A Clinicopathological Study on 76 Patients with Poorly-Differentiated Adenocarcionoma Colon and Rectum

Abstract

Among 2, 263 patients undergoing initial surgery for colorectal cancer, poorly-differentiated adenocarcinoma was found in 76 (3.6%) The clinicopathological characteristics and prognosis according to the stage of patients with poorly-differentiated adenocarcinoma were compared with those of the 1, 931 patients (85.3%) with well-and moderately-differentiated adenocarcinoma. The former tumor was more frequently found in the right side colon than the latter, and the percentage of type 3 was higher. As for tumor invasion, more advanced cases (ss or more) were more frequently observed in the poorly-differentiated adenocarcinoma group. Lymph node metastasis (75.0%), liver metastasis (17.1%), and peritoneal dissemination (15.0%) were significantly more common in the poorly-differentiated adenocarcinoma group, and tumors of stage IIIa or more were frequent. The 5-year survival rate of patients whose tumors were removed was 21.9% for poorly-differentiated adenocarcinoma and it was lower than that for other tumors (60.5%). When the prognosis was compared after curative operation, these was no significant difference in stage I+II, but survival was significantly worse for stage IIIa or more in poorly-differentiated adenocarcinoma. In conclusion, advanced disease was more common in patients with poorly-differentiated adenocarcinoma. Prognosis may be improved by early detection and by sufficient lymphadenectomy, while effective postoperative adjuvant chemotherapy is necessary for patients with progressive cancer.