Molecular detection of cytokeratin-19-positive cells in the peripheral blood of patients with operable breast cancer: evaluation of their prognostic significance

Recent translational research: circulating tumor cells in breast cancer patients

In breast cancer patients, hematogenous tumor cell dissemination can be detected, even at the single cell level, by applying immunocytochemical and molecular assays. Various methods for the detection of circulating tumor cells in the peripheral blood have been described. Results from recently reported studies suggest that circulating tumor cell levels may serve as a prognostic marker and for the early assessment of therapeutic response in patients with metastatic breast cancer. However, in early-stage breast cancer, the impact of circulating tumor cells is less well established than the presence of disseminated tumor cells in bone marrow; several clinical studies have demonstrated that cells of the latter type are an independent prognostic factor at primary diagnosis. In this article we briefly summarize recent studies examining the presence of circulating tumor cells in the blood and discuss further clinical applications.

Combination of multiple mRNA markers (PTTG1, Survivin, UbcH10 and TK1) in the diagnosis of Taiwanese patients with breast cancer by membrane array

OBJECTIVE

Early detection is a prerequisite to the effective reduction of morbidity and mortality from breast cancer. The present study intended to employ a high-throughput membrane array to detect a panel of mRNA markers expressed by circulating tumor cells (CTCs) in the peripheral blood of female patients with breast cancer.

METHODS

Peripheral blood was sampled from 92 breast cancer patients and 100 normal persons. CTCs were detected by using a membrane array technique. The markers used included the pituitary tumor transforming gene 1, survivin, UbcH10 and thymidine kinase 1.

RESULTS

The results showed that the membrane array could positively detect 5 cancer cells per 1 ml of peripheral blood in breast cancer cell dilution experiments. For the panel of 4 mRNA markers, sensitivity and specificity were elevated up to 86 and 88%, respectively. Furthermore, it was found that the patients' clinicopathological characteristics tumor size (p = 0.006), histologic grade (p = 0.012), lymph node metastasis (p = 0.001) and TNM stage (p = 0.006) significantly correlated with the positive detection rate of the multimarker panel.

CONCLUSIONS

These findings demonstrated that our multimarker membrane array method could detect CTCs in the circulation of breast cancer patients with considerably high sensitivity and specificity.

CK19 mRNA expression measured by reverse-transcription polymerase chain reaction (RT-PCR) in the peripheral blood of patients with non-small cell lung cancer treated by chemo-radiation: an independent prognostic factor

PURPOSE

To investigate the prognostic significance of circulating cancer cells in peripheral blood (PB) of patients with non-small cell lung cancer (NSCLC) treated by chemo-radiation with curative intent.

METHODS

Cytokeratin-19 (CK19) mRNA was measured by nested reverse-transcription polymerase chain reaction (RT-PCR) in PB from 67 NSCLC patients before and after chemo-radiation. The measurements of CK19 mRNA were compared to the outcome of therapy to evaluate its significance of prognoses.

RESULTS

The sensitivity and specificity of CK19 RT-PCR was 10(-7) and 96.7%, respectively. The positive rate of CK19 mRNA in PB before chemo-radiation was correlated only to N stage (p=0.014). In contrast, it was more closely correlated to histological types (adenocarcinoma versus non-adenocarcinoma) (p=0.019), weight loss (p=0.010), KPS status (p=0.027) and N stage (p=0.032) after chemo-radiation. CK19 status in PB before chemo-radiation did not permit predictions of overall survival (p=0.375) and progression-free survival (p=0.573). However, the patients with CK19 mRNA expression in PB after treatments had poorer overall survival (p<0.001) and progression-free survival (p<0.001) as compared to those with negative CK19 mRNA expression. The worst survivals were seen in patients with persistently positive CK19 mRNA expression both before and after treatments. Multivariate analyses demonstrated that the positivity of CK19 mRNA after chemo-radiation was an independent unfavorable prognostic factor for both overall survival and progression-free survival (p<0.001 and <0.001).

CONCLUSION

Only after chemo-radiation could the measurement of CK19 mRNA in PB predict the prognoses of NSCLC. Patients with the positive CK19 mRNA had shorter survival compared to the negative patients.

Biomarkers in breast cancer

Breast cancer is one of the most frequently diagnosed cancers among women in the western world. Due to the aggressive behaviour of some specific types and the possibility of an early diagnosis, breast cancer has been constantly studied. Tumour size, histological type, cellular and nuclear characteristics, mitotic index, vascular invasion, hormonal receptors and axillary lymph node status are biomarkers routinely used. However, these parameters are not enough to predict the course of this disease. Molecular biology advances have made it possible to find new markers, which have already been incorporated to the clinical practice. Their ultimate goal is to reduce mortality by identifying women at risk for the development of this disease, help diagnosis, determine prognosis, detect recurrences, monitor and guide treatment, and in particular cancers they are suited for general screening. Tumour markers in breast cancer were ranked in categories reflecting their clinical utility, according to the American College of Pathologists.

This article focuses on traditional and new molecular markers stratifying them into categories and emphasizing their relevance in the routine evaluation of patients with breast cancer.

HER2-positive circulating tumor cells indicate poor clinical outcome in stage I to III breast cancer patients

PURPOSE

Early metastasis in node-negative breast cancer indicates that breast cancer cells obviously can bypass the lymph nodes and disseminate directly hematogenous to distant organs. For this purpose, we evaluated the prognostic value of blood-borne, HER2-positive circulating tumor cells (CTC) in the peripheral blood from 42 breast cancer patients with a median follow-up of 95 months.

EXPERIMENTAL DESIGN

Cells were isolated by the patented combined buoyant density gradient and immunomagnetic separation procedure and analyzed by immunocytochemistry.

RESULTS

We detected one to eight CTCs in the peripheral blood of 17 of 35 patients (48.6%) presenting no overt metastasis. As a positive control, 7 of 7 (100%) patients with metastatic disease presented positive. Healthy persons and patients (n = 32) operated for nonmalignant diseases presented negative for CTCs. The presence and frequency of HER2-positive CTCs correlated with a significantly decreased disease-free survival (P < 0.005) and overall survival (P < 0.05). Interestingly, in 12 patients with HER2-positive CTCs, the primary tumor was negative for HER2 as assessed by immunohistochemical score and fluorescence in situ hybridization.

CONCLUSIONS

This study provides some evidence of a prognostic effect of HER2-positive CTCs in stage I to III breast cancer. Future studies have to determine the outcome of patients treated with HER2-targeting therapies with respect to HER2-positive CTC levels because it is not unlikely that high levels of HER2-positive CTCs reflect the activity of the tumor and may predict response to trastuzumab.

Molecular detection of EGFRvIII-positive cells in the peripheral blood of breast cancer patients

The aim of this study is to evaluate epidermal growth factor receptor variant III, EGFRvIII, a cancer specific mutant, as a possible marker for the diagnosis of breast cancer occult systemic disease. EGFRvIII mRNA was identified by an RT-nested PCR with a high sensitivity. In 102 women studied, the mutant was detected in the peripheral blood of 30% of 33 low risk, early stage patients, in 56% of 18 patients selected for neoadjuvant chemotherapy, in 63.6% of 11 patients with disseminated disease and 0% of 40 control women. In low risk, early stage patients, the presence of one or more tumour characteristics predicting recurrence such as the absence of oestrogen receptors and the presence of ERBB2 or histologic grades G2/G3 was significantly associated with EFGRvIII detection (p<0.05). EGFRvIII mRNA has characteristics to be a useful marker for the diagnosis of occult systemic disease in breast cancer. Follow-up studies will evaluate its clinical value as a decision criterion for systemic therapy.

