Esophageal Adenocarcinoma (EAC) – the cancer that occurs in the lower portion of the esophagus (the food pipe that runs between throat and stomach) is the most common form of cancer in the United States. In spite of a steady increase in the incidence of EAC over the past 3 decades, the prognosis remains poor. Barrett’s esophagus (BE) is the only known precursor for EAC and it is currently diagnosed using an endoscope. Sanford Markowitz at Case Western Reserve University, Ohio, and his colleagues have demonstrated the feasibility of a non-endoscopic molecular cytology screening method for BE and EAC (Moinova et al., Science Translational Medicine, Vol. 10, Issue 424, eaao5848)
The non-endoscopic swallowable balloon-based esophageal sampling device consists of a pill-sized capsule (16 × 9 mm) attached to a thin 2.16 mm silicone catheter (Fig. 1, A and B), which can be easily swallowed. After delivery into the stomach, the balloon is inflated by injecting 5 cm3 of air through the catheter (Fig. 1C). The inflated balloon can be gently moved through the distal esophagus to collect samples from the luminal epithelial surface. Subsequently, the balloon is deflated and inverted back into the capsule (Fig. 1D). After complete retrieval of the capsule through the mouth, DNA is extracted from the balloon surface for molecular analysis. One of the prime advantages of this balloon-based sampling device is its ability to deploy rapidly by inflation unlike the conventional sponge-based devices, which requires sufficient waiting time for the coating to dissolve. The ability of the balloon to retract back into its capsule after sampling protects the sample from dilution or contamination from the proximal esophagus or oral cavity. The swallowable balloon-based device enables a simple and rapid method to collect DNA samples from the distal esophagus of unsedated outpatients. A combination of this balloon-based sampling device with bisulfite sequencing for detecting DNA methylation, provides a highly sensitive and specific yet minimally invasive screening protocol that could be clinically used for the detection and screening of BE.
Fig. 1 Non-endoscopic balloon-based device: (A) Device capsule and catheter (a vitamin pill and a dime are included for size comparison); (B) Capsule containing inverted balloon for swallowing; (C) Capsule with inflated balloon for esophageal sampling; and (D) Capsule containing inverted balloon for device and biospecimen retrieval.
T.S.N. Sankara Narayanan
Recent Advancements in Science 