Detection and clinical implications of minimal residual disease in gastro-intestinal cancer

Circulating Tumor DNA for Early Cancer Detection

BACKGROUND

Cancer cells release circulating tumor DNA (ctDNA) into the bloodstream, which can now be quantified and examined using novel high-throughput sequencing technologies. This has led to the emergence of the "liquid biopsy," which proposes to analyze this genetic material and extract information on a patient's cancer using a simple blood draw.

CONTENT

ctDNA has been detected in many advanced cancers. It has also been proven to be a highly sensitive indicator of relapse and prognosis. Sequencing the genetic material has also led to the discovery of mutations targetable by existing therapies. Although ctDNA screening is more expensive, it is showing promise against circulating tumor cells and traditional cancer biomarkers. ctDNA has also been detected in other bodily fluids, including cerebrospinal fluid, urine, saliva, and stool. The utility of ctDNA for early cancer detection is being studied. However, a blood test for cancer faces heavy obstacles, such as extremely low ctDNA concentrations in early-stage disease and benign mutations caused by clonal hematopoiesis, causing both sensitivity and specificity concerns. Nonetheless, companies and academic laboratories are highly active in developing such a test.

CONCLUSION

Currently, ctDNA is unlikely to perform at the high level of sensitivity and specificity required for early diagnosis and population screening. However, ctDNA in blood and other fluids has important clinical applications for cancer monitoring, prognosis, and selection of therapy that require further investigation.

Dissecting the Heterogeneity of Circulating Tumor Cells in Metastatic Breast Cancer: Going Far Beyond the Needle in the Haystack

Although the enumeration of circulating tumor cells (CTC) defined as expressing both epithelial cell adhesion molecule and cytokeratins (EpCAM⁺/CK⁺) can predict prognosis and response to therapy in metastatic breast, colon and prostate cancer, its clinical utility (i.e., the ability to improve patient outcome by guiding therapy) has not yet been proven in clinical trials. Therefore, scientists are now focusing on the molecular characterization of CTC as a way to explore its possible use as a “surrogate” of tumor tissues to non-invasively assess the genomic landscape of the cancer and its evolution during treatment. Additionally, evidences confirm the existence of CTC in epithelial-to-mesenchymal transition (EMT) characterized by a variable loss of epithelial markers. Since the EMT process can originate cells with enhanced invasiveness, stemness and drug-resistance, the enumeration and characterization of this population, perhaps the one truly responsible of tumor recurrence and progression, could be more clinically useful. For these reasons, several devices able to capture CTC independently from the expression of epithelial markers have been developed. In this review, we will describe the types of heterogeneity so far identified and the key role played by the epithelial-to-mesenchymal transition in driving CTC heterogeneity. The clinical relevance of detecting CTC-heterogeneity will be discussed as well.

Disseminated tumor cells in the bone marrow negatively influence survival after resection of colorectal liver metastases

BACKGROUND

Despite all efforts in extending the resectability rates of colorectal liver metastases, thus improving the prognosis of the patients, tumor recurrence occurs in many patients. Occult dissemination of tumor cells might reflect a minimal residual disease that is not eliminated by primary surgery. Because the prognostic effect of disseminated tumor cells (DTC) is still uncertain in this clinical setting, we analyzed these cells in the peripheral blood and bone marrow of patients undergoing hepatic resection of colorectal liver metastases.

METHODS

In 108 patients with colorectal liver metastases, the presence of DTC in the peripheral blood and bone marrow was detected with CK20 RT-PCR. Clinical data were prospectively collected, and multiple variables were analyzed regarding their influence on overall survival.

RESULTS

DTC in the peripheral blood were detected in 40% of the patients. In 25% of the patients, DTC were detected in the bone marrow. The median follow-up was 34 months. Fifty-nine of 108 patients died from tumor relapse. Multivariate analysis determined detection of DTC in the bone marrow to be an independent prognostic factors for overall survival (P = 0.038).

CONCLUSIONS

This large series of patients with hepatic resection of colorectal liver metastases demonstrated that detection of CK20-positive DTC via RT-PCR in the bone marrow compartment negatively influences overall survival. The evidence of DTC in the bone marrow might serve as an additional individual marker to select patients for adjuvant treatment after liver metastases resection.

