Role of immunohistochemistry in the diagnosis of lung cancer

Histological-Based Stainings using Free-Floating Tissue Sections

Immunohistochemistry is a widely used technique to visualize specific tissue structures as well as protein expression and localization. Two alternative approaches are widely used to handle the tissue sections during the staining procedure, one approach consists of mounting the sections directly on glass slides, while a second approach, the free-floating, allows for fixed sections to be maintained and stained while suspended in solution. Although slide-mounted and free-floating approaches may yield similar results, the free-floating technique allows for better antibody penetration and thus should be the method of choice when thicker sections are to be used for 3D reconstruction of the tissues, for example when the focus of the experiment is to gain information on dendritic and axonal projections in brain regions. In addition, since the sections are kept in solution, a single aliquot can easily accommodate 30 to 40 sections, handling of which is less laborious, particularly in large-scale biomedical studies. Here, we illustrate how to apply the free-floating method to fluorescent immunohistochemistry staining, with a major focus on brain sections. We will also discuss how the free-floating technique can easily be modified to fit the individual needs of researchers and adapted to other tissues as well as other histochemical-based stainings, such as hematoxylin and eosin and cresyl violet, as long as tissue samples are properly fixed, typically with paraformaldehyde or formalin.

Advances in Diagnostic Procedures and Their Applications in the Era of Cancer Immunotherapy

Diagnostic procedures play critical roles in cancer immunotherapy. In this chapter, we briefly discuss three major diagnostic procedures widely used in immunotherapy: immunohistochemistry, next-generation sequencing, and flow cytometry. We also describe the uses of other diagnostic procedures and preclinical animal models in cancer immunotherapy translational research.

Identification of lung cancer gene markers through kernel maximum mean discrepancy and information entropy

BACKGROUND

The early diagnosis of lung cancer has been a critical problem in clinical practice for a long time and identifying differentially expressed gene as disease marker is a promising solution. However, the most existing gene differential expression analysis (DEA) methods have two main drawbacks: First, these methods are based on fixed statistical hypotheses and not always effective; Second, these methods can not identify a certain expression level boundary when there is no obvious expression level gap between control and experiment groups.

METHODS

This paper proposed a novel approach to identify marker genes and gene expression level boundary for lung cancer. By calculating a kernel maximum mean discrepancy, our method can evaluate the expression differences between normal, normal adjacent to tumor (NAT) and tumor samples. For the potential marker genes, the expression level boundaries among different groups are defined with the information entropy method.

RESULTS

Compared with two conventional methods t-test and fold change, the top average ranked genes selected by our method can achieve better performance under all metrics in the 10-fold cross-validation. Then GO and KEGG enrichment analysis are conducted to explore the biological function of the top 100 ranked genes. At last, we choose the top 10 average ranked genes as lung cancer markers and their expression boundaries are calculated and reported.

CONCLUSION

The proposed approach is effective to identify gene markers for lung cancer diagnosis. It is not only more accurate than conventional DEA methods but also provides a reliable method to identify the gene expression level boundaries.

Non-Specific Onset of Pulmonary Adenocarcinoma

Skin metastases are rarely found in lung cancer compared to other types of neoplasia. Of the types of lung cancer that can have skin metastases, the most common one is adenocarcinoma. Pulmonary cancer metastasizing to the skin has poor prognosis, usually the survival rate of the patients is 4-6 months. We present the case of a 59-year-old woman, smoker, high blood pressure, dyslipidemia, with two skin ertitemato-nodular lesions, incompletely delimited, with a diameter of 4-5cm, in the left arm (1/3 medio-external) and left latero-thoracic (near IV intercostal space) area, discovered during a regular medical examination at her family doctor’s practice. After multiple clinical and paraclinical investigations, almost 3 months after the initial presentation, the patient was diagnosed with stage IV pulmonary adenocarcinoma with supra and subdiaphragmatic lymph-node metastases, soft tissue metastases, liver metastases and breast metastases. Oncological treatment was initiated, but the patient's progression was unfavorable, her passing occurring 6 months after being diagnosed.

