After resection of macroscopic disease, catheters were fixed to the tumor bed.

However, surgical or endoscopic restaging showed residual microscopic or macroscopic disease in nine patients, with complete radiographic regression.

Twelve radically operated colorectal carcinoma patients without evidence of remaining macroscopic disease (stages I, II, and III) entered the study.

Experimental design: Twenty-four resected CRC patients without macroscopic disease were immunized seven times with recombinant CEA at four different dose levels over a 12-month period.