ALFAOMEGA-RETRÒ will be exploited to retrospectively collect clinical and imaging data and archival samples to be used for validation and correlative studies on markers discovered by cutting-edge translational projects within the AIRC5x1000 program "Insights into the evolving heterogeneity of colorectal cancer (CRC): from mechanism to therapies" (an ongoing multi-institutional research program).

ALFAOMEGA-RETRÒ, the retrospective "mirror" protocol of ALFAOMEGA (protocol n. IFOM-CPO003/2018/PO002), has been designed to build a retrospective collection of clinically annotated data and biological samples retrieved from colorectal cancer patients (CRC).

The repository will feed experimental precision research aimed at i) defining a new taxonomy of CRC based on evolutionary patterns (retrospectively assessed on patient's samples), ii) developing and evaluating innovative biomarker-specific therapeutic strategies derived from or together with ALFAOMEGA.

The following data and biological samples will be collected:

• Clinical Data (Demographics, Medical History, Cancer Diagnosis & History, Treatment Assessment,).
• Imaging Data (CT-Scans, MRI, PET...).
• Formalin-Fixed Paraffin-Embedded (FFPE) tissue (either from surgical resections or diagnostic biopsies).
• Frozen biological samples (blood, plasma, PBMC, stools, buccal swabs, urines, etc.).

Inclusion Criteria:

• Histologically-confirmed diagnosis of colorectal cancer (any stage).
• Age >18 years at the time of diagnosis.
• Availability of clinically-annotated radio-imaging data and/or diagnostic Formalin-Fixed Paraffin Embedded (FFPE) blocks (surgical resections and/or tumor biopsies), or at least 10 slides (preferably 20). FFPE tissue blocks are always preferred to slides.
• Verification that the patient could not be reached for informed consent in accordance with applicable national regulations.

Exclusion Criteria:

• if inclusion criteria are not met

at least 500 colorectal cancer patients at any stage who cannot be reached for an informed consent