Ultra-fast and automated immunohistofluorescent multistaining using a microfluidic tissue processor

Multistaining of a tissue section targeting multiple markers allows to reveal complex interplays in a tumor environment. However, the resource-intensive and impractically long nature of iterative multiplexed immunostainings prohibits its practical implementation in daily routine, even when using work-flow automation systems. Here, we report a fully automated and ultra-fast multistaining using a microfluidic tissue processor (MTP) in as short as 20 minutes per marker, by immunofluorescent staining employing commercially available tyramide signal amplification polymer precipitation by horse-radish peroxidase (HRP) activation. The reported duration includes (i) 15 minutes for the entire fluidic exchange and reagent incubation necessary for the immunostaining and (ii) 5 minutes for the heat-induced removal of the applied antibodies. Using the automated MTP, we demonstrated a 4-plex automated multistaining with clinically relevant biomarkers within 84 minutes, showing perfect agreement with the state-of-the-art microwave treatment antibody removal. The presented HRP-based method is in principle extendable to multistaining by both tyramides accommodating higher number of fluorescent channels and multi-color chromogenic staining. We anticipate that our automated multi-staining with a turn-around time shorter than existing monoplex immunohistochemistry methods has the potential to enable multistaining in routine without disturbing the current laboratory workflow, opening perspectives for implementation of -omics approaches in tissue diagnostics.

New insights into spectral histopathology: infrared-based scoring of tumour aggressiveness of squamous cell lung carcinomas

Spectral histopathology, based on infrared interrogation of tissue sections, proved a promising tool for helping pathologists in characterizing histological structures in a quantitative and automatic manner.

Spectral histopathology, based on infrared interrogation of tissue sections, proved a promising tool for helping pathologists in characterizing histological structures in a quantitative and automatic manner. In cancer diagnosis, the use of chemometric methods permits establishing numerical models able to detect cancer cells and to characterize their tissular environment. In this study, we focused on exploiting multivariate infrared data to score the tumour aggressiveness in preneoplastic lesions and squamous cell lung carcinomas. These lesions present a wide range of aggressive phenotypes; it is also possible to encounter cases with various degrees of aggressiveness within the same lesion. Implementing an infrared-based approach for a more precise histological determination of the tumour aggressiveness should arouse interest among pathologists with direct benefits for patient care. In this study, the methodology was developed from a set of samples including all degrees of tumour aggressiveness and by constructing a chain of data processing steps for an automated analysis of tissues currently manipulated in routine histopathology.

The future of lung cancer therapy: Striding beyond conventional EGFR and ALK treatments

Lung cancer, one of the most frequently diagnosed cancers worldwide has long relied on testing for the molecular biomarkers EGFR/ALK. However, achieving superior clinical outcomes for patients with lung cancer requires developing comprehensive techniques beyond contemporary EGFR/ALK testing. Current technologies are on par with molecular testing for EGFR/ALK in terms of efficacy, most of them failing to offer improvements perhaps primarily due to skepticism among clinicians, despite being recommended in the NCCN guidelines. The present study endeavored to minimize chemotherapy-dependence in EGFR/ALK-negative patient cohorts, and use evidence-based methods to identify ways to improve clinical outcomes. In total, 137 lung cancer cases obtained from 'PositiveSelect NGS data', comprising 91 males and 46 females, were investigated. EGFR- and ALK-positivity was used for data dichotomization to understand the therapeutic utility of rare gene alterations beyond just EGFR/ALK. Statistics obtained from PositiveSelect were collated with data from international studies to construct a meta-analysis intended to achieve better clinical outcomes. Upon dichotomization, 23% of cases harbored EGFR variants indicating that treating with EGFR TKIs would be beneficial; the remaining 77% exhibited no EGFR variants that would indicate favorable results using specific currently available chemotherapy practices. Similarly, 28% of cases had EGFR+ALK variants favoring EGFR/ALK-based targeted therapeutics; the remaining 72% harbored no EGFR/ALK variants with known beneficial chemotherapy routes. The present study aimed to overcome current inadequacies of targeted therapies in patients with a conventional EGFR/ALK-positive diagnosis and those in EGFR+ALK-negative cohorts. Upon analysis of the negative cohorts, significant and clinically relevant single nucleotide variants were identified in KRAS, ERBB2, MET and RET, with frequencies of 7, 1, 2 and 3% in patients who were EGFR-negative and 6, 1, 1, and 3% in patients who were EGFR and ALK-negative, respectively, enabling the use of targeted therapeutics aside from EGFR/ALK TKIs. From the results of the current study only 35% of the two negative arms (EGFR negative and EGFR+ALK negative) would be recommended NCCN or off-label chemotherapy; prior to the current study, the entire cohorts would have been recommended this treatment. The present study emphasizes the potential of comprehensive genomics in identifying hallmarks of lung cancer beyond EGFR/ALK, using broad-spectrum genetic testing and data-sharing among medical professionals to circumvent ineffective chemotherapy.