Biology and significance of circulating and disseminated tumour cells in colorectal cancer

PURPOSE

More than 130 years ago, circulating tumour cells (CTCs) and disseminated tumour cells (DTCs) have been linked to metastasis. Since then, a myriad of studies attempted to characterise and elucidate the clinical impact of CTCs/DTCs, amongst others in colorectal cancer (CRC). Due to a flood of heterogeneous findings regarding CTCs/DTCs in CRC, this review aims to describe the known facts about CTC/DTC biology and clinical impact.

METHODS

To identify the basic scientific literature regarding the biology and clinical impact of CTCs/DTCs in CRC, we reviewed the literature in the PubMed database. We focused on publications written in English and published until January 2012. As search terms, we used "colorectal cancer (CRC)", "colon cancer (CC)", "CTC", "DTC", "bone marrow (BM)", "lymph node (LN)", "peripheral blood (PB)", "significance" and "prognosis".

RESULTS

CTC detection and quantification under standardised conditions is feasible. Several studies in large patient settings have revealed prognostic impact of CTCs in CRC. CRC-derived DTC detection and analysis in BM exhibits a more heterogeneous picture but also shows clinical value. Furthermore, the presence of DTCs in LN has a strong prognostic impact in CRC.

CONCLUSIONS

Clinical relevance and prognostic significance of CTCs/DTCs in CRC have been clearly demonstrated in many experimental studies. The major challenge in CTC/DTC research is now to harmonise the various identification and detection approaches and consequently to conduct large prospective multi-institutional trials to verify the use of CTCs/DTCs as a valid prognostic and predictive biomarker for clinical routine.

Current clinical status of sentinel lymph nodes in colon and proximal rectal cancer

The postoperative report of the lymph node status of colorectal cancer in clinical practice is not a given fact. Among other factors, it is dependent on the experience and technique of the surgeon as well as the pathologist. Therefore a method like sentinel lymph node biopsy (SLNB) that identifies and provides for analysis the lymph node at highest risk for tumour involvement would be highly beneficial. Unlike in breast cancer or melanoma, SLNB is more difficult to apply in colorectal cancer and is still not ready for clinical routine application for these tumor entities. However, careful patient selection and expertise of the involved specialists can improve the quality and results of SLNB in colorectal cancer. Especially in the early stage cancer patients, SLNB may be helpful to identify the earliest signs of lymphatic dissemination (thereby upstaging the patient) or to encourage a limited extent of resection.

Organ-specific markers in circulating tumor cell screening: an early indicator of metastasis-capable malignancy

Circulating tumor cells (CTCs) represent an important biological link in the spread of primary solid tumors to the metastatic disease responsible for most cancer mortality. Their detection in the peripheral blood of patients with many different carcinomas has shown that tumor-cell dissemination can proceed at an early stage of tumor development and their presence is associated with poor clinical outcomes, particularly in metastatic disease. In this article we describe how the increasingly sensitive isolation and detailed molecular characterization of CTCs has greatly improved our understanding of metastatic proliferation. We focus on how CTC detection and knowledge of the molecular architecture of these cells can serve as biomarkers to signal metastasis-capable disseminating cells and predict therapy-specific response. This has marked clinical utility for improved selection of systemic therapies to the individual needs of a cancer patient, real-time monitoring of metastatic disease treatments and the development of new targeted therapies.

Postsurgery activation of dormant liver micrometastasis: a case report and review of literature

BACKGROUND

We present the case of a 55-year-old woman who underwent a Whipple procedure for pancreatic adenocarcinoma. The preoperative work-up showed no signs of liver metastasis and confirmed the patient's operability, but at less than 40 days postoperatively there were diffuse liver metastasis present on CT. This rapid evolution raises the question whether current staging systems are adequate in determining a patient's operability. It also suggests an interaction between the primary tumor and the host and the existence of disseminated tumor cells.

DISCUSSION

In this article, we give an explanation for the clinical evolution presented in our case using the "integrated organ" and the "concomitant resistance" hypotheses. We believe that, if these theories continue to prove their viability, the search for disseminated tumor cells will be essential for good clinical practice in this type of pathology.

Expression and prognostic significance of CEACAM6, ITGB1, and CYR61 in peripheral blood of patients with gastric cancer

BACKGROUND

We examined CEACAM6, ITGB1, and cyr61 concentrations from patients with gastric cancers (GCs) to assess their clinical application for diagnosing and monitoring diseases.

