Assessment of lymph node metastasis and vessel invasion in early rectal cancer.

Thirteen patients with rectal carcinoma seen between December 1980 and December 1990 have been reviewed to determine the risk of lymph node metastasis and its implication for subsequent treatment. The mean age was 64 years (from 38 to 79; 9 males, 4 females). The site of the tumor was predominantly in the lower rectum (53.8 percent). The polypoid (I) and flat-elevated ulcerated (IIa + IIc) subtypes were detected in seven and six lesions, respectively. Sphincter-saving techniques were carried out in eight cases, and five cases required Miles' operation. Neither postoperative complications nor deaths were noted. The mean follow-up period was 57 months (6 to 133 months). No recurrence or distant metastasis was found during this follow-up. IIa + IIc subtype lesions with deep submucosal invasion at or beyond Smlc level were closely related with lymphatic and vascular invasion. Although this association was not necessarily accompanied by an increased number of involved lymph nodes, major surgical resection is suggested in such IIa + IIc cases due to an increased possibility for lymph node metastasis.