Molecular detection of micrometastatic breast cancer in histopathology-negative axillary lymph nodes correlates with traditional predictors of prognosis: an interim analysis of a prospective multi-institutional cohort study

The Enigma of Mammaglobin: Redefining the Biomarker Paradigm in Breast Carcinoma

The continuous evolution of cancer biology has led to the discovery of mammaglobin, a potential novel biomarker for breast carcinoma. This review aims to unravel the enigmatic aspects of mammaglobin and elucidate its potential role in redefining the paradigm of breast carcinoma biomarkers. We will thoroughly examine its expression in tumoral and peritumoral tissues and its circulating levels in the blood, thereby providing insights into its possible function in cancer progression and metastasis. Furthermore, the potential application of mammaglobin as a non-invasive diagnostic tool and a target for personalized treatment strategies will be discussed. Given the increasing incidence of breast carcinoma worldwide, the exploration of novel biomarkers such as mammaglobin is crucial in advancing our diagnostic capabilities and treatment modalities, ultimately contributing to improved patient outcomes.

Global DNA 5hmC and CK195hmC+ Contents: A Promising Biomarker for Predicting Prognosis in Small Hepatocellular Carcinoma

Background: 5-Hydroxymethylcytosine (5hmC) with dynamic existence possesses multiple regulatory functions. Whereas, 5hmC’s impact on small hepatocellular carcinoma (SHCC) remains unclear. The present work focused on characterizing 5hmC content within SHCC and assessing the possibility of using global genomic 5hmC level as the predicative factor of clinical outcome. Methods: This study applied ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in measuring 5mC, 5fC and 5hmC contents. In addition, immunohistochemistry (IHC) was adopted to measure CK19 and 5hmC contents. Results: Research showed 5mC, 5hmC, and 5fC contents from global genomics of SHCC reduced extensively compared with healthy samples (p < 0.001). Moreover, SHCC was associated with lymph node metastasis (LNM). Greater 5mC and 5hmC levels were observed in non-metastasis group compared with the metastasis group (p < 0.001). Correlation analysis between the HBV DNA level and 5mC, 5fC and 5hmC levels exhibited that HBV DNA was associated with 5mC, 5hmC, and 5fC content reduction, which was verified in the cytological experiments. Moreover, 5hmC content had a negative correlation with the expression level of CK19 in SHCC. The decrease in 5hmC and CK19 containing 5hmC positive cell (called CK19^5hmC+) should be ascribed to the bad prognosis among SHCC patients. Conclusions: The contents of 5hmC and CK19^5hmC+ of genomic DNA might be adopted for predicting SHCC survival as an important biomarker.

Methylselenol producing selenocompounds enhance the efficiency of mammaglobin-A peptide vaccination against breast cancer cells

Previous phase I DNA-vaccine based clinical trials using Mammaglobin-A (Mam-A), a human breast tumor associated antigen (TAA), demonstrated that this agent was safe and efficient at treating patients with stage IV breast cancer. The long-term success of cancer vaccines is limited by the diminished expression of human leukocyte antigen (HLA) class I molecules in the tumor microenvironment. The current study assessed the impact of various selenocompounds on the expression of HLA class I molecules in THP-1 cells, an apparent proficient antigen that presents a human monocyte-like cell line, and their eventual activation of MamA2.1 (HLA-A2 immunodominant epitope of Mam-A) specific cytotoxic CD8⁺ T lymphocytes (CTLs). The results revealed that, following treatment with methylselenol producing compounds [methylselenic acid (MSA) and dimethylselenide (DMDSe)], the expression of HLA class-I was increased and components involved with the antigen presentation machinery of THP-1 cells were upregulated. Furthermore, CTLs activated by MamA2.1 peptide presenting THP-1 cells, pre-treated with MSA and DMDSe, demonstrated an enhanced cytotoxicity in HLA-A2⁺/Mam-A⁺ AU565 and UACC-812 breast cancer cell lines when compared with CTLs activated by THP-1 cells without drug treatment. However, no significant cytotoxicity was observed under similar conditions in HLA-A2⁺/Mam-A^- MCF-7 and MDA-MB-231 breast cancer cell lines. The results indicated that treatment with methylselenol producing compounds retained antigen-dependent activation of CD8⁺ T cells. The data of the current study demonstrated that MSA and DMDSe potentiated effector cytotoxic responses following TAA specific activation of CTLs, indicating their future role as vaccine adjuvants in cancer immunotherapy.

Oligodeoxynucleotides ODN 2006 and M362 Exert Potent Adjuvant Effect through TLR-9/-6 Synergy to Exaggerate Mammaglobin-A Peptide Specific Cytotoxic CD8+T Lymphocyte Responses against Breast Cancer Cells

Mammaglobin-A (MamA) is overexpressed in 40–80% of all human breast cancers. Recent phase I clinical trials of the MamA DNA vaccine showed encouraging safety outcomes. However, this vaccine elicited only a modest increase in MamA specific CD8+T lymphocyte (CTL) activation. As vaccine adjuvants play a critical role in enhancing the immunotherapeutic efficiency of vaccines, we tested the potential role of three synthetic CpG oligodeoxynucleotides (ODN2216—class A ODN, ODN2006—class B ODN, and ODN M362—class C ODN) to further enhance MamA specific CTL responses. Towards this, naïve CD8+T cells were obtained from healthy HLA-A2+ human donors. The HLA-A2 specific immunodominant epitope of MamA, MamA2.1 (LIYDSSLCDL), was utilized to activate naïve CD8+T cells. The THP-1 (HLA-A2+) cells were used as antigen presenting cells to stimulate naïve CD8+T cells along with (or without) co-treatment of various ODNs mentioned above. Activation of naïve CD8+T cells with the MamA2.1 peptide along with ODNs demonstrated enhanced MamA specific CTL mediated cytotoxicity on AU565 (HLA-A⁺/MamA⁺) breast cancer cells following co-treatment with ODN2006 and M362 compared to ODN2216 or MamA2.1 peptide alone. However, no significant cytotoxicity was noted upon treatment of MamA2.1 activated CTLs on MCF7 (HLA-A⁺/MamA⁻) cells, suggesting that the activation of CTLs is specific to the MamA antigen. Functional characterization studies demonstrated specific IL-12 mediated cross-talk between TLR-6 and -9 in THP-1 cells following stimulation with ODN2006 and M362, which was critical for the final cytotoxic activation of CD8+T lymphocytes. Based on these data, we conclude that ODN2006 and ODN M362 exerted a strong adjuvant effect through induction of the initial innate immune response through TLR9 upregulation followed by enhanced MamA specific CTL dependent adaptive immune responses. Our current data provide evidence for the application of Class-B/-C-CpG-ODNs as potential vaccine adjuvants towards enhancing the success of MamA based breast cancer vaccination.

