Quantitative evaluation of metastases in axillary lymph nodes of breast cancer

Greater negative lymph node count predicts favorable survival of patients with breast cancer in the setting of neoadjuvant chemotherapy and mastectomy

Aim: Adequate lymph node evaluation is recommended in patients with malignant tumors. However, the role of negative lymph nodes (NLNs) remains unclear in breast cancer (BC), especially in patients who have received neoadjuvant chemotherapy and mastectomy. Materials & methods: A total of 435 patients were included in the analysis. On multivariate analysis, NLN count was an independent predictor of 5 year disease-free survival and 5 year overall survival. Results: Patients with NLN count <10 showed significantly worse 5 year disease-free survival than those with NLN count ≥10 (34.8 and 78.2%; p = 0.000); the corresponding 5 year overall survival rates were also significantly different (52.0 and 82.7%; p = 0.000). Conclusion: This is the first study that confirms the relationship between NLN count and prognosis of patients in the setting of neoadjuvant chemotherapy and mastectomy. More NLNs imply better prognosis.

Predicting Sentinel Lymph Node Metastases in Infiltrating Breast Carcinoma With Vascular Invasion

Sentinel lymph node and clinically negative axillary node status was compared with well-known clinicopathological characteristics such as tumor size, histologic and nuclear grade, lymphovascular invasion, steroid receptor, and HER-2 status in patients with breast cancer (pT1 and pT2). Positive sentinel lymph nodes were found in 29 of 100 patients: 19 with metastases detected by hematoxylin and eosin staining and 10 with micrometastases confirmed by immunohistochemistry with cytokeratin. Positive sentinel lymph nodes were present in larger carcinomas ( P < 0.03), more frequently in tumors with negative PR status ( P < 0.037) and evident lymphovascular invasion ( P < 0.002). Lymphovascular invasion was also associated with breast cancer of higher histologic ( P = 0.011) and nuclear grade ( P = 0.039). Tumor size and the presence of lymphovascular invasion were found to be significant predictors of pathologically positive sentinel lymph node in T1 and T2.

Assessment of Cytokeratin-19 Gene Expression in Peripheral Blood of Breast Cancer Patients and Breast Cancer Cell Lines

Detection of cytokeratin-19 (CK19) expression as an epithelial-specific marker in circulating tumor cells (CTCs) of breast cancer patients can be important for diagnostic purposes. Comparison of CK19 expression in breast cancer cell lines can indicate that expression of this marker is different in various breast cancer cell lines based on their category. Thirty-five breast cancer patients were evaluated for detection of CK19 mRNA in their peripheral blood using CK19-specific primers and a nested reverse transcriptase polymerase chain reaction (RT-PCR) technique. CK19 expression levels were detected in MCF7, T47D, SK-BR-3, and MDA-MB-231 cell lines by semiquantitative RT-PCR and Western blot analyses. Statistical analysis of our data indicates that there is no significant difference between CK19 expression and histopathological parameters and some molecular markers, including Ki-67, HER-2, and P53, but there are statistically significant correlations between estrogen receptor (P = 0.040) and progesterone receptor (P = 0.046) with CK19 expression. CK19 expression was detected in MCF7, T47D, and SK-BR-3 cell lines but not in MDA-MB-231 cell line. More studies are needed to determine the relationship between this marker and other markers in the diagnosis and treatment of breast cancer. On the other hand, the study of different markers using breast cancer cell lines as experimental models of breast cancer could have an impact on improving the health outcomes of patients with breast cancer.

Number of negative lymph nodes is associated with disease-free survival in patients with breast cancer

BACKGROUND

The aim of this study was to evaluate the prognostic value of the number of negative lymph nodes (NLNs) in breast cancer patients after mastectomy.

METHODS

2,455 breast cancer patients who received a mastectomy between January 1998 and December 2007 were retrospectively reviewed. The prognostic impact of the number of NLNs with respect to disease-free survival (DFS) was analyzed.

