Study of Postoperative Concurrent Chemo-radiation With Capecitabine in Elderly Rectal Cancer Patients

Inclusion Criteria: * rectal adenocarcinoma, pathological stage II/III(T3-4 or N+, UICC 2002), radical surgery received. * interval between surgery and enrollment no less than two week and no more than 3 months. * KPS status no less than 70; life expectancy no less than 6 months. * without life-threatening complications, such as severe hypertension, coronary heart disease, cerebral vascular disease, uncontrolled diabetes, etc. * without severe drug allergy history. * hemoglobin \>= 100g/L, white blood cell \>= 3.5\*10E9/L, neutrophil \>= 1.5\*10E9/L, platelet \>= 100\*10E9/L. * Creatin \<= 1.5\* ULN(upper limit of normal), Total bilirubin \<= 2.5 ULN, AST and AST \<= 2.5\* ULN, AKP \<= 2.5\*ULN * do not receive chemotherapy before six months from enrollment. * no previously pelvic irradiation history * informed consent signed Exclusion Criteria: * other cancer history, except curable non-melanoma skin cancer or cervix in-situ carcinoma * allergy history to thymidine phosphorylase * previous pelvic irradiation history * receiving adjuvant chemotherapy in six months before enrollment * active infection existed * severe complication, such as acute myocardial infarction in 6 months, uncontrolled diabetes ( Plasma glucose concentrations in any time of a day≥11.1mmol/L）, severe cardiac arrhythmia， etc. * life expectancy less than 6 months * estimated cannot finish treatment * attend other clinical trials in four weeks before enrollment * receive other anti-cancer treatment currently * other conditions which regarded illegal by censors with full reasons. for example, some conditions may conflict from the protocol.