['Locally advanced colorectal cancer often requires extended resection to radically remove all tumor. This is the only chance for cure in these patients, but a higher complication rate would be expected. To evaluate the overall benefit for the patient, this study assesses morbidity and mortality as well as long-term survival of patients who underwent extended resection for a T3-T4 carcinoma.', 'Two hundred twenty patients with locally advanced adenocarcinoma of the colorectum were included. One hundred fifty presented with a T3 and 70 with a T4 tumor. Eighty-three patients underwent extended resection. In 38 patients extended en bloc resection was performed because of inflammatory adherence mimicking infiltration. Thirty-three patients who underwent extended resections were over 70 years of age. There were no significant differences between the groups that underwent extended or nonextended resections in age, sex, stage, or grading.', 'pT4 lesions were significantly more frequent in the extended resection group than in the nonextended resection group. Mean survival was 44 months after extended resections and 45 months after nonextended resections. In the extended resection group there was no significant difference in mean survival between pT3 and pT4 stage patients within 46 and 38 months, respectively. In patients who underwent nonextended resections, however, there was a significant difference in mean survival within 48 months for pT3 and 28 for pT4 patients (P < 0.05). Postoperative morbidity and mortality were comparable between the extended resection group and the non-extended resection group. The presence of residual tumor influenced prognosis of patients significantly; R0 resections fared significantly better than patients who underwent R1 or R2 resections (55 and 51 to 14/12 and 23/8 months) (P < 0.01). Nodal stage and International Union Against Cancer stage were also significant determinants of prognosis. After extended resections mean survival morbidity and 30-day mortality in patients more than 70 years was similar to those less than 70 years.'] Are extended resections beneficial for patients with locally advanced colorectal cancer?