RESULTS

The median follow-up time was 62.0 months, and the 5-year and 10-year DFS was 87.1% and 74.3%, respectively. The DFS of patients with >10 NLNs was significantly higher than that of patents with ≤10 NLNs, and the 5-year DFS rates were 87.5% and 69.5%, respectively (P < 0.001). Univariate Cox analysis showed that the NLN count (continuous variable) was a prognostic factor of DFS (hazard ratio [HR] = 0.913, 95% confidence interval [CI]: 0.896-0.930, P < 0.001). In multivariate Cox analysis, patients with a higher number of NLNs had a better DFS (HR = 0.977, 95% CI: 0.958-0.997, P = 0.022). Subgroup analysis showed that the NLN count had a prognostic value in patients at different pT stages and pN positive patients (log-rank P < 0.001). However, it had no prognostic value in pN0 patients (log-rank P = 0.684).

CONCLUSIONS

The number of NLNs is an independent prognostic factor of DFS in breast cancer patients after mastectomy, and patients with a higher number of NLNs have a better DFS.

Triple assessment of sentinel lymph node metastasis in early breast cancer using preoperative CTLG, intraoperative fluorescence navigation and OSNA

BACKGROUND

Sentinel lymph node biopsy (SLNB) became a standard surgical procedure for patients with early breast cancer; however, the optimal method of sentinel lymph node (SLN) identification remains controversial. The current study presents the protocol of our institution for preoperative and intraoperative SLN detection.

METHODS

Fifty female patients with early breast cancer and clinically node-negative axilla were enrolled in this study. All patients underwent preoperative CT lymphography (CTLG), intraoperative SLNB using fluorescence navigation, intraoperative one-step nucleic acid amplification (OSNA) and postoperative hematoxylin and eosin histopathological analysis. Prediction of metastasis by CTLG and detection of metastasis by OSNA were compared to results of histopathology as standard reference.

RESULTS

SLN were identified by preoperative CTLG and intraoperative SLNB with fluorescence navigation in all patients, the identification rate was 100 %. SLN metastases were detected as positive by OSNA in 9 patients (18 %), 4 were (++), 4 were (+) and 1 was (+I). SLN metastases were detected as positive by histopathology in 10 patients (20 %). The concordance rate between OSNA and permanent sections was 90 %. The negative predictive value of CTLG was 80 %.

CONCLUSION

Use of CTLG and fluorescence navigation made performing SLNB with high accuracy possible in institutions that cannot use the radioisotope method. OSNA provided accurate intraoperative method, allowing for completion of axillary node dissection during surgery and avoidance of second surgical procedure in patients with positive SLNs, thereby reducing patient distress and, finally, saving hospital costs.

Mesenchymal phenotype of CTC-enriched blood fraction and lymph node metastasis formation potential

Introduction

Circulating tumor cells (CTCs) that present mesenchymal phenotypes can escape standard methods of isolation, thus limiting possibilities for their characterization. Whereas mesenchymal CTCs are considered to be more malignant than epithelial CTCs, factors responsible for this aggressiveness have not been thoroughly defined. This study analyzed the molecular profile related to metastasis formation potential of CTC-enriched blood fractions obtained by marker unbiased isolation from breast cancer patients without (N−) and with lymph nodes metastases (N+).

Materials and Methods

Blood samples drawn from 117 patients with early-stage breast cancer were enriched for CTCs using density gradient centrifugation and negative selection with anti-CD45 covered magnetic particles. In the resulting CTC-enriched blood fractions, expression of CK19, MGB1, VIM, TWIST1, SNAIL, SLUG, HER2, CXCR4 and uPAR was analyzed with qPCR. Results were correlated with patients' clinicopathological data.

Results

CTCs (defined as expression of either CK19, MGB1 or HER2) were detected in 41% (20/49) of N− and 69% (34/49) of N+ patients (P = 0.004). CTC-enriched blood fractions of N+ patients were more frequently VIM (P = 0.02), SNAIL (P = 0.059) and uPAR-positive (P = 0.03). Positive VIM, CXCR4 and uPAR status correlated with >3 lymph nodes involved (P = 0.003, P = 0.01 and P = 0.045, respectively). In the multivariate logistic regression MGB1 and VIM-positivity were independently related to lymph node involvement with corresponding overall risk of 3.2 and 4.2. Moreover, mesenchymal CTC-enriched blood fractions (CK19−/VIM+ and MGB1+ or HER2+) had 4.88 and 7.85-times elevated expression of CXCR4 and uPAR, respectively, compared with epithelial CTC-enriched blood fractions (CK19+/VIM− and MGB1+ or HER2+).