A highly specific real-time RT-PCR method for the quantitative determination of CK-19 mRNA positive cells in peripheral blood of patients with operable breast cancer

The aim of the present study was to decrease the incidence of false positives and to better characterize marginally cytokeratin-19 (CK-19) mRNA positive peripheral blood samples from patients with early stage breast cancer. A new set of highly specific primers for CK-19, which avoids amplification of contaminating genomic DNA, was designed and evaluated to improve the specificity and sensitivity of the previously described methodology. The primers were specifically designed to avoid amplification of contaminating genomic DNA and CK-19 pseudogenes. The breast cancer cell line MCF-7 was used as positive control for the development and analytical evaluation of the assay, while peripheral blood samples from 62 healthy female individuals and 160 patients with early breast cancer were used for the evaluation of the sensitivity and specificity of the new primer pair. The novel designed primer pair was highly sensitive, as it detects up to 1 MCF-7 cell, and specific as none of the healthy individuals had detectable CK-19 mRNA positive cells in their peripheral blood. CK-19 mRNA positive cells were detected in 33 out of 160 (20.6%) patients with early breast cancer. Results obtained by the proposed optimized real-time RT-PCR protocol correlated well with those obtained in the same samples by our previously reported quantitative real-time RT-PCR [concordance in 198/222 (89.2%), p = 0.0022, McNemar test]. The improved method eliminates the incidence of false positives and is highly sensitive and specific. The method could be used in a clinical setting in the near future for continuous monitoring and quantification of circulating epithelial cells in the peripheral blood of patients with operable breast cancer, provided that a quite larger number of clinical samples with a known follow-up will be analyzed.

Validity of Messenger RNA Expression Analyses of Human Saliva

PURPOSE

The origins of expression microarray and reverse transcription-PCR (RT-PCR) signals in human saliva were evaluated.

EXPERIMENTAL DESIGN

The "RNA" extracts from human saliva samples were treated with vehicle, DNase, or RNase. Two-step amplification and hybridization to Affymetrix 133A cDNA microarrays were then done. Confirmatory RT-PCR experiments used conventionally designed PCR primer pairs for the reference housekeeper transcripts encoding 36B4, beta-actin, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA sequences, which are known to be homologous to genomic DNA pseudogene sequences. Negative controls included the omission of reverse transcriptase ("no-RT") to detect any DNA-derived signal. Finally, an RNA-specific RT-PCR strategy eliminated confounding signals from contaminating genomic DNA.

RESULTS

Microarray experiments revealed that untreated, DNase-treated, and RNase-treated "RNA" extracts from saliva all yielded negligible overall signals. Specific microarray signals for 36B4, beta-actin, and GAPDH were low, and were unaffected by RNase. Real-time quantitative RT-PCR reactions using conventional, non-RNA-specific primers on saliva samples yielded PCR products for 36B4, beta-actin, and GAPDH; DNase-treated saliva samples did not yield a PCR product, and the "no-RT" and "+RT" conditions yielded similar amounts of PCR product. The RNA-specific RT-PCR strategy, across all conditions, yielded no PCR product from saliva.

CONCLUSIONS

The combination of (a) a minimal microarray signal, which was unaffected by RNase treatment, (b) the presence of a conventional RT-PCR housekeeper product in both RNase-treated and no-RT saliva samples, (c) the absence of a conventional RT-PCR housekeeper product in DNase-treated conditions, and (d) the absence of a RNA-specific RT-PCR product shows that any microarray or RT-PCR signal in the saliva must arise from genomic DNA, not RNA. Thus, saliva extracts do not support mRNA expression studies.

Detection of Mammaglobin A-mRNA-positive circulating tumor cells in peripheral blood of patients with operable breast cancer with nested RT-PCR

OBJECTIVES

The development and validation of a nested RT-PCR methodology for the detection of Mammaglobin A-mRNA-positive circulating tumor cells in peripheral blood of patients with operable breast cancer and evaluation of its prognostic significance.

DESIGN AND METHODS

Different combinations of specific primers were in silico designed and selected, so that false positive results due to genomic DNA contamination were avoided. The specificity of the primers used was evaluated in 30 healthy individuals, 20 patients with colorectal cancer and 20 patients with non-small cell lung cancer. The method was applied in 101 patients with operable breast cancer before the administration of adjuvant chemotherapy and 39 patients with metastatic breast cancer.

RESULTS

Mammaglobin A-mRNA-positive cells were detected in 14/101 (13.9%) of early breast cancer patients but not in the control population studied (0%); 9 of them (64.3%) relapsed during the follow-up period. Mammaglobin A was detected in 7/39 (17.9%) of patients with verified metastasis. Multivariate analysis revealed the detection of Mammaglobin A-mRNA-positive cells, as an independent risk factor for reduced DFI.

CONCLUSIONS

Mammaglobin A is a highly specific molecular marker for the detection of circulating tumor cells in operable breast cancer, with important prognostic applications.

Prognostic significance of circulating tumour cells enumerated after filtration enrichment in early and metastatic breast cancer patients

BACKGROUND

We previously found a higher incidence of circulating tumour cells (CTCs) in women with metastatic breast cancer compared to early disease. In this study, we present follow-up data to explore the prognostic significance of these findings.

METHODS

CTCs were quantified by immunostaining and direct visualization after centrifugation and filtration enrichment of peripheral blood from 131 patients. Time to progression (TTP) and overall survival (OS) were defined as interval from first blood sampling to first documented disease progression, or death respectively. Lifetime data was analysed using Kaplan-Meier method, log-rank test and Cox proportional hazards model.

RESULTS

Follow-up data is available for 123 patients. In early disease, median CTC>or=4 best distinguished patients with shorter TTP (p=0.05, log-rank test). In univariate analysis, tumour size, grade, lymphovascular invasion (LVI) and receptor status significantly related to TTP but none of the covariates related to OS. In multivariate analysis, T stage was the only independent predictor of TTP. In metastatic disease, median CTC>or=13 optimally identified patients with shorter TTP (p=0.01). In univariate analysis, median CTC level >or=13 and prior lines of chemotherapy predicted for TTP while in multivariate analysis, median CTC level >or=13 was the only significant independent prognostic factor (p=0.02). No relationship between CTC level and OS was found in this subgroup.

CONCLUSION

Median CTC level determined in the course of treatment predicts for TTP in metastatic breast cancer. In early breast cancer, an association was found between CTC level and TTP although this did not reach statistical significance (p=0.05).

Breast Cancer–Specific mRNA Transcripts Presence in Peripheral Blood After Adjuvant Chemotherapy Predicts Poor Survival Among High-Risk Breast Cancer Patients Treated With High-Dose Chemotherapy With Peripheral Blood Stem Cell Support

Purpose

To study the prognostic significance of the presence of breast cancer–specific mRNA transcripts in peripheral blood (PB), defined by serial analysis of gene expression, in high-risk breast cancer (HRBC) patients undergoing high-dose chemotherapy after receiving adjuvant chemotherapy.