Real-Time Reverse-Transcription PCR to Quantify a Panel of 19 Genes in Breast Cancer: Relationships with Sentinel Lymph Node Invasion

At the Centre Oscar Lambret, the anticancer centre of the North of France, sentinel lymph node (SLN) procedures are routinely performed for localized (T0–T1, N0, M0) breast carcinoma without any previous treatment, in order to prevent the deleterious effects of axillary lymph node dissection. The present study was undertaken to assess if the expression in the tumor of a panel of 19 genes would allow to predict histological SLN involvement. We looked at cytokeratin 19 (CK19), mucin-1 (MUC1), mammaglobin (MGB1), cyclin D1 (CCND1), the four members of the HER/ErbB growth factor receptor family (EGFR, HER2–4), insulin-like growth factor-1 receptor (IGF-1R), estradiol receptors (ERcx, ERβ), progesterone receptor (PR), vascular endothelial growth factors (VEGF, VEGF-C), urokinase-like plasminogen activator (uPA), matrix metalloproteinases 2 and 9 (MMP2, MMP9), ets-related transcription factor ERM, and E-cadherin (CDH1). Their expression was quantified by real-time RT-PCR in 134 breast cancer samples and the relationships with SLN metastases were analyzed. A slight increase (35–40%) in CK19 and HER3 expression was observed in the tumors of patients with SLN metastases compared to those of patients without metastases, even if neither CK19 expression nor HER3 expression allowed to distinguish patients with micrometastases from patients with macrometastases. We conclude that the tumoral expression of biological parameters involved in cell proliferation or playing a critical role in the metastatic process, including tumor invasion and angiogenesis, is not strongly associated with SLN metastases.

Metas-Chip precisely identifies presence of micrometastasis in live biopsy samples by label free approach

Detecting the micrometastasis is a major challenge in patients’ survival. The small volume of the biopsied tissue results in limited number of histopathological samples and might reduce the rate of accurate diagnosis even by molecular technologies. We introduce a microelectronic biochip (named Metas-Chip) to detect the micrometastasis in unprocessed liquid or solid samples. It works based on the tendency of malignant cells to track single human umbilical vein endothelial cell (HUVEC)-sensing traps. Such cells detach themselves from the biopsied sample and invade the sensing traps by inducing membrane retraction and blebbing, which result in sharp changes in electrical response of the sensing elements. Metas-Chip identified the metastasis in more than 70 breast cancer patients, in less than 5 h. Moreover it detected the metastasis in lymph nodes of nine patients whom were missed by conventional pathological procedure. Multilevel IHC and real-time polymerase chain reaction (RT-PCR) tests confirmed the diagnosis.

Detecting metastatic cells in tumor/lymph node samples of breast cancer patients is extremely important for diagnosis. Here the authors develop a microelectronic biochip that detect the presence of invasive/metastatic cells in unprocessed biopsies and performs better than the current gold standards.

Comparative analysis of CD4+ and CD8+ T cells in tumor tissues, lymph nodes and the peripheral blood from patients with breast cancer

Background: CD4+ and CD8+ T cells are the main types of lymphocytes in cell-mediated immunity and play a central role in the induction of efficient immune responses against tumors. The frequencies of T cell subtypes in the peripheral blood and tumor tissues, and draining lymph nodes (dLN) can be considered as useful markers for evaluation of the immune system in cancers. Methods: In this study, the frequencies of CD4+ and CD8+ T cells in blood, tumor tissues, and dLN samples of breast cancer patients were compared with each other and with similar tissues from normal individuals. Immunophenotyping was carried out by flow cytometry and the expression levels of CXCL10, granzyme B, and mammaglobin were evaluated by real-time PCR. Results: In the peripheral blood, there were no differences in the T cell subsets between the patients and the normal individuals. The frequency of CD8+ T cells was significantly higher in tumor tissue than normal breast tissues while granzyme B expression was similar. Based on mammaglobin expression levels, dLN have been classified into micro- and macro-metastatic dLN. We found significantly lower frequency of CD4+ in macro-metastatic dLN than micro-metastatic dLN. CD8+ frequency was similar in both dLN; however, granzyme B expression was higher in micro-metastatic ones. There was not any significant difference in CXCL10 expression between the two types of dLN. Conclusion: Based on our results, although the tumor does not affect the systemic immunity, tumoral cells affect the local immune system in the tumoral tissues and the metastatic dLN.

An improved axillary staging system using the OSNA assay does not modify the therapeutic management of breast cancer patients

The one-step nucleic acid amplification (OSNA) assay is a molecular procedure that can identify deposits of breast cancer (BC) cells in the sentinel lymph node (SLN). We examined the consistency of the OSNA assay with a classic hematoxylin-eosin (H&E)-based immunohistochemistry (IHC) study and evaluated how OSNA-based axillary staging might impact the therapeutic management of BC patients. SLN biopsy results were considered to be positive in 60 patients (40%) in the OSNA group (N = 148) and in 43 (28%) patients in the IHC cohort (N = 153, p = 0.023). There was no difference in the macrometastasis (22% for OSNA, 15% for H&E, p = 0.139) or micrometastasis (19% for OSNA, 13% for H&E, p = 0.166) rates, but we found statistically significant differences in the number of isolated tumor cells (1% for OSNA, 11% for H&E, p < 0.001). There were no differences in the administration rate of adjuvant systemic therapy between the OSNA (66% in the SLN(+) patients) and the H&E (74% in the SLN(+) patients) groups (p = 0.159). The OSNA assay allows for the detection of SLN metastases more precisely than conventional pathologic methods but does not alter the therapeutic management of SLN(+) BC patients.

Treatment of sentinel node-positive breast cancer

Sentinel node biopsy has become well accepted as a minimally invasive means of accurately staging the axilla in breast cancer patients. Patients with metastases in the sentinel node(s) have traditionally proceeded to completion of axillary node dissection, whereas patients who are node negative can be spared the morbidity of this procedure. Recently, there has been some debate as to what constitutes node-positive disease and whether patients with metastasis in the sentinel node(s) require completion axillary dissection. This review addresses the controversies regarding the management of sentinel node-positive breast cancer patients.

Intra-operative use of one-step nucleic acid amplification (OSNA) for detection of the tumor load of sentinel lymph nodes in breast cancer patients

BACKGROUND

The purpose of this single-center study was to determine the practicability of the intra-operative use of one-step nucleic acid amplification (OSNA) as the only method for detection of SLN. The OSNA system has been well described and is supposed to be as accurate as conventional histology.

