The outcome of 5-fluorouracil chemotherapy after the completion of neoadjuvant chemoradiotherapy, administered until 2 weeks before rectal cancer resection

Background: In most institutions, locally advanced rectal cancer is treated with neoadjuvant chemoradiotherapy followed by surgery 6–8 weeks later, allowing time for tumor response and recovery from chemoradiotherapy-related toxicities. In our hospital, we continuously administer chemotherapy after the completion of chemoradiotherapy, until 2 weeks before surgery for most patients. Methods: This was a retrospective study. Patients received a diagnosis of adenocarcinoma of the rectum at our hospital between January 2003 and December 2008 and received neoadjuvant chemoradiotherapy and curative surgery. Chemoradiotherapy consisted of continuous infusion of 225 mg/m2 5-fluorouracil, 5 days per week. Radiation therapy was delivered at 1.8 Gy per day, 5 days per week for 5–6 weeks (median radiation dose, 50.4 Gy). Chemotherapy was continued until 2 weeks before surgery, and surgery was performed 6–8 weeks after completion of chemoradiotherapy. Results: The study included 119 patients (median age, 61 years; range, 24–84 years). Twenty-nine patients (24.4%) had a complete response and 65 (54.6%) had a partial response. Over a median follow-up duration of 52 months, 10 patients experienced local recurrence and 18 had distant metastasis. The 5-year overall and disease-free survival rates were 80.6% and 72.9%, respectively. Grade 3–4 toxicity only occurred in 14 patients (11.8%). Conclusion: Continued chemotherapy with 5-fluorouracil after completing neoadjuvant chemoradiotherapy until 2 weeks before surgery for locally advanced rectal cancer results in a good pathological control rate, with low toxicity. Patients who achieved a complete pathological response had a better long-term oncological outcome than those who did not