Methods

From 1994 to 2000, 84 HRBC patients (median age, 44 years; > 10 nodes; 74%) received adjuvant chemotherapy (fluorouracil, epirubicin, and cyclophosphamide for six cycles [83%] or doxorubicin and cyclophosphamide followed by paclitaxel) before undergoing one course of cyclophosphamide plus thiotepa plus carboplatin (STAMP V). Radiotherapy or hormone therapy was administered whenever indicated. Aliquots of apheresis-mononuclear blood cells were frozen from each patient. mRNA was isolated using an automatic nucleic acid extractor based on the magnetic beads technology; reverse transcription was performed using random hexamers. Cytokeratin 19, HER-2, P1B, PS2, and EGP2 transcripts were quantified to B-glucuronidase by real-time polymerase chain reaction (RT-PCR) using a linear DNA probe marked with a quencher and reporter fluorophores used in RT-PCR. Presence of PB micrometastases, estrogen receptor and progesterone receptor status, tumor size, age, tumor grade, number of nodes affected, and treatment with paclitaxel were included in the statistical analysis.

Results

Median follow-up was 68.3 months (range, 6 months to 103 months). Forty-seven relapses (56%) and 35 deaths (41.7%) were registered. Both tumor size and presence of micrometastases reached statistical significance according to the Cox multivariate model. Relapse hazard ratio (HR) for those patients with PB micrometastases was 269% (P = .006); death HR, 300% (P = .011). Time relapse was 53 months longer for patients without micrometastases: 31.3 v 84.2 months (P = .021).

Conclusion

PB micrometastases presence after adjuvant chemotherapy predicts both relapse and death more powerful than classical factors in HRBC patients undergoing high-dose chemotherapy. Micrometastases search using a gene panel appears to be a more accurate procedure than classical approaches involving only one or two genes.

Specific detection of cytokeratin 20-positive cells in blood of colorectal and breast cancer patients by a high sensitivity real-time reverse transcriptase-polymerase chain reaction method

A real-time reverse transcriptase-polymerase chain reaction (RT-PCR) method for detection of cytokeratin 20-positive cells in blood characterized by two novel features was developed and tested on 99 patients with colorectal cancer, 110 with breast cancer, and 150 healthy subjects. To optimize the specificity and sensitivity of the method, two novel features were used. First, a primer overlapping two adjacent exons was generated to inhibit nonspecific amplification both in healthy donors and cancer patients; second, a non-end-point first-round amplification was used to increase sensitivity. The number of first-round cycles was chosen to reach the highest level of sensitivity while conserving quantitative characteristics. PCR efficiency increased from 88.9% in single-round RT-PCR to 99.0% in nested real-time RT-PCR. To establish sensitivity and specificity of the method, HT29 cells were serially diluted with normal blood. Detection limit improved from 100 HT29 cells (single-round RT-PCR) to 1 to 10 cells (nested real-time RT-PCR) per 3 ml of whole blood. None of the healthy subjects was positive, whereas 22 and 29% of all colorectal and breast cancer patients, respectively, had cytokeratin 20 cell equivalents in blood. The association between cytokeratin 20 cell equivalents and metastasis was statistically significant for breast (P = 0.026) but not colorectal cancer patients (P = 0.361). Negativity of all 150 healthy controls examined confers diagnostic potential to the method.

Predictive and prognostic value of peripheral blood cytokeratin-19 mRNA-positive cells detected by real-time polymerase chain reaction in node-negative breast cancer patients

PURPOSE

To evaluate the predictive and prognostic value of peripheral blood cytokeratin-19 (CK-19) mRNA-positive cells in axillary lymph node-negative breast cancer patients.

PATIENTS AND METHODS

Peripheral blood was obtained from 167 node-negative breast cancer patients before the initiation of any systemic adjuvant therapy, and was analyzed for the presence of CK-19 mRNA-positive cells using a real time polymerase chain reaction assay. The association with known prognostic factors and the effect of CK-19 mRNA-positive cells on patients' prognosis was investigated.

RESULTS

CK-19 mRNA-positive cells were detected in the blood of 36 (21.6%) of the 167 patients. There was no correlation between the detection of CK-19 mRNA-positive cells in the peripheral blood and the various known pathologic and clinical prognostic factors; only overexpression of HER2 receptor (score 2+/3+) on the primary tumor was associated with a higher incidence of CK-19 mRNA-positive cell detection (P = .033). Multivariate analysis revealed that detection of peripheral blood CK-19 mRNA-positive cells was associated with early clinical relapse (P < .00001) and disease-related death (P = .008).

CONCLUSION

Detection of peripheral-blood CK-19 mRNA-positive cells is an independent predictive and prognostic factor for reduced disease-free interval and overall survival, respectively, in node-negative breast cancer patients.

Real-time RT-PCR detection of disseminated tumour cells in bone marrow has superior prognostic significance in comparison with circulating tumour cells in patients with breast cancer

This study assessed the ability of real-time reverse transcription–polymerase chain reaction (RT–PCR) analysis to detect disseminated epithelial cells (DEC) in peripheral blood (PB) and bone marrow (BM) of patients with breast cancer (BC). Detection of DEC in BM is an obvious choice in BC, but blood sampling is more convenient. The aim of this study was to evaluate whether the detection of DEC in either PB or BM predicts overall survival (OS). Peripheral blood and BM samples were collected from 148 patients with primary (stage M0, n=116/78%) and metastatic (stage M+, n=32/21%) BC before the initiation of any local or systemic treatment. Peripheral blood of healthy volunteers and BM of patients with a nonmalignant breast lesion or a haematological malignancy served as the control group. Disseminated epithelial cells was detected by measuring relative gene expression (RGE) for cytokeratin-19 (CK-19) and mammaglobin (MAM), using a quantitative RT–PCR detection method. The mean follow-up time was 786 days (+/− 487). Kaplan–Meier analysis was used for predicting OS. By taking the 95 percentile of the RGE of CK-19 (BM: 26.3 and PB: 58.7) of the control group as cutoff, elevated CK-19 expression was detected in 42 (28%) BM samples and in 22 (15%) PB samples. Mammaglobin expression was elevated in 20% (both PB and BM) of the patients with BC. There was a 68% (CK-19) and 75% (MAM) concordance between PB and BM samples when classifying the results as either positive or negative. Patients with an elevated CK-19 or MAM expression in the BM had a worse prognosis than patients without elevated expression levels (OS: log-rank test, P=0.0045 (CK-19) and P=0.025 (MAM)). For PB survival analysis, no statistical significant difference was observed between patients with or without elevated CK-19 or MAM expression (OS: log-rank test, P=0.551 (CK-19) and P=0.329 (MAM)). Separate analyses of the M0 and M+ patients revealed a marked difference in OS according to the BM CK-19 or MAM status in the M+ patient group, but in the M0 group, only MAM expression was a prognostic marker for OS. Disseminated epithelial cells, measured as elevated CK-19 or MAM mRNA expression, could be detected in both PB and BM of patients with BC. Only the presence of DEC in BM was highly predictive for OS. The occurrence of DEC in the BM is probably less time-dependent and may act as a filter for circulating BC cells. The use of either larger volumes of PB or performing an enrichment step for circulating tumour in blood cells might improve these results.

An evaluation of molecular markers for improved detection of breast cancer metastases in sentinel nodes

BACKGROUND AND OBJECTIVES

In patients with breast cancer (BC), the sentinel node (SN) is the first node in the axillary basin that receives the primary lymphatic flow and can be used to accurately assess the axillary nodal status without removal of the axillary contents. Currently, histology and/or immunohistochemistry are the routine methods of SN analysis. The primary objective of this study was to develop a reproducible reverse transcription (RT) PCR assay, with emphasis on achieving high specificity for accurate detection of BC micrometastases in the SN. To correct for the heterogeneity of BC cells, a multimarker approach was followed, with the further aim of improving the detection rate of the assay.

