Mammaglobin B as a novel marker for detection of breast cancer micrometastases in axillary lymph nodes by reverse transcription-polymerase chain reaction

A protein interaction landscape of breast cancer

[Figure: see text].

Non-Invasive Biomarkers for Early Detection of Breast Cancer

Breast cancer is the most common cancer in women worldwide. Accurate early diagnosis of breast cancer is critical in the management of the disease. Although mammogram screening has been widely used for breast cancer screening, high false-positive and false-negative rates and radiation from mammography have always been a concern. Over the last 20 years, the emergence of "omics" strategies has resulted in significant advances in the search for non-invasive biomarkers for breast cancer diagnosis at an early stage. Circulating carcinoma antigens, circulating tumor cells, circulating cell-free tumor nucleic acids (DNA or RNA), circulating microRNAs, and circulating extracellular vesicles in the peripheral blood, nipple aspirate fluid, sweat, urine, and tears, as well as volatile organic compounds in the breath, have emerged as potential non-invasive diagnostic biomarkers to supplement current clinical approaches to earlier detection of breast cancer. In this review, we summarize the current progress of research in these areas.

Mammaglobin-A, VEGFR3, and Ki67 in Human Breast Cancer Pathology and Five Year Survival

Background/Methods:

This study determines the co-expression of mammaglobin-A, vascular endothelial growth factor receptor-3 (VEGFR3) and Ki67 by immunohistochemistry (IHC) in tissue samples from 80 patients undergoing breast surgery (cancer or benign disease). The tissue expression was compared with the tumour histopathology and Kaplan Meier 5-year survival analysis was performed.

Results:

Positive breast tissue expression was observed in 53% samples for mammaglobin, 41% Ki67 and 65% VEGFR3 with a significant positive correlation between Ki67 and VEGFR3 co-expression. Ki67 and VEGFR3 expression correlated with the breast tumour grade and Ki67 expression also correlated with oestrogen receptor (ER) status. At 5 years post-operatively, 6/80 patients had died and 3 patients were alive but had cancer recurrence. High Ki67 expression significantly correlated with poor survival (disease-free and overall).

Conclusions:

In this study, VEGFR3 and Ki67 expression but not mammaglobin-A correlated with breast tumour pathology. Positive Ki67 expression was also associated with a poor 5-year survival outcome.

Detection of mammagloblin by RT-PCR as a biomarker for lymph node metastasis in breast cancer patients: A systematic review and meta-analysis

Background

This meta-analysis presents evidence regarding the diagnostic accuracy of mammaglobin detected using the RT-PCR technique, related to the presence of sentinel node metastasis in breast cancer patients.

Methods

The following databases were consulted: Cochrane, Lilacs, Scielo, Hinary, PubMed, Elsevier, Embase, ProQuest, the Universidad del Rosario´s Centro de Recursos Para el Aprendizaje y la Investigación (CRAI-UR) [Resource Center for Learning and Research], and the Google Scholar search engine. The quality of the studies was assessed using the QUADAS-2 and CASpe tools. The selected studies presented the necessary data to calculate diagnostic validity index of mammaglobin detection using RT-PCR, compared with the reference standard test. Global values for the sensitivity, specificity, positive predictive value, negative predictive value, probability ratios, diagnostic ORs, and summary ROC curves of this meta-analysis were obtained using the Meta-DiSc 1.4 program.

Results

Initially, 731 articles were obtained; but only 25 were included in the meta-analysis. Sensitivity was 84% (95% CI: 83% - 86%), and specificity was 92% (95% CI: 91% - 93%). Positive and negative predictive values were 9.26 (95% CI: 6.47–13.26) and 0.17 (95% CI: 0.13–0.23), respectively. The diagnostic OR was 66.34 (95% CI: 42.52–103.52). The predictive area under the sROC curve was 94.78 (Q = 0.8876).

Conclusions

The evaluated diagnostic index showed that the expression of the mammaglobin biomarker has diagnostic prediction for detecting lymph node metastasis in breast cancer patients, when analyzed using RT-PCR, although more than 50% heterogeneity was found.

Identification of secretaglobin Scgb2a1 as a target for developmental reprogramming by BPA in the rat prostate

Secretoglobins are a superfamily of secreted proteins thought to participate in inflammation, tissue repair, and tumorigenesis. Secretoglobin family 2A member 1 (Scgb2a1) is a component of prostatein, a major androgen-binding protein secreted by the rat prostate. Using a rat model for developmental reprogramming of susceptibility to prostate carcinogenesis, we identified, by RNA-seq, that Scgb2a1 is significantly upregulated (>100-fold) in the prostate of adult rats neonatally exposed to bisphenol A (BPA), with increased gene expression confirmed by quantitative RT-PCR and chromatin immunoprecipitation for histone H3 lysine 9 acetylation. Bisulfite analysis of both CpG islands located within 10 kb of the Scgb2a1 promoter identified significant hypomethylation of the CpG island upstream of the transcription start site of this gene in the reprogrammed prostate. These data suggest that expression of Scgb2a1 in the adult prostate could be epigenetically reprogrammed by BPA exposure during prostate development, with potential implications for cancer risk and response to chemotherapeutics associated with prostatein binding.

