The main reason of cancer-related mortality is the spread of cancer cells to distant sites (micrometastases). However, only a few small groups of tumor cells can metastasize by acquiring mechanism to decrease the immune response. Changes in the systemic inflammatory response to the tumor can be measured by blood-based parameters. In particular, the proportion of neutrophyls- lymphocytes (NL) has been evaluated for predicting the survival of patients with different types of cancer. The first strategy to treat colorectal cancer (CCR) is complete resection of the lesion. Nevertheless, some patients experience recurrence, probably due to residual micrometastases. We have demonstrated that analysis of some resistance proteins (Tyms / MRP1) in circulating tumor cells (CTCs) may predict treatment response in metastatic CCR patients (mCRC). We also note that the CTCs kinetics can show response to therapy. Patients with stage III disease in the colon / rectum, although showing high cure rate, generally fall locally or remotely and studies with blood markers in this group of patients is still scarce. Primary Objective: To investigate cells found in the blood (lymphocytes and neutrophils and CTCs) to verify if they can help in the choice of anti-neoplastic therapy in patients with advanced colon and rectum cancers. Secondary objectives: - to evaluate the influence of CTC kinetics in response to treatment of patients with advanced colon/rectum cancers; - to check the expression of treatment resistance, invasion and proliferation proteins (Tyms, TGF-βR, MMP-2, β-gal, Ki-67 and CD45) in CTCs and their correlation with response to treatment; - to check the mRNA expression of the same genes observed by immunocytochemistry in CTCs and their correlation with response to treatment; - to quantify CTCs, neutrophils and lymphocytes of patients included in this study and verify if there are correlation among their rates and progression-free survival. Methods: there will be collected 10 ml of blood of patients with advanced colon and rectal cancer for analysis of CTCs, lymphocytes / neutrophils. CTCs will be isolated, quantified and analyzed after separation by ISET method (Rarecells/France). The marker analysis of these cells will be done by immunocytochemistry and the gene expression will be assessed by RNAscope. The quantification of lymphocytes/neutrophils will be made by common blood count in Delboni laboratory. Expected Results: We propose to show that not only the count and the kinetics of CTCs, but also their molecular characteristics, can provide relevant information to clinicians. Hopefully, by quantification of neutrophils and lymphocytes, we will be able to identify new prognostic blood biomarkers that can direct clinicians to the best therapeutic choice.

Inclusion Criteria:- ECOG (Eastern Cooperative Oncology Group) Performance Status between 0 and 2; - patients undergoing surgery followed by adjuvant chemotherapy (locally advanced colon cancer) or initiating neoadjuvant chemotherapy followed by surgery (locally advanced rectal cancer); - disease measurable by RECIST criteria 1.1 (Response Evaluation Criteria in Solid Tumors); - medullary function assessed by peripheral blood sample considered normal; Renal and hepatic function tests up to 1.5 times the limit of normality.

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Exclusion Criteria:Patients younger than 18 years; -patients who have had surgery or surgical procedure in the last week; - patients who have had previous therapy in the last three weeks; - patients with previous history of another carcinoma in the last two years; - refuses to sign the TCLE

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colon (EC III) or rectum (EC II and III) cancer patients