COlorectal BReath Analysis (COBRA2)

NCT ID: NCT05844514

Last Updated: 2025-06-13

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Total Enrollment

720 participants

Study Classification

OBSERVATIONAL

Study Start Date

2022-09-23

Study Completion Date

2026-12-01

Brief Summary

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Colorectal cancer (CRC) is the second most common cause of cancer death in the United Kingdom, with approximately 17,000 deaths per year. The five-year survival rate from CRC is only 10% when discovered at a late stage, but exceeds 90% if diagnosed early. Symptoms related to CRC can be non-specific, therefore the decision to refer for a colonoscopy can be challenging.

There is a clear need to improve earlier detection of CRC so that patients with CRC can be identified earlier and faster, enabling them to start treatment more quickly.

The study team is developing a non-invasive breath test that detects small molecules called volatile organic compounds (VOCs) that are specific to CRC. For patients with non-specific symptoms, this test would help GPs to identify those patients that may have underlying CRC, who would benefit from referral for specialised CRC tests.

Detailed Description

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The COBRA1 study initially assessed VOCs in CRC and identified a list of 14 VOC biomarkers for CRC and provided a detection model with an area under the receiver operating characteristic curve of 0.91, sensitivity of 83% and specificity of 88% in symptomatic patients.

COBRA2 aims to develop and validate the clinical prediction model (CPM) in the detection of CRC based on the breath test. An exploratory comparison between the breath test and faecal immunochemical test (FIT) will also be carried out to assess whether combining both tests improves diagnostic performance.

Methods: COBRA2 is be a prospective, multicentre validation study. The study team are recruiting the following patients:

The following groups of patients are being recruited:

i) Control group: symptomatic patients who are attending a planned colonoscopy referred under the suspected lower GI cancer pathway. Any patient who is found to have histologically-proven CRC on colonoscopy will be analysed as part of the CRC group.

ii) CRC group: patients who either have a confirmed diagnosis of colorectal adenocarcinoma according to a biopsy, or who are due to undergo surgical resection for suspected CRC (with histological confirmation to follow within three months).

Target recruitment is 720 patients (470 controls, 250 CRC), aiming for 576 patients (376 controls, 200 CRC) with reliable and complete data. Participants are required to maintain a clear fluid diet for a minimum of 4-6 hours prior to sampling and should not have received bowel preparation. Participants will be asked to provide breath samples by exhaling into single-use breath collection bags and breath will be transferred using a precision pump onto thermal desorption (TD) tubes. Breath samples will be analysed with gas chromatography-mass spectrometry in accordance with existing quality control processes.

Conditions

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Colorectal Cancer

Study Design

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Observational Model Type

CASE_CONTROL

Study Time Perspective

PROSPECTIVE

Study Groups

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Control group - 470 patients

Symptomatic patients who are attending a planned colonoscopy referred under the suspected lower GI cancer pathway. Any patient who is found to have histologically-proven CRC on colonoscopy will be analysed as part of the CRC group.

Breath test

Intervention Type DIAGNOSTIC_TEST

Patients must be fasted for a minimum of 4-6 hours prior to breath sample collection. For patients undergoing colonoscopy or surgery, breath samples must be obtained prior to patients receiving bowel preparation in either outpatient clinic or pre-assessment clinic.

CRC group - 250 patients

Patients who either have a confirmed diagnosis of colorectal adenocarcinoma according to a biopsy, or who are due to undergo surgical resection for suspected CRC (with histological confirmation to follow within three months).

Breath test

Intervention Type DIAGNOSTIC_TEST

Patients must be fasted for a minimum of 4-6 hours prior to breath sample collection. For patients undergoing colonoscopy or surgery, breath samples must be obtained prior to patients receiving bowel preparation in either outpatient clinic or pre-assessment clinic.

Interventions

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Breath test

Patients must be fasted for a minimum of 4-6 hours prior to breath sample collection. For patients undergoing colonoscopy or surgery, breath samples must be obtained prior to patients receiving bowel preparation in either outpatient clinic or pre-assessment clinic.

Intervention Type DIAGNOSTIC_TEST

Eligibility Criteria

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Inclusion Criteria

* Patients aged ≥ 18 years referred from primary care with symptoms of suspected CRC.
* Patients with histologically confirmed colorectal adenocarcinoma (stages I-IV) who are treatment naïve (CRC group).

Exclusion Criteria

* Previous surgery altering the anatomy of the lower GI tract (e.g., hemicolectomy, anterior resection).
* Previous treatment (neoadjuvant chemotherapy or radiotherapy or immunotherapy) for CRC.
* Received bowel preparation for their colonoscopy procedure.
* History of any other cancer within three years.
* Unable or unwilling to provide informed written consent.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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National Institute for Health Research, United Kingdom

OTHER_GOV

Sponsor Role collaborator

Chelsea and Westminster NHS Foundation Trust

OTHER

Sponsor Role collaborator

Imperial College Healthcare NHS Trust

OTHER

Sponsor Role collaborator

Royal Marsden NHS Foundation Trust

OTHER

Sponsor Role collaborator

London North West Healthcare NHS Trust

OTHER

Sponsor Role collaborator

Imperial College London

OTHER

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Professor George B Hanna, PhD FRCS

Role: PRINCIPAL_INVESTIGATOR

Imperial College London

Locations

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Chelsea and Westminster Hospital

London, , United Kingdom

Site Status RECRUITING

Royal Marsden Hospital

London, , United Kingdom

Site Status ACTIVE_NOT_RECRUITING

St Mark's Hospital

London, , United Kingdom

Site Status ACTIVE_NOT_RECRUITING

St Mary's Hospital

London, , United Kingdom

Site Status RECRUITING

West Middlesex University Hospital

London, , United Kingdom

Site Status RECRUITING

Countries

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United Kingdom

Central Contacts

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Mr Michael G Fadel, BSc MBBS MRCS

Role: CONTACT

+44 (0)20 7594 3396

Facility Contacts

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Mr Christos Kontovounisios

Role: primary

Professor George B Hanna

Role: primary

Mr Christos Kontovounisios

Role: primary

References

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Fadel MG, Murray J, Woodfield G, Belluomo I, Laponogov I, Parker A, Converso V, Ellis JK, Wheatstone P, Hepburn J, Groves C, Monahan K, Saunders BP, Spanel P, Veselkov K, Cross AJ, Kontovounisios C, Sharples LD, Hanna GB; COBRA2 Collaborators. Non-invasive breath testing to detect colorectal cancer: protocol for a multicentre, case-control development and validation study (COBRA2 study). BMC Cancer. 2025 Jul 29;25(1):1230. doi: 10.1186/s12885-025-14520-2.

Reference Type DERIVED
PMID: 40731329 (View on PubMed)

Other Identifiers

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17SM3783 - SA 04

Identifier Type: -

Identifier Source: org_study_id

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