Molecular analysis of peripheral lung adenocarcinoma in brush cytology obtained by EBUS plus fluoroscopy-guided bronchoscopy

Efficacy of Robotic Bronchoscopy for Molecular Marker Analysis in Primary Lung Cancer

BACKGROUND

Molecular testing has become a more frequent necessity in NSCLC management. Using next-generation sequencing, multiple targets for therapy can be identified with small amounts of nuclear material. The authors evaluated the performance of robotic-assisted bronchoscopy in acquiring tissue that meets pre-analytic criteria for PD-L1 immunohistochemistry and/or next-generation sequencing.

MATERIALS AND METHODS

Patients with a diagnosis of primary lung cancer identified through robotic bronchoscopy were retrospectively reviewed. Pathology reports were assessed for results of molecular testing and detection of programmed death-ligand 1 (PD-L1). An independent pathologist evaluated each specimen type (smears, cell block, tissue biopsy, and/or touch prep) to determine whether each tissue type would meet pre-analytic criteria for attempting next-generation sequencing and/or PD-L1 immunohistochemistry.

RESULTS

Seventy-eight patients with primary lung were reviewed. By independent pathologic assessment of cytological smears, cell block, biopsy, and/or touch preparations, 72% of samples were found to be adequate for molecular and PD-L1 testing. Preanalytic adequacy (%) for next-generation sequencing (NGS) and PD-L1 staining was determined based on specimen type: cytological smear 48.6% for NGS; cell block 14.3% for NGS and 32.9% for PD-L1; biopsy 29.2% for NGS and 62.5% for PD-L1; and touch prep 61.4% for NGS.

CONCLUSION

Robotic-assisted bronchoscopy yielded samples that met preanalytic criteria for molecular testing in 72% of cases. These results support the use of robotic-assisted bronchoscopy for both the diagnosis and molecular testing of early-stage lung cancer.

Recommendations for optimizing the use of cytology in the diagnosis and management of patients with lung cancer

Non-small cell lung cancer (NSCLC) is one of the oncological entities with the greatest evolution in molecular diagnosis due to the large number of diagnostic biomarkers and new treatments approved by international regulatory agencies. An accurate, early diagnosis using the least amount of tissue is the goal for the establishing and developing precision medicine for these patients. Rapid on-site evaluation (ROSE) provides cytological samples of optimal quantity and quality for a complete diagnosis of NSCLC. The usefulness of cytological samples has been demonstrated, not only for massive parallel sequencing but also for the quantification of the expression of programmed death-ligand 1 (PD-L1) and tumour mutational burden (TMB). Pre-analytical, analytical, and post-analytical recommendations are made for the management and appropriate use of cytological samples in order to obtain all the information necessary for the diagnosis and treatment of patients with NSCLC according to current quality parameters.

Novel Robotic-Assisted Cryobiopsy for Peripheral Pulmonary Lesions

PURPOSE

Tissue acquisition in lung cancer is vital for multiple reasons. Primary reasons reported for molecular testing failure in lung cancer biopsy specimens include insufficient amount of tumor cells provided and inadequate tissue quality. Robotic bronchoscopy is a new tool enabling peripheral pulmonary lesion sampling; however, diagnostic yield remains imperfect possibly due to the location of nodules adjacent to or outside of the airway. The 1.1-mm cryoprobe is a novel diagnostic tool and accesses tissue in a 360-degree manner, thus potentially sampling eccentric/adjacent lesions. This study examines the diagnostic yield of the cryoprobe compared to standard needle aspiration and forceps biopsy. It additionally evaluates yield for molecular markers in cases of lung cancer.

METHODS

This is a retrospective analysis of 112 patients with 120 peripheral pulmonary lesions biopsied via robotic bronchoscopy using needle aspirate, forceps, and cryobiopsy.

RESULTS

The overall diagnostic yield was 90%. Nearly 18% of diagnoses were made exclusively from the cryobiopsy sample. Molecular analysis was adequate on all cryobiopsy samples sent. Digital imaging software confirmed an increase in quantity and quality of samples taken via cryobiopsy compared to needle aspirate and traditional forceps biopsy.

CONCLUSION

Using the 1.1-mm cryoprobe to biopsy PPN combined with the Ion robotic bronchoscopy system is safe, feasible, and provides more diagnostic tissue than needle aspirates or traditional forceps biopsies. The combination of cryobiopsy with robotic-assisted bronchoscopy increased diagnostic yield, likely due to its 360-degree tissue acquisition which is beneficial when targeting extraluminal lesions adjacent to the airway.

Radial endobronchial ultrasound-assisted transbronchial needle aspiration for pulmonary peripheral lesions in the segmental bronchi adjacent to the central airway

Background

Tissue samples from lesions located in the 3rd to 5th segmental bronchi are challenging to obtain. In this retrospective study, we aimed to evaluate the diagnostic rate of pulmonary peripheral lesions located in the 3rd to 5th segmental bronchi, near the inner field of lung on the computed tomography (CT) image and outside the bronchus, using radial endobronchial ultrasound (REBUS) followed by transbronchial needle aspiration (TBNA).

