The aim of this project is to promote the breath volatile marker concept for colorectal cancer (CRC) screening by advancing developing the application of a novel hybrid analyzer for the purpose.

The hybrid analyzer concept is expected to benefit of combining metal-oxide (MOX) and infrared spectrum (IR) sensor acquired data. The current study will be the first globally to address this concept in CRC detection. In addition, traditional methods, in particular, gas chromatography coupled to mass spectrometry (GC-MS) will be used to address the biological relevance of the VOCs emission from cancer tissue and will assist in further advances of the hybrid-sensing approach.

For addressing the aims of the project, four specific research objectives have been set:

1. To identify cancer-related VOCs emitted by the CRC tissue via the comparison of VOCs emitted from cancer tissue with VOCs emitted by non-cancerous tissue (ex vivo surgery material) by GC-MS.
2. To identify the VOCs differentiating human breath from CRC patients and controls (by GC-MS) as well as compare the chemical signature of CRC patients' breath to the chemical signature of cancer tissue.
3. To evaluate the performance of the set of sensors in the hybrid analyzer and the performance of particular sensors for detecting CRC; to develop and validate a mathematical model for CRC detection.
4. To validate the hybrid analyzer in real-life CRC screening settings, i.e. versus the generally accepted CRC screening approach of faecal occult blood detection.
5. To compare faecal microbiome between CRC group and control.

The scientific results to be obtained during the current project are expected to elucidate the origin and metabolism of volatile biomarkers of CRC. This achievement, in turn, will facilitate the implementation of a new screening test based on the newly developed hybrid analyser into medical practice.

Identification of the VOCs patterns by the sensor array for CRC patients when compared to controls. Addressing these objectives will allow an in-depth understanding of the physiological background for exhaled VOCs in CRC patients and facilitate the development of technologies able to identify the disease and its precursors from an exhaled breath sample.

Inclusion Criteria:

• Adult individuals (>18 years of age)

• Having signed the consent form

• Willingness to collaborate

• Able to provide a breath sample

  • For the cancer group: colorectal adenocarcinoma has to be documented histologically (histological diagnosis following gastric surgery is also accepted) or patients being confirmed adenocarcinoma during the course of the study.
  • For the non-cancer group: control group - any patient who have medical indications for a colonoscopy

Exclusion Criteria:

• The patient has not signed the consent form
• Patients who have had a complete bowel cleansing
• Other active malignancies
• Neoadjuvant chemotherapy, radiation therapy is currently underway
• Acute conditions (emergency surgery for the patient)
• Small bowel resection in the past
• Terminal renal failure (Chronic renal failure stage 4)
• Type I diabetes
• Bronchial asthma (active)

Cancer patient group: patients with known or suspected colorectal adenocarcinoma being admitted to the major specialized cancer centre in Latvia for diagnostic purpose, medical or surgical management will get recruited.

Control group patients will be recruited in the major specialized endoscopy centre (Digestive Diseases Centre "GASTRO") in Latvia.

Average m risk population: average risk population of both genders aged 40-64 at the time of inclusion lacking alarsymptoms for gastrointestinal cancer will get recruited. Those will be invited actively from the GP registries or registry of the National Health Services (the regulatory approval for this approach is already available). An equal proportion between the genders will be targeted.