METHODS

Three hundred and thirty SLNs from 143 breast cancer patients were analyzed in an intra-operative setting. The CK19-copy number was determined by OSNA and divided into 3 results ("-" no metastasis; "+" micrometastasis; "++" marcometastasis). If OSNA gave a positive result, an axillary lymph node dissection was carried out during the same session. The central 1-mm slice of each node was obtained for permanent histology. Additionally, the results were correlated to clinicopathological factors, and the time for the intra-operative use was evaluated.

RESULTS

Thirty-nine of the 143 patients were OSNA positive, 22 with macrometastatic and 17 with micrometastatic spread. The mean time for the OSNA run with one SLN was 34.4 min. We could show a correlation between the tumor size and OSNA positivity as well as between the numbers of OSNA positive SLNs with the tumor load of associated non-SLNs. Furthermore, we found that a cutoff CK19 copy number of 7,900/μL indicates a positive non-SLN result with the highest sensitivity (91 %) and specificity (61 %).

CONCLUSION

We found OSNA to be very helpful for the intra-operative determination of the tumor load of a SLN as a basis for decision-making concerning further surgical axillary intervention. OSNA allows precise differentiation of micro- from macrometastasis, and the CK19 copy number predicts the probability of tumor load in other axillary lymph nodes and might help to find adequate adjuvant treatment options. This objective method is well suitable for everyday use and may reduce the pathologic workload and the risk of secondary operative interventions with all associated costs and stress for the patients.

Is transplantation of cryopreserved ovarian tissue from patients with advanced-stage breast cancer safe? A pilot study

PURPOSE

To assess the safety of reimplantation of cryopreserved ovarian tissue from advanced-stage breast cancer patients.

METHODS

Cryopreserved ovarian cortical fragments were obtained from 13 advanced-stage breast cancer patients aged 17-35 years. After thawing, part of the ovarian cortical tissue was grafted to severe combined immunodeficient mice for 6 months. The presence of malignant mammary cells in ovarian tissue was evaluated after thawing as well as after grafting by 1) histology and immunohistochemistry (epithelial membrane antigen, Her2/neu and gross cystic disease fluid protein 15 identification), and 2) detection of the MGB2 gene by qPCR.

RESULTS

No malignant cells were evidenced by histology and immunohistochemistry. None of the mice died during the 6-month grafting period, nor developed macroscopically visible masses. MGB2 gene expression was detected by qPCR and confirmed by sequencing in frozen-thawed ovarian tissue in 4 cases and in grafts in 1 case.

CONCLUSIONS

This pilot study is the first to evaluate the risk of contamination of cryopreserved ovarian tissue from advanced-stage breast cancer patients by xenotransplantation for 6 months to immunodeficient mice, associated with more conventional screening methods. Our xenografting results are reassuring, but caution needs to be exercised, as MGB2 gene expression was detected in some cases. Larger numbers of ovarian tissue samples from patients with advanced-stage breast cancer are required to confirm our findings before ovarian tissue transplantation can be contemplated in these patients.

Potential applications of quantum dots in mapping sentinel lymph node and detection of micrometastases in breast carcinoma

Breast cancer cure aims at complete elimination of malignant cells and essentially requires detection and treatment of any micrometastases. Here, we present a review of the current methods in use and the potential role of the quantum dots (QDs) in detection and visualization of sentinel lymph node and micrometastases in breast cancer patients. The traditional histopathological, immunohistochemical, and reverse transcriptase polymerase chain reaction procedures being used for micrometastases detection had serious drawbacks of high false negativity, specificity variations and false positivity of the results. Photon emission fluorescence multiplexing characteristics of the quantum dots make them potentially ideal probes for studying the dynamics of cellular processes over time such as continuous tracking of cell migration, differentiation, and metastases. In breast cancer, QDs based molecular and genomic detections had an unparallel high sensitivity and specificity.

Immunohistochemical characterization of neoplastic cells of breast origin

Background

After skin cancer, breast cancer is the most common malignancy in women. Tumors of unknown origin account for 5-15% of malignant neoplasms, with 1.5% being breast cancer. An immunohistochemical panel with conventional and newer markers, such as mammaglobin, was selected for the detection of neoplastic cells of breast origin. The specific objectives are: 1) to determine the sensitivity and specificity of the panel, with a special emphasis on the inclusion of the mammaglobin marker, and 2) to compare immunohistochemistry performed on whole tissue sections and on Tissue Micro-Array.

Methods

Twenty-nine metastatic breast tumors were included and assumed as tumors of unknown origin. Other 48 biopsies of diverse tissues were selected and assumed as negative controls. Tissue Micro-Array was performed. Immunohistochemistry for mammaglobin, gross cystic disease fluid protein-15, estrogen receptor, progesterone receptor and cytokeratin 7 was done.

Results

Mammaglobin positive staining was observed in 10/29 cases, in 13/29 cases for gross cystic disease fluid protein-15, in 20/29 cases for estrogen receptor, in 9/29 cases for progesterone receptor, and in 25/29 cases for cytokeratin 7. Among the negative controls, mammaglobin was positive in 2/48, and gross cystic disease fluid protein-15 in 4/48.

Conclusions

The inclusion of MAG antibody in the immunohistochemical panel for the detection of tumors of unknown origin contributed to the detection of metastasis of breast cancer. The diagnostic strategy with the highest positive predictive value (88%) included hormone receptors and mammaglobin in serial manner.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1366310812718988

Detection of prolactin inducible protein mRNA, a biomarker for breast cancer metastasis, using a molecular beacon-based assay

Mortality due to breast cancer is increasingly linked to early, undetected metastasis, making methods for earlier detection acutely necessary. We describe the development of an assay based on molecular beacon (MB) chemistry with fluorescence detection to monitor a breast cancer biomarker for the analysis of breast cancer metastasis. The MB assay is based on the complementary base-pairing interactions of the MB nucleic acid with mRNA indicative of breast cancer metastasis. The presence of mRNA is characterized by an increase in the fluorescence intensity of the molecular beacon. The assay gives a linear, reproducible response to prolactin inducible protein mRNA, with a limit of detection in the high picomolar range. This method sensitively and specifically identifies a biomarker directly in serum samples in minimal time and with a straightforward procedure, dramatically reducing the total time for sample analysis over current methods from days to hours. The potential impact of this work in detection and understanding of breast cancer metastasis lies in improvements in simplicity, accuracy, and speed over current methods, which could allow for improved patient treatment and prognoses. Ultimately, additional sample throughput will result in better understanding of disease progression.