SCGB2A1 is a novel prognostic marker for colorectal cancer associated with chemoresistance and radioresistance

We recently showed that liver metastatic tissue from patients with colorectal cancer (CRC) was a useful model for identifying novel, hypoxia-inducible genes and prognostic markers. We showed that the expression of secretoglobin, family 2A, member 1 (SCGB2A1) was a potential prognostic factor for CRC. Here, we further evaluated the prognostic impact and function of SCGB2A1 in 222 patients with CRC. The impact of SCGB2A1 expression on disease-free survival (DFS) and overall survival (OS) was assessed with mRNA expression profiling. The function of SCGB2A1 was analyzed by evaluating mRNA expression profiles in cells derived from patients with CRC and by testing the effects of transfecting SCGB2A1 into different CRC-derived cell lines. We evaluated the effects of SCGB2A1 on proliferation, chemosensitivity, radiation sensitivity and sphere formation. Univariate and multivariate analyses indicated that the expression of SCGB2A1 was an independent prognostic factor for CRC (p<0.05), together with lymph node metastasis (p<0.05). Enforced expression of SCGB2A1 in CRC-derived cell lines promoted proliferation (DLD1, SW480 and LoVo cells; p<0.05), decreased chemosensitivity to 5-fluorouracil and oxaliplatin (DLD1 and SW480 cell lines; p<0.05), and significantly increased the viability of irradiated cells (DLD1, SW480 and LoVo cell lines; p<0.05). SCGB2A1 expression was also correlated to cancer stemness-related genes (Wnt, Zeb1 and Twist). Consistent with this correlation, SCGB2A1 expressing cells (SW480) showed increased sphere formation (p<0.05). These results indicated that SCGB2A1 represented a novel, prognostic factor for CRC, and that expression of SCGB2A1 correlated with chemoresistance, radioresistance and cancer cell stemness.

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.

Mammaglobin B (SCGB2A1) is a novel tumour antigen highly differentially expressed in all major histological types of ovarian cancer: implications for ovarian cancer immunotherapy

Background:

We studied the genetic fingerprints of ovarian cancer and validated the potential of Mammaglobin b (SCGB2A1), one of the top differentially expressed genes found in our analysis, as a novel ovarian tumour rejection antigen.

Methods:

We profiled 70 ovarian carcinomas including 24 serous (OSPC), 15 clear-cell (CC), 24 endometrioid (EAC) and 7 poorly differentiated tumours, and 14 normal human ovarian surface epithelial (HOSE) control cell lines using the Human HG-U133 Plus 2.0 chip (Affymetrix). Quantitative real-time PCR and immunohistochemistry staining techniques were used to validate microarray data at RNA and protein levels for SCGB2A1. Full-length human-recombinant SCGB2A1 was used to pulse monocyte-derived dendritic cells (DCs) to stimulate autologous SCGB2A1-specific cytotoxic T-lymphocyte (CTL) responses against chemo-naive and chemo-resistant autologous ovarian tumours.

Results:

Gene expression profiling identified SCGB2A1 as a top differentially expressed gene in all histological ovarian cancer types tested. The CD8+ CTL populations generated against SCGB2A1 were able to consistently induce lysis of autologous primary (chemo-naive) and metastatic/recurrent (chemo-resistant) target tumour cells expressing SCGB2A1, whereas autologous HLA-identical noncancerous cells were not lysed. Cytotoxicity against autologous tumour cells was significantly inhibited by anti-HLA-class I (W6/32) monoclonal antibody. Intracellular cytokine expression measured by flow cytometry showed a striking type 1 cytokine profile (i.e., high IFN-γ secretion) in SCGB2A1-specific CTLs.

Conclusion:

SCGB2A1 is a top differentially expressed gene in all major histological types of ovarian cancers and may represent a novel and attractive target for the immunotherapy of patients harbouring recurrent disease resistant to chemotherapy.

Metaplastic and medullary mammary carcinomas do not express mammaglobin

Mammaglobin A (MG-A) is purportedly useful for detecting metastatic carcinomas suspected to be of breast origin and has been advocated as a useful marker of micrometastasis in sentinel lymph nodes and minimal residual tumor in bone marrow. Little is known about its expression frequency in histologic subtypes of breast cancer. Excisional biopsy specimens from 1,079 untreated invasive mammary carcinomas were evaluated for immunohistochemical expression of MG-A. In addition to estrogen (ER) and progesterone receptors (PR) and HER2, staining for p63 and HLA-DR was used to further characterize histologic subtypes. Of the carcinomas, 36 were classified as metaplastic (based on morphologic features, ER-/PR-/HER2-, p63+), 38 as medullary (ER-/PR-/HER2-, HLA-DR+), and 1,005 as ductal, no special type (NST). All metaplastic and medullary carcinomas were negative for MG-A. Of 1,005 ductal carcinomas, NST, 492 (49.0%) were MG-A+, 62.0% with a reaction in fewer than 25% of the cells. MG-A immunohistochemical studies failed to detect all medullary and metaplastic cancers and more than 50% of ductal carcinomas, NST. In two thirds of MG-A+ ductal carcinomas, the reaction was only focal and usually in a minority of cells. These findings suggest that MG-A has limited value in identifying the mammary origin of carcinomas, particularly in small biopsy specimens used to detect metastasis or minimal residual disease.

