EUS-guided FNA for diagnosis of solid pancreatic neoplasms: a meta-analysis.

BACKGROUND: Preoperative diagnosis of solid pancreatic lesions remains challenging despite advancement in imaging technologies. EUS has the benefit of being a minimally invasive, well-tolerated procedure, although results are operator-dependent. The addition of FNA (EUS-guided FNA) provides samples for cytopathologic analysis, a major advantage over other imaging techniques. OBJECTIVE: To determine the diagnostic accuracy of EUS-FNA for pancreatic cancer. DESIGN: This is a meta-analysis of published studies assessing the diagnostic capability of EUS-FNA. Relevant studies were identified via MEDLINE and were included if they used a reference standard of definitive surgical histology or clinical follow-up of at least 6 months. MAIN OUTCOME MEASUREMENTS: Data from selected studies were analyzed by using test accuracy meta-analysis software, providing a pooled value for sensitivity, specificity, diagnostic odds ratio, and summary receiver operating characteristic curve. Cytology results were classified as inadequate, benign, atypical, suspicious, or malignant. Predefined subgroup analysis was performed. RESULTS: Thirty-three studies published between 1997 and 2009 were included, with a total number of 4984 patients. The pooled sensitivity for malignant cytology was 85% (95% confidence interval [CI], 84-86), and pooled specificity was 98% (95% CI, 0.97-0.99). If atypical and suspicious cytology results were included to determine true neoplasms, the sensitivity increased to 91% (95% CI, 90-92); however, the specificity was reduced to 94% (95% CI, 93-96). The diagnostic accuracy of EUS-FNA was enhanced in prospective, multicenter studies. LIMITATION: Publication bias was not a significant determinant of pooled accuracy. CONCLUSION: This meta-analysis demonstrates that EUS-FNA is a highly accurate diagnostic test for solid neoplasms of the pancreas and should be considered when algorithms for investigating solid pancreatic lesions are being planned.

Variation of volatile organic compound levels within ambient room air and its impact upon the standardisation of breath sampling.

The interest around analysis of volatile organic compounds (VOCs) within breath has increased in the last two decades. Uncertainty remains around standardisation of sampling and whether VOCs within room air can influence breath VOC profiles. To assess the abundance of VOCs within room air in common breath sampling locations within a hospital setting and whether this influences the composition of breath. A secondary objective is to investigate diurnal variation in room air VOCs. Room air was collected using a sampling pump and thermal desorption (TD) tubes in the morning and afternoon from five locations. Breath samples were collected in the morning only. TD tubes were analysed using gas chromatography coupled with time-of-flight mass spectrometry (GC-TOF-MS). A total of 113 VOCs were identified from the collected samples. Multivariate analysis demonstrated clear separation between breath and room air. Room air composition changed throughout the day and different locations were characterized by specific VOCs, which were not influencing breath profiles. Breath did not demonstrate separation based on location, suggesting that sampling can be performed across different locations without affecting results.