Mammaglobin-A cDNA vaccination of breast cancer patients induces antigen-specific cytotoxic CD4+ICOShi T cells

Mammaglobin-A (Mam-A) is a 10 kDa secretory protein that is overexpressed in 80 % of primary and metastatic human breast cancers. Previous studies from our laboratory demonstrated that Mam-A cDNA vaccine can induce Mam-A-specific CD8 T cell responses and mediate regression of human breast cancer xenografts in NOD/SCID mice. In this article, we present our results on a phase I clinical trial of a Mam-A cDNA vaccination in breast cancer patients with stage-IV metastatic disease, including the impact of vaccination on the expression of the inducible co-stimulator molecule (ICOS) on CD4 T cells. Specimens from seven patients with stage-IV metastatic cancer were available for these analyses. Patients were vaccinated with a Mam-A cDNA vaccine on days 0, 28, and 56, and immune responses were assessed at serial time points following vaccination. At 6 months following the first vaccination, flow cytometric analysis demonstrated a significant increase in the frequency of CD4+ICOS(hi) T cells from 5 ± 2 % pre-vaccination to 23 ± 4 % (p < 0.001), with a concomitant decrease in the frequency of CD4+FoxP3+ T cells (regulatory T cells [Treg]) from 19 ± 6 to 10 ± 5 % (p < 0.05). ELISpot analysis of CD4+ICOS(hi) sorted T cells demonstrated that following vaccination the cytokines produced by Mam-A-specific T cells switched from IL-10 (78 ± 21 spm pre-vaccination to 32 ± 14 spm 5 months post-vaccine p < 0.001) to IFN-γ (12 ± 6 spm pre-vaccination to 124 ± 31 spm 5 months post-vaccine p < 0.001). The ratio of CD4+ICOS(hi) T cells to CD4+FoxP3+ T cells increased from 0.37 ± 0.12 before vaccination to 2.3 ± 0.72 (p = 0.021) following vaccination. Further, these activated CD4+ICOS(hi) T cells induced preferential lysis of human breast cancer cells expressing Mam-A protein. We conclude that Mam-A cDNA vaccination is associated with specific expansion and activation of CD4+ICOS(hi) T cells, with a concomitant decrease in Treg frequency. These encouraging results strongly suggest that Mam-A cDNA vaccination can induce antitumor immunity in breast cancer patients.

Diagnostic performance of one-step nucleic acid amplification for intraoperative sentinel node metastasis detection in breast cancer patients

The purpose of this prospective multicenter study was to assess one-step nucleic acid amplification (OSNA) for intraoperative sentinel lymph node (SLN) metastasis detection in breast cancer patients, using final histology as the reference standard. OSNA results were also compared to intraoperative histology SLN evaluation and to standard clinicopathological risk markers. For this study, fresh SLNs were cut in four blocks, and alternate blocks were used for OSNA and histology. CK19 mRNA copy number was categorized as strongly positive, positive or negative. Positive histology was defined as presence of macrometastasis or micrometastasis. When discrepancies occurred, the entire SLNs were subjected to histological studies and the node lysates to additional molecular studies. Five hundred three SLN samples from 233 patients were studied. Mean time to evaluate two SLNs was 40 min. Sensitivity per patient was 91.4% (95% CI, 76.9-98.2%), specificity 93.3% (95% CI, 88.6-96.6%), positive likelihood ratio 13.7 and negative likelihood ratio 0.1. Sensitivity was 63.6% for frozen sections and 47.1% for touch imprint cytology. Both methods were 100% specific. Positive histology and positive OSNA were significantly associated with highest clinical stage, N1 status and vascular invasion; and OSNA results correlated with HER2/neu status and benefited patients with negative histology. These findings show that OSNA assay can allow detection of SLN metastasis in breast cancer patients intraoperatively with a good sensitivity, thus minimizing the need for second surgeries for axillary lymph node detection.

Ratio between positive lymph nodes and total excised axillary lymph nodes as an independent prognostic factor for overall survival in patients with nonmetastatic lymph node-positive breast cancer

BACKGROUND.: The status of the axillary lymph nodes in nonmetastatic lymph node-positive breast cancer (BC) patients remains the single most important determinant of overall survival (OS). Although the absolute number of nodes involved with cancer is important for prognosis, the role of the total number of excised nodes has received less emphasis. Thus, several studies have focused on the utility of the axillary lymph node ratio (ALNR) as an independent prognostic indicator of OS. However, most studies suffered from shortcomings, such as including patients who received neoadjuvant therapy or failing to consider the use of adjuvant therapy and tumor receptor status in their analysis. METHODS.: We conducted a single-center retrospective review of 669 patients with nonmetastatic lymph nodepositive BC. Data collected included patient demographics; breast cancer risk factors; tumor size, histopathological, receptor, and lymph node status; and treatment modalities used. Patients were subdivided into four groups according to ALNR value (<.25, .25-.49, .50-.74, .75-1.00). Study parameters were compared at the univariate and multivariate levels for their effect on OS. RESULTS.: On univariate analysis, both the absolute number of positive lymph nodes and the ALNR were significant predictors of OS. On multivariate analysis, only the ALNR remained an independent predictor of OS, with a 2.5-fold increased risk of dying at an ALNR of ≥.25. CONCLUSIONS.: Our study demonstrates that ALNR is a stronger factor in predicting OS than the absolute number of positive axillary lymph nodes.

Expression of CK19 in invasive breast carcinomas of special histological types: implications for the use of one-step nucleic acid amplification

BACKGROUND

The sentinel lymph node (SLN) is the first lymph node to receive the lymphatic drainage of a primary tumour; based on the knowledge that CK19 is positive in more than 95% of breast carcinomas, a molecular method for intraoperative diagnosis of SLN metastases (the one-step nucleic acid amplification (OSNA) assay) was developed.

AIMS

To evaluate CK19 immunoreactivity in a series of special histological types of breast carcinoma in order to verify whether the OSNA assay can be used in all breast cancer cases independently of the histological type.

METHODS

116 samples of invasive breast carcinomas of special type were investigated for CK19 immunoreactivity in tissue microarrays (TMA); negative cases were evaluated in the entire tissue tumour tissue.

RESULTS

Of the 116 cases, 88.9% were positive CK19. Micropapillary and apocrine carcinomas were all positive for CK19 in TMAs. The tubular (93%), mucinous (86%), medullary typical and atypical (84%), mixed carcinomas (83%) increased the rate of positivity for this marker to 100% after repeating the immunostain in whole tissue of negative TMA cases, because the expression of those cases was focal.

