Comparative assessment of the diagnostic value of transbronchial lung biopsy and bronchoalveolar lavage fluid cytology in lung cancer

Risk of malignancy assessment of the different cytologic categories in respiratory cytology samples according to the new guidelines of the Papanicolaou Society of Cytopathology

BACKGROUND

Cytology is extremely important for diagnosis of lung carcinoma and the Papanicolaou Society of Cytopathology (PSC) had proposed a new classification system for respiratory cytology for better communication between physicians and better patient management. The objective of this study is to analyze our samples in accordance with this classification and to evaluate the diagnostic accuracy of various cytologic techniques and to assess the risk of malignancy.

METHODS

Eight hundred and twenty respiratory cytology specimens (FNA, BAL, washing, brushing, sputum) collected between 2019 and 2022 were classified according to the PSC system and the risk of malignancy was assessed for each category using follow-up surgical samples. Sensitivity, specificity, and accuracy rates were determined based on a categorial approach, according to a similar study.

RESULTS

The data of 820 respiratory cytology specimens from 576 patients were analyzed. 2.6% of these were non-diagnostic, 64.1% were NM, 5% were AC, 0.4% were N-B-LG, 4% were SM and 23.9% were ML. The risk of malignancy for each diagnostic category were: 42.8% for non-diagnostic, 31.2% for NM, 43.9% for AC, 87.9% for SM, 94.3% for ML. Sensitivity and specificity was calculated using only the malignant cases considered as positive tests and was 45.57% and 97.34% respectively.

CONCLUSION

Our results correlated with the PSC system, and it was considered useful in clinical practice. However, more studies should be performed to evaluate the usefulness of this system. The ROMs of each category and the impact of different techniques should be further studied.

A 52-Year-Old Man Who Smokes With Rapidly Progressive Respiratory Failure

CASE PRESENTATION

A 52-year-old White man, who currently smokes, was admitted to the medical ICU with worsening shortness of breath. The patient was dyspneic for a month and had been clinically diagnosed with COPD by his primary care doctor and started on bronchodilators and supplemental oxygen. He had no known medical history or recent illness. His dyspnea worsened rapidly over the next month, prompting admission to the medical ICU. He was on high-flow oxygen followed by noninvasive positive pressure ventilation and then mechanical ventilation. He denied cough, fever, night sweats, or weight loss at the time of admission. There was no history of work-related or occupational exposures, drug intake, or recent travel. Review of systems was negative for arthralgia, myalgia, or skin rash.

Comparison of small biopsy and cytology specimens: Subtyping of pulmonary adenocarcinoma

Objectives

The aims of this study was to investigate the use of cytologic samples for subclassification of lung adenocarcinoma and the cytologic-histologic correlation in lung adenocarcinoma subtypes using small samples.

Methods and Methods

Cytological characteristics of lung adenocarcinoma subtypes were summarized by a literature review. Cytology samples from 115 patients with lung adenocarcinoma confirmed by small biopsies were classified by subtype. The diagnostic concordance of subtypes between biopsy and cytology samples was assessed.

Results

Among the 115 cases, 62 (53.9%) had acinar predominant pattern, 16 (13.9%) were papillary predominant pattern, 29 (25.2%) had solid predominant pattern, 3 (2.6%) had lepidic predominant pattern, and 5 (4.3%) had micropapillary predominant pattern. All corresponding cytologic samples were classified into five subtypes based on cytomorphology features, with concordance rates of 74.2% (46 patients) in c-acinar subtype, 56.3% (nine patients) in c-papillary subtype, 24.1% (seven patients) in c-solid subtype, 66.7% (two patients) in c-lepidic subtype, and 40% (two patients) in c-micropapillary subtype. Collectively, the cytology and small biopsy concordance rate was approximately 57.4%.

Conclusion

Subtyping of lung adenocarcinoma using cytologic specimens is challenging and the consistency rate varies with the subtype. Acinar predominant tumors have an excellent cytologic-histologic correlation compared to tumors with predominant solid or micropapillary pattern. Evaluating cytomorphologic features of different lung adenocarcinoma subtypes can reduce the false-negative rate of lung adenocarcinoma, particularly for the mild, atypical micropapillary subtype, and improve diagnostic accuracy.

