PurposeThe aim of this study is to evaluate the efficacy and the safety of additional 4-week chemotherapy with capecitabine during the resting periods after a 6-week neoadjuvant chemoradiotherapy (NCRT) in patients with locally advanced rectal cancer.MethodsRadiotherapy was delivered to the whole pelvis at a total dose of 50.4 Gy for 6 weeks. Oral capecitabine was administered at a dose of 825 mg/m2 twice daily for 10 weeks. Surgery was performed 2-4 weeks following the completion of chemotherapy.ResultsBetween January 2010 and September 2011, 44 patients were enrolled. Forty-three patients underwent surgery, and 41 patients completed the scheduled treatment. Pathologic complete remission (pCR) was noted in 9 patients (20.9%). T down-staging and N down-staging were observed in 32 patients (74.4%) and 33 patients (76.7%), respectively. Grade 3 to 5 toxicity was noted in 5 patients (11.4%). The pCR rate was similar with the pCR rates obtained after conventional NCRT at our institute and at other institutes.ConclusionThis study showed that additional 4-week chemotherapy with capecitabine during the resting periods after 6-week NCRT was safe, but it was no more effective than conventional NCRT.