CONCLUSION

Most breast cancer cases were positive for CK19, independent of the histological type; therefore the OSNA assay can be used in all breast cancer cases with a potential low rate of false negative for CK19 detection of micrometastasis. There is an important variation between the positivity assessed on TMAs and the entire tissue; these findings can be clinically relevant because in some cases CK19 is evaluated on core-needle biopsy prior to surgery.

Detection of lymph node involvement by cytokeratin immunohistochemistry is an independent prognostic factor after curative resection of esophageal cancer

BACKGROUND

Involved lymph nodes (LN) are a negative prognostic factor in esophageal cancers. To assess the role of nodal micrometastases, we performed immunohistochemical analyses of LN after resection of node-negative esophageal cancers and correlated the results with survival.

METHODS

Seventy patients with esophageal cancer after curative resection and conventionally negative nodes were included. The LN were examined with six consecutive sections (three hematoxylin and eosin (HE) stained and three stained immunohistochemically with the cytokeratin (CK) antibodies AE1/AE3). Survival was evaluated uni- and multivariately. Median follow-up was 4.1 years.

RESULTS

Immunohistochemical analysis showed CK-positive LN in 16 (23%) patients. Of those 16 cases with CK-positive LN, nine had aviable macrometastases, ten had CK-positive scars/fibrosis and five had viable micrometastases. All patients with aviable macrometastases or CK-positive scars/fibrosis had undergone neoadjuvant chemoradiation. Five-year survival was 48% in all patients. In univariate analysis, survival was worse in patients with CK-positive LN (5-year survival of 30% vs. 54% in CK-negative LN; p < 0.02) and in patients with squamous cell carcinoma (5-year survival of 38% vs. 75% in adenocarcinoma; p = 0.05). Multivariate analysis revealed CK-positive LN (p = 0.02) and (borderline) squamous cell carcinoma (p = 0.06) as negative prognostic factors.

CONCLUSIONS

The immunohistochemical analysis of LN may detect (viable or non-viable) tumor cells in lymph nodes after resection of conventionally node-negative esophageal cancers. Conventional pathological analysis by HE, therefore, understages esophageal cancer in these cases. The detection of CK-positive cells in resected LN is an independent prognostic factor in otherwise LN-negative esophageal cancer.

Intraoperative assessment of sentinel lymph nodes in breast cancer

BACKGROUND

Sentinel lymph node biopsy (SLNB) reduces the morbidity of axillary clearance and is the standard of care for patients with clinically node-negative breast cancer. The ability to analyse the sentinel node during surgery enables a decision to be made whether to proceed to full axillary clearance during primary surgery, thus avoiding a second procedure in node-positive patients.

METHODS

Current evidence for intraoperative sentinel node analysis following SLNB in breast cancer was reviewed and evaluated, based on articles obtained from a MEDLINE search using the terms 'sentinel node', 'intra-operative' and 'breast cancer'.

RESULTS AND CONCLUSION

Current methods for evaluating the sentinel node during surgery include cytological and histological techniques. Newer quantitative molecular assays have been the subject of much recent clinical research. Pathological techniques of intraoperative SLNB analysis such as touch imprint cytology and frozen section have a high specificity, but a lower and more variably reported sensitivity. Molecular techniques are potentially able to sample a greater proportion of the sentinel node, and could have higher sensitivity.

Snook KL, Layer GT, Jackson PA, de Vries CS, Shousha S, Sinnett HD, Nigar E, Singhal H, Chia Y, Cunnick G, Kissin MW. Multicentre evaluation of intraoperative molecular analysis of sentinel lymph nodes in breast carcinoma

Background

Ideally, intraoperative sentinel lymph node (SLN) analysis in breast cancer should be automated, have high concordance with extensive histopathology, and be applicable in any hospital setting. A prospective multicentre evaluation of the one-step nucleic acid amplification (OSNA) automated molecular diagnostic system of SLN analysis was undertaken.

Methods

Intraoperative examination of SLNs from 204 patients with breast cancer was performed by OSNA at four sites in the UK. Half of each SLN was assessed by OSNA (for cytokeratin 19 mRNA) and the remaining half was paraffin embedded for intensive histological examination at ten levels. Discordant cases were reanalysed by further molecular biological techniques and by additional histological examination of all remaining nodal material to ascertain whether the discordance was due to an uneven distribution of metastases, known as tissue allocation bias (TAB).

Results

After exclusion of samples affected by TAB, the overall concordance rate for OSNA versus histopathology was 96·0 per cent, with a sensitivity of 91·7 per cent and a specificity of 96·9 per cent. The median time to process a single SLN was 32 (range 22–97) min, and that for two nodes 42 (30–73) min.

Conclusion

OSNA enables accurate automated intraoperative diagnosis and can be used successfully in different UK hospitals. When the SLN is shown to be positive, the patient can undergo immediate axillary clearance under the same anaesthetic rather than having a delayed second procedure.

Ratio between positive lymph nodes and total excised axillary lymph nodes as an independent prognostic factor for overall survival in patients with nonmetastatic lymph node-positive breast cancer

BACKGROUND

The status of the axillary lymph nodes in nonmetastatic lymph node-positive breast cancer (BC) patients remains the single most important determinant of overall survival (OS). Although the absolute number of nodes involved with cancer is important for prognosis, the role of the total number of excised nodes has received less emphasis. Thus, several studies have focused on the utility of the axillary lymph node ratio (ALNR) as an independent prognostic indicator of OS. However, most studies suffered from shortcomings, such as including patients who received neoadjuvant therapy or failing to consider the use of adjuvant therapy and tumor receptor status in their analysis.

METHODS

We conducted a single-center retrospective review of 669 patients with nonmetastatic lymph nodepositive BC. Data collected included patient demographics; breast cancer risk factors; tumor size, histopathological, receptor, and lymph node status; and treatment modalities used. Patients were subdivided into four groups according to ALNR value (<0.25, 0.25-0.49, 0.50-0.74, 0.75-1.00). Study parameters were compared at the univariate and multivariate levels for their effect on OS.

RESULTS

On univariate analysis, both the absolute number of positive lymph nodes and the ALNR were significant predictors of OS. On multivariate analysis, only the ALNR remained an independent predictor of OS, with a 2.5-fold increased risk of dying at an ALNR of ⩾0.25.

CONCLUSIONS

Our study demonstrates that ALNR is a stronger factor in predicting OS than the absolute number of positive axillary lymph nodes.