Positive bone marrow biopsy is associated with a decreased disease-free survival in patients with operable breast cancer

BACKGROUND

Bone marrow (BM) biopsy has been suggested as an independent prognostic factor in patients with breast cancer.

METHODS

Patients operated for breast cancer from June 2000 to April 2008 were enrolled in this protocol after signing an informed consent. After primary surgery, BM aspirate from the iliac crest was obtained and 5-10 cc of blood collected. Since 2002 a peripheral blood (PB) sample was also obtained. Both carcinoembryonic antigen (CEA) and Mammaglobin-specific nested reverse-transcription polymerase chain reaction (RT-PCR) were used to examine BM and PB samples. Physicians and patients were blinded to results.

RESULTS

Two hundred seventy-three patients underwent BM and/or PB test. The median age of the patients was 63 years (31-80 years), and the median tumor diameter was 1.5 cm (0.1-6 cm). BM aspirates were unsuccessful in nine patients, and RT-PCR was not technically feasible in 18 women, leaving 246 patients available for analysis of results and follow-up. Among them, 110 patients (45%) had either a BM or a PB test positive for CEA or Mammaglobin (Test+). At median follow-up of 60 months, 31 events (deaths or relapse) occurred (13%). Disease-free survival (DFS) was significantly lower in the Test+ group (BP and/or PB) (P<0.001). This effect was independent of nodal status. At 5 years, event-free survival for Node-/Test- patients was 46/49 (94%) and for Node+/Test+ patients was 21/33 (64%), while patients with only one status positive (Node-/Test+ or Node+/Test-) had an intermediate disease-free survival (35/43, 81%) (P=0.005). In a subgroup analysis, RT-PCR results for BM and Mammaglobin retained statistical significance on DFS (P<0.001), while those for PB and CEA did not.

CONCLUSIONS

This study confirms that RT-PCR of the BM is an independent prognostic factor for disease-free survival of breast cancer patients, and may improve their staging, allowing better strategies for therapy and follow-up.

Mammaglobin B is an independent prognostic marker in epithelial ovarian cancer and its expression is associated with reduced risk of disease recurrence

Background

Traditional prognostic factors in epithelial ovarian cancer (EOC) are inadequate in predicting recurrence and long-term prognosis, but genome-wide cancer research has recently provided multiple potentially useful biomarkers. The gene codifying for Mammaglobin B (MGB-2) has been selected from our previous microarray analysis performed on 19 serous papillary epithelial ovarian cancers and its expression has been further investigated on multiple histological subtypes, both at mRNA and protein level. Since, to date, there is no information available on the prognostic significance of MGB-2 expression in cancer, the aim of this study was to determine its prognostic potential on survival in a large cohort of well-characterized EOC patients.

Methods

MGB-2 expression was evaluated by quantitative real time-PCR in fresh-frozen tissue biopsies and was validated by immunohistochemistry in matched formalin fixed-paraffin embedded tissue samples derived from a total of 106 EOC patients and 27 controls. MGB-2 expression was then associated with the clinicopathologic features of the tumors and was correlated with clinical outcome.

Results

MGB-2 expression was found significantly elevated in EOC compared to normal ovarian controls, both at mRNA and protein level. A good correlation was detected between MGB-2 expression data obtained by the two different techniques. MGB-2 expressing tumors were significantly associated with several clinicopathologic characteristics defining a less aggressive tumor behavior. Univariate survival analysis revealed a decreased risk for cancer-related death, recurrence and disease progression in MGB-2-expressing patients (p < 0.05). Moreover, multivariate analysis indicated that high expression levels of MGB-2 transcript (HR = 0.25, 95%, 0.08–0.75, p = 0.014) as well as positive immunostaining for the protein (HR = 0.41, 95%CI, 0.17–0.99, p = 0.048) had an independent prognostic value for disease-free survival.

Conclusion

This is the first report documenting that MGB-2 expression characterizes less aggressive forms of EOC and is correlated with a favorable outcome. These findings suggest that the determination of MGB-2, especially at molecular level, in EOC tissue obtained after primary surgery can provide additional prognostic information about the risk of recurrence.

Application of immunohistochemistry to breast lesions

CONTEXT

Immunohistochemistry has an expanding role in mammary pathology that has been facilitated by a growing list of available antibodies and a better understanding of biology.

