Double Blinded Randomized Clinical Trial of the Effect of Open Versus Laparoscopic Colectomy on Neutrophils in Patients With Colon Cancer

Colorectal cancer is the leading cause of death worldwide. Tumour cell extravasation plays a key role in tumour metastasis. There are evidences tumour cell-leukocyte interactions may support tumour cell invasion and could create an optimal microenvironment for tumour growth at the metastatic site. Neutrophils produce free radicals and proteases; they could cause tumour cytolysis, as well as promote tumour growth and metastasis. It seems that neutrophils play an important role in the context of tumour and angiogenesis.

It is not well understood why FasL induces immune privilege in some organs but elicits inflammation. To explain these apparently conflicting phenomena, it is important to investigate the mechanism of FasL-induced inflammation in detail. Fas/FasL can serve as potential targets for effective antitumor therapy. This research will be useful to eludicate the importance of neutrophil in colorectal cancer. We will investigate the possible role of neutrophil activity and FasL-induced neutrophil infiltration on tumor growth in colorectal cancer. sFas and sFasL could be a way to measure the balance of apoptotic and immunoescape effect after surgical resection of colon cancer.

If the number of neutrophils in peripheral blood mirrors the situation in the tumor tissue, these data could support the investigation of neutrophil-targeted therapies in anti-cancer strategy.

Inflammation-dependent angiogenesis seems to be a central force in tumor growth and expansion, a concept supported by the observation that the use of anti-inflammatory drugs, leads to angiogenesis inhibition. The mechanisms of inflammatory angiogenesis could provide new approaches to target, cure, or prevent tumor angiogenesis. Investigation of the physiologic regulation of IL-17 may thus be useful for the treatment in clinical settings characterized by persistent neovascularisation.

Inhibition of neutrophil elastase might not only reduce the inflammatory response, but could also prevent cancer cell progression. Anti-neutrophil elastase therapy after tumour resection might be an important strategic approach for managing postoperative complications and preventing cancer recurrence.

Patients will be allocated to laparoscopic or conventional open colorectal surgery after eligibility had been confirmed and informed consent given. Randomization will be performed by computer; sequencing was based on a list of variable block sizes for a single centre without further stratification. The randomization list and opaque envelopes will be generated by independent personnel not otherwise involved in the trial. Information on the operation will be remain in consecutively numbered and sealed envelopes that will be stored in a specific box at the clinical site. The envelope containing the allocation will be added to a patient's file shortly before he or she enter the operating theatre. The envelope will be then open and the surgeon will perform the assigned procedure. Until the day of discharge of participants, nurses and other medical staff will be blinded for the type of surgery performed in patients with colorectal cancer by applying a covering abdominal bandage.

During the trial, all blood samples will be retrieved and assessed by a cytologist and molecular biologist blinded to the study arms.