Identification of immunodominant HLA-B7-restricted CD8+ cytotoxic T cell epitopes derived from mammaglobin-A expressed on human breast cancers

Mammaglobin-A (MGBA), a 10-kD protein, is over expressed in 80% of primary and metastatic human breast cancers. Breast cancer patients demonstrate high frequencies of CD8(+) cytotoxic T lymphocytes (CTL) specific to MGBA. Defining CD8(+) CTL responses to HLA class I-restricted MGBA-derived epitopes assumes significance in the context of our ongoing efforts to clinically translate vaccine strategies targeting MGBA for prevention and/or treatment of human breast cancers. In this study, we define the CD8(+) CTL response to MGBA-derived candidate epitopes presented in the context of HLA-B7, which has a frequency of 17.7% in Caucasian and 15.5% in African American populations. We identified seven MGBA-derived candidate epitopes with high predicted binding scores for HLA-B7 using a computer algorithm. Membrane stabilization studies with TAP-deficient T2 cells transfected with HLA-B7 indicated that MGBA B7.3 (VSKTEYKEL), B7.6 (KLLMVLMLA), B7.7 (NPQVSKTEY), and B7.1 (YAGSGCPLL) have the highest HLA-B7 binding affinities. Further, two CD8(+) CTL cell lines generated in vitro against T2.B7 cells individually loaded with MGBA-derived candidate epitopes showed significant cytotoxic activity against MGBA B7.1, B7.3, B7.6, and B7.7. In addition, the same CD8(+) CTL lines lysed the HLA-B7(+)/MGBA(+) human breast cancer cell line DU-4475 but had no significant cytotoxicity against HLA-B7(-) or MGBA(-) breast cancer cell lines. Cold-target inhibition studies strongly suggest that MGBA B7.3 is an immunodominant epitope. In summary, our results define HLA-B7-restriced, MGBA-derived, CD8(+) CTL epitopes with all of the necessary features for developing novel vaccine strategies against HLA-B7 expressing breast cancer patients.

A quantitative reverse transcription-PCR assay for rapid, automated analysis of breast cancer sentinel lymph nodes

We have previously reported that a quantitative reverse transcription (QRT)-PCR assay accurately analyzes sentinel lymph nodes (SLNs) from breast cancer patients. The aim of this study was to assess a completely automated, cartridge-based version of the assay for accuracy, predictive value, and reproducibility. The triplex (two markers + control) QRT-PCR assay was incorporated into a single-use cartridge for point-of-care use on the GeneXpert system. Three academic centers participated equally. Twenty-nine positive lymph nodes and 30 negative lymph nodes were analyzed to establish classification rules. SLNs from 120 patients were subsequently analyzed by QRT-PCR and histology (including immunohistochemistry), and the predetermined decision rules were used to classify the SLNs; 112 SLN specimens produced an informative result by both QRT-PCR and histology. By histological analysis, 21 SLNs were positive and 91 SLNs were negative for metastasis. QRT-PCR characterization produced a classification with 100% sensitivity, 97.8% specificity, and 98.2% accuracy compared with histology (91.3% positive predictive value and 100% negative predictive value). Interlaboratory reproducibility analyses demonstrated that a 95% prediction interval for a new measurement (DeltaCt) ranged between 0.403 and 0.956. This fully automated QRT-PCR assay accurately characterizes breast cancer SLNs for the presence of metastasis. Furthermore, the assay is not dependent on subjective interpretation, is reproducible across three clinical environments, and is rapid enough to allow intraoperative decision making.

Identification and biologic significance of micrometastases in axillary lymph nodes in patients with invasive breast cancer

CONTEXT

The presence or absence of metastases in axillary lymph nodes is one of the most important prognostic factors for patients with breast cancer. During the past decade sentinel lymph node (SLN) biopsy has been increasingly adopted as a minimally invasive staging alternative to complete axillary node dissection.

OBJECTIVE

Sentinel lymph nodes are more likely to contain metastases than non-SLNs. In routine clinical practice SLNs are assessed by diverse methodologies including multiple sectioning, immunohistochemical staining, and molecular diagnostic tests. Despite the lack of standard histopathologic protocols during the years detailed evaluation of SLNs has resulted in an increased detection of small (micro) metastases.

DATA SOURCES

Breast cancer with micrometastases constitutes a heterogenous group of tumors with variable clinical outcome regarding the risk of additional metastases in the remaining axillary lymph nodes and to patients' survival.

CONCLUSION

The clinical significance of micrometastases has been subject to great controversy in patients with breast cancer. In this review we highlight controversies regarding micrometastases especially in relation to SLNs.

Molecular detection of lymph node metastases in breast cancer patients: results of a multicenter trial using the one-step nucleic acid amplification assay

PURPOSE

Accurate assessment of metastasis in sentinel lymph nodes (SLN) of breast cancer is important but involves a heavy workload for the pathologist. We conducted a multicenter clinical trial in Japan to evaluate a new automated assay system for cytokeratin 19 mRNA, the one-step nucleic acid amplification (OSNA) assay (Sysmex), to detect lymph node metastasis of breast cancer.

EXPERIMENTAL DESIGN

Surgically obtained axillary lymph nodes were sectioned into four pieces, two of which were examined with the OSNA assay. The other two adjacent pieces were examined with H&E and immunohistochemical staining for cytokeratin 19. Serial sections at 0.2-mm intervals were used in trial 1 to determine the specificity of the OSNA assay, and three pairs of sections cut from the sliced surfaces of the pieces were used in trial 2 to compare the accuracy of the OSNA assay with that of a routine pathologic examination for SLNs in Japan.

RESULTS

In trial 1, the sensitivity and specificity were 95.0% [95% confidence interval (95% CI), 75.1-99.9%] and 97.1% (95% CI, 91.8-99.4%), respectively, for 124 axillary lymph nodes obtained from 34 patients. In trial 2, the agreement between findings of the assay and of the pathologic examination was 92.9% (95% CI, 90.1-95.1%) for 450 axillary lymph nodes obtained from 164 patients.

CONCLUSION

The OSNA assay can detect lymph node metastasis as accurately as can conventional pathology and thus can be an effective addition to or alternative for rapid intraoperative examination of SLNs.

Sentinel lymph node molecular pathology in breast carcinoma

OBJECTIVES

The prognosis of breast cancer patients depends on primary tumor resection and axillary lymph nodes examination. The purpose of this study was to analyze by molecular biology techniques the presence of mammaglobin A and B messenger RNA in breast sentinel lymph node (SLN) by reverse-transcription polymerase chain reaction (RT-PCR).

METHODS

Sentinel lymph nodes from 50 patients with a diagnosis of breast cancer were prospectively studied between June 2004 and August 2006. Lymph nodes were all examined every 2 mm by intraoperative cytology. Hematoxylin-eosin (HE), immunohistochemistry (IHC) with cytokeratin (clone AE1-AE3, DAKO, dilution 1:100), and molecular biology techniques were used in all cases.

