The immunohistochemical detection of lymph node metastases from infiltrating lobular carcinoma of the breast

Lack of Clinical Value for Immunohistochemistry for Sentinel Lymph Node Assessment in Invasive Lobular Carcinoma

BACKGROUND

The distinct histologic appearance of invasive lobular carcinoma (ILC) may pose diagnostic challenges for sentinel lymph node (SLN) analysis. We evaluated the impact of cytokeratin immunohistochemistry (IHC) on SLN assessment in ILC and its contribution to pathologic nodal upstaging.

METHODS

We identified ILC patients treated with SLN surgery at our institution between September 2008 and August 2021. IHC for SLN assessment was employed at the discretion of the pathologist. Differences between groups evaluated with and without IHC were compared using Chi-square tests.

RESULTS

Overall, 608 cases of ILC were identified in patients who underwent SLN surgery. IHC was used in 301 cases (49.5%) and was not associated with cT category, pT category, or tumor grade. Use of IHC increased detection of SLN+ disease when isolated tumor cells (ITCs) were included in the analysis (35.9% with IHC vs. 21.2% without IHC; p < 0.001). There was no effect on nodal upstaging to micrometastatic disease (pN1mi) or greater (21.9% with IHC vs. 21.2% without IHC; p = 0.82). IHC did not increase the number of positive SLNs detected (median 1 with and without IHC) nor did it increase axillary lymph node dissection (ALND) rates (11.6% with IHC vs. 15.3% without IHC; p = 0.18).

CONCLUSION

IHC improved detection of pN0(i+) disease among ILC patients undergoing SLN surgery. IHC did not increase upstaging to pN1mi or higher categories of nodal disease, detection of a greater number of positive SLNs, or ALND rates. Our data suggest routine use of IHC for SLN assessment in ILC patients does not add clinical utility.

Isolated Tumor Cells in Sentinel Lymph Nodes of Primary Invasive Breast Carcinoma: A Cohort Analysis

BACKGROUND

The practice of performing routine cytokeratin immunohistochemistry (CK-IHC) on sentinel lymph nodes in early stage invasive breast cancer leads to frequent identification of isolated tumor cells (ITCs), the clinical significance of which remains unclear. After emergence of guidelines that suggested limited clinical utility of ITC detection, routine CK-IHC (rCK-IHC) staining was discontinued at our institution. We studied the rate and clinical utility of ITC detection before and after the discontinuation of rCK-IHC.

PATIENTS AND METHODS

We retrospectively reviewed 2 cohorts of 250 consecutive early stage invasive breast cancer (IBC) patients with sentinel lymph node biopsies (SLNBs) in 2010 to 2011 (rCK-IHC) and 2015 to 2016 (selective CK-IHC [sCK-IHC]). Variables abstracted included: tumor histology, tumor size, grade, lymphatic-vascular invasion, hormone receptor expression, HER2 status, and nodal status including ITCs. All cases from the 2015 to 2016 cohort for which sCK-IHC was performed underwent pathology review. A clinical review of treatment decision effect and cost analysis was undertaken. Data were analyzed using descriptive statistics and Fisher exact test.

RESULTS

In the rCK-IHC cohort, all 250 cases underwent CK-IHC staining versus 57 cases in the sCK-IHC cohort. There were 23 ITC cases observed in the rCK-IHC cohort compared with 11 in the sCK-IHC cohort (P = .049). Excluding lobular carcinomas, 19 ITC cases were observed with rCK-IHC versus 7 with sCK-IHC (P = .02). ITC detection did not affect adjuvant treatment decision-making and resulted in savings of at least Can$8000.

CONCLUSION

Selective rather than routine use of CK-IHC staining for SLNB evaluation in early-stage IBC results in decreased ITC detection without affecting treatment decisions and leads to cost savings.

Prognostic Significance of the Expression of Immuno-Histochemically Detectable Differentiation Markers in Laryngeal Carcinomas

Expression of immunocytochemically detectable markers in 100 cases of laryngeal carcinomas, homogeneous for staging and treatment, was correlated with clinical evolution of the disease. Follow-up for a minimum of 5 years was obtained in all cases. Paraffin sections were re-cut and stained in immunoperoxidase with monoclonal KL1, detecting medium-to-low molecular weight keratins, and with monoclonal HMFG2, revealing a surface glycoprotein. Expression of KL1-related antigen did not correlate with prognosis, whereas cases extensively positive for monoclonal HMFG2 (more than 50% cells stained) had a significantly better recurrence-free rate. In a group of tumors classified as Grade 3 (histologically poorly differentiated) and expressing a low degree of HMFG2-detectable surface glycoprotein (< 50 % cells stained), a high rate of recurrences (93%) was observed. This study indicates that the combined use of morphologic and biologic (immunohistochemical) criteria may constitute an independent parameter of primary importance in predicting the evolution of laryngeal carcinomas.