Conclusions

Tumors of N+ patients have superior CTC-seeding and metastatic potential compared with N- patients. These differences can be attributed to VIM, uPAR and CXCR4 expression, which endow tumor cells with particularly malignant phenotypes.

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.

A mammaglobin-A targeting agent for noninvasive detection of breast cancer metastasis in lymph nodes

Pathologic axillary lymph node (ALN) status is an important prognostic factor for staging breast cancer. Currently, status is determined by histopathology following surgical excision of sentinel lymph node(s), which is an invasive, time consuming, and costly procedure with potential morbidity to the patient. Here, we describe an imaging platform for noninvasive assessment of ALN status, eliminating the need for surgical examination of patients to rule out nodal involvement. A targeted imaging probe (MamAb-680) was developed by conjugation of a mammaglobin-A-specific monoclonal antibody to a near-infrared fluorescent dye. Using DNA and tissue microarray, mammaglobin-A was validated as a cell-surface target that is expressed in ALN-positive patient samples but is not expressed in normal lymph nodes. In vivo selectivity was determined by i.v. injection of MamAb-680 into mice with mammaglobin-A-positive and -negative mammary fat pad (MFP) tumors; and by peritumoral MFP injection of the targeted imaging probe in mice with spontaneous ALN metastases. Fluorescence imaging showed that probe was only retained in positive tumors and metastases. As few as 1,000 cells that endogenously express mammaglobin-A were detected in ALN, indicating high sensitivity of this method. Translation of this approach offers considerable potential as a noninvasive clinical strategy to stage breast cancer.

Simple experimental and spontaneous metastasis assays in mice

Many steps of the metastatic cascade can be reproduced in simple in vitro assays such as tumour cell interactions with matrix proteins, proteolysis, chemotaxis, haptotaxis, and invasion into matrices or explanted tissues. Nevertheless, there are no fully adequate substitutes for the complexity of the in vivo process. Here, we describe two "experimental" metastasis assays to yield lung or liver colonies (mimicking established micrometastatic disease), and two spontaneous metastasis assays for breast and prostate carcinomas. Examples include either murine tumour cell lines in syngeneic immunocompetent mice or human tumour xenografts in immunodeprived mice.

The endothelin axis stimulates the expression of pro-inflammatory cytokines and pro-migratory molecules in breast cancer

We investigated the effects of the endothelin-1 (ET-1) receptor dual antagonist (Bosentan®) on the inflammatory cytokines and the chemoattractant molecules associated with breast cancer growth and the development of tumor infiltration in bone explants. Immunocompetent mice implanted with the murine mammary carcinoma 4T1 cells in a skin-fold chamber and treated with Bosentan® had reduced tumor growth (p < .05). ET-1 promoted the secretion of the anti-inflammatory soluble tumor necrosis factor (TNF) receptor and IL12 p40 in vitro. The Bosentan® treatment in vivo was associated with a local increase of the anti-inflammatory IL-1α cytokine concentration and decrease of the pro-inflammatory TNF-α and IL-17 cytokine concentrations (p < .05).

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.

Molecular assessment of sentinel lymph node in breast cancer management

Sentinel lymph node biopsy (SLNB) is becoming accepted as standard of care for axillary staging in breast cancer. World Health Organization (WHO) re-classification of axillary metastases into macrometastases, micrometastases and individual tumour cells has highlighted the issues of sampling and further histological examination of the initially negative SLNB. Molecular detection of metastatic breast cancer cells in lymph nodes is now available as a commercial kit for intraoperative use and can resolve the sampling issue. Semiquantitative assessment of axillary lymph node tumour burden can now be made using two separate technologies (histology and reverse transcriptase-polymerase chain reaction). The clinical implications of low metastatic axillary lymph node tumour burden are not clear, and future trials need to include molecular data. The consequences of the availability of molecular assessment are reviewed.

