Researching the efficacy of chemotherapy in high risk stage II colon cancer patients retrospectively

The use of adjuvant chemotherapy in patients with stage II colon cancer is not recommended for routine. It has been reported that applying adjuvant chemotherapy in high-risk patients (T4 tumor, poorly differentiated histology, presence of mucinous component, lymphovascular invasion, perineural invasion, presentation with intestinal obstruction or perforation, close or positive surgical tip, inadequate lymph node dissection and high preoperative CEA levels ) is an appropriate approach. However, this issue is still controversial and not clearly understood, thus further studies are needed. In this study, we investigated the effect of identified risk factors on the survival in stage II colon cancer patients. In the study, 79 stage II colon cancer patients that referred to Karadeniz Technical University Faculty of Medicine, Medical Oncology Clinic, between January 2006 and December 2011 were included. In patients, for the delivery of chemotherapy, the situations defined as high risk factors were to be taken into account primarily. However, in some patients; co-morbid diseases, additional malignancies, age and preferences of the patient were kept in the forefront. 5-year overall survival rate of stage II colon cancer patients that received and that did not received chemotherapy were 82.8 ± 6.4 % and 79.3% ± 6.1 % respectively, and there was no statistically significant difference. Of patients with risk factors; chemotherapy receiving patients were compared with those that did not, in terms of survival. According to this assessment, 5-year overall survival rate of chemotherapy receiving patients was 84.2 ± 9.2 % and it?s higher when compared to those did not receive chemotherapy. The overall survival rate of patients without the risk factor and chemotherapy was 52.1 ± 13.7 %. There was a significant difference in overall survival between 2 groups (p = 0.014 ). In between 2 groups; 30 patients that has at least one risk factor and received chemotherapy, and 29 patients without any risk factor and chemotherapy, there was no statistically significant difference in terms of survival. In terms of 5-year survival rates, the patients did not take chemoterapy without any risk factor had the survival rate of 92.9 ± 6.9 %, and the patients taking chemotherapy with at least one risk factor had survival rate of 84.2 ± 9.2 %. When 7 risk factors were analyzed about how they impact on the survival, the patients who has a well or moderately differentiated histological grade has better prognosis than patients with poorly differentiated histological grade or mucinous component including pathology (p=0,01). In comparison of survival rates of patients with T3 and T4 tumor size, a significant difference in favor of T3 was found (p=0.012). As a result, adjuvant chemotherapy is thought to have a positive effect on survival in patients with risk factors who are diagnosed in stage II colon cancer.