METHODS

In total, 73 markers were evaluated, of which 7 were breast epithelial markers and 66 were either cancer testis or tumour associated antigens. Twelve BC cell lines and 30 SNs (from 30 patients) were analysed using RT-PCR to determine the in vitro and in vivo detection rates for each of the markers. In addition, 20 axillary nodes obtained from a patient with brain death were used as controls to optimise the PCR cycle numbers for all the markers.

RESULTS

Of the 30 SNs, 37% (11/30) were positive on haematoxylin and eosin analysis. Extensive immunohistochemical (IHC) analyses of the haematoxylin and eosin negative nodes confirmed the presence of very small numbers of BC cells in an additional 40% (12/30) of SNs. Molecular analysis with the hMAM-A alone identified metastases in 70% (21/30) of SNs. Using MAGE-A3 in combination with hMAM-A identified metastases in 90% (27/30) of patients. Seven SNs (23%) were negative for micrometastases (with haematoxylin and eosin and IHC) but RT-PCR positive for either hMAM-A or MAGE-A3.

CONCLUSIONS

As IHC analysis resulted in a 77% detection rate compared with 37% for haematoxylin and eosin analysis, we consider that IHC is essential in order not to miss SN micrometastases. Molecular analysis with hMAM-A and MAGE-A3 allows detection of BC micrometastases with a 90% detection rate. However, the clinical value of histologically negative but RT-PCR positive SNs can only be determined with long term follow up.

Circulating tumor cells: the 'leukemic phase' of solid cancers

It is well known that malignant cells circulate in the bloodstream of patients with solid tumors. However, the biological significance of circulating tumor cells (CTCs) and the clinical relevance of their detection are still debated. Besides technical issues regarding CTC-detection methods, discontinuous shedding of CTCs from established cancer deposits, genomic instability and metastatic inefficiency might underlie the conflicting results currently available. Nevertheless, technological advances and recent clinical findings are prompting researchers to dissect CTC biology further. Here, we review these recent findings, and discuss the prospects for the identification and molecular characterization of the CTC subset that is responsible for metastasis development. This would provide a formidable tool for prognosis evaluation, anticancer-drug development and, ultimately, cancer-therapy personalization.

Multiple signaling pathways are activated during insulin-like growth factor-I (IGF-I) stimulated breast cancer cell migration

In order to display the full metastatic phenotype, the cancer cell must acquire the ability to migrate. In breast cancer, we have previously shown that insulin-like growth factor I (IGF-I) enhances cell motility in the highly metastatic MDA-231BO cell line by activating the type I IGF receptor (IGF1R). This motility response requires activation of IRS-2 and integrin ligation. In order to identify the key molecules downstream of IRS-2, we examined several signaling pathways known to be involved in cell motility. Focal adhesion kinase (FAK) was not activated by IGF-I, but IGF-I caused redistribution of FAK away from focal adhesion plaques. IGF-I treatment of MDA-231BO cells activated RhoA and inhibition of Rho-kinase (ROCK) inhibited the IGF-mediated motility response. The mitogen activated protein kinase (MAPK), p38, was also activated by IGF-I and inhibition of p38 by SB203580 blocked IGF-I induced cell motility. ROCK inhibition with Y-27632 also inhibited p38 phosphorylation suggesting that p38 lies downstream of ROCK. Both Erk1,2 and phosphatidyl-3 kinase (PI3K) were required for IGF-I stimulated cell motility, but only PI3K appeared to be directly downstream of IGF-I. Thus, IGF-I activation of its receptor coordinates multiple signaling pathways required for cell motility. Defining the key molecules downstream of the type I IGF receptor may provide a basis for optimizing therapies directed at this target.

RT-PCR determination of maspin and mammaglobin B in peripheral blood of healthy donors and breast cancer patients

BACKGROUND

The aim of the present study was to evaluate the accuracy of two markers, maspin and mammaglobin B, singly or in combination, to detect breast cancer. To define better the potential and limits of the two markers for diagnostic purposes, blood positivity was analyzed in relation to clinical, pathological and biological tumor characteristics.

PATIENTS AND METHODS

The markers were determined in peripheral blood (PB) samples from 27 healthy donors and 140 previously untreated patients using nested reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTS

Positivity for maspin in blood samples was observed in 24% of patients with an 89% specificity. For mammaglobin B, positivity was observed in 7% of patients and never in healthy donors. The presence of maspin was correlated with cell proliferation of the primary tumor (P = 0.015), whereas mammaglobin B positivity correlated with pathological stage (P = 0.013). The presence of either marker was significantly related to nodal status.

CONCLUSIONS

Our results indicate that the two markers in association could represent a potentially useful non-invasive tool to detect breast cancer. The validation of these markers as indicators of high risk of relapse is ongoing in a series of patients with an adequate follow-up.

Presence of erbB2 mRNA in the plasma of breast cancer patients is associated with circulating tumor cells and negative estrogen and progesterone receptor status

Several studies have demonstrated that tumor cell-derived RNA is presented in the plasma from breast cancer patients. However, no studies have focused on the detection of plasma erbB2 mRNA in breast cancer. In this study the expression of erbB2 mRNA in the plasma was analyzed in 106 breast cancer patients and 50 healthy subjects by using a nested RT-PCR strategy, and the circulating tumor cells were also detected by using a nested RT-PCR for detection of mammaglobin transcripts in the peripheral blood. Plasma erbB2 mRNA was detectable in 46 (43.3%) breast cancer patients, whereas only 5 normal subjects (10%) were positive in the control group (p = 0.001). The presence of erbB2 mRNA in the plasma was not associated with menopausal status, erbB2 expression in primary tumor tissues, tumor size, histological grade, Ki-67 expression or lymph node involvement, but it exhibited a trend for correlation with increasing tumor stages (p = 0.085), and the presence of erbB2 mRNA in the plasma was significantly associated with negative estrogen receptor (ER) and progesterone receptor (PR) status of the primary tumors (p = 0.031 and 0.026, respectively). Furthermore, in a small subset of 36 breast cancer patients we found the presence of plasma erbB2 mRNA was significantly correlated with the occurrence of circulating tumor cells (p = 0.01). Our study suggests that breast cancer patients with the presence of erbB2 mRNA in the plasma may have a high malignancy or an aggressive phenotype, and frequently detecting plasma erbB2 mRNA may provide a novel approach for monitoring breast cancer progression or response to treatment.

