Prognostic impact of disseminated tumor cells detected by CK20 RT-PCR in patients with colorectal and gastric carcinoma

Background: Disseminated tumor cells can be detected in patients with gastr ointestinal carcinomas by Cytokeratin 20 (CK 20) RT-PCR in all tumor stages . This study analysed the prognostic relevance of the preoperative detectio n of disseminated cells in the bone marrow and venous blood of patients wit h colorectal or gastric carcinoma. Methods: Bone marrow and blood of 74 patients with colorectal and 78 patien ts with gastric carcinoma were analysed by our established CK 20 RT-PCR. Pa tients were followed up for a mean time of 21 months (3 - 55 months). Results: Patients with colorectal carcinoma: In 27.9% (17/61) disseminated tumor cells were detected in bone marrow (BM) and 16% (8/50) in venous bloo d (VB). The detection rate increased with the UICC tumor stage in both comp artments. Survival analyses according to Kaplan-Meier revealed a significan t shorter survival for patients with positive results in the bone marrow an d also in the venous blood compared to negative tested patients (BM: p = 0. 0001,VB: p = < 0.0001). Patients with gastric carcinoma: In 20.7% (12/58) disseminated tumor cells were found in the bone marrow and in 15.2% in the venous blood (7/46). The detection rate increased in both compartments with the UICC tumor stage. Su rvival analyses showed a significant difference for positive compared to ne gative tested patients in the bone marrow (p = 0.0091),but no difference fo r the venous blood (p = 0.9263). Conclusion: The detection of disseminated tumor cells by CK 20 RT-PCR in th e bone marrow of patients with colorectal carcinoma and gastric carcinoma i s therefore of prognostic relevance. Due to the lower detection rates the p rognostic impact of the detection in venous blood particular in gastric can cer patients has to be proven by additional analyses.