Colorectal cancers account for 783,000 new cases and cause 437,000 deaths per year across the world. Diagnosis in the early stages improves survival rates. Up to now, these cancers are mostly diagnosed only at later stages of the disease's course through histoimmune staining and molecular biology processes on the tissues biopsied from the gastrointestinal system under invasive diagnostic procedures of colonoscopy.

Oral fluid presents a large protein complexity and has been recently used as a diagnostic biofluid for oral, as well as systematic diseases. Using oral fluid as a bio-marker for the colorectal cancer can be advantageous as it contains gastrointestinal fluids, in addition to bacteria and bacteria lysate, which can also serve as a bio-markers' source for colorectal cancers. Proteomic technologies provide the tools needed to discover and identify disease-associated biomarkers.

The aim of the present study is to identify salivary bio-markers in patients suffering from colorectal cancers.

Inclusion Criteria:

• Has not yet started treatment for the identified cancer

Exclusion Criteria:

• medically compromised patients
• congenital syndromes
• being treated with radiotherapy or chemotherapy.

Patients identified with gastric, colorectal (including pre-cancer polyps) or pancreatic cancer