The effect of surgical resection of experimental "primary" adenocarcinoma of the colon of survival and incidence of metastases.

The effect of surgical resection of "primary" tumors classified by size at the time of resection has been studied in two tumor cell lines derived from dimethylhydrazine-induced colonic neoplasms in the Buffalo strain rat. Surgical treatment of colon cancer in the rat yields results similar to those for human carcinoma. Some of the smallest tumors resected were associated with metastases and this finding suggests a need for effective postoperative adjuvant therapy. The incidence of metastases and the size of the tumor were inveresely related to survival, e.g., the smaller the tumor or the sooner the excision, the greater the survival of the animal. The operated animal model studied here could prove to be very useful for evaluating various forms of systemic therapy for the control of micrometastases associated with colonic neoplasms.