Bronchoalveolar Lavage Fluid-Isolated Biomarkers for the Diagnostic and Prognostic Assessment of Lung Cancer

Lung cancer is considered one of the most fatal malignant neoplasms because of its late detection. Detecting molecular markers in samples from routine bronchoscopy, including many liquid-based cytology procedures, such as bronchoalveolar lavage fluid (BALF), could serve as a favorable technique to enhance the efficiency of a lung cancer diagnosis. BALF analysis is a promising approach to evaluating the tumor progression microenvironment. BALF's cellular and non-cellular components dictate the inflammatory response in a cancer-proliferating microenvironment. Furthermore, it is an essential material for detecting clinically significant predictive and prognostic biomarkers that may aid in guiding treatment choices and evaluating therapy-induced toxicities in lung cancer. In the present article, we have reviewed recent literature about the utility of BALF analysis for detecting markers in different stages of tumor cell metabolism, employing either specific biomarker assays or broader omics approaches.

Accuracy of Bronchial Cytological Diagnosis in Lung Lesions in Comparison with Histopathology

The incidence of lung cancer has been increasing in the recent years. Bronchial cytology using Papanicolaou society of cytopathology (PSC) system is an effective method for triaging patients. The present study attempts to evaluate the bronchial cytological diagnosis with histopathological correlation of lung lesions.

Aims

i. To study the cytological features of lung lesions. ii. To assess the sensitivity, specificity, and diagnostic accuracy of bronchial cytology of lung lesions in comparison with histopathology.

Settings and Design

Prospective study at the tertiary care hospital.

Methods and Material

It included 63 cases of lung lesions, evaluated using the PSC system for reporting respiratory cytology. The cytological diagnosis was correlated with the final histopathological diagnosis. The study was conducted between January 2019 and June 2020.

Statistical Analysis Used

SPSS 20.0 software.

Results

The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of bronchial cytology was 60%, 89%, 90%, 58.62%, and 71.42%, respectively.

Conclusions

Bronchial cytology including bronchial wash, bronchial brush, endobronchial ultrasound/transbronchial needle aspiration, and computerized tomography-guided fine needle aspiration cytology can be used to increase the sensitivity and specificity for definitive diagnosis and better management.

Application of Non-Blood-Derived Fluid Biopsy in Monitoring Minimal Residual Diseases of Lung Cancer

Lung cancer is one of the most fatal malignant tumors in the world. Overcoming this disease is difficult due to its late diagnosis and relapse after treatment. Minimal residual disease (MRD) is described as the presence of free circulating tumor cells or other tumor cell derivatives in the biological fluid of patients without any clinical symptoms of cancer and negative imaging examination after the treatment of primary tumors. It has been widely discussed in the medical community as a bridge to solid tumor recurrence. Radiology, serology (carcinoembryonic antigen), and other clinical diagnosis and treatment methods widely used to monitor the progression of disease recurrence have obvious time-limited and -specific defects. Furthermore, as most samples of traditional liquid biopsies come from patients’ blood (including plasma and serum), the low concentration of tumor markers in blood samples limits the ability of these liquid biopsies in the early detection of cancer recurrence. The use of non-blood-derived fluid biopsy in monitoring the status of MRD and further improving the postoperative individualized treatment of patients with lung cancer is gradually ushering in the dawn of hope. This paper reviews the progress of several non-blood-derived fluid samples (urine, saliva, sputum, and pleural effusion) in detecting MRD in lung cancer as well as selecting the accurate treatment for it.

Cell-free DNA from bronchoalveolar lavage fluid (BALF): a new liquid biopsy medium for identifying lung cancer

Background

Differentiating malignant lung tumors from benign pulmonary nodules is a great challenge. While the analysis of bronchoalveolar lavage fluid (BALF) is used for diagnosing infections and interstitial lung diseases, there is limited evidence to support its use for lung cancer diagnosis. This study aimed to interrogate the potential of using BALF cell-free DNA (cfDNA) to discriminate malignant lesions from benign nodules.

