The immunology of large bowel carcinoma in a rat model.

A rat large bowel carcinoma model has been established with close similarities to the immunological features of the corresponding human neoplasms as far as those are presently known: (1) common antigens with tissue-type specificity, (2) expression of immunogenic gut-specific embryonal antigens, (3) cell-mediated immunity present in tumor bearers, whose sera are capable of blocking the lymphocyte effect specifically, and (4) rapid disappearance of the serum blocking activity after tumor excision. It is suggested that this model is therefore particularly suitable for further detailed analysis of the potential function in vivo of tissue-type specific antigens. In addition, this model appears to be applicable to correlating alterations in immune status with tumor course after various modes of intervention such as chemotherapy and immunotherapy alone, or in combination with surgery.