Purpose: The aim of our study was to determine the five-year survival of patients with colorectal carcinoma whose Dukes classification had changed following fat clearance of the mesocolon or mesorectum.
Methods: One hundred three patients with colorectal carcinoma were followed up at a special clinic for at least five years after surgery. The tumors from these patients had previously been given a Dukes classification before and after fat clearance.
Results: Four of the five patients whose Dukes status changed from B to C as a result of fat clearance died of malignant disease during the five-year follow-up period. After fat clearance it was apparent that Dukes B patients survived, on average, 11 months longer than Dukes C patients. A significantly increased mean number of positive nodes was found after fat clearance in Dukes C cases, both in those who were alive at five years and those who died of their malignant disease.
Conclusions: The fat clearance technique is a useful aid to improving the accuracy of the Dukes classification and has prognostic significance. It should be used in specimens of colorectal carcinoma, which on initial examination appear to be Dukes B cases.