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.

One-step nucleic acid amplification for intraoperative detection of lymph node metastasis in breast cancer patients

PURPOSE

Detection of sentinel lymph node (SLN) metastasis in breast cancer patients has conventionally been determined by intraoperative histopathologic examination of frozen sections followed by definitive postoperative examination of permanent sections. The purpose of this study is to develop a more efficient method for intraoperative detection of lymph node metastasis.

EXPERIMENTAL DESIGN

Cutoff values to distinguish macrometastasis, micrometastasis, and nonmetastasis were determined by measuring cytokeratin 19 (CK19) mRNA in histopathologically positive and negative lymph nodes using one-step nucleic acid amplification (OSNA). In an intraoperative clinical study involving six facilities, 325 lymph nodes (101 patients), including 81 SLNs, were divided into four blocks. Alternate blocks were used for the OSNA assay with CK19 mRNA, and the remaining blocks were used for H&E and CK19 immunohistochemistry-based three-level histopathologic examination. The results from the two methods were then compared.

RESULTS

We established CK19 mRNA cutoff values of 2.5 x 10(2) and 5 x 10(3) copies/muL. In the clinical study, an overall concordance rate between the OSNA assay and the three-level histopathology was 98.2%. Similar results were obtained with 81 SLNs. The OSNA assay discriminated macrometastasis from micrometastasis. No false positive was observed in the OSNA assay of 144 histopathologically negative lymph nodes from pN0 patients, indicating an extremely low false positive for the OSNA assay.

CONCLUSION

The OSNA assay of half of a lymph node provided results similar to those of three-level histopathology. Clinical results indicate that the OSNA assay provides a useful intraoperative detection method of lymph node metastasis in breast cancer patients.

Transcription-reverse transcription concerted reaction and minimal residual disease in axillary sentinel nodes of breast cancer

AIMS

To investigate the use of transcription-reverse transcription concerted reaction (TRC) to detect axillary lymph node metastases.

METHODS

Metastases in 423 lymph nodes obtained from 50 breast cancer patients were investigated by routine pathological hematoxylin and eosin (H and E) staining and quantitative analysis of carcinoembryonic antigen (CEA) mRNA by TRC. Enhanced pathological studies, serial sectioning and immunohistochemistry were conducted for cases which were negative by routine pathology, but positive by TRC.

RESULTS

Pathological examination identified metastatic disease in 67 lymph nodes. TRC CEA mRNA results were concordant with 89.8% of these cases at a threshold of 100 copies. TRC identified 30 false negative nodes, which was reduced to 15 by excluding node biopsies yielding less than 40 microg total RNA. Twelve nodes were histologically negative for cancer, but positive according to TRC. Serial sectioning and immunohistochemical analysis of these nodes revealed macrometastatic lesions in three, micrometastasis in one, and isolated tumor cells in two.

CONCLUSION

TRC for the detection of CEA mRNA may complement routine pathological examination by sentinel lymph node biopsy (SNB) in early breast cancer. We have started an enhanced pathological examination with serial sectioning on all excised sentinel nodes to set the best threshold for the TRC method.

Predictive value of GADD153, p21 and c-Jun for chemotherapy response in gastric cancer

