Molecular testing of non-small cell lung carcinoma biopsy and cytology specimens

The basics of commonly used molecular techniques for diagnosis, and application of molecular testing in cytology

Molecular diagnostics has expanded to become the standard of care for a variety of solid tumor types. With limited diagnostic material, it is often desirable to use cytological preparations to provide rapid and accurate molecular results. This review covers important pre-analytic considerations and limitations, and a description of common techniques that the modern cytopathologist should understand when ordering and interpreting molecular tests in practice.

Neoadjuvant Chemo-Immunotherapy for Locally Advanced Non-Small-Cell Lung Cancer: A Review of the Literature

Non-small cell lung cancer accounts for approximately 80–85% of all lung cancers and at present represents the main cause of cancer death among both men and women. To date, surgery represents the cornerstone; nevertheless, around 40% of completely resected patients develop disease recurrence. Therefore, combining neoadjuvant chemo-immunotherapy and surgery might lead to improved survival. Immunotherapy is normally well tolerated, although significant adverse reactions have been reported in certain patients treated with inhibitors of immune checkpoints. In this review, we explore the current literature on the use of neoadjuvant chemo-immunotherapy followed by surgery for treatment of locally advanced non-small-cell lung cancer, with particular attention to the histological aspects, ongoing trials, and the most common surgical approaches. In conclusion, neoadjuvant immunotherapy whether combined or not with chemotherapy reveals a promising survival benefit for patients with advanced non-small-cell lung cancer; nevertheless, more data remain necessary to identify the best candidates for neoadjuvant regimens.

Influence of deep-freezing and MGG staining on DNA and RNA quality in different types of lung adenocarcinoma cytological smears

BACKGROUND

Preserving the optimal quality of DNA and RNA is mandatory for molecular testing in lung adenocarcinoma cytological smears (LACSs).

METHODS

DNA and RNA were isolated from 90 frozen unstained and 46 May Grünwald Giemsa (MGG) stained LACSs prepared from bronchial washing (BW), bronchial brushing (BB), and pleural effusion (PE) samples during 3 years. Concentrations of nucleic acids in all LACSs were assessed by spectrophotometric analysis. Fragmentation of DNA and RNA was determined by PCR amplification of selected genes. Amplicons of 100, 200, 300, 400, and 600 bp were used for DNA and 108 bp-long HPRT1 transcript fragment for RNA fragmentation analysis.

RESULTS

Among 90 frozen LACSs, significantly lower DNA concentrations of BB and RNA concentrations of BW samples frozen for 6-10 months were observed in comparison with samples frozen for longer periods (p < .05). Among 46 paired LACSs, 44 (95.7%) frozen and 15 (32.6%) MGG-stained samples showed 600 bp-long DNA amplicons. Statistically significant difference (p < .05) in the fragmentation of DNA between frozen and MGG-stained LACSs was observed (p < .05), with DNA being less fragmented in frozen LACSs. In addition, 33 (71.7%) frozen and 36 (78.2%) MGG-stained LASCs showed HPRT1 gene amplicon of 108 bp. RNA was less fragmented in 3-year old MGG-stained samples than in LACSs frozen for 3 years.

CONCLUSION

DNA and RNA extracted from frozen and MGG-stained LACSs showed different results depending on the time of storage and/or type of samples, but in general all samples had adequate quantity and quality for downstream molecular testing.

Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for Diagnosis and Staging of Lung Cancer

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS TBNA) is fundamental to the diagnosis of lung cancer, as many patients present with more advanced stages of lung cancer, with enlarged hilar and mediastinal lymph nodes. It also represents a way to sample pulmonary masses directly to make the diagnosis, whereby no other accessible tissue is present and the mass sits adjacent to a large central airway. Very importantly also, EBUS TBNA is the widely accepted first procedure in lung cancer staging. A combined procedure of EUS TBNA can be performed to improve diagnostic accuracy.

Rapid on-site evaluation using telecytology: A major cancer center experience

BACKGROUND

Rapid on-site evaluation (ROSE) with cytology preparations plays a critical role in minimally invasive procedures. The time spent by a pathologist performing ROSE is unpredictable and could be used for more cost-effective activities. The solution encountered by several institutions to address this issue is the use of telecytology (TC). This study analyzes the experience of using telecytology for ROSE in a major cancer center over a period of over 2 years.

METHODS

A retrospective analysis of all remote TC evaluations for adequacy on fine needle aspiration (FNA) and touch preparations (TP) of core biopsies (CB) performed at a major cancer center was performed. The preliminary adequacy assessment was then compared to the adequacy assessment at final diagnosis.