RESULTS

Deferred study with routine techniques showed subcapsular metastasis in 3/50 cases. Out of 50 cases, 5 were detected with IHC, and 2 of them were negative for HE. Multiplex RT-PCR allowed the detection of 18/50 positive SLN, which included the 5 above-mentioned cases. The other SLN studied (32/50) showed no metastases with the methods herein implemented.

CONCLUSIONS

The epidemiologic impact of incomplete SLN study has been observed, as the HE technique fails to identify all SLN with micrometastases. In our opinion, SLN should be studied with IHC and molecular biology techniques. The multiplex RT-PCR technique for A and B mammaglobin proves to be specific and sensitive. This study will serve to formulate hypotheses. Further research, including a larger population and a longer-term follow-up period, will be required to confirm these hypotheses. Should our findings be confirmed in the future, molecular biology determinations could modify patients' staging and treatment.

MicroRNA-mediated inhibition of prostate-derived Ets factor messenger RNA translation affects prostate-derived Ets factor regulatory networks in human breast cancer

Prostate-derived Ets factor (PDEF) is an ETS transcription factor expressed in normal tissues with high epithelial cell content and noninvasive breast cancer cells. A putative tumor suppressor PDEF protein expression is often lost during progression to a more invasive phenotype. Interestingly, PDEF mRNA has been found to be retained or even overexpressed in the absence of protein; however, the mechanisms for this remain to be elucidated. This study identifies two microRNAs (miRNA) that directly act on and repress PDEF mRNA translation, leading to the loss of PDEF protein expression and the gain of phenotypes associated with invasive cells. In addition, we show that these miRNAs are elevated in human breast tumor samples. Together, these data describe a mechanism of regulation that explains, for the first time, the lack of correlation between PDEF mRNA and protein levels, providing insight into the underexplored role of posttranscriptional regulation and how this contributes to dysregulated protein expression in cancer. These observations have critical implications for therapeutically targeting miRNAs that contribute to cancer progression.

Molecular diagnosis of sentinel lymph node metastases in cervical cancer using squamous cell carcinoma antigen

PURPOSE

To clarify the prognostic value of molecular diagnosis of SLN metastases in cervical cancer using SCCA.

EXPERIMENTAL DESIGN

All SLNs and primary tumors, part of non-SLNs, were harvested from 36 patients with cervical cancer. Expression levels of SCCA, cytokeratin 19 (CK19), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA in 178 samples (29 primary tumors, 5 histologic positive nodes, 60 histologic negative SLNs, 69 non-SLNs, and 15 normal nodes) were assessed by quantitative reverse transcription-PCR assay. The quantitative value of SCCA or CK19 mRNA was described as each value relative to GAPDH mRNA. The cutoff value was set at the upper limit of the quantitative value of nodes from noncancer patients, and those above this value constituted the molecular metastasis group.

RESULTS

The SCCA mRNA expression values were more than 1 x 10(3) in 28 primary tumors and all histologic positive nodes, and its expression levels in SLNs were higher than in non-SLNs. SLNs from patients with adverse prognostic features had higher SCCA mRNA expression levels. Four histologic negative SLNs were diagnosed molecular metastases based on SCCA mRNA. Two cases with histologically uninvolved pelvic nodes recurred. Survival analysis indicates that molecular lymphatic metastasis based on elevated SCCA mRNA level is the best predictor of recurrence. However, CK19 is not a suitable marker due to its low specificity and relative higher baseline expression in normal nodes.

CONCLUSIONS

SCCA mRNA levels for molecular diagnosis of SLN metastases in cervical cancer more accurately identifies patients at risk for recurrence than the routine histology does.

The number of positive nodes and the ratio of positive to excised nodes are significant predictors of survival in women with micrometastatic node-positive breast cancer

BACKGROUND

To evaluate the prognostic impact of the number of positive nodes and the lymph node ratio (LNR) of positive to excised nodes on survival in women diagnosed with nodal micrometastatic breast cancer before the era of widespread sentinel lymph node biopsy.

METHODS

Subjects were 62,551 women identified by the Surveillance Epidemiology and End Results database, diagnosed with pT1-2pN0-1 breast cancer between 1988 and 1997. Kaplan-Meier breast cancer-specific survival (BCSS) and overall survival (OS) were compared between three cohorts: node-negative (pN0, n=57,980) nodal micrometastasis all <or=2mm (pNmic, N=1818), and macroscopic nodal metastasis >2mm but <2 cm (pNmac, n=2753). Nodal subgroups were examined by the number of positive nodes (1-3 versus >or= 4) and the LNR (<or=0.25 versus >0.25).

RESULTS

Median follow-up was 7.3 yr. Ten-year BCSS and OS in pNmic breast cancer were significantly lower compared to pN0 disease (BCSS 82.3% versus 91.9%, p<0.001 and OS 68.1% versus 75.7%, p<0.001). BCSS and OS with pNmic disease progressively declined with increasing number of positive nodes and increasing LNR. OS with pNmic was similar to pNmac disease when matched by the number of positive nodes and by the LNR. Both pN-based and LNR-based classifications were significantly prognostic of BCSS and OS on Cox regression multivariate analysis.

CONCLUSION

Nodal micrometastasis is associated with poorer survival compared to pN0 disease. Mortality hazards with nodal micrometastasis increased with increasing number of positive nodes and increasing LNR. The number of positive nodes and the LNR should be considered in risk estimates for patients with nodal micrometastatic breast cancer.

Intra-operative rapid diagnostic method based on CK19 mRNA expression for the detection of lymph node metastases in breast cancer

Staging by sentinel node (SN) biopsy is the standard procedure for clinically node-negative breast cancer patients. Intra-operative analysis of the SN allows immediate axillary lymph node (ALN) dissection in SN positive patients, but a quick, reliable and reproducible method is lacking. We tested the suitability of a quantitative cytokeratin 19 (CK19) mRNA one step nucleic acid amplification (OSNA#) technique (OSNA-CK19) for intra-operative SN analysis. OSNA-CK19 involves a short manual sample preparation step and subsequent fully automated amplification of CK19 mRNA based on reverse transcription loop-mediated isothermal amplification, with results available within 30–40 min. OSNA-CK19 was compared to histological staining (Hematoxylin&Eosin and CAM5.2 and CK19 immunostaining) of 346 frozen ALNs from 32 breast cancer patients, using half of the lymph node for each method. 267 samples were negative and 61 positive by both methods. Three samples were histology positive and OSNA-CK19 negative. Fifteen samples were histology negative and OSNA-CK19 positive, 11 of which had copy numbers close to the cut-off level of OSNA-CK19. Seven of these 15 samples were RT-PCR positive for epithelial markers and/or showed CK19 protein expression by Western blot suggesting the presence of tumor deposits in the lymph node part investigated by OSNA-CK19. Concordance with histology was 94.8%, and 96.8% after exclusion of the latter 7 discordant cases. Sensitivity was 95.3% and specificity was 94.7% before and 97.1% after discordant case investigation. Our results indicate that OSNA-CK19 can potentially be useful in an intra-operative clinical setting to detect SN tumor involvement in breast cancer patients.

