Transoesophageal endoscopic ultrasound-guided fine-needle aspiration of pleural effusion for the staging of non-small cell lung cancer

Comparison of the SuperARMS and ARMS for detecting EGFR mutations in liquid-based cytology specimens from NSCLC patients

BACKGROUND

Non-surgical cytological specimens are adequate not only for accurate histological subtyping but also for molecular profiling. A modified amplification refractory mutation system polymerase chain reaction (ARMS PCR), known as SuperARMS PCR, was improved by optimizing the primers designation, which provides a higher sensitivity and specificity approach for free plasma DNA detection. It is unclear whether SuperARMS PCR detects epidermal growth factor receptor (EGFR) mutations in cytology samples. The aim of this study was to compare the EGFR mutations detected by ARMS PCR and SuperARMS PCR in cytology samples derived from advanced non-small cell lung cancer (NSCLC) patients.

METHODS

From March 2016 to March 2018, a total of 234 cytological samples were obtained from primary or metastatic lesions of NSCLC, including 144 fine-needle aspirations (FNAs), 36 endobroncheal ultrasonography (EBUS) FNAs, 36 transbronchial needle aspirations (TBNAs) and 18 pleural effusion (PLEs). EGFR mutations were simultaneously detected using an ADx-ARMS EGFR kit (Amoy Diagnostics CO., ltd., Xiamen, China) and an ADx-SuperARMS EGFR kit (Amoy Diagnostics CO., ltd., Xiamen, China). Digital droplet PCR (ddPCR) and next-generation sequencing (NGS) were further used to verify the EGFR mutant inconsistent samples.

RESULTS

All of the 234 patients with advanced or recurrent NSCLC were diagnosed and assessed by two cytopathologists, and their EGFR mutation statuses were successfully detected by ARMS and SuperARMS. Importantly, the SuperARMS and ARMS methods showed a highly concordant result of 94.0% (220/234) (95%CI: 85.0, 95.0%). The positive rate of the SuperARMS was higher than the ARMS in the cytology samples for EGFR detection (46.2% vs. 40.2%). The specific EGFR mutation sites in 16 samples (6.8%) were not completely consistent between the SuperARMS and ARMS. A total of 14 patients showed EGFR mutations when detected by SuperARMS, but by ARMS there were EGFR wild-type. Two patients were detected as having one more EGFR mutation site by SuperARMS than by ARMS. ddPCR and NGS were used to further confirm the EGFR mutations in these inconsistent samples. Eight samples had the same mutation results as the SuperARMS, and 6 samples were not verified because the remaining DNA was insufficient. A total of 78 EGFR mutation patients received Tyrosine Kinase Inhibitor (TKI) treatment. The overall objective response rate (ORR) was 88.5% (69/78) for EGFR TKI treatment.

CONCLUSION

SuperARMS showed a high sensitivity and specificity for EGFR detection and thus, is expected to become a routine test in the clinic to be used as a widely available, easy-to-operate and sensitive method for EGFR mutation detection in liquid-based cytology samples.

Endoscopic ultrasound-guided transesophageal thoracentesis for minimal pleural effusion

BACKGROUND

Pleural effusion is a common finding both in patients with benign and malignant diseases of pleura and lung with diagnostic thoracentesis establishing the diagnosis in the majority of cases. The diagnostic thoracentesis can be done either blindly or under the guidance of ultrasound or computed tomography. However, minimal pleural effusion is difficult to sample even under image guidance. Endoscopic ultrasound (EUS) is known to detect smaller volume of pleural effusion and, thus, can help in guiding thoracentesis.

AIM

To analyze the safety and efficacy of EUS-guided diagnostic thoracentesis in patients with undiagnosed minimal pleural effusion retrospectively.

METHODS

Retrospective analysis of the data of patients with minimal pleural effusion, who underwent EUS-guided transesophageal diagnostic thoracentesis over last 2 years, was performed.

RESULTS

Thirteen patients (11 male; mean age 46.7 ± 16.2 years) with undiagnosed minimal pleural effusion underwent successful EUS-guided transesophageal diagnostic thoracentesis using a 22-G needle. Seven (53%) patients had fever on presentation whereas two presented with cough and loss of appetite. Eight to 54 mL fluid was aspirated with an attempt to completely empty the pleural cavity. There were no complications of the procedure.

CONCLUSIONS

EUS-guided diagnostic thoracentesis is a safe and effective alternative for evaluating patients with minimal pleural effusion.

Endoscopic ultrasound-guided evaluation of the pleura and cases of pleural effusion

The most efficient and cost-effective approach for the diagnosis of pleural exudates remains uncertain and is a subject of controversy. Essential factors to be considered include the respective diagnostic yields of thoracocentesis, closed pleural biopsy, and thoracoscopy. The role of endoscopic ultrasound (EUS) of the esophagus as a modality for the evaluation of pleural exudates has not yet been evaluated. The applied anatomy of the pleura has been discussed. The techniques involved in the EUS imaging of different aspects of the pleura in normal cases and in cases with pleural effusion are elaborated. The practical application of this knowledge can be useful in EUS-guided sampling of the pleural wall, pleural nodules, and in cases of pleural effusion.

Endoscopic ultrasound in the diagnosis and staging of lung cancer

We reviewed the role of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and esophageal ultrasound guided fine needle aspiration (EUS-FNA) in the pretherapeutic assessment of patients with proven or suspected lung cancer. EUS-FNA and EBUS-TBNA have been shown to have a good diagnostic accuracy in the diagnosis and staging of lung cancer. In the future, these techniques in combination with positron emission tomography/computed tomographic may replace surgical staging in patients with suspected and proven lung cancer, but until then surgical staging remains the gold standard for adequate preoperative evaluation.

Expanding the horizons of endoscopic ultrasound: diagnosis of non-digestive pathologies

Endoscopic ultrasound (EUS) is mainly used for the evaluation and sampling of mediastinal and abdominal lymph nodes, luminal and submucosal lesions of the upper and lower gastrointestinal tract, as well as in the diagnostic approach for pancreatic, biliary and liver disease. However, several non-digestive pathologies may be encountered as well, expanding the diagnostic potential of EUS. In this article, we present nine examples of extra-digestive abnormalities detected by means of EUS, including pathologies of the thyroid gland, mediastinal and abdominal vessels, lungs, kidney and the urinary bladder. The purpose of this article is to review the capabilities of EUS beyond routine evaluation of gastrointestinal organs.