Optimizing cytological specimens of EUS-FNA of solid pancreatic lesions: A pilot study to the effect of a smear preparation training for endoscopy personnel on sample quality and accuracy

Droplet digital polymerase chain reaction detection of KRAS mutations in pancreatic FNA samples: Technical and practical aspects for routine clinical implementation

BACKGROUND

Pancreatic adenocarcinoma (PDAC) is associated with a 5-year survival rate of less than 6%, and current treatments have limited efficacy. The diagnosis of PDAC is mainly based on a cytologic analysis of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) samples. However, the collected specimens may prove noncontributory in a significant number of cases, delaying patient management and treatment. The combination of EUS-FNA sample examination and KRAS mutation detection can improve the sensitivity for diagnosis. In this context, the material used for molecular analysis may condition performance.

METHODS

The authors prospectively compared the performance of cytologic analysis combined with a KRAS droplet digital polymerase chain reaction (ddPCR) assay for PDAC diagnosis using either conventional formalin-fixed, paraffin-embedded cytologic samples or needle-rinsing fluids.

RESULTS

Molecular testing of formalin-fixed, paraffin-embedded cytologic samples was easier to set up, but the authors observed that the treatment of preanalytic samples, in particular the fixation process, drastically reduced ddPCR sensitivity, increasing the risk of false-negative results. Conversely, the analysis of dedicated, fresh needle-rinsing fluid samples appeared to be ideal for ddPCR analysis; it had greater sensitivity and was easily to implement in clinical use. In particular, fluid collection by the endoscopist, transportation to the laboratory, and subsequent freezing did not affect DNA quantity or quality. Moreover, the addition of KRAS mutation detection to cytologic examination improved diagnosis performance, regardless of the source of the sample.

CONCLUSIONS

Considering all of these aspects, the authors propose the use of an integrated flowchart for the KRAS molecular testing of EUS-FNA samples in clinical routine.

Minimally Invasive Cytopathology and Accurate Diagnosis: Technical Procedures and Ancillary Techniques

In recent years, the demand for cytopathological accurate diagnoses has increased as expanding minimally invasive procedures obtain materials from patients with advanced cancer for diagnostic, prognostic, and predictive purposes. However, inadequate knowledge of cytopathological technical procedures and ancillary techniques by clinicians remains the most common reason for the limited availability of cytopathology. The objectives of this review were to understand the technical procedures, ancillary techniques, and application and effectiveness of various types of tests in cytopathology. Each of the many ancillary technologies described in the literature has specific advantages and limitations and laboratories select one or more methods depending on their infrastructure and expertise to achieve the goal from initial screening of the disease to the final diagnosis of the cytopathology. This paper systematically reviews the development of cytopathology, summarizes the existing problems in cytopathology and the new progress of auxiliary examination, to provide a theoretical basis for the advanced development of cytopathological diagnostic technologies and to consolidate the minimally invasive and accurate diagnosis of cytopathologies for clinicians. Cytopathology offers many advantages over other clinical examinations, particularly for minimally invasive and accurate diagnosis.

Optimizing cytological specimens of EUS-FNA of solid pancreatic lesions: A pilot study to the effect of a smear preparation training for endoscopy personnel on sample quality and accuracy

BACKGROUND

In the absence of rapid on-side pathological evaluation, endoscopy staff generally "smears" endoscopic ultrasound guided fine needle aspiration (EUS-FNA) specimens on a glass slide. As this technique is vulnerable to preparation artifacts, we assessed if its quality could be improved through a smear-preparation-training for endoscopy staff.

METHODS

In this prospective pilot study, 10 endosonographers and 12 endoscopy nurses from seven regional EUS-centers in the Netherlands were invited to participate in a EUS-FNA smear-preparation-training. Subsequently, post training slides derived from solid pancreatic lesions were compared to pre-training "control" slides. Primary outcome was to assess if the training positively affects smear quality and, consequently, diagnostic accuracy of EUS-FNA of solid pancreatic lesions.

RESULTS

Participants collected and prepared 71 cases, mostly pancreatic head lesions (48%). Sixty-eight controls were selected from the pretraining period. The presence of artifacts was comparable for smears performed before and after training (76% vs 82%, P = .36). Likewise, smear cellularity (≥50% target cells) before and after training did not differ (44% (30/68) vs 49% (35/71), P = .48). Similar, no difference in diagnostic accuracy for malignancy was detected (P = .10).

CONCLUSION

In this pilot EUS-FNA smear-preparation-training for endoscopy personnel, smear quality and diagnostic accuracy were not improved after the training. Based on these results, we plan to further study other training programs and possibilities.