METHODS

Real-time reverse transcription-polymerase chain reaction was used to detect the expressions of CEA, CEACAM6, ITGB1, IGF1R, CK20, cyr61, and S100A4 in peripheral blood karyocyte from 82 patients with GC, 24 patients with recurrence, and 37 healthy volunteers. Receiver operating characteristics (ROC) curves were constructed.

RESULTS

There were significant association between these CEACAM6, ITGB1, and cyr61 and TNM Stages and distant metastasis. The AUC of CEACAM6 was 0.884 ± 0.044 (P = 0.0001), the AUC of cyr61 was 0.833 ± 0.047 (P = 0.0001), and the AUC of ITGB1 was 0.838 ± 0.042 (P = 0.0001) by differentiating preoperative GC patients from healthy volunteers from ROC curve analysis. The AUC of CEACAM6 was 0.761 ± 0.066 (P = 0.001), the AUC of CYR61 was 0.762 ± 0.063 (P = 0.001), and the AUC of ITGB1 was 0.824 ± 0.051 (P = 0.0001), by differentiating recurrence of GC from healthy volunteers from ROC curve analysis.

CONCLUSION

The method of detecting the expression of CEACAM6, ITGB1, and CYR61 in peripheral blood of GC patients was more sensitive than CEA, IGF1R, CK20, and S100A4 for the early diagnosis of metastasis and recurrence.

Phase II clinical trial of postoperative S-1 monotherapy for gastric cancer patients with free intraperitoneal cancer cells detected by real-time RT-PCR

BACKGROUND

We have previously reported the molecular detection of peritoneal micrometastases in patients with gastric cancer by quantifying carcinoembryonic antigen (CEA) mRNA in the peritoneal washes. Patients with CEA mRNA exceeding a cutoff value have a significant risk for developing peritoneal carcinomatosis, but optimal treatment for this population remains unknown.

METHODS

CEA mRNA (+) patients with gastric cancer were treated postoperatively with S-1 monotherapy. Overall survival, the primary endpoint of this phase II trial, was compared with the historical control, which is comprised of CEA mRNA (+) patients who were not given postoperative chemotherapy.

RESULTS

A total of 32 patients with CEA mRNA (+) gastric cancer were enrolled. Twelve patients (37.5%) relapsed; ten showed peritoneal relapse. Three-year survival was similar between the study population and the historical control (67.3% vs. 67.1%, respectively).

CONCLUSIONS

S-1 monotherapy, which significantly reduced risk for recurrence in stage II/III gastric carcinoma in another phase III trial, seems not to be as effective in eradicating free cancer cells in the abdominal cavity.

A pilot study of S-1 plus cisplatin versus 5-fluorouracil plus cisplatin for postoperative chemotherapy in histological stage IIIB-IV (M0) gastric cancer

BACKGROUND

Although its efficacy is unproven, 5-fluorouracil plus cisplatin (FP) is used to prevent postoperative relapse in gastric cancer. We investigated the safety and feasibility of S-1 plus cisplatin (SP) vs. FP for stage IIIB-IV (M0) gastric cancer.

METHODS

Following curative resection, 41 stage IIIB-IV (M0) gastric cancer patients were assigned to SP (eight 14-day cycles of S-1 [40 mg/m(2) twice daily] plus cisplatin [60 mg/m(2) day 1] administered every 3 weeks) or FP (six 3-day cycles of FU [1 g/m(2) per day] plus cisplatin [80 mg/m(2) day 1] every 4 weeks). Doses were reduced based on predefined criteria.

RESULTS

Patient characteristics were balanced between the two arms. In total, 124 cycles of SP (N = 20, median = 7, range 1-8) and 113 cycles of FP (N = 21, median 6, range 1-6) were administered. The median relative dose intensity per patient was 75% (49.99-100%) for S-1, 100% (75-100%) for cisplatin in SP, and 100% (64-100%) for 5-FU, 100% (60-100%) for cisplatin in FP. The relative dose intensity of FP was stable, while that of SP decreased during treatment. After median follow-up of 7.9 months (3.8-14.55), the median RFS was not reached. Relapse occurred in two (10%) patients on SP and five (23.8%) in the FP arm (P = 0.24). The incidence of grade 3-4 granulocytopenia was 36.8% with SP and 14.3% with FP. Grade 3-4 non-hematologic toxicities included fatigue (5.2% with SP vs. 4.8% with FP), vomiting (10.5% with SP vs. 0% with FP), and infection (5.2% with SP vs. 0% FP).