Sentinel lymph node as a target of molecular diagnosis of lymphatic micrometastasis and local immunoresponse to malignant cells

The sentinel lymph node (SLN) is defined as the lymph node(s) first receiving lymphatic drainage from the site of the primary tumor. The histopathological status of SLN is one of the most significant predictors of recurrence and overall survival for most clinical stage I/II solid tumors. Recent progress in molecular techniques has demonstrated the presence of micrometastatic tumor cells in SLN. There is now a growing body of data to support the clinical relevance of SLN micrometastasis in a variety of solid tumors. Increasing the sensitivity of occult tumor cell detection in the SLN, using molecular-based analysis, should enable a more accurate understanding of the clinical significance of various patterns of micrometastatic nodal disease. The establishment of metastasis to SLN might not be simply reflected by the flow dynamics of lymphatic fluid that drains from the primary site to the SLN, and the transportation of viable cancer cells. Recent studies have demonstrated that primary tumors can actively induce lymphangiogenesis and promote SLN metastasis. Moreover chemokine receptors in tumor cells may facilitate organ-specific tumor metastasis in many human cancers and some experimental models. In contrast, recent clinical and preclinical studies regard SLN as the first lymphoid organ to respond to tumor antigenic stimulation. SLN dramatically show morphological, phenotypical and functional changes that indicate immune suppression by tumor cells. The immune suppression in SLN results in failure of prevention or eradication of tumor metastasis. The mechanism of immunomodulation remains unclear; however, several regulatory molecules produced by tumor cells and tumor-associated macrophages or lymphocytes are likely to be responsible for inducing the immune suppression in SLN. Further studies may develop a novel immunotherapy that overcomes tumor-induced immune suppression and can prevent or eradicate SLN metastasis.

Comparative evaluation of an extensive histopathologic examination and a real-time reverse-transcription-polymerase chain reaction assay for mammaglobin and cytokeratin 19 on axillary sentinel lymph nodes of breast carcinoma patients

OBJECTIVE

To assess the accuracy of a commercially available real-time reverse-transcription-polymerase chain reaction assay for mammaglobin and cytokeratin 19 mRNAs [GeneSearch Breast Lymph Node (BLN) Assay, Veridex LLC, Warren, NJ] in the detection of axillary sentinel lymph nodes (SLNs) metastases in patients with breast carcinoma.

SUMMARY BACKGROUND DATA

Because of the lack of standardized and widely accepted protocols for a truly accurate histopathologic examination of SLN, the relative merits of alternative assays based on the identification of tumor specific mRNA markers deserve further assessment.

METHODS

: A prospective series of 293 consecutive SLNs from 293 patients was evaluated. The BLN assay results were compared with those of an extensive histopathologic examination of the entire SLNs performed on serial frozen sections cut at 40 to 50 microm intervals.

RESULTS

The BLN assay correctly identified 51 of 52 macrometastatic and 5 of 20 micrometastatic SLNs, with a sensitivity of 98.1% to detect metastases larger than 2 mm, 94.7% for metastases larger than 1 mm, and 77.8% for metastases larger than 0.2 mm. The overall concordance with histopathology was 90.8%, with specificity of 95.0%, positive predictive value of 83.6%, and negative predictive value of 92.9%. When the results were evaluated according to the occurrence of additional metastases to non-SLN in patients with histologically positive SLNs, the assay was positive in 33 (91.7%) of the 36 patients with additional metastases and in 22 (66.6%) of the 33 patients without further echelon involvement.

CONCLUSIONS

The sensitivity of the reverse-transcription -polymerase chain reaction assay is comparable to that of the histopathologic examination of the entire SLN by serial sectioning at 1.5 to 2 mm.

Detection of mammaglobin mRNA in peripheral blood is associated with high grade breast cancer: interim results of a prospective cohort study

BACKGROUND

We sought to examine the detection rate of cancer cells in peripheral blood (PBL) and in bone marrow (BM) using an established 7-gene marker panel and evaluated whether there were any definable associations of any individual gene with traditional predictors of prognosis.

METHODS

Patients with T1-T3 primary breast cancer were enrolled into a prospective, multi-institutional cohort study. In this interim analysis 215 PBL and 177 BM samples were analyzed by multimarker, real-time RT-PCR analysis designed to detect circulating and disseminated breast cancer cells.

RESULTS

At a threshold of three standard deviations from the mean expression level of normal controls, 63% (136/215) of PBL and 11% (19/177) of BM samples were positive for at least one cancer-associated marker. Marker positivity in PBL demonstrated a statistically significant association with grade II-III (vs. grade I; p = 0.0083). Overexpression of the mammaglobin (mam) gene alone had a statistically significant association with high tumor grade (p = 0.0315), and showed a trend towards ER-negative tumors and a high risk category. There was no association between marker positivity in PBL and the pathologic (H&E) and/or molecular (RT-PCR) status of the axillary lymph nodes (ALN).

CONCLUSION

This study suggests that molecular detection of circulating cancer cells in PBL detected by RT-PCR is associated with high tumor grade and specifically that overexpression of the mam gene in PBL may be a poor prognostic indicator. There was no statistically significant association between overexpression of cancer-associated genes in PBL and ALN status, supporting the concept of two potentially separate metastatic pathways.

Molecular oncology: current trends in diagnostics

Applications of molecular diagnostics to oncology have been slow to make their way to the clinical laboratory. While numerous genes and mutation spectra have been found to be involved in tumorigenesis, it is only recently that these findings begin to become useful in a clinical setting. Building on the technical knowledge obtained from molecular infectious disease testing, new instruments and assays have been developed to answer similar questions regarding qualitative, quantitative and genotyping issues. In this manuscript we describe two current examples of clinical molecular diagnostic applications, the assessment of BCR–ABL in chronic myelogenous leukemia patients and the detection of tumor cells in the sentinel lymph nodes of breast cancer patients, to demonstrate the role of molecular techniques in a routine clinical setting.