The inflammatory response within Dukes' B colorectal cancers: implications for progression of micrometastases and patient survival

Abstract

Objectives: The aim of this study was to determine the relationship between the inflammatory response in primary colorectal carcinomas, patient outcome, and the fate of bone marrow micrometastases.

Methods: The populations studied were a) 155 consecutive patients with Dukes' B colorectal cancer and follow-up for a mean of 5 yr, from the Mercy Hospital, Cork, and b) 260 consecutive patients with rectal carcinoma Dukes' B and follow-up for >10 yr, from St. Mark's Hospital, London. The primary tumor was assessed for the Jass and "Crohn's-like" lymphoid reactions. In 36 consecutive patients, bone marrow aspirates were examined for micrometastases before and > or = 6 months postoperatively.

Results: The relationship between prognosis and the inflammatory reactivity in the tumors was similar in both populations. In the Mercy group there were two deaths among 40 patients who had coexistent Jass and Crohn's-like infiltrates. This contrasted with 25 deaths among 58 patients in whom both infiltrates were absent (p < 0.005). Results were intermediate in cases in which either type of inflammatory reaction was present alone. In the St. Mark' s patients similar prognostic differences were sustained for up to 10 yr. Bone marrow micrometastases were present in 12/36 patients preoperatively and in 14/36 postoperatively. Seven of 12 patients with preoperative micrometastases were negative postoperatively, indicating clearance of tumor cells. Nine of 24 who tested negative preoperatively had micrometastases postoperatively. The clearance and presence of postoperative micrometastases was related to the immunological responses in the primary tumor.

Conclusions: These results demonstrate an association between the inflammatory reaction, prognosis, and clearance of micrometastases, indicating a systemic antitumor reaction that confers a survival advantage.