OBJECTIVE To investigate the clinical efficacy of three-dimensional conformal radiotherapy(3D-CRT)for local y advanced or postoperatively relapsed rectal cancer,and to examine the changes in cancer multi-biomarkers. METHODS Sixty patients with locally advanced or postoperatively relapsed rectal cancer were randomly divided into two groups after 40 Gy external radiation,namely a late-course 3D-CRT group and a conventional radiotherapy group that served as the control.There were 30 patients in each group.For patients in the 3D-CRT group,multi-biomarkers were measured before and after radiotherapy and after relapse. RESULTS Response rates in the 3D-CRT and the control groups were 86.7%(26/30)and 70%(21/30)respectively,without a significant difference (P>0.05).The 1-,2-and 3-year survival rates were 80%,53.3%and 36.7% in the 3D-CRT group;in the control group the rates were 56.7%,40%and 13.3%respectively,with a significant difference(P=0.0213).CEA,CA19-9, CA242 and FER decreased after radiotherapy in the 3D-CRT group,P<0.01, indicating a significant difference.The values after relapse were higher than those without relapse,P<0.01,indicating a significant difference. CONCLUSION Conventional radiotherapy with a 3D-CRT boost gives better therapeutic effect to patients with locally advanced or postoperatively local y relapsed rectal cancer.A multi-biomarker protein chip diagnosis system can be utilized as an effective tool to determine the therapeutic effect and prognosis. OBJECTIVE To investigate the clinical efficacy of three-dimensional conformal radiotherapy (3D-CRT) for local y advanced or postoperatively relapsed rectal cancer, and to examine the changes in cancer multi-biomarkers. METHODS Sixty patients with locally advanced or postoperatively relapsed rectal cancer were randomly divided into two groups after 40 Gy external radiation, namely a late-course 3D-CRT group and a conventional radiotherapy group that served as the control.There were 30 patients in each group. For patients in the 3D-CRT group, multi- RESULTS Response rates in the 3D-CRT and the control groups were 86.7% (26/30) and 70% (21/30) respectively, without a significant difference (P> 0.05) The 1-, 2- and 3-year survival rates were 80%, 53.3% and 36.7% respectively in the 3D-CRT group; in the control group the rates were 56.7%, 40% and 13.3% respectively, with a significant difference (P = 0.0213) .CEA, CA19-9, CA242 and FER decreased after radio P <0.01, indicating a significant difference. The values ​​after relapse higher than those without relapse, P <0.01, indicating a significant difference. CONCLUSION Conventional radiotherapy with a 3D-CRT boost gives better therapeutic effect to patients with locally advanced or postoperatively local y relapsed rectal cancer. A multi-biomarker protein chip diagnosis system can be utilized as an effective tool to determine the therapeutic effect and prognosis.