Tumour inflammatory infiltrate predicts survival following curative resection for node-negative colorectal cancer.

BACKGROUND A pronounced tumour inflammatory infiltrate is known to confer a good outcome in colorectal cancer. Klintrup and colleagues reported a structured assessment of the inflammatory reaction at the invasive margin scoring low grade or high grade. The aim of the present study was to examine the prognostic value of tumour inflammatory infiltrate in node-negative colorectal cancer. METHODS Two hundred patients had undergone surgery for node-negative colorectal cancer between 1997 and 2004. Specimens were scored with Jass' and Klintrup's criteria for peritumoural infiltrate. Pathological data were taken from the reports at that time. RESULTS Low-grade inflammatory infiltrate assessed using Klintrup's criteria was an independent prognostic factor in node-negative disease. In patients with a low-risk Petersen Index (n=179), low-grade infiltrate carried a threefold increased risk of cancer death. Low-grade infiltrate was related to increasing T stage and an infiltrating margin. CONCLUSION Assessment of inflammatory infiltrate using Klintrup's criteria provides independent prognostic information on node-negative colorectal cancer. A high-grade local inflammatory response may represent effective host immune responses impeding tumour growth.