Methods

This retrospective study enrolled patients whose preoperative CT examinations showed a lesion located in the segmental bronchi (3rd to 5th), yet adjacent to the inner field of lung on the CT image. REBUS followed by TBNA was used to acquire tissue samples from these lesions. A bronchoscope was used to reach the bronchi surrounding the lesion, and an ultrasound probe was used to determine the lesion's location. Then, the ultrasound probe was withdrawn, and puncture was performed at the location that was determined by ultrasound. The tissue specimens obtained were subjected to pathological examination.

Results

Nineteen patients were enrolled in this study including 15 males and 4 females with an average age of 55 years old. Of the enrollees, 8 patients (42.1%) were successfully diagnosed with samples obtained through TBNA, including 6 cases of lung cancer, 1 case of non-specific inflammation, and 1 case of cryptococcal infection. The diagnostic rate was 42.1%. No post-procedural complications were observed among the patients. There was no significant difference in nodule diameter between patients with a diagnostic sample and those in whom TBNA failed to provide a diagnosis (2.99±0.96 vs. 2.26±1.27 cm, P=0.20).

Conclusions

With the assistance of REBUS, TBNA can acquire sufficient samples to achieve a reasonably diagnostic rate for parenchymal lung lesions located near the inner field of lung on the CT image without intrabronchial invasion.

Testing EGFR with Idylla on Cytological Specimens of Lung Cancer: A Review

The current standard of care for advanced non-small-cell lung cancer is based on detecting actionable mutations that can benefit from targeted therapy. Comprehensive genetic tests can have long turn-around times, and because EGFR mutations are the most prevalent actionable mutation, a quick detection would enable a prompt initiation of targeted therapy. Furthermore, the scarcity of diagnostic material means that sometimes only cytologic material is available. The Idylla™ EGFR assay is a real-time PCR–based method able to detect 51 EGFR mutations in 2.5 h. Idylla is validated for use only on FFPE sections, but some researchers described their experiences with cytological material. We reviewed the relevant literature, finding four articles describing 471 cases and many types of cytological input material: smears, cell-block sections, suspensions, and extracted DNA. The sensitivity, specificity, and limit of detection appear comparable to those obtained with histological input material, with one exception: the usage of scraped stained smears as input may reduce the accuracy of the test. In conclusion, usage of cytological material as input to the Idylla EGFR test is possible. A workflow where common mutations are tested first and fast, leaving rarer mutations for subsequent comprehensive profiling, seems the most effective approach.

Time-related changes in cell morphology and biomarker immunoreactivity for cells stored in a buffer-based cell medium

OBJECTIVE

Buffer-based cell media (BBCM) are a valuable tool in the post-collection processing of cytology samples, though with poorly defined effects on cell properties. In this study, time-related changes in cell morphology and biomarker immunoreactivity were evaluated for cells stored at room temperature in a BBCM prepared with bovine serum albumin (BSA) and ethylene diamine tetraacetic acid (EDTA).

METHODS

Cytospins were prepared at five consecutive 24-hour intervals (0, 24, 48, 72, 96) from three human cell lines (MCF7, SK-MEL-28, FaDu) suspended and stored in BBCM. Preservation of cell morphology was evaluated on Papanicolaou-stained cytospins from the percentages of apoptotic cells. Preservation of immunoreactivity was evaluated for cytokeratins, oestrogen receptors, Ki67, and melanoma markers from the percentages of cells positive for the corresponding immunocytochemical reactions.

RESULTS

Cell morphology was well preserved for the majority of cells of the three lines stored for 24 and 48 hours (93%, 97%, 98% and 62%, 81%, 88%, respectively), while the majority of cells were apoptotic after 72 and 96 hours (70%, 47%, 39% and 77%, 70%, 59%, respectively). The immunoreactivity of cytokeratins remained unchanged during the entire 96 hours, while that of melanoma markers (S100, HMB45, Melan-A) decreased by 27%, 2%, and 3%, respectively. The immunoreactivity of oestrogen receptors and Ki67 decreased by 29% and 17% after the first 24 hours, and was completely lost after 96 hours.

CONCLUSIONS

A BBCM with the addition of BSA and EDTA facilitates good preservation of cell morphology and immunoreactivity of biomarkers for up to 48 hours at room temperature.

Bronchial brushing cytology is comparable to bronchial biopsy for epidermal growth factor receptor mutation test in non-small cell lung cancer

Objectives:

Bronchial brushing (BB) is often used to obtain supplementary samples for diagnosing lung cancer. We examined the possibility of epidermal growth factor receptor (EGFR) testing on BB samples and compared them with bronchial biopsy samples.

Material and Methods:

We used 150 BB samples with non-small cell carcinoma submitted to our department within 2 years. Biopsy samples were concurrently submitted for histologic diagnosis. We used the peptide nucleic acid clamping method for EFGR mutation test. Histologic diagnosis identified 137 cases of adenocarcinomas and 13 cases of non-small cell lung carcinoma, not otherwise specified. Each sample was assessed for adequacy and DNA content for EGFR mutation test.