Significance of immunohistochemistry in breast cancer

The biological characteristics of the tumour are used to estimate prognosis and select appropriate systemic therapy for patients with (breast) cancer. The advent of molecular technology has incorporated new biomarkers along with immunohistochemical and serum biomarkers. Immunohistochemical markers are often used to guide treatment decisions, to classify breast cancer into subtypes that are biologically distinct and behave differently, and both as prognostic and predictive factors. Steroid hormone receptors, markers of tumour proliferation, and factors involved in angiogenesis and apoptosis are of scientific interest. In this review we will provide information on the immunohistochemical markers used in the management of breast cancer patients using available data from the literature. We consider the utility of established immunohistochemical markers, and discuss the challenges involved in integrating novel molecular markers into clinical practice.

Significance of immunohistochemistry in breast cancer

The biological characteristics of the tumour are used to estimate prognosis and select appropriate systemic therapy for patients with (breast) cancer. The advent of molecular technology has incorporated new biomarkers along with immunohistochemical and serum biomarkers. Immunohistochemical markers are often used to guide treatment decisions, to classify breast cancer into subtypes that are biologically distinct and behave differently, and both as prognostic and predictive factors. Steroid hormone receptors, markers of tumour proliferation, and factors involved in angiogenesis and apoptosis are of scientific interest. In this review we will provide information on the immunohistochemical markers used in the management of breast cancer patients using available data from the literature. We consider the utility of established immunohistochemical markers, and discuss the challenges involved in integrating novel molecular markers into clinical practice.

Modified Alcian blue enhances the intraoperative diagnosis of sentinel lymph node metastasis in invasive lobular carcinoma: a prospective study

CONTEXT

The sensitivity of an intraoperative diagnosis of sentinel lymph node metastasis of invasive lobular carcinoma using conventional staining is low.

OBJECTIVE

To develop a fast, modified, Alcian blue stain to decrease the intraoperative false-negative results in testing for metastatic invasive lobular carcinoma.

DESIGN

Modified Alcian blue was optimized. Patients who had invasive lobular carcinoma on needle biopsy were candidates for this study. Touch preparations from every sentinel lymph node were prospectively prepared in the same manner, one stained with modified Alcian blue and one with conventional staining. These slides were independently interpreted.

RESULTS

A total of 121 sentinel lymph nodes from 31 patients with invasive lobular carcinoma were studied. There were 11 patients (35.5%) who had at least one positive lymph node test result. There were a total of 18 positive lymph node results (14.9%). Although 10 sentinel lymph nodes with abnormalities were detected in 7 patients with conventional staining, modified Alcian blue detected 15 sentinel lymph node abnormalities in 10 patients. Modified Alcian blue increased the sensitivity compared with conventional staining from 63.6% to 90.9% (calculated based on the number of patients) and from 55.6% to 83.3% (calculated based on number of sentinel lymph nodes). The staining process takes approximately 11 minutes.

CONCLUSIONS

Modified Alcian blue stain is a relatively rapid, cheap, highly sensitive, and specific method of detecting metastatic invasive lobular carcinoma. This method can be used in conjunction with conventional staining methods used intraoperatively.

Comparison of intraoperative frozen section analysis for sentinel lymph node biopsy during breast cancer surgery for invasive lobular carcinoma and invasive ductal carcinoma

BACKGROUND

Sentinel lymph node (SLN) biopsy is the standard of care for the surgical assessment of the axilla during breast cancer surgery. However, the diagnostic accuracy of intraoperative frozen section analysis for confirming metastatic involvement of SLNs in cases of invasive lobular carcinoma (ILC) versus that of invasive ductal carcinoma (IDC) has generated controversy secondary to a frequently low-grade cytologic appearance and an often discohesive pattern displayed by metastatic lymph nodes in ILC. In the current report, we present a comparison of intraoperative frozen section analysis for confirming the presence of metastatic disease within SLNs during breast cancer surgery for ILC and IDC.

METHODS

We evaluated the results of 131 consecutive cases of ILC from 1997 to 2008 and 133 cases of IDC (selected by a random sequence generator program) from amongst 1163 consecutive cases of IDC from the same time period. All cases had at least one SLN that had both intraoperative frozen section analysis and confirmatory permanent section analysis performed.

RESULTS

No statistically significant difference was found in the sensitivity (67% vs. 75%, P = 0.385), specificity (100% vs. 100%), accuracy (86% vs. 92%, P = 0.172), false negative rate (33% vs. 25%, P = 0.385), negative predictive value (81% vs. 89%, P = 0.158), and positive predictive value (100% vs. 100%) for frozen section analysis for confirming the presence of metastatic disease within SLNs during breast cancer surgery for ILC and IDC.

