Surgery is the primary treatment for colon cancer. However, the rate of recurrence or metastasis in colon cancer can be as high as 30%, even in stages 1 and 2 . Most colon cancer-related deaths are caused by metastatic disease . Many patients with colon cancer harbour micrometastases and disseminated tumour cells at the time of surgery . Whether the micrometastases develop into clinically significant metastases depends on the immune system's ability to eradicate them.The aim of the study is to declare the effect of epidural-intravenous based anesthetic technique on anti-tumor immunity and in comparison to epidural inhalational based anesthetic technique in patients undergoing open surgical resection of colon cancer.

Inclusion Criteria:

• Age 20-70 yrs.
• ASA class I and II
• Elective open surgery for non-metastatic cancer colon stage I,II

Exclusion Criteria:

• Patient refusal
• Known allergy to the study medications
• Patients with compromised immune function ( associated blood diseases, immunosuppressive drugs, chemotherapeutic agents, corticosteroids)
• Contraindications to epidural insertion e.g. infection at insertion site and coagulopathy