Comparison of the clinical significance of occult tumor cells in blood and bone marrow in breast cancer

Immunocytochemical (ICC) detection of disseminated tumor cells (DTC) in bone marrow (BM) in early breast cancer is an independent prognostic factor. The significance of circulating tumor cells (CTC) in peripheral blood (PB) needs further exploration and comparison to DTC detection. PB and BM were prospectively collected from 341 breast cancer patients median 40 months after operation. PB samples were analyzed for tumor cells by a negative immunomagnetic technique (10x10(6) cells/test). BM aspirates were analyzed by standard ICC (2x10(6) cells/test). CTC were present in 10% of the patients and DTC in 14%. Thirty-seven relapses and 14 breast cancer deaths have occurred at median 66 months after diagnosis. Both CTC-status and DTC-status were significantly associated with disease free survival (DFS) (event rate: CTC-positive 26.5% vs. CTC-negative 9.1%; DTC-positive 29.2% vs. DTC-negative 7.8%) (p<0.001/p<0.001, log rank) and breast cancer specific survival (event rate: CTC-positive 17.6% vs. CTC-negative 2.6%; DTC-positive 12.5% vs. DTC-negative 2.7%) (p<0.001/p<0.001). The presence of both CTC and DTC (n=8) resulted in an especially poor prognosis (p<0.001). In node negative patients, DTC-status, but not CTC-status, predicted differences in DFS (p=0.006 vs. p=0.503). Excluding 23 patients with breast cancer-related events prior to the sample collections, CTC detection was not significantly associated with DFS/distant-DFS (p=0.158/0.193), in contrast to DTC detection (p<0.001/<0.001). Presence of CTC and absence of DTC did not affect DFS (p=0.516). Applied to early stage disease, CTC analysis of increased volumes of PB appears less sensitive and prognostic than standard DTC analysis. Currently, this does not support an exchange of BM with PB for analysis of occult tumor cells.

Simultaneous detection of multiple mRNA markers CK19, CEA, c-Met, Her2/neu and hMAM with membrane array, an innovative technique with a great potential for breast cancer diagnosis

The objective of this study was mainly to develop and evaluate a membrane array-based method simultaneously detecting the expression levels of a multiple mRNA marker panel in the peripheral blood for used in complementary breast cancer diagnosis. The mRNA markers employed included cytokeratin 19 (CK-19), carcinoembryonic antigen (CEA), c-Met, Her2/neu, and mammaglobin (hMAM). The specimens of peripheral blood were collected from 80 healthy women and 102 female patients with breast cancer. The expression levels of molecular markers were evaluated by real-time Q-PCR and membrane array. Data obtained from real-time Q-PCR and membrane array were subjected to linear regression analysis, revealing that there was a high degree of correlation between the results of these two methods (r=0.979, P<0.0001). The result of membrane array assay with a combined panel of five mRNA markers was demonstrated to achieve sensitivity of 80.6%, and specificity of 83.8% for breast cancer detection, much higher than those of analysis of single marker. In addition, we demonstrated that the membrane array method could detect circulating cancer cells at a density as low as five cancer cells per 1 ml of blood. The analysis of correlation between the outcome of membrane array and clinicopathological characteristics indicated that overexpression of the multiple marker panel was significantly correlated with tumor size (P=0.030) and TNM stage (0.009). In conclusion, the detection of circulating cancer cells by means of membrane array simultaneously monitoring five mRNA markers could significantly enhance the sensitivity and specificity for cancer cell detection.

Detection and quantification of circulating tumor cells in mouse models of human breast cancer using immunomagnetic enrichment and multiparameter flow cytometry

BACKGROUND

Circulating tumor cells (CTCs) in the peripheral blood of breast cancer patients may be an important indicator of metastatic disease and poor prognosis. However, the use of experimental models is required to fully elucidate the functional consequences of CTCs. The purpose of this study was to optimize the sensitivity of multiparameter flow cytometry for detection of human tumor cells in mouse models of breast cancer.

METHODS

MDA-MB-468 human breast cancer cells were serially diluted in whole mouse blood. Samples were lysed and incubated with a fluorescein isothiocyanate-conjugated anti-human leukocytic antigen antibody and a phycoerythrin-conjugated anti-mouse pan-leukocyte CD45 antibody. Samples were then immunomagnetically depleted of CD45-positive leukocytes, fixed, permeabilized, and stained with propidium iodide before flow cytometric analysis.

RESULTS

Human breast cancer cells could be differentiated from mouse leukocytes based on increased light scatter, cell surface marker expression, and aneuploid DNA content. The method was found to have a lower sensitivity limit of 10(-5) and was effective for detecting human breast cancer cells in vivo in the circulation of experimental mice carrying primary human mammary tumors.

CONCLUSIONS

This technique has the potential to be a valuable and sensitive tool for investigating the biological relevance of CTCs in experimental mouse models of breast cancer.

Breast cancer metastasis: markers and models

Breast cancer starts as a local disease, but it can metastasize to the lymph nodes and distant organs. At primary diagnosis, prognostic markers are used to assess whether the transition to systemic disease is likely to have occurred. The prevailing model of metastasis reflects this view--it suggests that metastatic capacity is a late, acquired event in tumorigenesis. Others have proposed the idea that breast cancer is intrinsically a systemic disease. New molecular technologies, such as DNA microarrays, support the idea that metastatic capacity might be an inherent feature of breast tumours. These data have important implications for prognosis prediction and our understanding of metastasis.

Detection of CK-19 mRNA-positive cells in the peripheral blood of breast cancer patients with histologically and immunohistochemically negative axillary lymph nodes

BACKGROUND

To investigate the incidence of direct hematogenous spread of cancer cells in patients with early-stage breast cancer by studying the presence of occult tumor cytokeratin-19 (CK-19) mRNA(+) cells in the peripheral blood in relation to the status of sentinel (SLNs) and (ALNs) axillary lymph nodes.

PATIENTS AND METHODS

SLNs and ALNs from 111 patients with operable stage I-II breast adenocarcinoma were evaluated for the presence of tumor cells by hematoxylin-eosin (H&E) staining and, if negative, by immunohistochemistry (IHC) using an anti-CK-19 antibody. Peripheral blood was also analyzed for the presence of CK-19 mRNA(+) cells by nested RT-PCR, before the initiation of adjuvant treatment and in CK-19 mRNA(+) patients following the completion of adjuvant chemotherapy and hormonal treatment.

RESULTS

After both H&E staining and IHC analysis, 29 (26%) patients were ALN negative (N0). In 78 (70%) patients H&E staining and in four (3.6%) IHC analysis revealed tumors cells, and these patients were considered as ALN positive (N+). Peripheral blood CK-19 mRNA(+) cells were detected in nine (31%) out of 29 N0 and in 31 (38%) out of 82 N + patients (P=0.5) before any adjuvant treatment. Adjuvant chemotherapy and hormone treatment resulted in the disappearance of the CK-19 mRNA(+) cells in all N0 patients and in 15 out of 31 N + patients. After a median follow-up of 40 months, all the N0 CK-19 mRNA(+) patients were relapse-free whereas four (13%) N + CK-19 mRNA(+) patients had relapsed.

CONCLUSIONS

Direct hematogenous dissemination of occult tumor cells may occur in a substantial proportion of patients with early-stage breast cancer. The prognostic implication of the detection of these cells requires long follow-up periods and further studies.

Distinct hypermethylation profile of primary breast cancer is associated with sentinel lymph node metastasis

PURPOSE

Gene promoter region hypermethylation is a significant event in primary breast cancer. However, its impact on tumor progression and potential predictive implications remain relatively unknown.

EXPERIMENTAL DESIGN

We conducted hypermethylation profiling of 151 primary breast tumors with association to known prognostic factors in breast cancer using methylation-specific PCR for six known tumor suppressor and related genes: RASSF1A, APC, TWIST, CDH1, GSTP1, and RAR-beta2. Furthermore, correlation with sentinel lymph node (SLN) tumor status was assessed as it represents the earliest stage of metastasis that is readily detected. Hypermethylation for any one gene was identified in 147 (97%) of 151 primary breast tumors. The most frequently hypermethylated gene was RASSF1A (81%).

