Cytosponge™ Feasibility Study in Tanzania

The Cytosponge™ consists of a spherical mesh enclosed in a gelatine capsule and attached to a string. The capsule is swallowed with the use of water and allowed to reach the stomach while remaining attached to the suture which is held onto by the patient or nurse (and which is affixed to a card preventing inadvertent swallowing of the suture). In the stomach the capsule is left for up to 5 minutes where it dissolves allowing the sponge to expand to its full size. It is then withdrawn using the suture, and as it does so collects cells from the lining of the oesophagus. After retrieval the Cytosponge™ containing the cytological specimen placed in preservative fluid. The typical cell yield of the procedure is 250,000. These cells are used to prepare a clot which is fixed with formalin and embedded in paraffin for sectioning and slide preparation. Slides are then examined under a microscope for pathological diagnosis and characterisation. This device was approved by the UK Medicines and Healthcare Products Regulatory Agency (MHRA) in 2008 and is a Class 1 device according to European Medical Devices 93/42/EEC as implemented in the United Kingdom by The Medical Devices Regulations 2002 (SI No 618).

Healthy adult (>30 years) volunteers will be recruited during routine visits to the Majengo Healthcare Centre in Moshi, Tanzania where they will be informed of the study and invited to participate. Their participation will then involve the following:

• Completing a short lifestyle questionnaire.
• Swallowing the Cytosponge™ device to collect cells from their oesophagus.
• Being contacted by telephone 7-days post procedure to assess acceptability.

The following endpoints will be investigated:

Core:

• Response rate of participants invited to swallow device.
• Proportion of participants able to swallow the device within three attempts and number of attempts taken (frequency distribution of 1, 2 and 3 attempts).
• Post-swallow acceptability of device as per a previously employed satisfaction score (graded 0-10)
• Proportion of collected sponges successfully processed into paraffin blocks.
• Prevalence of ESD as determined by examination by a trained pathologist.
• Prevalence of benign oesophageal pathologies (inflammation, candidiasis, eosinophilic oesophagitis).

Extended (subject to future funding):

• Prevalence of positivity for antibodies against chemical exposures and proliferation markers.
• DNA yield from cells collected from the device.
• DNA methylation profiles.
• Genetic mutations in candidate cancer-relevant gene panel.

Inclusion criteria

• 30 years or older.
• Resident of Kilimanjaro Region for 10 years or more.

Exclusion criteria

• Eaten or drank within the last 4 hours.
• Known current pregnancy.
• Objection to CytoSCCAPE data collection.
• Symptoms of dysphagia (difficulty swallowing).
• Recorded history of oropharyngeal, esophageal or gastric cancer
• Received prior surgical intervention to the esophagus.
• Esophageal varices, stricture or requiring esophageal dilation.
• Recorded cirrhosis of the liver.
• Swallowing difficulty due to cerebrovascular accident or neurological disorder.
• Recent history of vomiting blood.
• Recent use of anticoagulation therapy/medication.
• Myocardial infarction or any cardiac event within the last 6 months.
• Lacking capacity to provide informed consent.
• Unwilling to swallow beef gelatine capsule due to dietary preferences.