OBJECTIVE

To explore the key role of immunohistochemistry in guiding adjuvant therapy decisions and sentinel node staging in breast cancer, as well as the role of immunohistochemistry as an aid to distinguishing usual ductal hyperplasia from atypical ductal hyperplasia/low-grade carcinoma in situ; subtyping a carcinoma as ductal or lobular, basal or luminal; ruling out microinvasion in extensive intraductal carcinoma; distinguishing invasive carcinoma from mimics; and establishing that a metastatic carcinoma of unknown primary site has originated in the breast.

DATA SOURCES

Current literature is reviewed, including clinical and pathologic journals.

CONCLUSIONS

As new, targeted treatments for breast cancer are developed, pathologists can expect additional immunohistochemistry applications in the future.

Overexpression of mammaglobin B in epithelial ovarian carcinomas

OBJECTIVE

Mammaglobin B is a uteroglobin gene family member recently found highly differentially expressed in serous papillary ovarian cancer by gene expression profiling. In order to evaluate its potential as a novel ovarian cancer biomarker, in this study we quantified and compared Mammaglobin B expression in various histologic types of epithelial ovarian carcinomas (EOC).

METHODS

Mammaglobin B expression was evaluated by real-time PCR and/or immunohistochemistry in fresh-frozen biopsies and paraffin-embedded tissues derived from a total of 137 patients including 69 primary EOC with different histologies, 28 serous papillary omental metastasis, 8 borderline tumors, 26 benign cystadenomas and 14 normal ovaries.

RESULTS

High levels of Mammaglobin B gene expression were detected in 100% (68 out of 68) of the ovarian cancer biopsies tested by real-time PCR. In contrast, normal human ovarian surface epithelium (HOSE) expressed negligible levels of Mammaglobin B mRNA (EOC versus HOSE, p<0.01). Although Mammaglobin B gene expression levels were higher in endometrioid, mucinous and undifferentiated tumors when compared to serous papillary tumors, clear cell tumors and those with mixed histology, these differences were not statistically significant. In agreement with real-time PCR results, EOC were found to express significantly higher levels of Mammaglobin B protein when compared to normal ovaries and benign cystadenomas (p<0.01). However, only 29 out of 68 (42%) of the EOC samples found positive for Mammaglobin B by real-time PCR showed immunoreactivity by IHC.

CONCLUSIONS

Mammaglobin B gene is highly expressed in EOC and may represent a novel molecular marker for multiple histological types of ovarian cancer. Additional studies to evaluate the clinical utility of Mammaglobin B as a diagnostic and/or therapeutic target in ovarian cancer are warranted.

Multimarker RT-PCR assay for the detection of minimal residual disease in sentinel lymph nodes of breast cancer patients

The presence of metastases in lymph nodes is the most powerful prognostic factor in breast cancer patients. Routine histological examination of lymph nodes has limited sensitivity for the detection of breast cancer metastases. The aim of the present study was to develop a multimarker reverse transcriptase-polymerase chain reaction (RT-PCR) assay for the detection of minimal residual disease in sentinel nodes of breast cancer patients. RNA was extracted from 30 sentinel lymph nodes (SLN) obtained from 28 patients, three primary breast cancers (positive controls), three lymph nodes from patients with benign diseases, and peripheral blood lymphocytes of 10 healthy volunteers (negative controls). RT-PCR was performed using the following markers; cytokeratin (CK)-19, NY-BR-1 and mammaglobin B. RT-PCR results were compared to enhanced histopathologic examination and immunohistochemistry (IHC). All three positive controls showed strong PCR amplification for all three markers. None of the 13 negative controls was amplified by any of the three markers. Among the 30 SLN analysed, breast cancer metastases were detected in six SLNs by routine histology, in eight by IHC and in 15 by RT-PCR. We conclude that a multimarker RT-PCR assay probing for NY-BR-1, mammaglobin-B, and CK-19 is more sensitive compared to enhanced pathologic examination. This method may prove to be of value in breast cancer staging and prognosis evaluation.

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.

Mammaglobin and CRxA-01 in pleural effusion cytology

BACKGROUND

The most common causes of malignant pleural effusions in women are metastatic lung carcinomas and breast carcinomas. It is often very difficult to distinguish between breast carcinomas and other metastatic carcinomas when they share a similar morphology and a similar cytokeratin profile (CK7-positive/CK20-negative [CK7+/CK20-]). To better differentiate between metastatic mammary carcinomas and other metastatic carcinomas in pleural effusion cytology, the authors studied the potential use of a novel antibody, CRxA-01, which was identified by a cDNA subtraction library, together with a well characterized antibody against mammaglobin.