Current and Prospective Protein Biomarkers of Lung Cancer

Lung cancer is a malignant lung tumor with various histological variants that arise from different cell types, such as bronchial epithelium, bronchioles, alveoli, or bronchial mucous glands. The clinical course and treatment efficacy of lung cancer depends on the histological variant of the tumor. Therefore, accurate identification of the histological type of cancer and respective protein biomarkers is crucial for adequate therapy. Due to the great diversity in the molecular-biological features of lung cancer histological types, detection is impossible without knowledge of the nature and origin of malignant cells, which release certain protein biomarkers into the bloodstream. To date, different panels of biomarkers are used for screening. Unfortunately, a uniform serum biomarker composition capable of distinguishing lung cancer types is yet to be discovered. As such, histological analyses of tumor biopsies and immunohistochemistry are the most frequently used methods for establishing correct diagnoses. Here, we discuss the recent advances in conventional and prospective aptamer based strategies for biomarker discovery. Aptamers like artificial antibodies can serve as molecular recognition elements for isolation detection and search of novel tumor-associated markers. Here we will describe how these small synthetic single stranded oligonucleotides can be used for lung cancer biomarker discovery and utilized for accurate diagnosis and targeted therapy. Furthermore, we describe the most frequently used in-clinic and novel lung cancer biomarkers, which suggest to have the ability of differentiating between histological types of lung cancer and defining metastasis rate.

Diagnostic Utility of Bronchial Brush-Tip Washings for the Immunohistochemical Assessment of Peripheral Lung Lesions

OBJECTIVES

Immunohistochemistry (IHC) is an important component of lung cancer diagnosis and management, although performance can be limited due to tissue availability. We describe a novel technique for processing brush-tip washings (BTW) and evaluate the feasibility of IHC testing on these samples.

STUDY DESIGN

All patients who had cell blocks (CB) created from BTW following bronchoscopic investigation of peripheral lung lesions were included. CB were assessed for adequate material before undergoing IHC staining.

RESULTS

75 patients were included in the study, with bronchoscopic diagnosis of malignancy achieved in 77%. Sixty-seven samples (89%) had sufficient cells for diagnosis on CB and 56 of these (84%) proved amenable to IHC. CB created from BTW were the sole specimens available for IHC subtyping in 7 patients (9%).

CONCLUSIONS

CB are easily created from BTW and are a simple method for increasing the diagnostic utility of bronchoscopic specimens without increasing the risk or duration of bronchoscopy. IHC can be easily performed in a high proportion of cases, increasing the likelihood of accurate sub-typing of tumours following diagnostic bronchoscopy.

Brain metastasis as initial presentation of papillary adenocarcinoma of the lung: case report

The authors describe the case of a 33-year-old patient with history of seizures alone without any previous symptom, being diagnosed with brain metastases from primary papillary adenocarcinoma of the lung. Emphasis is given to the diagnostic investigation for brain metastasis and prognostic evaluation of papillary adenocarcinoma of the lung, and a brief literature review on such diseases is performed.

