A Study of Rectal Cancer with Perineural Invasion in Special Reference to Clinico: Pathological Factors

Rectal cancer of 218 patients were analyzed retrospectively for the relationship between nine factors and perineural invasion. The nine factors were age, sex, division of the rectum*, histological differentiation*, depth of invasion of the tumor*, lymphatic vessel invasion*, venous invasion*, lymph node metastasis* and Dukes' stage classification. Perineuralinvasion was found in 25.7% of all patients and had the closest statistical relationship to the following factors: depth of invasion of the tumor, lymph node metastasis, Dukes' classification, histological differentiation and venous invasion. Perineural invasion was notpresent in Dukes'A classification but existed in l3.7Vo of Dukes' B and in 44.6% of Dukes'C. The S-year cumulative survival rate in Dukes' A cases was 92%. In Dukes' B cases with perineural invasion, the survival rate was 35.5% as opposed to 72% in those without perineuralinvasion. In Dukes' C cases, the survival rate was 10% as opposed to 37Vo in those without perineural invasion. Therefore, perineural invasion was regarded as one factor in prognosis and made worsened the rate of survival of patients with rectal cancer. *Defined by Rules of Japanese Research Socity for Cancer of Colon and Rectum.(Jinnai: Jpn. J. Surg.13: 557-598, 1983)