We investigated 141 bone marrow and 104 venous blood isolates from gastrointestinal cancer patients with a cytokeratin (CK) 20-specific nested reverse transcription PCR for the detection of disseminated tumor cells at time of primary tumor resection. In colorectal cancer patients, 20 of 65 (31%) bone marrow and 9 of 52 (17%) venous blood isolates yielded a CK 20 mRNA-positive result in a stage-dependent manner. The detection rates for gastric cancer patients were 11 of 49 (22%) and 5 of 30 (17%) for bone marrow and venous blood, respectively. In pancreatic cancer patients, positive signals were found in advanced tumor stage. A duplex PCR system improved the feasibility of the test. After analyzing 70 sets of bone marrow and venous blood isolates from colorectal, gastric, and pancreatic cancer patients, we observed a higher detection rate in bone marrow isolates. Survival of patients with CK 20 mRNA-positive findings was significantly shorter than that of negatively tested patients.
This work was supported in part by the Deutsche Krebshilfe e.V. (Bonn, Germany) and by the Paul Blümel Stiftung (Hannover, Germany).