Impact of Adjuvant Chemotherapy in Patients With Colon Cancer

The present study aims to investigate the impact of adjuvant chemotherapy with 5-FU isolated and associated with oxaliplatin in cardiac autonomic control and endothelium-dependent vascular function in patients undergoing colectomy for stages II and III colon cancer. Will be performed evaluation of cardiac and vascular function, autonomic control, functional capacity and blood evaluations.

Cancer is a major public health problem. Colorectal cancer is the third most common cancer in men and women around the world. Despite advances in surgical and pharmacological treatment, this type of cancer remains a leading cause of cancer death in Western countries. The adjuvant chemotherapy treatment based on the use of fluoropyrimidine, especially 5-fluorouracil (5-FU) is the mainstay of the pharmacological treatment of colorectal cancer. This treatment showed benefit in overall survival and progression-free survival in the adjuvant treatment of patients with stage II and III disease. In the last decade, the combination treatment with oxaliplatin has shown benefit in patients with either metastatic disease as with locoregional disease who underwent surgical treatment. However, the increased use of 5-FU and oxaliplatin, and increased patient survival have caused increased incidence of adverse events. 5-FU has cardiotoxic effects that may range from 1.2 to 18% depending upon the drug administration. Another adverse event of chemotherapy for colon cancer is neurotoxicity. Peripheral neuropathy is one of the toxicities associated with treatment with Oxaliplatin and its characteristics to be dose-dependent and cumulative. Thus, the adjuvant chemotherapy with 5-FU and oxaliplatin may cause cardiotoxicity, changes in vascular function and increased oxidative stress. What is not known are the effects of treatment of 5-FU and oxaliplatin in cardiac autonomic modulation and peripheral vascular function. Therefore, the present study aims to investigate the impact of adjuvant chemotherapy with 5-FU isolated and associated with oxaliplatin in cardiac autonomic control and endothelium-dependent vascular function in patients undergoing colectomy for stages II and III colon cancer. Will be performed evaluation of cardiac and vascular function, autonomic control, functional capacity and blood evaluations.

Patients with stage II disease undergoing adjuvant 5-FU treatment will be allocat in chemotherapy-1 group, while stage III patients undergoing combined adjuvant chemotherapy (5FU + Oxaliplatin) will be allocat to the Chemotherapy group -2.

Inclusion Criteria: Scale of Performance Status 0 - 1 Patients submitted to colectomy for adenocarcinoma of colon stages II and III. Exclusion Criteria: Severe pulmonary disease Decompensated cardiovascular disease Neurological disease Insulin-dependent diabetes mellitus Dialysis renal insufficiency