METHODS

A computer search for patients with malignant pleural effusion specimens between January 1992 and November 2002 generated 228 patients, 71 of whom had cell block material and a known clinical history. Primary malignancies among these patients included 20 breast carcinomas, 32 lung carcinomas, 4 endometrial carcinomas, 9 ovarian carcinomas, 4 gastrointestinal carcinomas, and 2 genitourinary carcinomas. All specimens were immunostained with anti-CK7, CK20, CRxA-01, and mammaglobin antibodies. Only CK7-positive/CK20-negative (CK7+/CK20-) specimens were included in the current study, and only definitive membranous staining for CRxA-01 and cytoplasmic staining for mammaglobin were considered to be positive.

RESULTS

For patients with metastatic breast carcinomas, mammaglobin was positive in 11 of 20 (55%) tissue specimens and CRxA-01 was positive in 12 of 20 (60%) tissue specimens. When CRxA-01 and mammaglobin were used together, 16 of 20 (80%) tissue specimens were positive for mammaglobin or/and CRxA-01 antibodies. This staining pattern was not seen for tissue specimens from patients with other metastatic carcinomas. Two of 4 (50%) uterine carcinoma specimens and 6 of 9 (67%) ovarian carcinoma specimens were positive for CRxA-01 only.

CONCLUSIONS

CRxA-01 and mammaglobin were expressed in most metastatic breast carcinoma specimens. Other CK7+/CK20- carcinoma specimens did not express mammaglobin and showed weak or negative staining for CRxA-01. When used together, CRxA-01 and mammaglobin greatly improved the sensitivity and specificity for the detection of metastatic breast carcinoma in pleural effusion specimens.

Persistence of bone marrow micrometastases in patients receiving adjuvant therapy for breast cancer: Results at 4 years

We have previously developed a quantitative PCR (QPCR) technique for the detection of cytokeratin 19 (CK19) transcripts in blood and bone marrow and compared this to immunocytochemistry (ICC). Together, both have shown promise for monitoring therapeutic efficacy in patients with metastatic breast cancer. The aim of this study was to determine the feasibility and value of these assays for minimal residual disease (MRD) in monitoring efficacy of adjuvant therapy following surgery for primary breast cancer. Bone marrow aspirates and peripheral blood samples were taken at the time of surgery from patients with primary breast cancer and no evidence of metastases on conventional scans. These were tested for the presence of CK19 mRNA transcripts and cytokeratin positive cells. Follow-up bone marrow aspirates were taken at 3, 6, 12, 24, 36 and 48 months. Prior to surgery, 51% of patients displayed evidence of disseminated cancer cells in the bone marrow by either or both QPCR and ICC. Of 91 patients who had repeat samples assayed, 87% and 65% had positive results at some time using QPCR and ICC, respectively. All patients received adjuvant systemic therapy and in 44 cases where there was a positive result in either the pretreatment or 3-month aspirate, 32/44 (73%) showed a fall in CK19:ABL ratio (QPCR) and 15/24 (63%) showed a reduction in the number of cytokeratin-positive cells (ICC) during follow-up. These results indicate that MRD persists despite adjuvant therapy in a majority of patients with primary breast cancer up to 4 years following surgery.

Mammaglobin: a candidate diagnostic marker for breast cancer

Mammaglobin, known for its mammary tissue specificity, has been discussed as a promising diagnostic marker in breast cancer for almost 10 years. In particular, the application of mammaglobin RT-PCR to detect disseminated breast cancer cells has been reported. More than 25 publications evaluate the detection of mammaglobin mRNA in lymph node, blood, and bone marrow specimens of breast cancer patients. Recently, structural details about the mammaglobin complex have been discovered, and these findings can be implemented to optimize detection of the secreted protein. This review summarizes the findings of almost 50 published studies and the current knowledge about the diagnostic utility of mammaglobin.

Combination of cytology, fluorescence in situ hybridization for aneuploidy, and reverse-transcriptase polymerase chain reaction for human mammaglobin/mammaglobin B expression improves diagnosis of malignant effusions

PURPOSE

The identification of malignant cells in effusions by conventional cytology is hampered by its limited sensitivity. The aim of this study was to improve tumor cell detection in effusions by molecular approaches.

MATERIALS AND METHODS

A total of 157 effusions from patients with tumors and 72 effusions from patients without a history or evidence of malignancy were included in this study. All effusion specimens were evaluated in parallel by cytology, fluorescence in situ hybridization (FISH) for aneuploidy, and reverse-transcriptase polymerase chain reaction (RT-PCR) for expression of human mammaglobin (hMAM) and mammaglobin B (hMAM-B).

RESULTS

In effusions from patients with tumors, the sensitivities of tumor cell detection by cytology, FISH, and hMAM and hMAM-B detection were 46.2%, 53.3%, 36.4%, and 57.7%, respectively. The corresponding specificities were 94.4%, 97.0%, 87.1%, and 88.6%. Notably, a high percentage of effusions containing malignant cells were in fact transudates, indicating the necessity for molecular diagnostic work-up of transudates collected from patients with tumors. Dependent on the tumor type, the use of appropriate marker combinations improved tumor cell detection in effusions significantly. By combining all four diagnostic tests, a positive test result indicating the presence of malignancy was achieved in 81.1%, with a fairly good specificity of 70.1%.

