Value of adjuvant chemotherapy for colon and rectal cancer from a surgeon’s point of view



Survival of patients with colon and rectal cancer is constantly increasing. In order to further improve prognosis the development of distant metastases after primary tumor resection has to be further reduced. Adjuvant chemotherapy is standard for UICC III colon cancer using fluoropyrimidines or intensified regimens including oxaliplatin. However, many patients receive adjuvant treatment without benefit but suffer from toxicity, in case of oxaliplatin even from life-long chronic neurotoxicity. The aim of this overview is to summarize data for adjuvant treatment of colon and rectal cancer with special focus on UICC substage and age and to discuss points of criticism from a surgical point of view. Adjuvant chemotherapy with 5-fluorouracil (5-FU) and folinic acid (FA) clearly increases survival in colon cancer UICC stage III. Addition of oxaliplatin is especially beneficial for patients with pT3/4pN2 tumors (UICC IIIc). Older patients (≥ 70 years of age) should receive adjuvant treatment as well, because they benefit to the same extent as younger patients. Overall risk reduction by adjuvant treatment is overestimated due to better pre-operative staging (CT) and quality of surgery and pathology resulting in less local recurrence and stage migration. The effects of adjuvant treatment in rectal cancer are less pronounced compared to colon cancer. Especially after the use of neoadjuvant radiochemotherapy in combination with high quality surgery effects of additional adjuvant treatment still have to be clearly established. In summary, adjuvant treatment for colon cancer is well established and should include old patients as well. To reduce side effects and increase efficacy adjuvant treatment should be individualized on the basis of UICC substaging and clinical risk factors, maybe also including molecular subtyping. These strategies may help to further increase the effectiveness of adjuvant treatment in colon and also rectal cancer