RESULTS

A total of 12 949 adequacy assessments were analyzed. The most common sites biopsied in our institution were lymph node, lung, and liver. There were 7725 adequacy assessments for CB (59.7%), while adequacy assessment for FNA specimens represented 40.3% (n = 5224) of the total number of specimens evaluated by ROSE. Perfect concordance between initial adequacy assessment and the adequacy assessment at final cytologic diagnosis was 93% (12 049/12 949). The final diagnosis adequacy upgrade rate was 6.7% (n = 863), and the adequacy downgrade (a specimen considered adequate on-site that was determined to be nondiagnostic on final examination) was 0.3% (n = 37).

CONCLUSIONS

TC can be easily implemented with the current technologies available. It is cost-effective and allows for better patient care with a more efficient use of the pathologist's time and laboratory resources.

Transcriptomic Alterations in Lung Adenocarcinoma Unveil New Mechanisms Targeted by the TBX2 Subfamily of Tumor Suppressor Genes

T-box (TBX) transcription factors are evolutionary conserved genes and master transcriptional regulators. In mammals, TBX2 subfamily (TBX2, TBX3, TBX4, and TBX5) genes are expressed in the developing lung bud and tracheae. Our group previously showed that the expression of TBX2 subfamily was significantly high in human normal lungs, but markedly suppressed in lung adenocarcinoma (LUAD). To further elucidate their role in LUAD pathogenesis, we first confirmed abundant expression of protein products of the four members by immunostaining in adult human normal lung tissues. We also found overall suppressed expression of these genes and their corresponding proteins in a panel of human LUAD cell lines. Transient over-expression of each of the genes in human (NCI-H1299), and mouse (MDA-F471) derived lung cancer cells was found to significantly inhibit growth and proliferation as well as induce apoptosis. Genome-wide transcriptomic analyses on NCI-H1299 cells, overexpressing TBX2 gene subfamily, unraveled novel regulatory pathways. These included, among others, inhibition of cell cycle progression but more importantly activation of the histone demethylase pathway. When using a pattern-matching algorithm, we showed that TBX's overexpression mimic molecular signatures from azacitidine treated NCI-H1299 cells which in turn are inversely correlated to expression profiles of both human and murine lung tumors relative to matched normal lung. In conclusion, we showed that the TBX2 subfamily genes play a critical tumor suppressor role in lung cancer pathogenesis through regulating its methylating pattern, making them putative candidates for epigenetic therapy in LUAD.

From Uniplex to Multiplex Molecular Profiling in Advanced Non-Small Cell Lung Carcinoma

Non-small cell lung carcinoma is a leading cause of cancer death worldwide. Understanding the molecular biology of survival and proliferation of cancer cells led to a new molecular classification of lung cancer and the development of targeted therapies with promising results. With the advances of image-guided biopsy techniques, tumor samples are becoming smaller, and the molecular testing techniques have to overcome the challenge of integrating the characterization of a panel of abnormalities including gene mutations, copy-number changes, and fusions in a reduced number of assays using only a small amount of genetic material. This article reviews the current knowledge about the most frequent actionable molecular abnormalities in non-small cell lung carcinoma, the new approaches of molecular analysis, and the implications of these findings in the context of clinical practice.

Systemic and targeted therapies for early-stage lung cancer

BACKGROUND

Even with aggressive surgical treatment, relapse rates remain high for patients with resectable non-small-cell lung cancer (NSCLC). In an effort to improve survival in these patients, numerous clinical trials have evaluated neoadjuvant and adjuvant chemotherapy.

METHODS

The authors reviewed the results of the prospective randomized clinical trials that have established adjuvant chemotherapy as the standard of care for patients with surgically resected NSCLC. In addition, the authors summarize data on predictive and prognostic markers for patients with early-stage NSCLC and discuss novel therapies and clinical trials currently underway in early-stage NSCLC.

RESULTS

Three large randomized clinical trials and two meta-analyses have demonstrated a survival benefit for adjuvant cisplatin-based chemotherapy compared with surgery alone in patients with early-stage NSCLC. As a result, adjuvant cisplatin-based chemotherapy is recommended as the standard of care in these patients. Numerous promising biomarkers and agents have been developed in the metastatic setting and are currently being evaluated in the adjuvant setting.

CONCLUSIONS

While adjuvant chemotherapy has improved survival for patients with early-stage NSCLC, the prognosis for early-stage lung cancer remains poor. Incorporation of molecular markers and targeted therapies into the management of patients with advanced NSCLC has improved outcomes. Development of these strategies in the adjuvant setting offers the potential to increase cure rates in patients with early-stage NSCLC.