Circulating Tumor Extracellular Vesicles for Non-Invasive Monitoring of Metastatic Colorectal Cancer

Retrospective Cohort Inclusion Criteria:

* Age ≥ 18 years;
* Histologically confirmed diagnosis of colorectal adenocarcinoma;
* Radiological evidence of metastatic or locally advanced unresectable disease;
* First-line treatment for metastatic disease already completed or ongoing according to standard clinical practice;
* Availability of stored biological samples collected at least at one of the protocol-defined time points (baseline, post-treatment, disease progression);
* Informed consent acquisition will be performed in accordance with Article 110-bis of the Italian Privacy Code.

Retrospective Cohort Exclusion Criteria:

* Absence of suitable biological samples or samples unsuitable for molecular analyses;
* Incomplete clinical data preventing the performance of the planned analyses;
* Insufficient quality of stored biological samples for the assessment of EV-RNA and EV-PROT analyses.

Prospective Cohort Inclusion Criteria:

* Age ≥ 18 years;
* Histologically confirmed diagnosis of colorectal adenocarcinoma;
* Radiological evidence of unresectable metastatic disease;
* Patients not previously treated for metastatic disease (prior completed adjuvant/neoadjuvant therapy is allowed if completed ≥ 6 months before study enrollment);
* Indication for first-line treatment with chemotherapy ± biological therapy according to standard clinical practice;
* Ability to understand the study procedures and provide written informed consent.

Prospective Cohort Exclusion Criteria:

* Previous systemic treatment for metastatic disease (except prior adjuvant/neoadjuvant therapy as specified above);
* Ongoing pregnancy or breastfeeding;
* Legal incapacity or limitation in the ability to provide informed consent.