Methods

Fifty-three patients with solid pulmonary nodules (≤2 cm) were prospectively enrolled, including 21 confirmed with benign disease and 32 with malignant tumors. Mutations were profiled for 30 tumor tissues and 40 BALFs. Paired BALFs and plasma from 48 patients underwent DNA methylation profiling. A methylome-based classification model was developed for BALF and plasma separately.

Results

Among the 30 patients with paired tissues and BALFs, 96.7% and 70% had alterations detected from their tissues (79 alterations) and BALFs (53 alterations), respectively. Using tissues as references, BALFs revealed 14 new alterations and missed 41. BALF mutation displayed a sensitivity of 71%, specificity of 77.8%, and accuracy of 72.5% in detecting lung cancer. BALF methylation achieved an accuracy of 81.3%, with both sensitivity and specificity being 81%. Plasma methylation showed a 66.7% sensitivity, 71.4% specificity, and 68.8% accuracy. BALF methylation also demonstrated 82.4% sensitivity in stage I patients. Parallel bronchoscopy, lavage cytology, and bronchial brushing demonstrated an inferior sensitivity of 23%, 3.1%, and 9.7%, respectively, compared with BALF methylation and mutation (P<0.0001).

Conclusions

BALF cfDNA can serve as a liquid biopsy media for both mutation and methylation profiling, demonstrating better sensitivities in distinguishing small malignant tumors from benign nodules than conventional methods.

Keywords

Lung cancer diagnosis; pulmonary nodule; bronchoalveolar lavage fluid (BALF); methylation; genomic mutation

Bronchoalveolar lavage: role in the evaluation of pulmonary interstitial disease

INTRODUCTION

Bronchoalveolar lavage (BAL), a noninvasive, well-tolerated procedure is an important diagnostic tool that can facilitate the diagnosis of various lung diseases. This procedure allows the assessment of large alveolar compartments, by providing cells as well as non-cellular constituents from the lower respiratory tract. Alterations in BAL fluid and cells ratio reflects pathological changes in the lung parenchyma. In some cases, clinicians use BAL as a differential diagnosis guide for interstitial lung disease.

AREAS COVERED

In this review, we summarized the diagnostic criteria for BAL in interstitial lung diseases, pulmonary infections, lung cancer and other pathologies such as fat embolism, gastroesophageal reflux and collagen vascular disease. For this review, we have selected scientific papers published in the PubMed database in our area of interest. We aimed to highlight the usefulness of BAL in respiratory pathology.

EXPERT OPINION

Although BAL fluid analyzes has an essential role in the diagnostic work-up of many lung pathologies, it should be performed in selected patients. For accurate results, the BAL technique is very important to be standardized.

A rapid liquid biopsy of lung cancer by separation and detection of exfoliated tumor cells from bronchoalveolar lavage fluid with a dual-layer "PERFECT" filter system