CONCLUSION

S-1 plus cisplatin was feasible and tolerable as adjuvant treatment for stage IIIB-IV (M0) gastric cancer. However, because of decreased relative dose intensity during treatment, further study is warranted to determine optimal dosage and combination.

Kallikrein-related peptidase 13 (KLK13) gene expressional status contributes significantly in the prognosis of primary gastric carcinomas

OBJECTIVES

Gastric cancer is a fatal human malignancy with poor prognosis. Modifications in gene expression, including those of the kallikrein-related peptidase family, have been portrayed in gastric carcinogenesis. Given KLK13 involvement in human malignancies, we aimed to uncover its prognostic strength in stomach cancer.

DESIGN AND METHODS

Quantitative analysis of KLK13 profiles was accomplished in human gastric cancer cells and in a statistically significant sample size of stomach tissue specimens with the development of the highly sensitive real-time PCR methodology.

RESULTS

Decreased KLK13 expression was demonstrated in cancerous compared with their matching non-malignant pairs (p=0.002) and in poorly differentiated gastric tumors (p=0.029). KLK13-positive patients were shown to live considerably longer (p=0.014) and with low risk of disease recurrences (p=0.043).

CONCLUSIONS

This is the first study disclosing the possible clinical utility of KLK13 as a new tumor biomarker capable of predicting a favorable outcome for gastric cancer patients.

Molecular analysis and prognostic impact of the novel apoptotic gene BCL2L12 in gastric cancer

Stomach cancer comprises a malignancy with feeble prognosis. In gastric carcinogenesis, molecular alterations in the apoptosis-related genes have been described. In this study, the expression of BCL2-like-12 (BCL2L12) gene, discovered and cloned by members of our group, was investigated in a statistically significant sample size of cancerous and non-cancerous stomach tissues and gastric cancer cells with quantitative real-time PCR methodology. BCL2L12 transcript was indicated in cancer gastric tissues to range from 29 to 53200 mRNA copies BCL2L12/10(6) mRNA copies GAPDH. Significant associations of BCL2L12 with gastric tumors of the early stages (I/II) (p=0.044) and of intestinal histotype (p=0.034) was substantiated. Both univariate and multivariate analyses disclosed, respectively, BCL2L12 relationship with disease-free (p=0.006 and p=0.025) and overall patients' survival (p=0.007 and p=0.022). Our results open new horizons for the possible application of BCL2L12 as a novel prognostic indicator of gastric cancer.

Circulating tumor cells in gastrointestinal cancer

Since the first report in the nineteenth century, there have been numerous reports on the isolation and characterization of circulating tumor cells (CTCs) in peripheral blood in patients with various carcinomas. In general, CTCs have been observed in the peripheral blood of cancer patients at very low concentrations of 10(-7)-10(-8) of normal peripheral blood cells. The characterization is of considerable biomedical interest in order to understand how these cells can travel via the blood stream to anatomically distant sites and form metastatic disease. Recent progress in molecular oncology enables us to detect the CTCs in blood with highly sensitivity and specificity, and several studies have indicated the prognostic value of CTC detection in patients with gastrointestinal cancers. Detection and measurement of CTCs in patients with gastrointestinal cancers such as colorectal, gastric, and pancreatic cancers can be useful as a promising tool for judging tumor stage, predicting the distant metastasis and patient survival, and monitoring the response to cancer therapy. Standard procedures for CTC detection have to be established, and the clinical relevance should be verified in large-scale clinical trials. However, CTC detection is suggested to provide useful information for the tumor staging and anticancer treatments in clinical practices in the near future.

Detection of disseminated tumor cells in bone marrow of gastric cancer using magnetic activated cell sorting and fluorescent activated cell sorting

BACKGROUND AND AIM

Magnetic activated cell sorting (MACS) and fluorescent activated cell sorting (FACS) were employed to enrich and detect the gastric cancer cells from a cell line in a model system, and to enrich and detect disseminated tumor cells (DTCs) from bone marrow (BM) of patients with gastric cancer.