We sought to determine whether changes in the expression of early response genes (GADD153, p21 and c-Jun) are indicators of chemotherapy response in gastric cancer. Three human gastric cancer cell lines were exposed to 5-fluorouracil or cisplatin in vitro. Xenografts of TMK-1 cells in nude mice were also treated with 5-fluorouracil or cisplatin in vivo. For each of these treatments, we tested for a correlation between early gene expression levels and inhibition ratios derived at a later time. A 5-fluorouracil derivative, S-1, and cisplatin were administered to 12 patients with advanced gastric cancer for 3 weeks. Gene expression levels were measured using biopsy specimens obtained by endoscopy soon after initiation of chemotherapy. There was a significant correlation between expression levels of these genes at 24 h and inhibition ratios at 72 h in vitro. Cut-off values determined from receiver-operating characteristic curves were 1.3 for GADD153, 1.8 for p21 and 2.1 for c-Jun There was also a significant correlation between gene expression levels at 2 days and inhibition ratios at 21 days in vivo. Cut-off values were 1.8 for GADD153, 1.9 for p21 and 2.2 for c-Jun. Levels of early response gene expression in patients showing progressive disease were significantly lower than those in patients with partial response. Changes in the expression of the three early response genes soon after drug administration could improve predictions of the final outcome of chemotherapy in gastric cancer.

Quantitative Detection of Micrometastases in Pelvic Lymph Nodes in Patients with Clinically Localized Prostate Cancer by Real-time Reverse Transcriptase-PCR

PURPOSE

Routine pathologic examination can miss micrometastatic tumor foci in the lymph nodes of patients with prostate cancer, resulting in confusion during tumor staging and clinical decision-making. The objective of this study was to clarify the significance of micrometastases in pelvic lymph nodes in patients who underwent radical prostatectomy for prostate cancer.

EXPERIMENTAL DESIGN

The expression of prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) in 2,215 lymph nodes isolated from 120 patients with clinically localized prostate cancer was assessed by a fully quantitative real-time reverse transcriptase-PCR. We regarded specimens in which either PSA or PSMA mRNAs were positive as proof of the "presence of micrometastasis." Immunohistochemical staining of lymph node specimens with an antibody against PSA was also done.

RESULTS

Pathologic examinations detected tumor cells in 29 lymph nodes from 11 patients, and real-time reverse transcriptase-PCR further identified micrometastasis in 143 lymph nodes from 32 patients with no pathologic evidence of lymph node involvement. The presence of micrometastatic cancer cells was confirmed by immunohistochemical staining in 61 lymph nodes from 17 patients with pathologically negative lymph nodes. The presence of micrometastases was significantly associated with other conventional prognostic variables, including serum PSA value, pathologic stage, Gleason score, and tumor volume. Biochemical recurrence was detected in 32 patients, 17 of whom were negative for lymph node metastasis by pathologic examination (including 4 patients with pathologically organ-confined disease), but were diagnosed as having micrometastasis. Biochemical recurrence-free survival rate in patients without micrometastasis was significantly higher than in those with micrometastasis irrespective of the presence of pathologically positive nodes. Furthermore, only the presence of micrometastasis was independently associated with biochemical recurrence regardless of other factors examined.

CONCLUSIONS

These findings suggest that approximately 30% of clinically localized prostate cancers shed cancer cells to the pelvic lymph nodes, and that biochemical recurrence after radical prostatectomy could be explained, at least in part, by micrometastases in pelvic lymph nodes.

Significance of micrometastases in pelvic lymph nodes detected by real-time reverse transcriptase polymerase chain reaction in patients with clinically localized prostate cancer undergoing radical prostatectomy after neoadjuvant hormonal therapy

OBJECTIVE

To clarify the significance of micrometastases in pelvic lymph nodes in patients treated by radical prostatectomy (RP) for prostate cancer after neoadjuvant hormonal therapy (NHT).

PATIENTS AND METHODS

The study included 52 patients with clinically localized prostate cancer who received NHT followed by RP. The expression of prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) in 989 lymph nodes isolated from the 52 patients were assessed by a fully quantitative real-time reverse-transcriptase polymerase chain reaction (RT-PCR). We regarded specimens in which either PSA or PSMA mRNA were positive as showing the 'presence of micrometastasis'. Lymph node specimens were also stained immunohistochemically with an antibody against PSA.

