Directed balloon cytology of the esophagus: A novel device for obtaining circumferential cytologic sampling

Safety and Feasibility of a Novel Esophageal Balloon for Circumferential Cytologic Sampling

OBJECTIVES

A prior publication introduced the Strome-Blitzer balloon's ability to obtain circumferential esophageal cytologic sampling. This GLP study was requisite for FDA approval to determine if equivalent cell capture and cellularity was observed with the balloon compared to surface sampling brushes and to determine the balloon's usability for naive otolaryngologists.

METHODS

Three naïve users tested the Hobbs brush and Strome-Blitzer balloon on 4 Yorkshire swine. Four anatomical sites were sampled, beginning distally and ending proximally. In 2 animals, the balloon was used first distally and in the remaining 2, 4 new Hobbs brushes were used distally first. Moving proximally, the balloon and brushes were sequentially alternated. In follow-the-leader fashion, the balloon was introduced trans-orally followed by an endoscope to the desired site. The balloon was inflated exposing the abrasive strips to contact the esophageal mucosa. Moving the balloon 1 to 2 cm superiorly and inferiorly effected circumferential cell capture. The balloon was collapsed and removed, preserving the cellularity. The Hobbs brush was passed through the scope's channel. Four brushes, 1 per quadrant, obtained the samples at an anatomical site. The balloon was rated as pass/fail on the following: delivery, kinking, usability, and malfunction. A blinded veterinary pathologist evaluated the cytology.

RESULTS

There was no device malfunction, mucosal trauma, or difficulty with device use. Balloon cytologic samples were comparable in cellularity and quality to the brush.

CONCLUSION

A single balloon sampling was comparable to 4 brushes in capturing diagnostically relevant cellular volumes and architecture. Naïve users easily performed the procedures after reading the guidelines.

LEVEL OF EVIDENCE

3.

Validation of the use of a fluorescent PARP1 inhibitor for the detection of oral, oropharyngeal and oesophageal epithelial cancers

For oral, oropharyngeal and oesophageal cancer, the early detection of tumours and of residual tumour after surgery are prognostic factors of recurrence rates and patient survival. Here, we report the validation, in animal models and a human, of the use of a previously described fluorescently labelled small-molecule inhibitor of the DNA repair enzyme poly(ADP-ribose) polymerase 1 (PARP1) for the detection of cancers of the oral cavity, pharynx and oesophagus. We show that the fluorescent contrast agent can be used to quantify the expression levels of PARP1 and to detect oral, oropharyngeal and oesophageal tumours in mice, pigs and fresh human biospecimens when delivered topically or intravenously. The fluorescent PARP1 inhibitor can also detect oral carcinoma in a patient when applied as a mouthwash, and discriminate between fresh biopsied samples of the oral tumour and the surgical resection margin with more than 95% sensitivity and specificity. The PARP1 inhibitor could serve as the basis of a rapid and sensitive assay for the early detection and for the surgical-margin assessment of epithelial cancers of the upper intestinal tract.

Screening for esophageal squamous cell carcinoma: recent advances

Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer worldwide, with a high mortality due to advanced stage at diagnosis. Although most common in an area known as the Asian Esophageal Cancer Belt, which extends from the Caspian Sea to northern China, and in parts of Africa, high-risk populations also exist elsewhere in the world. Screening for ESCC has been practiced in a few geographic areas and high-risk populations, with varying levels of success. Esophageal squamous dysplasia is recognized as the precursor lesion for ESCC. Endoscopic screening for ESCC/esophageal squamous dysplasia is expensive and not sufficiently available in many high-risk regions. Recent advances in non-endoscopic screening enhanced by biomarker-based disease detection have raised the prospect of improved accuracy and availability of screening for esophageal squamous dysplasia and early stage ESCC. Development of a cost-effective, accurate, and well-tolerated screening test, if applied in endemic areas and high-risk populations, has the potential to reduce mortality from this deadly disease worldwide. In this review, we summarize recent developments in endoscopic and non-endoscopic screening modalities.