Characteristics of variants of colorectal carcinoma that do not metastasize to lymph nodes

Summary The clinical and pathologic characteristics of colorectal carcinomas that did not metastasize to mesenteric lymph nodes have been compared with the same characteristics of carcinomas that did metastasize to lymph nodes by computer-programmed analysis of significant differences in 420 cancers in the first group and 344 cancers in the second group. Characteristics associated with an increased probability of metastasis to lymph nodes included the past or present association of skin cancers, the existence of metastases outside the field of resection, and the characteristics of the cancer margins (greater stromal and vascular infiltration by cancer and less inflammatory cell infiltration). Factors associated with a decreased likelihood of metastasis to lymph nodes included favorable characteristics of the cancer margins (“pushing” or circumscribed margin and denser infiltration of inflammatory cells), deep local extension through the bowel wall into mesenteric fat and adjacent organs, and absence of distant metastases. The nonmetastasizing variants were found among tumors of all sizes and histologic grades. Further studies of the individual characteristics of both cancers and hosts are necessary for development of an infallible method of identifying tumors that have not metastasized. Such a method could permit the use of localized ablation more frequently. Read at the meeting of the American Proctologic Society, Boston, Massachusetts, June 16 to 18, 1969. Supported in part by USPHS Grants CA-09741 and CA-08023.