METHODS

Fifteen patients with benign gastric lesions and 35 patients with gastric cancer who received curative operations between December 2002 and June 2003 were selected. Mononuclear cells were separated from their BM. Cells from cell line OCUM-2M were seeded with 10-grade ratio into mononuclear cells from patients with benign gastric lesion. After labeling by MACS minibeads conjugated with cytokeratin (CK) 7/8 antibodies, anti-CK-fluorescein isothiocyanate (FITC), and anti-CD45-perdinin chlorophyll protein (PerCP), the samples were enriched twice using an MS+/RS+ positive separation column. The FACS analysis was conducted on these samples before and after MACS enrichment. The results were analyzed using clinopathological parameters.

RESULTS

Disseminated tumor cells were detected in the BM of 25 (71.43%) patients with gastric cancer. The frequencies of DTCs were 1.38 x 10(-8)-2.40 x 10(-5), 2.19 x 10(-7)-3.70 x 10(-5), 4.01 x 10(-6)-8.57 x 10(-5) in patients with well, moderately, and poorly differentiated carcinoma, respectively (P = 0.026). Disseminated tumor cells in BM had close correlation with tumor tumor-node-metastasis (TNM) stage (P = 0.034) and cancer-free survival (P = 0.035).

CONCLUSION

Disseminated tumor cells are very common in the BM of gastric cancer patients. Poor histological differentiation and more advanced TNM stage have more DTCs in the BM of gastric cancer patients. Patients with DTCs tend to have a poor prognosis.

Cancer micrometastasis and tumour dormancy

Many epithelial cancers carry a poor prognosis even after curative resection of early stage tumours. Tumour progression in these cancer patients has been attributed to the existence and persistence of disseminated tumour cells (DTC) in various body compartments as a sign of minimal residual disease. Bone marrow (BM) has been shown to be a common homing organ and reservoir for DTC. A significant correlation between the presence of DTC in BM and metastatic relapse has been reported in various tumour types. However, only a portion of patients with DTC in BM at primary surgery relapse. Thus far, little is known about the conditions required for the persistence of dormancy or the escape from the dormant phase into the active phase of metastasis formation. Thereby, this peculiar stage of conceivably balanced tumour cell division and death may last for decades in cancer patients. Most likely, the ability of a dormant DTC to "be activated" is a complex process involving (i) somatic aberrations in the tumour cells, (ii) the interaction of the DTC with the new microenvironment at the secondary site, and (iii) hereditary components of the host (i.e., cancer patient). In this review, we will summarize the key findings of research on micrometastatic cancer cells and discuss these findings in the context of the concept of tumour dormancy.

Circulating tumor cells and bone marrow micrometastasis

Sensitive immunocytochemical and molecular assays allow the detection of single circulating tumor cells (CTC) in the peripheral blood and disseminated tumor cells (DTC) in the bone marrow as a common and easily accessible homing organ for cells released by epithelial tumors of various origins. The results obtained thus far have provided direct evidence that tumor cell dissemination starts already early during tumor development and progression. Tumor cells are frequently detected in the blood and bone marrow of cancer patients without clinical or even histopathologic signs of metastasis. The detection of DTC and CTC yields important prognostic information and might help to tailor systemic therapies to the individual needs of a cancer patient. In the present review, we provide a critical review of (a) the current methods used for detection of CTC/DTC and (b) data on the molecular characterization of CTC/DTC with a particular emphasis on tumor dormancy, cancer stem cell theory, and novel targets for biological therapies; and we pinpoint to (c) critical issues that need to be addressed to establish CTC/DTC measurements in clinical practice.

Recent advances in conventional and molecular prognostic factors for gastric carcinoma

Despite radical surgery, the prognosis of patients who have gastric carcinoma remains unsatisfactory because of the intrinsic but unpredictable aggressiveness of this malignancy. During the past decade an ever-growing list of molecular prognostic factors has been proposed based on the discovery of the mechanisms underlying gastric cancer aggressiveness. Studies performed in larger and more homogeneous series of patients and adequate statistical analysis are warranted before any of the candidate biomarkers can be implemented in the routine clinical setting for the identification of patients at higher risk and thus for the selection of candidates for adjuvant or more aggressive therapies.

Detection of survivin-expressing circulating cancer cells (CCCs) in peripheral blood of patients with gastric and colorectal cancer reveals high risks of relapse

BACKGROUND

We previously demonstrated that the detection of circulating cancer cells (CCCs) expressing survivin mRNA could provide valuable information for predicting metastasis and recurrence in breast cancer. The objective of this study was to investigate whether or not the detection of survivin expression in the peripheral blood could also have significant effects on the clinical outcomes of patients with gastric and colorectal cancer.