CONCLUSION

Molecular techniques are definitely useful to detect malignancy in cytologically negative effusions. Tumor cell detection in effusions can be significantly improved by FISH and PCR techniques applying appropriate molecular markers. This finding should help to improve tumor staging, prognostic assessment, and treatment monitoring.

Quantitative evaluation of metastases in axillary lymph nodes of breast cancer

We have established a highly sensitive and quantitative reverse transcriptase–polymerase chain reaction (RT–PCR) method to detect axillary lymph node metastases of breast cancer. Amplifying cytokeratin 19 (CK19) mRNA transcripts using real-time TaqMan PCR made it possible to quantify axillary metastatic burden. Metastases in 358 axillary lymph nodes obtained from 23 breast cancers of 22 patients were investigated by conventional haematoxylin and eosin (H&E) staining, immunohistochemical staining and quantitative RT–PCR assay. The detection rates of axillary lymph node metastasis using H&E staining, immunohistochemistry and RT–PCR assay were 4.5, 5.9 and 13.1%, respectively. RT–PCR assay was the most sensitive of these three methods for detecting lymph node metastases. Cytokeratin 19 mRNA expression values of both histologically and immunohistochemically positive lymph nodes were significantly higher than the values for lymph nodes judged to be negative by both histological and immunohistochemical methods (P<0.0001), and those of histologically negative, but immunohistochemically positive lymph nodes were significantly higher than the values for lymph nodes judged to be negative by both histological and immunohistochemical methods (P<0.0001). Furthermore, metastatic rates of sentinel nodes were higher than the rates of nonsentinel lymph nodes as measured by all three methods. These results indicate that quantitative RT–PCR assay is a sensitive and reliable method for detecting lymph node metastasis. Furthermore, quantification of metastases in sentinel lymph nodes by quantitative RT–PCR assay may be useful to assess the entire axillary burden of breast cancer patients.

Patterns of regional lymph node involvement in intrahepatic cholangiocarcinoma of the left lobe

Lymph node involvement is an important prognostic factor in intrahepatic cholangiocarcinoma. Besides the nodes in the hepatoduodenal ligament, recent studies have suggested that the nodes around the cardiac portion of the stomach or along the gastric lesser curvature can be affected when the primary tumor is located in the left hepatic lobe. However, the distribution of metastatic nodes has not been well described in this disease. Thirteen patients with intrahepatic cholangiocarcinoma in the left hepatic lobe were enrolled in this study. Lymphatic mapping was performed by means of both histologic examination and reverse transcriptase-polymerase chain reaction assays. Nodal involvement around the cardiac portion of the stomach or along the lesser gastric curvature (left pathway) was found in 7 (54%) of 13 patients by histologic examination or reverse transcriptase-polymerase chain reaction, whereas positive nodes in the hepatoduodenal ligament (right pathway) were found in 6 (46%) of 13 patients. Two patients (15%) had positive nodes only in the left pathway. Therefore, for a more accurate clinical staging of intrahepatic cholangiocarcinoma in the hepatic left lobe, lymph nodes around the cardiac portion of the stomach and along the lesser gastric curvature should be examined in addition to nodes in the hepatoduodenal ligament.

Clinical relevance of reverse transcriptase-polymerase chain reaction for the detection of axillary lymph node metastases in breast cancer

BACKGROUND

The mammary sentinel lymph node procedure can increase the detection of axillary metastases by 45% compared with standard axillary dissection. Some investigators have reported that reverse transcriptase-polymerase chain reaction (RT-PCR) increases metastasis detection even more, but it is uncertain whether a positive RT-PCR test in the face of a negative histological evaluation is clinically meaningful.

METHODS

RT-PCR for epithelial glycoprotein 2 and cytokeratin 19 was performed on sentinel and pooled nonsentinel axillary lymph nodes from 108 women with clinical stage I or II breast cancer who were followed up for a median of 40 months.

RESULTS

Axillary metastases were detected on standard tissue sections in 26% and by RT-PCR in 30%. Results for the two tests were concordant for 80% of the cases. RT-PCR upstaged 16%. Tumors from women whose lymph nodes were positive only by RT-PCR were phenotypically similar to those from women with no metastases detected by any method. Moreover, 4-year actuarial distant disease-free survival was 100% for women with metastases detected by RT-PCR only, as compared with 74% for those with metastases detected by routine histology (P =.03) and 93% for those with no metastases detected by either method (P =.04).

CONCLUSIONS

Analysis of sentinel lymph nodes by RT-PCR for epithelial glycoprotein 2 and cytokeratin 19 is unlikely to provide clinically useful information.