Separation and detection of exfoliated tumor cells (ETCs) from bronchoalveolar lavage fluid (BALF), namely the liquid biopsy of BALF, has been proved to be a valuable tool for the diagnosis of lung cancer. Herein, we established a rapid liquid biopsy of BALF based on a dual-layer PERFECT (precise, efficient, rapid, flexible, easy-to-operate, controllable and thin) filter system for the first time. Methods: The dual-layer PERFECT filter system consists of an upper-layer filter with large micropores (feature size of 49.4 ± 0.5 μm) and a lower-layer filter with small micropores (9.1 ± 0.1 μm). The upper-layer filter contributes to the isolation of cell clusters and removal of mucus from BALF samples, meanwhile the lower-layer one targets for the separation of single ETCs. First, separation of 10000 spiked A549s (cultured lung cancer cells) from 10 mL clinical BALF samples (n=3) were performed to investigate the performance of the proposed system in rare cell separation. Furthermore, separation and detection of ETCs and ETC clusters from clinical BALF samples were performed with this system to test its efficacy and compared with the routine cytocentrifuge. The clinical BALF samples were collected from 33 lung cancer-suspected patients with visible lesions under bronchoscope. The final histopathological results showed that 20 samples were from lung cancer positive patients while the other 13 cases were from lung cancer negative patients. Results: The recovery rate of spiked A549 cells from clinical BALF samples with the developed system (89.8 ± 5.2%) is significantly higher than that with the cytocentrifuge (13.6 ± 7.8%). In the preliminary clinical trial, although 33 clinical BALF samples with volume ranging from 6 mL to 18 mL showed greatly varied turbidity, filtrations could be finished within 3 min for 54.6% of samples (18/33), and 10 min at most for the rest. The dual-layer PERFECT filter system is proved to have a much higher sensitivity (80.0%, 95% CI: 55.7%-93.4%) than the routine cytocentrifuge (45.0%, 95% CI: 23.8%-68.0%), p=0.016 (McNemar test, two-tail). Moreover, the sensitivity of this platform is neither interfered by the variations of turbidity of the BALF samples, nor associated with the types of lung cancer. Conclusions: The easy and rapid processing of BALF samples with varying volume and turbidity, competitive sensitivity and good versatility for different lung cancer types will make the established dual-layer PERFECT filter system a promising approach for the liquid biopsy of BALF. The high-performance BALF-based liquid biopsy will improve the cytopathological identification and diagnosis of lung cancer.

Multivariate Analysis Of The Diagnostic Yield Of Conventional Bronchoscopy In Peripheral Lung Adenocarcinoma

Background

The new subtypes of lung adenocarcinoma reflect local invasive growth, pulmonary alveoli, and intraluminal spreading, while the effective improvement of the diagnostic yield of bronchoscopy still remains unclear. This study aims to explore whether the subtypes of lung adenocarcinoma and other factors affect the diagnostic yield of bronchoscopy.

Methods

All patients were performed 64-row CT examination and bronchoscopy.

Results

The bronchus cutoff sign in 48 cases and the endoscopic diagnostic yield was 60.4%. The lumen of the lobes and segments was invaded in 59 cases, and the endoscopic diagnostic yield was 54.2%.The lymph node metastasis was detected in 46 cases, and the endoscopic diagnostic yield was 60.9%. In addition, 42 cases showed acinar type-predominant, and the endoscopic diagnostic yield was 28.6%. Eighteen cases showed solid type-predominant, and the endoscopic diagnostic yield was 33.3%. The micropapillary type-predominant was noted in 17 cases, with the endoscopic diagnostic yield as 94.1%. The papillary type-predominant was in 14 cases, and the endoscopic diagnostic yield was 42.9%. The lepidic type-predominant was seen in 13 cases, and the endoscopic diagnostic yield was 7.7%. The mean diameter of tumors with a positive endoscopic diagnostic yield was 4.34±2.65cm, and the mean diameter of tumors with a negative diagnostic yield was 2.83±1.47cm. Multivariate analysis showed that micropapillary lung adenocarcinoma affected the endoscopic diagnostic yield (OR=37.594, 95% CI: 4.074-346.94) .Tumor diameter affects endoscopic diagnostic yield (OR=1.39, 95% CI: 1.073-1.802), bronchus cutoff sign is easy to obtain endoscopic diagnostic yield (OR=4.86, 95% CI: 1.606-14.704), and lymph node metastasis affects the endoscopic diagnostic yield (OR=3.696, 95% CI: 1.255-10.883).

Conclusion

The micropapillary subtype lung adenocarcinoma has a certain influence on the diagnostic yield of bronchoscopy. When the lung adenocarcinoma has a large tumor diameter, bronchus cutoff sign and lymph node metastasis, it is easy to obtain a diagnostic yield of bronchoscopy.