METHODS

Survivin-expressing CCCs in peripheral blood samples obtained from 55 gastric cancer patients, 86 colorectal cancer patients, and 87 healthy volunteers were quantitatively examined by using a RT-PCR ELISA. Its clinical significance was statistically evaluated.

RESULTS

The CCCs in the peripheral blood samples were detected in 45.4% and 44.0% of gastric and colorectal cancer patients, respectively. The presence of survivin-expressing CCCs was found to be significantly associated with the degree of tumor penetration, nodal status, and disease stages for both types of cancers. During a follow-up period of 36 months, patients who had a positive detection at the time of the initial assay test had a higher relapse rate than those who had a negative detection. As well, survivin-expressing CCCs were statistically shown to be a significant and independent predictor for cancer recurrence. The detection of survivin-expressing CCCs was also demonstrated to be more accurate in terms of predicting recurrence than traditional detection methods such as plasma carcinoembryonic antigen (CEA) measurements.

CONCLUSION

The detection of CCCs expressing survivin mRNA could be used to accurately identify gastric and colorectal cancer patients with high risks of relapse.

Detection, clinical relevance and specific biological properties of disseminating tumour cells

Most cancer deaths are caused by haematogenous metastatic spread and subsequent growth of tumour cells at distant organs. Disseminating tumour cells present in the peripheral blood and bone marrow can now be detected and characterized at the single-cell level. These cells are highly relevant to the study of the biology of early metastatic spread and provide a diagnostic source in patients with overt metastases. Here we review the evidence that disseminating tumour cells have a variety of uses for understanding tumour biology and improving cancer treatment.

Pancreatic cancer--low survival rates

INTRODUCTION

Cancers of the pancreas are identified in 11 800 to 13 500 patients each year in Germany. Epidemiological studies prove smoking and chronic alcohol consumption as causes of about 30% of pancreatic cancers.

METHODS

Selective literature review.

RESULTS

Only patients within TNM stage I and II have after oncologic tumor extirpation a chance for long term survival. Controlled prospective clinical trials demonstrated adjuvant chemotherapy yielding an additional significant survival benefit. The 3- and 5-year-survival after R0-resection and adjuvant chemotherapy are about 30% and below 15% respectively. Using the criteria of observed 5-year-survival less than 2% of all pancreatic cancer patients are alive. After R0-resection the median survival time is between 17 and 28 months, after R1/2-resection between 8 and 22 months.

DISCUSSION

Pancreatic cancer is even today for more than 95% of the patients incurable. Strategies to prevent pancreatic cancer are intended to stop smoking and chronic alcohol consumption and early surgical extirpation of cystic neoplastic lesions. For patients with established pancreatic cancer risk a follow-up protocol is discussed.

Detection of disseminated tumor cells in liver biopsies of colorectal cancer patients is not associated with a worse prognosis

BACKGROUND

Liver metastases occur frequently in colorectal cancer and are probably caused by disseminated tumor cells having been trapped in the liver. The prognostic significance of hematogenous tumor cell dissemination has already been demonstrated for blood and bone marrow of patients with colorectal cancer. The aim of this study was to investigate the frequency and prognostic significance of disseminated tumor cells in liver biopsies of colorectal cancer patients.

METHODS

Liver biopsies from 100 patients with UICC stage I-III colorectal cancer were taken prospectively during resection of the primary tumor. Liver biopsies obtained from 16 patients with benign gastrointestinal diseases served as negative controls. Liver samples from seven patients with liver cirrhosis were additionally taken. Liver biopsies were examined using a reverse transcriptase (RT)-PCR assay to amplify cytokeratin (CK) 20 transcripts. The median follow-up of the patients was 55 months.

RESULTS

Disseminated tumor cells were detected in liver samples of 10/100 (10%) patients with UICC stage I-III colorectal cancer. Liver specimens from all seven patients with liver cirrhosis were CK 20-positive, whereas 16 patients with other benign gastrointestinal diseases were all CK 20-negative. There was no correlation between tumor cell detection in liver biopsies and survival of the patients. The only significant prognostic factor on uni- and multivariate analysis was the UICC stage.

CONCLUSIONS

This study demonstrates that detection of disseminated tumor cells in liver samples from patients with UICC stage I-III colorectal cancer has no prognostic influence. UICC classification was the strongest prognostic factor in this patient series.