RESULTS

Hypermethylation of the CDH1 was significantly associated with primary breast tumors demonstrating lymphovascular invasion (P = 0.008), infiltrating ductal histology (P = 0.03), and negative for the estrogen receptor (P = 0.005), whereas RASSF1A and RAR-beta2 gene hypermethylation were significantly more common in estrogen receptor-positive (P < 0.001) and human epidermal growth factor receptor 2-positive (P < 0.001) tumors, respectively. In multivariate analysis, hypermethylation of GSTP1 and/or RAR-beta2 was significantly associated with patients having macroscopic SLN metastasis compared with those with microscopic or no sentinel node metastasis (odds ratio, 4.59; 95% confidence interval, 2.02-10.4; P < 0.001). In paired SLN metastasis, CDH1 was the most frequently methylated gene (90%) and provides evidence in patients corroborating its role in the clinical development of metastasis.

CONCLUSION

Hypermethylation profiling of primary breast tumors is significantly associated with known pathologic prognostic factors and may have additional clinical and pathologic utility for assessing patient prognosis and predicting early regional metastasis.

Effect of different cytokines on mammaglobin and maspin gene expression in normal leukocytes: possible relevance to the assays for the detection of micrometastatic breast cancer

In cancer patients, the ability to detect disseminated tumour cells in peripheral blood or bone marrow could improve prognosis and consent both early detection of metastatic disease and monitoring of the efficacy of systemic therapy. These objectives remain elusive mainly due to the lack of specific genetic markers for solid tumours. The use of surrogate tissue-specific markers can reduce the specificity of the assays and give rise to a clinically unacceptable false-positive rate. Mammaglobin (MAM) and maspin are two putative breast tissue-specific markers frequently used for detection of occult tumour cells in the peripheral blood, bone marrow and lymph nodes of breast cancer patients. In this study, it was evaluated whether MAM and maspin gene expression may be induced in the normal blood and bone marrow cells exposed to a panel of cytokines, including chemotactic factors (C5a, interleukin (IL)-8), LPS, proinflammatory cytokines (TNF-α, IL-1β) and growth factors (IL-3, granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor). The experimental data show that all cytokines included in the panel, except for IL-8, were able to induce maspin expression; on the contrary, MAM gene was never induced. These results suggest that MAM is more specific than maspin and that the possible interference of cytokines should be taken into account in interpreting molecular assays for detection of isolated tumour cells.

Detection of circulating epithelial cells in the blood of patients with breast cancer: comparison of three techniques

This study compares the sensitivities and specificities of three techniques for the detection of circulating epithelial cells in the blood of patients with breast cancer. The number of circulating epithelial cells present in the blood of 40 patients with metastatic breast cancer and 20 healthy volunteers was determined by: immunomagnetic separation (IMS) and laser scanning cytometry (LSC), cell filtration and LSC and a multimarker real-time RT–PCR assay. Numbers of cytokeratin-positive cells identified and expression of three PCR markers were significantly higher in the blood of patients with breast cancer than in healthy volunteers. Using the upper 95% confidence interval of cells detected in controls to determine positive patient samples: 30% of patients with metastatic breast cancer were positive following cell filtration, 48% following IMS, and 60, 45 and 35% using real-time RT–PCR for cytokeratin 19, mammaglobin and prolactin-inducible peptide. Samples were significantly more likely to be positive for at least one PCR marker than by cell filtration (83 vs 30%, P<0.001) or IMS (83 vs 48%, P<0.001).The use of a multimarker real-time RT–PCR assay was therefore found to be the most sensitive technique for the detection of circulating epithelial cells in the blood of patients with breast cancer.

Detection of isolated tumor cells in peripheral blood and in BM: evaluation of a new enrichment method

Cell enrichment methods that deal with larger volumes of peripheral blood and BM are needed for increased sensitivity of detection, characterization and quantification of isolated tumor cells (ITC). This study was designed to evaluate a new procedure, the RosetteSep-Applied Imaging Rare Event (RARE) detection method, which depletes the majority of the erythrocytes and leucocytes in a peripheral blood (PB) sample, thereby negatively enriching tumor cells if present. This enrichment procedure allows for increased sensitivity, by analyzing a 5-10 fold larger volume of blood, compared with a direct immunocytochemical (ICC) technique, with minimal impact on laboratory workload. Model experiments showed comparable tumor cell recoveries between the two tested methods, both in PB and BM. Clinical samples were evaluated using paired PB and BM samples from 95 carcinoma patients. Analysis of PB results showed that 25.3% had > or = 1 tumor cell detected by the RARE procedure, compared with 5.2% after direct ICC analysis, analyzing a 10-fold larger volume by the RARE procedure. The direct ICC analysis of BM from the same patients revealed 16.8% positive. The ITC detection differed both quantitatively and qualitatively between BM and PB, as samples with high numbers of ITC in BM were still negative in PB. The clinical significance of ITC in blood still needs to be established. However, the easy access of peripheral blood, and the increased sensitivity obtained by increasing the sample volume with the RARE procedure, suggests that the value of peripheral blood analysis should be tested in parallel in studies where ITC detection in BM is performed.

Trastuzumab Administration Can Effectively Target Chemotherapy-Resistant Cytokeratin-19 Messenger RNA–Positive Tumor Cells in the Peripheral Blood and Bone Marrow of Patients With Breast Cancer

PURPOSE

The detection of disseminated occult breast cancer cells in peripheral blood and bone marrow is associated with poor prognosis. Since a high proportion of these cells express the HER-2 receptor, we evaluated the effectiveness of the anti-HER-2 antibody trastuzumab (Herceptin) administration to eliminate them.

EXPERIMENTAL DESIGN

Thirty patients with prior chemotherapy exposure were recruited to the study on the basis of having detectable cytokeratin-19 (CK-19) mRNA transcripts by nested reverse transcription (RT)-PCR in the peripheral blood and/or bone marrow. There were 13 patients with stage I, II, or III breast cancer and 17 with stage IV disease. They were treated in two cohorts with either 4 to 8 weekly infusions of trastuzumab at 2 mg/kg (4 mg/kg loading dose; 20 patients) or 2 to 3 infusions every 3 weeks at 6 mg/kg (8 mg/kg loading dose; 10 patients). All of the patients' samples were also analyzed for HER-2 by nested RT-PCR, but detectable HER-2 messenger RNA (mRNA) was not required for inclusion in the study. After trastuzumab infusions, patients were closely monitored by nested RT-PCR and real-time RT-PCR for the detection of CK-19 mRNA-positive cells.

RESULTS

Before trastuzumab infusions, CK-19 mRNA-positive cells were detected in the peripheral blood (n = 10), bone marrow (n = 14), or both (n = 6). In 25 of 30 patients (83%), HER-2 mRNA expression was detected by nested RT-PCR in the pretrastuzumab CK-19-positive sample. After trastuzumab infusions, overall, 28 of 30 (93%) patients became CK-19 mRNA negative by nested RT-PCR and 20 of 30 (67%) by real-time RT-PCR. After a median follow-up of 6 months (range 2 to 22+), the median duration of CK-19 mRNA negativity by nested RT-PCR was 9, 12, and 6 months for stage I/II, III, and IV disease, respectively.

CONCLUSIONS

Therapy-resistant CK-19 mRNA-positive cells in the peripheral blood and bone marrow can be effectively targeted by trastuzumab administration. Further studies are needed to evaluate the prognostic significance of the disappearance of these cells.