Molecular pathology of tumor metastasis. II. Molecular staging and differential diagnosis

Molecular Pathology of Tumor Metastasis With the development of non-invasive methods, diagnosis of metastasis from various solid malignancies has become a routine task for diagnostic pathology. However, the differential diagnosis between primary and metastatic cancers and the precise identification of various metastatic cancer types requires the coordinated use of various morphological (light- and electron microscopic-), immunological and molecular techniques. The detection of the lymphatic spread of the primary tumor may now based on the sentinel lymph node technology while the identification of the hematogenous progression may be based on the analysis of the peripheral blood and the bone marrow. More and more frequently these techniques employ highly sensitive immunological and molecular techniques. Accordingly, clinical staging is now confronted with the results of molecular staging, where the only techniques which are able to detect cancer cells are immunocytochemistry or nucleic acid-based methodology. Although several clinical studies have provided evidences for the impact of the immunocytochemistry-based identification of micrometastases on the survival of patients with various type of cancers, none of these methods have become part of standard diagnostic protocols. Although more sensitive molecular techniques are being introduced to identify micrometastasis, their clinical significance is yet unknown. Multicentric clinical trials are now warranted to establish the clinical impact of molecular staging in various cancer types. Without the integration of these methods into the prognostic/predictive pathological protocols it is difficult to envision significant improvement in the results of cancer therapy.

Reverse transcription-polymerase chain reaction assay for multiple mRNA markers in the detection of breast cancer metastases in sentinel lymph nodes

The identification of specific tumor mRNA markers by reverse transcription-polymerase chain reaction might be a valuable diagnostic adjunct for the detection of breast cancer metastases in axillary sentinel lymph nodes (SLNs). In this study we have compared the diagnostic accuracy of an extensive histopathologic examination of 146 SLNs from 123 breast carcinoma patients with that of the evaluation of 5 mRNA markers. When analyzed individually, none of the different markers attained a sensitivity higher than 77.8%, and the general concordance with the histopathologic findings ranged from 78.8 to 83.6%. In a multiple-marker assay, taking into account the expression of at least 1 of the 5 tumor markers, the sensitivity of the test rose to 95.6%, with a specificity of 66.3% and a general concordance with the histopathologic status of 75.3%. Finally, when at least 2 of 3 markers (maspin, cytokeratin 19 and mammaglobin 1) were expressed, the concordance with either SLN or axillary lymph node status was highest (88.4% and 84.6%, respectively). The high prevalence of positive reverse transcription-polymerase chain reaction assays in histologically uninvolved SLNs, however, may hamper extensive application of these techniques in the clinical setting.

Quantitative real-time RT-PCR detection of breast cancer micrometastasis using a multigene marker panel

Real-time RT-PCR is a relatively new technology that uses an online fluorescence detection system to determine gene expression levels. It has the potential to significantly improve detection of breast cancer metastasis by virtue of its exquisite sensitivity, high throughput capacity and quantitative readout system. To assess the utility of this technology in breast cancer staging, we determined the relative expression levels of 12 cancer-associated genes (mam, PIP, mamB, CEA, CK19, VEGF, erbB2, muc1, c-myc, p97, vim and Ki67) in 51 negative-control normal lymph nodes and in 17 histopathology-positive ALNs. We then performed a receiver operating characteristic (ROC) curve analysis to determine the sensitivity and specificity levels of each gene. Areas under the ROC curve indicated that the most accurate diagnostic markers were mam (99.6%), PIP (93.3%), CK19 (91.0%), mamB (87.9%), muc1 (81.5%) and CEA (79.4.0%). mam was overexpressed in 16 of 17 lymph nodes known to contain metastatic breast cancer at levels ranging from 22- to 2.8 x 10(5)-fold above normal mean expression, whereas PIP was overexpressed from 30- to 2.2 x 10(6)-fold above normal in 13 lymph nodes. Real-time RT-PCR analysis of pathology-negative LN from breast cancer patients revealed evidence of overexpression of PIP (6 nodes), mam (3 nodes) and CEA (1 node) in 8 of 21 nodes (38%). Our results provide evidence that mam, PIP, CK19, mamB, muc1 and CEA can be applied as a panel for detection of metastatic and occult micrometastatic disease.

Lacryglobin in human tears, a potential marker for cancer

Lacrygobin has been identified in human tears. This protein has high sequence homology to the mammaglobins, proteins upregulated in breast cancer and in breast cancer metastasis. In order to investigate the utility of tear screening for cancer tear samples were collected from patients with different types of cancer and compared to controls. Tear samples were taken from five controls and eight breast, six lung, five colon, one prostate and three ovary cancer patients. Tears were analysed using 2-D gel electrophoresis (n = 25) and 1-D electrophoresis (n = 3). Lacryglobin was present in the following percentage of patients: breast cancer (88%), lung (83%), colon (100%), ovary (33%), prostate (100%) and controls (60%). Two control patients with lacryglobin had a family history of breast and prostate cancer. Lacryglobin was detected in some but not all tear samples and further studies are warranted to investigate its potential as a marker for cancer.