Results:

Among BB samples, 28 had exon 19 deletion, 21 had mutations in exon 21, 99 were wild type, and analysis of two failed. The EGFR mutation rate in BB samples was 33.1% (49/148). Among bronchial biopsy samples, 26 had exon 19 deletion, 20 had mutations in exon 21, 92 were wild type, and analysis of 12 failed. The EGFR mutation rate using biopsy sample was 33.8% (46/136). The mutation detection results were nearly identical in both groups of samples (131/138, 94.9%). However, in two cases, an exon 21 mZutation was detected in biopsy samples but not in BB samples. In five cases, exon 19 deletion (two cases) and exon 21 mutation (three cases) were detected in BB but not in biopsy samples. The median DNA content was 58.83 ng for BB samples and 48.47 ng for biopsy samples. The failure rate for BB samples was lower than for biopsy samples. Overall, the BB samples were comparable to bronchial biopsy samples in terms of DNA quantity and mutation detection results.

Conclusion:

We conclude that in case of inadequate biopsy samples, BB samples can be used as a substitute material for EGFR mutation test.

Bronchoscopic tissue yield for advanced molecular testing: are we getting enough?

The treatment of advanced lung cancer has become increasingly personalized over the past decade as a result of the improved understanding of tumor molecular biology and anti-tumor immunity. An adequate tumor sample is central to targetable mutation analysis, and immunologic profiling. The majority of lung cancer patients currently present at an advanced disease stage, so that diagnosis and staging are largely based on small biopsy and cytology specimens. Flexible bronchoscopy techniques play a prominent role in the acquisition of these diagnostic specimens. This narrative review summarizes the available evidence with regards to the role of various conventional and advanced flexible bronchoscopy techniques in acquiring sufficient tissue for mutation analysis and programmed death-ligand 1 (PD-L1) testing.

Ultrasound-Guided Transthoracic Fine-Needle Aspiration: A Reliable Tool in Diagnosis and Molecular Profiling of Lung Masses

INTRODUCTION

Pulmonary adenocarcinoma is a major cause of mortality worldwide. The majority of patients present with advanced stage disease, and minimally invasive procedures are desirable for diagnosis and treatment plans. Herein, we report our experience with percutaneous/transthoracic needle aspiration (TT-NA) in the cytologic diagnosis of pulmonary adenocarcinoma.

MATERIAL AND METHODS

After institutional review board approval, the cytopathology electronic data system was searched for all consecutive TT-NA of the lung masses from January 2011 to November 2015. Patients' medical records were reviewed and cytologic materials were evaluated.

RESULTS

A total of 151 specimens were identified, with a mean age of 62.8 years; 62.9% of the patients had a prior history of malignancy. Carcinoma/adenocarcinoma was the most common (80%) diagnosis. The targeted lesions were predominantly located in the lung (56.3%, 81/151) and pleural based (27.8%, 42/151). The mean size of the lesions was 3.6 cm. Cytology specimens were adequate in 70.9% of the cases, while 72.8% (110/151) of the cases also had concurrent core biopsy. A malignant diagnosis was rendered in the majority of the cases (64.9%). In 71% of the cases, immunohistochemistry/histochemistry studies were successfully performed. Molecular/genetic studies were requested in 80% of the cases and had adequate material. Complications of the procedure were seen in 9.9% of the patients including pneumothorax (7.9%) and hemoptysis (1.9%).

CONCLUSION

TT-NA is a relatively safe and reliable technique in the assessment of pulmonary lesions.

EGFR and KRAS Mutations in the Non-Tumoral Lung. Prognosis in Patients with Adenocarcinoma

Tumor recurrence is frequent and survival rates remain extremely low in lung adenocarcinoma (ADC). We hypothesize that carcinogenic factors will promote loco-regional modifications not only in the future tumor, but throughout the exposed lung.

OBJECTIVE

To analyze whether the most prevalent mutations observed in ADC can also be observed in the non-neoplastic lung tissue, as well as the short-term prognosis implications of this finding.

METHODS

Non-tumoral lung parenchyma specimens obtained during surgery from 47 patients with EGFR and/or KRAS abnormalities in their ADC tumors underwent similar genomic testing. Short-term outcomes were also recorded.

RESULTS

The same mutations were present in the tumor and the histologically normal tissue in 21.3% of patients (SM group). Although local recurrences were similar in both groups, distant metastases were more frequent in the former (60 vs. 5.4%, p < 0.001). Moreover, SM patients showed lower time-to-progression (8.5 vs. 11.7 months, p < 0.001) and disease-free survival (8.5 vs. 11.2 months, p < 0.001). COX regression showed a higher risk of progression or death (DFS) in the SM group (HR 5.94, p < 0.01]. Similar results were observed when adjusting for potential confounding variables.

CONCLUSIONS

These results confirm that genetic changes are present in the apparently normal lung in many ADC patients, and this finding has prognostic implications.