Clinical significance of immunocytochemical detection of tumor cells using digital microscopy in peripheral blood and bone marrow of breast cancer patients

PURPOSE

The presence of tumor cells in bone marrow has been reported to represent an important prognostic indicator in breast cancer, but the clinical significance of circulating cells in peripheral blood is less well known. The aim of this study was to evaluate the feasibility of identifying cytokeratin (CK)-expressing cells in peripheral blood with an automat-assisted immunohistochemical detection system and to compare it with detection of tumor cells in bone marrow samples.

EXPERIMENTAL DESIGN

Cytospun Ficoll fractions of peripheral blood and bone marrow were obtained simultaneously in 114 breast cancer patients at different stages of the disease (I to IV) before treatment with chemotherapy. The pancytokeratin (CK) monoclonal antibody A45-B/B3 (anti-CKs 8, 18, and 19) was used for epithelial cell detection. Immunostained cells were detected by an automated cellular imaging system (ChromaVision Medical System).

RESULTS

CK+ cells were detected in 28 (24.5%) patients in blood and in 67 (59%) patients in bone marrow. Twenty-six (93%) patients with CK-positive cells in blood also had positive bone marrow (P < 0.001). Positive cells were detected in peripheral blood in 3/39 (7.5%) operable breast cancers (stage I/II), 9 of 36 (25%) locally advanced breast cancers (stage III), and 16 of 39 (41%) patients with metastatic disease (stage IV; P = 0.017). In the subgroup of nonmetastatic patients (n = 75), prognostic factors for poor disease-free survival were: absence of estrogen receptor; presence of CK+ cells in bone marrow (P = 0.012); clinical nodal involvement; large tumor size (T4); and presence of tumor emboli. Presence of circulating CK+ cells in the peripheral blood was not statistically correlated with disease-free survival. On multivariate analysis, independent indicators for disease-free survival were: absence of estrogen receptor (P = 0.043) and presence of CK+ cells in bone marrow (P = 0.076).

CONCLUSIONS

The clinical relevance of circulating epithelial cells as a prognostic factor is not supported by the present data, especially in comparison with tumor cells in the bone marrow. However, this method of detection may be useful to monitor the efficacy of treatment in advanced or metastatic breast cancer.

Immunocytochemical detection of epithelial cells in the bone marrow of primary breast cancer patients: a meta-analysis

PURPOSE

The immunocytochemical detection of epithelial cells in the bone marrow (BM) of breast cancer (BC) patients has been shown to have prognostic importance in several studies. We conducted a systematic review of the literature and a meta-analysis to assess the specificity, rate of positivity and correlation with known prognostic variables as well as with disease free (DFS) and overall survival (OS).

DESIGN

We performed a systematic review from the published literature. We included studies with at least 20 previously untreated BC patients as well as non-BC controls that evaluated the presence of epithelial cells in BM using immunocytochemistry (IC).

RESULTS

We identified 14 eligible studies with 3253 BC patients and 532 controls. Our results showed that IC has an overall rate of positivity of 31% (95% CI: 30-33%), and specificity of 96% (compared to normal patients) (95% CI: 0.94-0.98). We observed significant direct correlations between IC BM positivity and the primary tumor's presence with expression of estrogen receptors, larger size and higher histologic grade as well as with the presence of more than 3 positive axillary lymph nodes. At 5 years of follow up IC positivity correlated directly with a lower DFS (relative risk=1.60; 95% CI: 1.39-1.83) and OS (relative risk=1.73; 95% CI: 1.29-2.31). The prognostic impact of BM positivity seemed to decrease with time.

CONCLUSIONS

We conclude that the finding of epithelial cells in BM of BC patients correlates with several known prognostic factors and has adverse impact in the DFS and OS of these patients that seems, however, to decrease with time.

Bone marrow micrometastases and circulating tumor cells: current aspects and future perspectives

Early tumor cell dissemination at the single-cell level can be revealed in patients with breast cancer by using sensitive immunocytochemical and molecular assays. Recent clinical studies involving more than 4000 breast cancer patients demonstrated that the presence of disseminated tumor cells in bone marrow at primary diagnosis is an independent prognostic factor. In addition, various assays for the detection of circulating tumor cells in the peripheral blood have recently been developed and some studies also suggest a potential clinical relevance of this measure. These findings provide the basis for the potential use of disseminated tumor cells in bone marrow or blood as markers for the early assessment of therapeutic response in prospective clinical trials.

The detection of circulating breast cancer cells in blood

At present, sampling of the lymph nodes or bone marrow for the detection of regions of metastatic disease in patients with breast cancer can only be undertaken at the time of initial diagnosis and surgery. However, the sampling of these tissues and the methods used are inaccurate, time consuming, and cannot be used for easy routine screening to determine disease recurrence and response to treatment. Because of the problems encountered with current methods and tissues sampled at the time of breast cancer diagnosis, this review discusses the urgent requirement for and potential development of a quick, simple, and accurate diagnostic test utilising the haematogenous system, a source of circulating tumour cells in patients with breast cancer, and highly sensitive molecular biological techniques, such as reverse transcription polymerase chain reaction. In addition, this review also highlights potential problems that may be encountered and should be avoided when devising such a test.

P53and K-rasmutations are frequent events in microscopically negative surgical margins from patients with nonsmall cell lung carcinoma

BACKGROUND

The objective of the current study was to determine whether tumor cells harboring P53 and K-ras mutations could be detected in histopathologically tumor-free surgical margins in patients with nonsmall cell lung carcinoma who underwent complete pulmonary resection.

METHODS

In 118 consecutive patients, DNA obtained from primary tumors and from surgical margins was extracted for molecular analysis. A fragment of P53 gene encompassing exons 5-8 and codon 12 of the K-ras gene were amplified with the polymerase chain reaction technique and were assayed for the presence of mutations.

RESULTS

P53 and K-ras mutations were found in 30% and 39% of primary tumors, respectively, and in 11 (9%) and 22 (18%) apparently tumor-free surgical margins, respectively. At least 1 of those mutations was found in surgical margins in 29 patients (25%), and both mutations were found in 2 patients (1.7%). P53 mutations in surgical margins accompanied mutations in primary tumors in 9 of 35 patients (26%), and K-ras mutations accompanied mutations in primary tumors in 20 of 46 patients (44%). Among patients with either mutation in primary tumors, the incidence of at least 1 mutation in surgical margins was 43% (28 of 65 patients). In four patients, mutations (two K-ras mutations and two P53 mutations) were found in surgical margins despite the absence of the corresponding mutations in primary tumors. The presence of mutations in primary tumors and in surgical margins was not related significantly to clinical characteristics or to patient outcomes.

CONCLUSIONS

P53 and K-ras mutations are frequent events in surgical margins determined to be tumor free on light microscopy. The clinical relevance of these findings remains to be established.

Revision of breast cancer staging: the 6th edition of the TNM Classification

A Breast Task Force comprised of nationally known experts in the field of breast cancer treatment was charged with recommending additions and changes for the 6th edition of the TNM Classification that were based on published evidence and/or were consistent with widespread clinical consensus. Additions made to the staging system were designed to facilitate the uniform collection of clinically relevant information about new techniques for the detection of metastatic cells. These additions include quantitative criteria to distinguish micrometastases from isolated tumor cells, and specific identifiers to record the use of sentinel lymph node biopsy, immunohistochemical (IHC) staining, and molecular biology techniques. Revisions of the previous staging system are related to the number of affected axillary lymph nodes and to the classification of level III axillary lymph nodes and lymph nodes outside of the axilla.