Therapeutic Potential of Andrographolide Isolated from the Leaves of Andrographis paniculata Nees for Treating Lung Adenocarcinomas

Andrographolide is one of the major diterpene lactones found in Andrographis paniculata Nees and exhibits remarkable inhibitory effects on various cancers. In this study, the antipulmonary cancer effects of andrographolide were studied in a lung tumor mouse model induced by human vascular endothelial growth factor A₁₆₅ (hVEGF-A₁₆₅). These results demonstrated that andrographolide significantly reduced the expression of hVEGF-A₁₆₅ compared with a mock group in the Clara cells of the lungs. In addition, andrographolide also decreased tumor formation by reducing VEGF, EGFR, Cyclin A, and Cyclin B expression on the transcriptional and translational levels. These results indicated that andrographolide treatment on the overexpression of VEGF can arrest the cell cycle, which induced pulmonary tumors in transgenic mice. In conclusion, the antiangiogenesis and chemotherapeutic potential of andrographolide may provide a cure for pulmonary tumors in the future.

An investigation of growth factors and lactoferrin in naturally occurring ovine pulmonary adenomatosis

Ovine pulmonary adenomatosis (OPA), also known as jaagsiekte, is a transmissible beta retrovirus-induced lung tumour of sheep that has several features resembling human bronchoalveolar carcinoma (BAC). Angiogenesis has been suggested to be one of the most important factors underlying tumour growth and invasion. This process involves the action of growth factors including vascular endothelial growth factor (VEGF)-C, basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF)-C and its receptor (PDGFR-α). Bovine lactoferrin (bLF), an iron and heparin-binding glycoprotein secreted into various biological fluids, has been implicated in innate immunity and has anti-inflammatory and anti-tumour functions. Tissues from 16 cases of OPA were compared with tissues from seven healthy control sheep by immunohistochemistry. Expression of the markers was assessed semi-quantitatively by ascribing an immunoreactivity score (IRS) with a maximum value of 300. VEGF-C, bFGF, PDGF-C, PDGFR-α and bLF signals were detected in 10/16, 15/16, 12/16, 15/16 and 10/16 of the OPA cases studied, respectively. bLF expression was weak in the neoplastic epithelial cells (IRS 21.4 ± 10.0) in contrast to high levels detected in infiltrating macrophages and plasma cells (IRS 141.3 ± 24.8 and 140.0 ± 25.1, respectively). The PDGFR-α IRS was elevated for neoplastic epithelial cells (108.9 ± 18.2) and was lowest for macrophages and plasma cells (20.4 ± 13.1 and 13.7 ± 12.4, respectively). These results suggest that bFGF, VEGF-C and PDGF-C have roles in the pathogenesis of OPA. bLF may activate macrophages and plasma cells in these lesions, but limited expression of bLF by neoplastic cells may be a consequence of defective or impaired function of this molecule.

Association between decreases in type V collagen and apoptosis in mouse lung chemical carcinogenesis: a preliminary model to study cancer cell behavior

OBJECTIVE

The importance of type V collagen and its relationships with other types of collagen and with vascular and epithelial apoptosis were studied in a model of chemical carcinogenesis in the mouse lung.

METHODS

TWO GROUPS OF MALE BALB/C MICE WERE STUDIED: a) animals that received two intraperitoneal doses of 3 g/kg urethane carcinogen (urethane group = 24); and b) animals submitted to a sham procedure, comparable to the test group (control group = 7). Both groups were sacrificed after 120 days. In situ detection of apoptosis, immunohistochemistry, immunofluorescence and histomorphometry were used to evaluate the fraction occupied by the tumor, vascular and epithelial apoptosis, and type V, III and I collagen fibers in the lung parenchyma from both groups.

RESULTS

The lung parenchyma from the urethane group showed low fractions of vascular and epithelial apoptosis as well as reduced type V collagen fibers when compared to the control group. A significant direct association was found between type V and III collagen fibers and epithelial apoptosis, type V collagen fibers and vascular apoptosis, and type V and type I collagen fibers.

CONCLUSION

The results show that a direct link between low amounts of type V collagen and decreased cell apoptosis may favor cancer cell growth in the mouse lung after chemical carcinogenesis, suggesting that strategies aimed at preventing decreased type V collagen synthesis or local responses to reduced apoptosis may have a greater impact in lung cancer control.