RESULTS

Pathological examinations detected tumour cells in 11 lymph nodes from four patients, and real-time RT-PCR further identified micrometastasis in 40 lymph nodes from 19 patients with no pathological evidence of nodal involvement. The presence of micrometastatic cancer cells was confirmed by immunohistochemical staining in 19 lymph nodes from 11 patients with pathologically negative nodes. The presence of micrometastases was significantly associated with other conventional prognostic variables, including the pretreatment serum PSA level, biopsy Gleason score and surgical margin status. The biochemical recurrence-free survival rate in patients with no micrometastasis was significantly higher than that in those with micrometastasis. Furthermore, multivariate analysis identified the presence of micrometastasis as an independent factor predicting biochemical recurrence.

CONCLUSIONS

Although residual foci of atrophic prostate cancer cells in resected lymph nodes after NHT can be difficult to diagnose by routine pathological examination, the present results show the usefulness of quantitative real-time RT-PCR targeting PSA and PSMA genes for detecting micrometastatic tumour foci in pelvic lymph nodes from patients with localized prostate cancer treated by NHT followed by RP. Furthermore, the present findings suggest that micrometastases in pelvic lymph nodes might be, at least partly, important in the development of biochemical recurrence in some patients undergoing RP after NHT.

Detection of occult carcinomatous diffusion in lymph nodes from head and neck squamous cell carcinoma using real-time RT-PCR detection of cytokeratin 19 mRNA

The aim of the present study was to evaluate the occult lymph node carcinomatous diffusion in head and neck squamous cell carcinoma (HNSCC). A total of 1328 lymph nodes from 31 patients treated between 2004 and 2005 were prospectively evaluated by routine haematoxylin–eosin–safran (HES) staining, immunohistochemistry (IHC) and real-time Taqman reverse–transcriptase polymerase chain reaction (real-time RT–PCR) assay. Amplification of cytokeratin 19 (CK19) mRNA transcripts using real-time RT–PCR was used to quantify cervical micrometastatic burden. The cervical lymph node metastatic rates determined by routine HES staining and real-time RT–PCR assay were 16.3 and 36.0%, respectively (P<0.0001). A potential change in the nodal status was observed in 13 (42.0%) of the 31 patients and an atypical pattern of lymphatic spread was identified in four patients (12.9%). Moreover, CK19 mRNA expression values in histologically positive lymph nodes were significantly higher than those observed in histologically negative lymph nodes (P<0.0001). These results indicate that real-time RT–PCR assay for the detection of CK19 mRNA is a sensitive and reliable method for the detection of carcinomatous cells in lymph nodes. This type of method could be used to reassess lymph node status according to occult lymphatic spread in patients with HNSCC.

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.

Assessing the status of axillary sentinel lymph nodes of breast carcinoma patients by a real-time quantitative RT-PCR assay for mammaglobin 1 mRNA

The aim of the study was to assess the accuracy of a real-time quantitative RT-PCR (qRT-PCR) assay for mammaglobin 1 mRNA in the detection of metastatic breast cancer in axillary sentinel lymph nodes (SLN), comparing the results with those of qualitative RT-PCR assays and of an extensive histopathological examination. A retrospective series of 81 SLN from 72 patients and a validation series of 61 SLN from 61 patients were evaluated. In the retrospective series, the qRT-PCR assay was positive for 23 (28.4%) of the 81 SLN. The overall concordance with histopathology was 93.8%, with a sensitivity of 90.9%, a specificity of 94.9%, a positive predictive value (PPV) of 87% and a negative predictive value (NPV) of 96.6%. In the same series, qualitative RT-PCR showed an overall concordance with histopathology of 86.4%, a sensitivity of 72.7%, a specificity of 91.5%, a PPV of 76.2% and a NPV of 90%. In the validation series, including 23 patients with pure in situ carcinoma, the real-time qRT-PCR assay showed an overall concordance with the histopathologic findings of 93.4%, with a sensitivity of 75.0%, a specificity of 94.7%, a PPV of 50.0% and a NPV of 98.2%. We conclude that real-time qRT-PCR assays for mammaglobin 1 are more sensitive and specific that qualitative RT-PCR assays for the detection of metastatic breast carcinoma in axillary SLN, but it should not be regarded as a possible substitute for an extensive histopathological scrutiny of the SLN in the clinical practice.

