Incomplete 5-FU based adjuvant chemotherapy in patients with stage III colon cancer significantly prolongs overall survival

Purpose: Adjuvant chemotherapy is considered standard of care in patients with stage III colon cancer. Because of different reasons in many patients not all chemotherapy cycles are completed or chemotherapy is completely withheld. Methods: We analyzed the data of 215 consecutive patients with UICC stage III colon cancer between 01/1997 and 01/2010. Incomplete adjuvant chemotherapy was defined as completion of less than 2/3 of the planned chemotherapy cycles. Results: Of 104 patients with adjuvant therapy, 46 patients had incomplete chemotherapy. We were able to show a statistically significant survival advantage concerning disease-free 5-year-survival between patients with incomplete and without chemotherapy (76% vs. 53%, (p = 0,003). This superior effect was even more pronounced with regard to overall 5-year-survival with 82% vs. 57% (p = 0,001). No statistically significant differences were shown between complete and incomplete adjuvant chemotherapy. Conclusions: Although our study was not randomized we were able to show a highly statistically significant survival advantage of incomplete adjuvant chemotherapy in patients with UICC stage III colon cancer. If side effects of chemotherapy are tolerable for the patient, temporary limitations of the individual quality of life are outweighed by the survival advantage even if therapy is not completed.