AIM:To assess the significance of interleukin(IL)-24 and vascular endothelial growth factor(VEGF)expression in lymph-node-positive rectal cancer. METHODS:Between 1998 and 2005,90 rectal adenocarcinoma patients with lymph node involvement were enrolled.All patients received radical surgery and postoperative pelvic chemoradiotherapy of 50.4-54.0 Gy.Chemotherapy of 5-fluorouracil and leucovorin or levamisole was given intravenously during the first and last week of radiotherapy,and then monthly for about 6 mo.Expression of IL-24 and VEGF was evaluated by immunohistochemical staining of surgical specimens, and their relations with patient characteristics and survival were analyzed.The median follow-up of surviving patients was 73 mo(range:52-122 mo). RESULTS:IL-24 expression was found in 81 out of 90 patients;31 showed weak intensity and 50 showedstrong intensity.VEGF expression was found in 64 out of 90 patients.Negative and weak intensities of IL-24 expression were classified as negative expression for analysis.IL-24 expression was significantly reduced in poorly differentiated tumors in comparison with well or moderately differentiated tumors(P=0.004),N2b to earlier N stages(P=0.016),and stageⅢc to stageⅢ a orⅢb(P=0.028).The number of involved lymph nodes was also significantly reduced in IL-24-positive patients in comparison with IL-24-negative ones. There was no correlation between VEGF expression and patient characteristics.Expression of IL-24 and VEGF was not correlated with survival,but N stage and stages were significantly correlated with survival. CONCLUSION:IL-24 expression was significantly correlated with histological differentiation,and inversely correlated with the degree of lymph node involvement in stageⅢrectal cancer. AIM: To assess the significance of interleukin (IL) -24 and vascular endothelial growth factor (VEGF) expression in lymph-node-positive rectal cancer. METHODS: Between 1998 and 2005,90 rectal adenocarcinoma patients with lymph node involvement were enrolled. All patients received radical surgery and postoperative pelvic chemoradiotherapy of 50.4-54.0 Gy. Chemotherapy of 5-fluorouracil and leucovorin or levamisole was given intravenously during the first and last week of radiotherapy, and then monthly for about 6 months. Expression of IL-24 and VEGF was evaluated by immunohistochemical staining of surgical specimens, and their relations with patient characteristics and survival were analyzed. median follow-up of surviving patients was 73 mo (range: 52-122 mo). RESULTS: IL-24 expression was found in 81 out of 90 patients; 31 showed weak intensity and 50 showedstrong intensity. VEGF expression was found in 64 out of 90 patients. Negative and weak intensities of IL-24 expression were classified as negative expression for analysis. IL-24 expression was significantly reduced in poorly differentiated tumors in comparison with well or moderately differentiated tumors (P = 0.004), N2b to earlier N stages (P = 0.016), and stage IIIc to stage IIIa or IIIb ) The number of involved lymph nodes was also significantly reduced in IL-24-positive patients in comparison with IL-24-negative ones. There was no correlation between VEGF expression and patient characteristics. Expression of IL-24 and VEGF was not correlated with survival, but N stage and stages were highly correlated with survival. CONCLUSION: IL-24 expression was significantly correlated with histological differentiation, and inversely correlated with the degree of lymph node involvement in stage IIIrectal cancer.