Transbronchial cryobiopsy followed by as-needed surgical lung biopsy versus immediate surgical lung biopsy for diagnosing interstitial lung disease (the COLD study): a randomised controlled trial

BACKGROUND

An adequate diagnosis for interstitial lung disease (ILD) is important for clinical decision making and prognosis. In most patients with ILD, an accurate diagnosis can be made by clinical and radiological data assessment, but in a considerable proportion of patients, a lung biopsy is required. Surgical lung biopsy (SLB) is the most common method to obtain tissue, but it is associated with high morbidity and even mortality. More recently, transbronchial cryobiopsy has been introduced, with fewer adverse events but a lower diagnostic yield than SLB. The aim of this study is to compare two diagnostic strategies: a step-up strategy (transbronchial cryobiopsy, followed by SLB if the cryobiopsy is insufficiently informative) versus immediate SLB.

METHODS

The COLD study was a multicentre, randomised controlled trial in six hospitals across the Netherlands. We included patients with ILD with an indication for lung biopsy as assessed by a multidisciplinary team discussion. Patients were randomly assigned in a 1:1 ratio to the step-up or immediate SLB strategy, with follow-up for 12 weeks from the initial procedure. Patients, clinicians, and pathologists were not masked to the study treatment. The primary endpoint was unexpected chest tube drainage, defined as requiring any chest tube after transbronchial cryobiopsy, or prolonged (>24 h) chest tube drainage after SLB. Secondary endpoints were diagnostic yield, in-hospital stay, pain, and serious adverse events. A modified intention-to-treat analysis was performed. This trial is registered with the Dutch Trial Register, NL7634, and is now closed.

FINDINGS

Between April 8, 2019, and Oct 24, 2021, 122 patients with ILD were assessed for study participation; and 55 patients were randomly assigned to the step-up strategy (n=28) or immediate SLB (n=27); three patients from the immediate SLB group were excluded. Unexpected chest tube drainage occurred in three of 28 patients (11%; 95% CI 4-27%) in the step-up group, and the number of patients for whom the chest tube could not be removed within 24 h was 11 of 24 patients (46%; 95% CI 2-65%) in the SLB group, with an absolute risk reduction of 35% (11-56%; p=0·0058). In the step-up strategy, the multidisciplinary team diagnostic yield after transbronchial cryobiopsy alone was 82% (64-92%), which increased to 89% (73-96%) when subsequent SLB was performed after inconclusive transbronchial cryobiopsy. In the immediate surgery strategy, the multidisciplinary team diagnostic yield was 88% (69-97%). Total in-hospital stay was 1 day (IQR 1-1) in the step-up group versus 5 days (IQR 4-6) in the SLB group. One (4%) serious adverse event occurred in step-up strategy versus 12 (50%) in the immediate SLB strategy.

INTERPRETATION

In ILD diagnosis, if lung tissue assessment is required, a diagnostic strategy starting with transbronchial cryobiopsy, followed by SLB when transbronchial cryobiopsy is inconclusive, appears to result in a significant reduction of patient burden and in-hospital stay with a similar diagnostic yield versus immediate SLB.

FUNDING

Netherlands Organisation for Health Research and Development (ZonMW) and Amsterdam University Medical Centers.

Performance insights of endobronchial ultrasonography (EBUS) and mediastinoscopy for mediastinal lymph node staging in lung cancer

INTRODUCTION

Endobronchial Ultrasonography (EBUS) and mediastinoscopy are used for mediastinal lymph node staging in patients with suspected non-small cell lung carcinoma (NSCLC). In our hospital, confirmatory mediastinoscopy has been largely abandoned, which may reduce the number of surgical interventions and health care costs. This study provides insight into EBUS and mediastinoscopy performance in patients with proven NSCLC from January 2007 until January 2019.

METHODS

This is a single-centre, retrospective study, evaluating unforeseen N2 rates, negative predictive value and survival, providing insight into the diagnostic yield of EBUS and mediastinoscopy. Surgical lung resection with lymph node dissection was used as reference.

RESULTS

A total of 418 patients with proven NSCLC after lung resection (mean age: 66 years; 61 % male) and 118 patients who underwent mediastinoscopy, have been included in the study. The overall prevalence of N2 metastases after lung resection was 10.5 %. The percentage of unforeseen N2 cases after negative EBUS was 14.5 %, and 14.3 % after negative mediastinoscopy. Over the past nine years, none of the confirmatory mediastinoscopies were tumor positive after negative EBUS results. The median survival in patients with surgically confirmed N2 metastases was 33 months, compared to 23 months in patients with EBUS/mediastinoscopy-proven N2 metastases.

CONCLUSION

Despite optimisation of mediastinal staging procedures, it remains difficult to identify all patients with N2 metastases in the workup of NSCLC. In our institute, confirmatory mediastinoscopy has no added value after tumor-negative EBUS procedures, and has been abandoned as standard procedure.

Correlation between content of viral DNA and evidence of mature virus particles in HPV-1, HPV-4, and HPV-6 induced virus acanthomata

In HPV-1 and HPV-4 induced warts as well as in HPV-6 positive condylomata acuminata the quantity of viral DNA encapsulated into virus particles was determined and compared to the total amount of viral DNA present in the papillomas. As shown by filter hybridization using 3H-labeled viral DNA molecularly cloned in Escherichia coli, the amount of total viral DNA found in HPV-1 or HPV-4 induced skin warts is similar. HPV-4 DNA, however, is encapsulated into virus particles with less efficiency. HPV-6 DNA can be detected only at minute amounts in condylomata acuminata and the percentage of DNA recovered from virions is extremely low.