Circulating tumour cells in breast cancer

By use of modern immunological and molecular analytical techniques, cells with the characteristics of tumour cells can be detected in the blood of many patients with breast cancer. The ability to detect and characterise such cells routinely could have a profound influence on the early diagnosis of breast cancer, risk stratification in the adjuvant setting, early detection of relapse, and the development of new targeted strategies. In this review we discuss current techniques to detect circulating breast-cancer cells and the limitations of these approaches. We also review the clinical studies in breast cancer and discuss the potential relevance of this research to the future management of the disorder.

Prognostic Value of Cytokeratin 19 Fragment (CYFRA 21–1) and Cytokeratin-Positive Cells in Bone Marrow Samples of Breast Cancer Patients

The aim of this study was to investigate the relationship between the detection of micrometastatic cells by immunocytochemistry (ICC) with an anticytokeratin antibody and cytokeratin fragment (CYFRA 21–1) expression detected by an immunofluorescent assay in bone marrow of breast cancer patients. Micrometastatic CK+ cells were screened with a pancytokeratin antibody A45 B/B3 from bone marrow aspiration samples of 102 breast cancer patients (65 primary tumors, 10 local recurrences and 27 distant metastases). CYFRA 21-1 levels were assessed in bone marrow supernatant of these patients before collection of the mononucleated interface cells on a Ficoll-Hypaque density gradient and in 20 control patients. CYFRA 21-1 and CK+ cell detection by ICC were both correlated with clinical stage. CYFRA 21-1 was significantly elevated in patients with micrometastatic disease detected by ICC: 4.77 ng/mL (± 10.87 SD) versus 1.00 ng/mL (± 1.36 SD) in patients with negative ICC (p=0.01). In univariate analysis, a CYFRA 21-1 value ≥1 ng/mL and the presence of CK+ cells were associated with a poorer survival for patients with stage I to III breast cancer (n=65). On multivariate analysis, only pathological nodal status and presence of CK+ cells in bone marrow were independent prognostic factors for overall survival. In conclusion, in this series CYFRA 21-1 was correlated with detection of CK+ cells by ICC in bone marrow, but cannot replace ICC. The presence of CK+ cells in bone marrow remains a strong independent prognostic factor in primary breast cancer.

Real-time quantitative RT-PCR and detection of tumour cell dissemination in breast cancer patients: plasmid versus cell line dilutions

BACKGROUND

We previously developed a real-time quantitative RT-PCR technique to detect breast carcinoma cells in peripheral blood (PB). The aim of the current study was to improve cytokeratin 19 (CK19) quantification using plasmid dilutions of cloned PCR fragments to obtain a more reliable and reproducible quantification of CK19 transcripts.

MATERIALS AND METHODS

PB samples of 14 stage IV breast cancer patients and 23 healthy controls were examined with RT-PCR using plasmid quantification.

RESULTS

Median CK19+ copy numbers of one and 11 were detected in the control group and stage IV breast cancer patients, respectively (Mann-Whitney, P </=0.0001). When comparing the results obtained using cell line dilutions with those obtained using plasmid dilutions, a good correlation was observed (r(2) = 0.98).

CONCLUSIONS

Plasmid dilutions are more reliable than cell line dilutions for quantification of gene expression, and more objective criteria for positivity could be defined based on the characteristics of the standard curve (slope and intercept). A more universally accepted agreement on the definition of the cut-off value for positivity is needed.

Peripheral blood circulating cytokeratin-19 mRNA-positive cells after the completion of adjuvant chemotherapy in patients with operable breast cancer

BACKGROUND

The purpose of this study was to evaluate the prognostic significance of the molecular detection of cytokeratin 19 (CK-19) mRNA-positive cells in the peripheral blood of women with operable breast cancer after the completion of adjuvant chemotherapy.

PATIENTS AND METHODS

Blood from 161 patients with stage I and II breast cancer, obtained after the completion of adjuvant chemotherapy, was tested by nested RT-PCR for CK-19 mRNA detection. Using univariate and multivariate analyses possible interactions with other prognostic factors and association of CK-19 mRNA detection with risk of relapse, disease-free interval (DFI) and overall survival were investigated.

RESULTS

After completion of adjuvant chemotherapy, 27.3% of patients had peripheral blood CK-19 mRNA-positive cells; there was no association of this finding with any other prognostic factors or the type of chemotherapy regimen used. For patients with less than four involved axillary lymph nodes the risk of relapse was 3.81 [95% confidence interval (CI) 1.06-13.71] times higher, and the DFI was significantly reduced (P = 0.028) if CK-19 mRNA-positive cells were detectable in the blood after the completion of adjuvant chemotherapy. In contrast, for patients with four or more involved lymph nodes, the presence of CK-19 mRNA-positive cells after adjuvant chemotherapy did not significantly affect the risk of relapse or DFI. Furthermore, the risk of relapse was higher (hazards ratio 3.70; 95% CI 1.09-13.89) and the DFI was reduced (P = 0.022) for patients with detectable CK-19 mRNA-positive cells following adjuvant cyclophosphamide, methotrexate and 5-fluorouracil (CMF) as compared with epirubicin, cyclophosphamide and 5-fluorouracil (FEC) or sequential taxotere-epirubicin and cyclophosphamide (T/EC) chemotherapy.

CONCLUSIONS

The detection of CK-19 mRNA-positive cells in the peripheral blood after adjuvant chemotherapy may be of clinical relevance for patients with early breast cancer and less than four involved axillary lymph nodes.

Assessment of highly angiogenic and disseminated in the peripheral blood disease in breast cancer patients predicts for resistance to adjuvant chemotherapy and early relapse

The assessment of tumor molecular features in combination with the detection of occult malignant cells may provide important clinical information, beyond the standard staging of breast cancer. Using a nested RT-PCR technique, we assessed prospectively the presence of cytokeratin-19 (CK19) mRNA positive cells in the blood of 100 operated patients with breast cancer before the initiation of adjuvant chemotherapy and local radiotherapy. Tissue samples were prospectively collected and analyzed for estrogen (ER) and progesterone (PgR) receptor, c-erbB-2 overexpression, mutant-p53 and bcl-2 protein accumulation, proliferation index and microvessel density (MVD). CK-19 mRNA-positive cells were detected in the peripheral blood of 33% of patients. Simultaneous display of high intratumoral MVD and of CK-19 mRNA-positive cells, which characterized highly angiogenic and disseminated in the peripheral blood (HAD) disease was noted in 25% of patients. Detection of CK-19 positive cells was significantly associated with increased MVD (p = 0.002). In univariate analysis (median follow-up 30 months) CK19 mRNA detection and MVD were the most significant factors related to a short relapse-free survival (RFS), (p < 0.0001). In multivariate analysis, CK19 positivity, high MVD and c-erbB-2 overexpression were the only significant and independent variables associated with relapse (p = 0.0005, 0.03 and 0.04, respectively). Patients with HAD had an expected relapse rate close to 70% vs. <5% in the remaining patients irrespectively of the used chemotherapy regimen. The simultaneous presence of high MVD and CK19-positive cells in the blood of patients with early breast is linked with poor prognosis, which cannot be improved with standard chemotherapy regimens.