Disseminated tumor cells in pancreatic cancer patients detected by immunocytology: A new prognostic factor

Using an immunocytological approach, we previously showed that disseminated cancer cells are frequently found in peritoneal cavity and bone marrow sam ples of gastrointestinal and pancreatic cancer patients. Recently, we demon strated that the detection of isolated tumor cells could serve as a new pro gnostic factor in gastric and colorectal cancer, Thus far, no conclusive da ta concerning the clinical implication of minimal residual disease in pancr eatic cancer exist. In this study, we investigated peritoneal lavage and bo ne marrow samples of 80 pancreatic cancer patients to determine the predict ive value of immunocytologically detected disseminated tumor cells, Therefo re, immunocytological findings were correlated with the clinical follow-up data (median observation time, 10.7 months; range, 2-61 months), and the fi ndings in peritoneal cavity and bone marrow samples were compared. Fifty-tw o % of the patients showed minimal residual disease at least in one compart ment (39% positive lavage and 38% positive bone marrow samples). The detect ion rate of isolated tumor cells increased in parallel to the tumor stage, The presence of tumor cells in the peritoneal cavity significantly correlat ed with the survival time of the patients (P = 0.0035). In bone marrow samp les, a strong trend was seen (P = 0.06). The evaluation of both compartment s increased the number of positive patients and resulted in a highly signif icant correlation: all patients who were positive in at least one compartme nt died within 18 months, whereas negative patients showed a 5-year surviva l rate of 30% (P < 0.0001). We recommend immunocytological investigation of peritoneal cavity and bone marrow samples as a new prognostic marker in pa ncreatic cancer patients.