Effectiveness of Bronchofiberoscopy in Diagnosis of Lung Lesions

Lung cancer is the most common cause of cancer-related deaths. A short survival rate often results from belated diagnosis made in advanced stages. Therapy individualization requires the collection of a viable material for histopathological examination, which often brings difficulties. This study was performed in a group of 110 patients suspected of malignancy in chest computed tomography. All subjects underwent bronchofiberoscopy. Bronchoalveolar lavage (BAL) and endobronchial brushing were performed in all cases, whereas forceps tissue biopsy was taken if mucous membrane abnormalities were observed. In case of a negative result of bronchofiberoscopy invasive methods were implemented. A malignant neoplasm was diagnosed in 106 cases. Overall, cancer cells (positive result) were found in 45 patients (42.0%) subjected to bronchofiberoscopy. Cytology was positive in 38 (35.8%) and histopathological examination in 30 (28.3%) specimens. Eleven samples of BAL (10.3%) were positive. Endobronchial brushing was more effective, with 27 positive samples (25.5%). Forceps tissue biopsy was performed in 33 cases with 90% sensitivity. The most frequent cancer subtype found was squamous cell carcinoma. No severe complications of bronchofiberoscopy were observed. We conclude that bronchofiberosocpy is a safe diagnostic procedure for lung lesions, but its sensitivity and specificity are low. Only when there are mucous macroscopic changes observed, a precise diagnosis is possible.

Bronchoalveolar Lavage Proteomics in Patients with Suspected Lung Cancer

Lung cancer configures as one of the deadliest types of cancer. The future implementation of early screening methods such as exhaled breath condensate analysis and low dose computed tomography (CT) as an alternative to current chest imaging based screening will lead to an increased burden on bronchoscopy units. New approaches for improvement of diagnosis in bronchoscopy units, regarding patient management, are likely to have clinical impact in the future. Diagnostic approaches to address mortality of lung cancer include improved early detection and stratification of the cancers according to its prognosis and further response to drug treatment. In this study, we performed a detailed mass spectrometry based proteome analysis of acellular bronchoalveolar lavage (BAL) fluid samples on an observational prospective cohort consisting of 90 suspected lung cancer cases which were followed during two years. The thirteen new lung cancer cases diagnosed during the follow up time period clustered, based on liquid chromatography-mass spectrometry (LC-MS) data, with lung cancer cases at the time of BAL collection. Hundred and thirty-tree potential biomarkers were identified showing significantly differential expression when comparing lung cancer versus non-lung cancer. The regulated biomarkers showed a large overlap with biomarkers detected in tissue samples.

The utility of cytology in the diagnosis of adenocarcinoma lung: A tertiary care center study

Introduction:

Pulmonary adenocarcinoma harbors various molecular abnormalities that include epidermal growth factor mutation, anaplastic lymphoma kinase gene re-arrangement, K-RAS mutations. The availability of targeted therapy against these molecular markers has revolutionized personalized medicine. Accurate cytological diagnosis of pulmonary adenocarcinoma will aid in utilising the cytology smears for molecular testing.

Objective:

The objective of this retrospective study was to evaluate the diagnostic efficacy of various cytology samples in the diagnosis of pulmonary adenocarcinoma.

Materials and Methods:

The study included a retrospective case series of 50 patients with biopsy proven non small cell lung carcinoma of adenocarcinoma subtype. The corresponding cytology reports of all the 50 cases were analyzed for different samples including broncho-alveolar lavage (BAL), bronchial washings, bronchial brush smears, pleural fluid, sputum and guided fine needle aspiration cytology (FNAC) of lung and metastatic lymph nodes. The overall cyto-diagnosis efficacy as well that of various cytological samples were analyzed.

Results:

Multiple cytology samples were received in 14 of 50 cases. The overall diagnostic efficacy of the various cytology samples in the diagnosis of malignancy was 78% and 66.6% cases were accurately typed as non small cell lung carcinoma-adenocarcinoma. The best cytological sample for the detection of pulmonary adenocarcinoma was bronchial brush smears which had a detection rate of 70%. In fine needle aspiration cytology samples and bronchial washings the detection rate was 65.5% and 25% respectively.

Discussion and Conclusion:

In cases where the cytological diagnosis is certain the tissue biopsies can be simultaneously tested for EGRF and ALK gene mutations. Repeat biopsies are often required due to small amount of tumor tissue or necrotic biopsies. Alternate use of cytological specimen for molecular testing can be done when a diagnosis of pulmonary adenocarcinoma is established.