Detection of occult metastasis in patients with breast cancer

The most important factor affecting the outcome of patients with invasive cancer is whether the tumor has spread, either regionally (to regional lymph nodes) or systemically. However, a proportion of patients with no evidence of systemic dissemination will develop recurrent disease after primary "curative" therapy. Clearly, these patients had occult systemic spread of disease that was undetectable by routinely employed methods (careful pathological, clinical, biochemical, and radiological evaluation). In addition, the success of adjuvant therapy is assumed to stem from its ability to eradicate occult metastases before they become clinically evident. Therefore, methods for the detection of occult metastases in patients with the earliest stage of cancer, i.e., prior to detection of metastases by any other clinical or pathological analysis, have received a great deal of attention.

Bone marrow micrometastases detected by RT-PCR for mammaglobin can be an alternative prognostic factor of breast cancer

PURPOSE

To evaluate a new prognostic factor of breast cancer, bone marrow micrometastases which was detected by RT-PCR for mammaglobin, a sensitive molecular marker of breast cancer, was examined.

MATERIALS AND METHODS

One hundred and eleven samples from stage I-III breast cancer patients were examined. Bone marrow micrometastases and clinicopathological parameters, which were age, tumor size, lymph node metastasis and status of the estrogen receptor, were evaluated for the prognostic factor by statistical analysis.

RESULTS

Median follow-up time was 21.1 months. Thirty-three (29.7%) out of 111 samples were RT-PCR positive. Eight cases (24.2%) in this group showed recurrent lesions in the distant organs. Whereas six (7.7%) out of 78 RT-PCR negative patients had distant recurrences. In the premenoposal patients, and in the patients with axillary lymph node metastases, RT-PCR positive cases showed significantly higher distant recurrent rate. Bone marrow micrometastases, axillary nodal status, and estrogen receptor were independent prognostic factors for breast cancer by both univariate and multivariate analysis.

CONCLUSIONS

Bone marrow micrometastases detected by RT-PCR for mammaglobin can be a useful predictive marker for early distant recurrence of breast cancer.

Molecular detection and characterisation of circulating tumour cells and micrometastases in solid tumours

The detection and molecular characterisation of circulating tumour cells (CTC) and micrometastases may have important prognostic and therapeutic implications. Because their numbers are very small, these tumour cells are not easily detected using conventional methods. In the last decade, numerous groups have attempted to detect occult tumour cells in solid malignancies using the highly sensitive reverse transcriptase polymerase chain reaction (RT-PCR). These assays were in the vast majority directed against tissue-specific markers. PCR was shown to be superior to conventional techniques in detecting occult tumour cells allowing the identification of one malignant cell mixed with 1-10 million normal cells. In some tumours like melanoma and prostatic carcinoma, tissue-specific transcripts were detected with high specificity in the blood of patients with localised and advanced disease. In some reports, PCR was shown to be a strong predictor of poorer outcome. However, due to the many limitations of PCR (e.g false-positives), many groups are developing new approaches for the detection of occult tumour cells. The most attractive technique involves immunomagnetic isolation of CTC and micrometastases prior to downstream analysis. The tumour-rich magnetic fraction can be subjected to RT-PCR, immunocytochemistry and in situ hybridisation. This will lead to better quantification and molecular characterisation of these tumour cells. In conclusion, the molecular detection and characterisation of occult tumour cells offer a great opportunity for better stratifying patients with solid tumours and for developing new prognostic markers and targeted therapies.

Mammaglobin B gene as a novel marker for lymph node micrometastasis in patients with abdominal cancers

Mammaglobin B is a recently-isolated gene speculated to belong to the uteroglobin gene family and is overexpressed in primary breast cancers. We investigated mammaglobin B mRNA expression in various cancers of the digestive system. Given the absence of mammaglobin B expression in normal lymph nodes, we also assessed the usefulness of mammaglobin B as a marker for lymph node micrometastases in cancer patients. Mammaglobin B gene transcripts were frequently detected by reverse transcriptase-polymerase chain reaction (RT-PCR) assay in primary tumors of the esophagus (2/3), stomach (7/7), colon (15/15), pancreas (4/6), common bile duct (6/6), cholangioma (2/2) and gall bladder (1/1). Mammaglobin B overexpression was observed in three of 15 cases (20%) of colon cancer, suggesting its possible contribution to colon carcinogenesis. Down-regulated mammaglobin B expression was observed in hepatoma cells in comparison with corresponding non-cancerous livers (3/3). RT-PCR assay of mammaglobin B detected 14 of 15 histologically positive lymph nodes from patients with gastric cancer, colon cancer and cholangioma. Seven of 32 (22%), three of nine (33%), and three of seven (43%) histologically negative nodes from patients with gastric, colon and cholangiocellular carcinoma, respectively, were found to express mammaglobin B mRNA. Our results showed that expression of mammaglobin B was frequently detected in cancers originating in digestive organs, especially adenocarcinomas, and that mammaglobin B gene detected by RT-PCR may be a potentially useful molecular marker for lymph node micrometastases of various digestive organ cancers.