than viewed using microscopy. Expert commentary: This review summarizes the technical and regulatory issues concerning the standardization of molecular tests in pathology. A vision of the future perspectives of technological changes is also provided.