Detection of Circulating Tumor Cells in Colorectal Cancer by Immunobead-PCR Is a Sensitive Prognostic Marker for Relapse of Disease

Abstract

Background: Recurrent and metastatic carcinoma of the colorectum remains a major problem, with survival at 5 years post curative resection still only about 50%. Moreover, up to 30% of patients who present with early stage disease also relapse and die within 5 years, suggesting the presence of micrometastatic disease at diagnosis. One route of metastatic spread is via the blood stream, hence the detection of tumor cells in blood is likely to provide an important predictive tool with respect to relapse of disease. We have developed a sensitive molecular technique to identify tumor cells in blood using mutations in codon 12 of the K-ras gene as a marker. Materials and Methods: Twenty-seven patients whose tumor carried a mutation in codon 12 of K-ras were studied for the presence of tumor cells in perioperative peripheral blood samples. Immunomagnetic beads, labeled with an epithelial-specific antibody, were used to harvest epithelial cells from blood. K-ras mutations were identified in this selected population using a polymerase chain reaction (PCR)-based analysis (immunobead-PCR). Results: Circulating K-ras mutant cells were detected in 9 of 27 patients; seven of these nine patients have since died due to recurrent or metastatic disease. Mutant cells were not detected in 18 patients, and 16 of 18 have remained disease free (median follow-up: 16 months; range: 7-42 months). I(aplan-Meier analysis showed that detection of K-ras mutant cells in blood was associated with significantly reduced disease-free survival (p = 0.0001). Conclusion: This study indicates that detection of circulating tumor cells perioperatively by immunobead-PCR provides a sensitive prognostic marker for recurrent and metastatic colorectal cancer.

Detection of colonic cells in peripheral blood of colorectal cancer patients by means of reverse transcriptase and polymerase chain reaction

“…Detection of occult neoplastic cells in patients with colorectal cancer has been carried out using different targets. K-ras mutations have been reported as a useful marker when samples of the primary tumour are available to confirm the mutation (Hardingham et al, 1995).…”

“…In contrast, the presence of circulating tumour cells is expected to be associated with a poor prognosis (Hardingham et al, 1995).…”

“…it has been possible to identify circulatinc cancer cells in patients xxith different neoplasms (Smith et al 1991: Moreno et al 1992: Tada et al 1993: Hillaire et al 1994. including colorectal cancer (Hardingham et al 1995: Jonas et al 1996: Denis et al 1997 Nakamori et al. : Wonc et al 1997.…”

A single step density gradient separation for large scale enrichment of mobilized peripheral blood progenitor cells collected for autotransplantation

“…[4][5][6][7] Therefore, the use of in vitro purging techniques is now considered a major issue in PBPC-based autografting procedures. Peripheral blood leukocytes are becoming the preferred source of hematopoietic progenitor/stem cells for Applying in vitro purging techniques to blood-derived progenitors, a few specific problems have emerged, mainly autologous transplantation.…”

Detection of circulating carcinoma cells by telomerase activity

“…Detection of circulating tumour cells and micrometastases in cancer patients could be useful in determining prognosis and in monitoring systemic therapies (Hardingham et al, 1995;Diel et al, 1996;Pantel et al, 1996). Various techniques have been described using conventional cytology, immunochemistry, polymerase chain reaction (PCR) or reverse transcriptase-PCR (RT-PCR), but most of them have limited sensitivity and/or specificity.…”