Identification of New Non-invasive, Predictive, and Diagnostic Biomarkers for Colorectal Cancer

Given the observational nature of the study, patients who access our Institute for diagnostic tests or procedures planned as part of normal clinical practice will be enrolled.

This study involves three enrollment arms:

Arm 1: Patients undergoing surgery at the Department of Surgery with a diagnosis of CRC;

Arm 2: Subjects who attend our Institution's Department of Digestive Endoscopy for a colonoscopy performed for diagnostic purposes, with a negative endoscopic examination result;

Arm 3: Subjects who attend our Institution's Department of Digestive Endoscopy for a colonoscopy performed for diagnostic purposes, or patients undergoing surgery at the Department of Surgery, in whom the presence of an adenoma with high-grade dysplasia, a condition considered pre-cancerous, will be found.

Patients recruited in Arm 1, should they decide to participate in the study, will sign the prepared informed consent form. They will undergo a family, pathological, and pharmacological history review, and subsequently, a blood sample will be taken. At the follow-up visit, patients will undergo another blood draw. After the surgical procedure, 'leftover tissue' samples-that is, portions of tissue no longer needed for diagnostic purposes-will be collected for the identification of macromolecules (nucleic acids, proteins, carbohydrates, fats, etc.).

Subjects potentially eligible for enrollment in arms 2 and 3, should they decide to participate in the study, will sign the study-specific informed consent form, will undergo a history review, and a subsequent blood sample will be taken.

At the end of the colonoscopy, subjects who are found to be free of disease will be enrolled in Arm 2 and will form the healthy subject cohort. In the event that a suspicious polyp is found during the colonoscopy and a biopsy is taken, the result of the histological examination will be awaited. In the case of a diagnosis of Adenoma with high-grade dysplasia, the subject will be enrolled in Arm 3.

Blood samples taken from subjects enrolled in all study arms will be used for the determination of tumor markers used in clinical practice, such as CEA, CA19.9, and AFP. Any remaining blood samples will be processed to obtain serum and plasma and will be stored in a Biobank. Subsequently, they will be used for the measurement of potential biomarkers, such as FGF-21, PPY, and SOD3, using ELISA (Enzyme-linked Immunosorbent Assay).

Using ATR-FTIR technology (Attenuated Total Reflectance - Fourier Transform Infrared Spectroscopy), serum, plasma, and tissues will be analyzed to determine their composition in terms of macromolecules (nucleic acids, proteins, carbohydrates, fats). The purpose of this investigation will therefore be to identify any alterations in the characteristic absorption profile of the disease. The ATR-FTIR technique is a variant of traditional Fourier Transform Infrared Spectroscopy. In the ATR-FTIR system, broad-spectrum radiation in the IR region is channeled into a Fourier transform spectrometer where the light is made to interfere. Leaving the spectrometer, and before the radiation detector, the radiation is passed through a crystal with a high refractive index, on which the sample to be analyzed is placed. When the light meets the contact surface between the crystal and the sample, it is completely reflected, but an evanescent wave is generated which penetrates the sample to distances on the order of a micrometer. This interaction between the evanescent wave and the sample leads to the selective absorption of the characteristic wavelengths of the molecules present. The outgoing radiation is processed according to the traditional FTIR spectroscopy method, i.e., performing a Fourier transform operation on the collected signal, thus obtaining the so-called "absorption spectrum," which provides information on the sample's composition. Compared to the traditional FTIR technique, this methodology is particularly useful for analyzing surfaces and solid or liquid samples, including opaque ones or those characterized by high absorption, without complex preparations and with measurement times on the order of a minute.

Finally, the extraction of Extracellular Vesicles (EVs) will be performed from the biological samples of the enrolled patients to characterize the expressed proteins, such as CD147, A33, and FZD10.

• Variation of macroconstituents [Time frame: From enrollment to the day of the visit after 20 days]