Pathologic examination of the axillary sentinel lymph nodes in patients with early-stage breast carcinoma: current and resolving controversies on the basis of the European Institute of Oncology experience

Several controversial aspects of sentinel lymph node biopsy (SLNB) for patients with early-stage, node-negative breast carcinoma have been dealt with and resolved in the past decade since its introduction. Unfortunately, however, there is still no consensus on how best to examine sentinel lymph nodes (SLN) histologically. As a consequence, the protocols for SLN examination are remarkably variable in different institutions, leading to a very poor reproducibility of the data stemming from investigations on series of patients whose SLNs have been evaluated according to diverse protocols. Patient outcomes, however, can be optimised only by standardization of the whole procedure of SLNB, with particular reference to the histopathologic scrutiny. Lack of a standardized histopathologic protocol likely derives also from the uncertainties about the clinical implications of minimal lymph node involvement (isolated tumour cells and micrometastases) with regard both to the risk of additional metastases to non-sentinel lymph nodes of the same basin and to the prognostic value for patients' survival. This review aims at highlighting some of the controversial issues of the histopathologic examination of the SLNs, including the number of sections and cutting intervals, the use of immunohistochemistry and the role of molecular biology assays.

Real-time quantitative RT-PCR detection of disseminated endometrial tumor cells in peripheral blood and lymph nodes using the LightCycler System

OBJECTIVE

Some endometrial cancer patients without clinical evidence of extrauterine spread die as a result of recurrence even after curative operation. These recurrences may arise from occult tumor cells that are not detected by conventional methods. The goal of this study was to develop a quantitative method for the detection of disseminated tumor cells (DTCs) in the peripheral blood (PB) and lymph nodes (LNs) of patients with endometrial cancer.

METHODS

Ninety-eight PB samples from 30 patients and 218 LNs from 14 patients were studied. Real-time quantitative analysis was performed using a LightCycler instrument and a TaqMan probe for cytokeratin 19 (CK19) as a marker gene.

RESULTS

This method resulted in the reproducible quantitation of 10 to 10(6) MCF-7 cells (CK19-expressing breast cancer cell line) per 10(6) peripheral blood nucleated cells. CK19 mRNA expression was detected in 28 PB samples and in 62 LNs. Only three preoperative PB samples and one postoperative PB sample (from four patients) and 33 LNs (from six patients) were PCR-positive. The PCR-positive rate of LNs was higher in patients with pathologically metastatic (path-positive) LNs than in patients with path-negative but PCR-positive LNs. Furthermore, the CK19 mRNA background expression rate was higher in the LNs of path-negative but PCR-positive patients than in LNs of path-negative and PCR-negative patients.

CONCLUSIONS

Real-time qRT-PCR with TaqMan probes is a sensitive, specific and rapid method for the detection of DTCs in PB and LNs. Additional studies with larger numbers of patients and adequate follow-up would be of benefit.

Detection of Micrometastases in Pelvic Lymph Nodes in Patients Undergoing Radical Cystectomy for Focally Invasive Bladder Cancer by Real-time Reverse Transcriptase-PCR for Cytokeratin 19 and Uroplakin II

PURPOSE

The objective of this study was to clarify the significance of micrometastases in pelvic lymph nodes in patients who underwent radical cystectomy for bladder cancer.

EXPERIMENTAL DESIGN

We included 40 patients with locally invasive bladder cancer who underwent radical cystectomy and pelvic lymphadenectomy. Expression of cytokeratin 19 (CK19), uroplakin II (UP II), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in 760 lymph nodes were assessed by a fully quantitative real-time reverse transcription-PCR (RT-PCR) assay. The quantification value of CK19 or UP II mRNA was described as each value relative to GAPDH mRNA. In this study, we regarded specimen in which either CK19 or UP II mRNA was positive as "presence of micrometastasis."

RESULTS

Routine pathologic examinations detected tumor cells in 29 lymph nodes from six patients. Real-time RT-PCR identified positive expression of CK19 and UP II mRNAs in 49 lymph nodes from 10 patients and 98 lymph nodes from 16 patients, respectively. Of 633 lymph nodes from 34 patients with no pathologic evidence of nodal involvement, 13 nodes from five patients and 58 nodes from 10 patients were diagnosed as positive for CK19 and UP II mRNAs expression, respectively, by real-time RT-PCR. Presence of micrometastases was significantly associated with other conventional prognostic variables, including pathologic stage and microvascular invasion. Disease recurrence was occurred in eight patients, among whom four patients were negative for lymph node metastasis by routine pathologic examination and diagnosed as having micrometastasis by real-time RT-PCR assay. Furthermore, cause-specific survival rate in patients without micrometastasis was significantly higher than that in those with micrometastasis, irrespective of the presence of pathologic-positive nodes.

CONCLUSIONS

Approximately 30% of locally invasive bladder cancer shed cancer cells to pelvic lymph nodes, and disease recurrence after radical cystectomy could be explained, at least in part, by micrometastases in pelvic lymph nodes.

Proteomics of breast cancer: Enhanced expression of cytokeratin19 in human epidermal growth factor receptor type 2 positive breast tumors

The human epidermal growth factor receptor, type 2 (HER-2/neu or c-erbB-2) is a 185 kDa transmembrane protein that is phosphorylated upon ligand binding and dimerization with members of the HER/c-erbB family and regulates cell growth and differentiation. Its overexpression is strongly associated with advanced disease, metastasis and poor clinical outcome. To better understand the mechanisms underlying the poor prognosis of breast tumors with HER-2/neu-positive status, parallel proteomic analyses were performed on estrogen receptor-negative and node-positive breast tumors with or without overexpression of the HER-2/neu oncogene, using laser capture microdissection and two-dimensional gel electrophoresis. The differentially expressed proteins were identified by peptide mass fingerprinting using matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Cytokeratin 19 (CK19), one of the identified proteins, was highly expressed in the HER-2/neu-positive breast tumors when compared with HER-2/neu-negative breast tumors. The enhanced overexpression of CK19 in HER-2/neu-positive tumors was further analyzed using semiquantitative reverse-transcription polymerase chain reaction, Western blotting and reverse-phase protein arrays. Immunohistochemical staining of sections from a breast tumor tissue microarray of 97 tumors showed moderate to strong staining against anti-CK19 antibody in 20 (5 with moderate and 15 with strong staining) of the 26 HER-2/neu-positive tumors (76.9%) and in 22 (12 with moderate and 10 with strong staining) of 52 HER-2/neu-negative tumors (48%) (p = 0.002). Our results indicate that CK19, an intermediate fragment of the cytoskeleton, and other proteins showing differential expression, are likely to be intricately involved in intra- and intercellular molecular events driving the more aggressive tumor proliferation, invasion and metastasis associated with HER-2/neu-positive tumors.

Recent development of sentinel lymph node biopsy for breast cancer in Japan

The number of breast cancer cases undergoing sentinel lymph node biopsy (SLNB) has been increasing with the number of articles published in Japan. SLNB using the dye method alone is performed in about one-third of patients. Analysis of questionnaire responses from 40 institutions in Japan revealed an identification rate by the dye method alone of 87%, compared with 96% using the combined method; the combined method is now recognized in Japan as superior to the dye method alone. No dyes have been specifically approved by the government for use in SLNB, and physicians have been using several inappropriate dyes as tracers for SLNB, such as indocyanine green, patent blue, indigo carmine, and isosulfan blue. The colloidal radiotracers used in Japan include tin colloid, stannous phytate, rhenium sulfate and human serum albumin. Albumin colloid and sulfur colloid are not commercially available in Japan. Small-size tin colloids, stannous phytate and rhenium sulfate all yield good results in terms of detection and false-negative rates. Provided that the surgeon has adequate experience in SLNB, a negative sentinel node can serve as a substitute for negative results from axillary lymph node dissection. Although many institutions have introduced SLNB, few reports have focused on the results of SLNB without axillary dissection because of short follow-up times and small number of patients. The final decision as to whether SLNB is an adequate substitute for axillary dissection awaits the results of prospective randomized trials.