CONCLUSION

Since there was no statistically significant difference in sensitivity, specificity, accuracy, false negative rate, negative predictive value, and positive predictive value between frozen section analysis of SLNs for patients with ILC and IDC, the clinical accuracy of confirming metastatic involvement of SLNs on frozen section analysis for ILC should not be considered inferior to the clinical accuracy for IDC. Therefore, frozen section analysis of all SLNs during breast cancer surgery in patients with ILC should remain the standard of care in order to reduce the risk of the need of a later, separate axillary lymph node dissection.

Strong impact of micrometastatic tumor cell load in patients with esophageal carcinoma

BACKGROUND

To assess the role of immunohistochemically detectable nodal microinvolvement of patients with "curatively" resected esophageal carcinoma.

METHODS

In 73 patients with resectable esophageal carcinoma [squamous cell carcinoma (SCC), n = 45 (61.6%); adenocarcinoma (AC), n = 28 (38.4%)] a total of 2174 lymph nodes (LN) were removed. In each of the 1958 LN classified as negative on conventional histopathology, immunohistochemistry was performed using the anticytokeratin antibody AE1/AE3. To determine the role of the amount of residual tumor load, the patients were grouped according to the percentage of LN affected with micrometastasis (0%, <11%, and > or =11%).

RESULTS

Tumor cells were immunohistochemically detected in 47 LN (2.4%) from 25 (34.2%) patients. Five-year overall survival probability (5-YSP) of 30% in pN(0 )patients with detected occult tumor cells in LN was significantly worse than that in those without nodal microinvolvement (76%, P = 0.021), hereby resembling that of pN1-patients (24%, P = 0.84). Median overall survival in patients with no (0%), low (<11%), and high (>11%) micrometastatic tumor load was 43, 27, and 11 months, respectively. Substratification according to histological type showed that, in patients with AC, the presence of nodal microinvolvement had a significant impact on 5-YSP (0% versus 65%; P = 0.03), whereas in patients with SCC, differences of 5-YSP were only of borderline significance (24% versus 53%; P = 0.081).

CONCLUSION

Minimal tumor cell load as assessed by the ratio of micrometastatically affected LN is a complementary tool for better risk stratification of patients with esophageal carcinoma.

Nodal microinvolvement in patients with carcinoma of the papilla of vater receiving no adjuvant chemotherapy

BACKGROUND

To assess the prognostic significance of nodal microinvolvement in patients with carcinoma of the papilla of Vater.

METHODS

From 1993 to 2003 at the University Clinic Hamburg, 777 patients were operated upon pancreatic and periampullary carcinomas. The vast majority of patients were operated upon pancreatic ductal adenocarcinoma (n = 566, 73%), followed by carcinomas of the papilla of Vater (n = 112, 14%), pancreatic neuroendocrine carcinomas (n = 39, 5%), intraductal papillary mucinous neoplasms (n = 33, 4%), and distal bile duct carcinomas (n = 27, 3%). Fresh-frozen tissue sections from 169 lymph nodes (LNs) classified as tumor free by routine histopathology from 57 patients with R0 resected carcinoma of the papilla of Vater who had been spared from adjuvant chemotherapy were immunohistochemically (IHC) examined, using a sensitive IHC assay with the anti-epithelial monoclonal antibody Ber-EP4 for tumor cell detection. With regard to histopathology, 39 (63%) of the patients were staged as pT1/pT2, 21 (37%) as pT3/pT4, 30 (53%) as pN0, while 38 (67%) as G1/G2.

RESULTS

Of the 169 "tumor-free" LNs, 91 LNs (53.8%) contained Ber-EP4-positive tumor cells. These 91 LNs were from 40 (70%) patients. The mean overall survival in patients without nodal microinvolvement of 35.8 months (median-not yet reached) was significantly longer than that in patients with nodal microinvolvement (mean 16.6; median 13; p = 0.019). Multivariate Cox regression analysis for overall survival revealed that grading was the most significant independent prognostic factor (p = 0.001), followed by nodal microinvolvement (p = 0.013).

CONCLUSIONS

The influence of occult tumor cell dissemination in LNs of patients with histologically proven carcinoma of the papilla of Vater supports the need for further tumor staging through immunohistochemistry.

Pancreatic cancer: a generalized disease--prognostic impact of cancer cell dissemination

BACKGROUND

Pancreatic ductal adenocarcinoma is the fifth leading cause of death among all malignancies, leading to approximately 40,000 deaths each year in Europe. The annual incidence rate for all types of pancreatic cancer is approximately nine new cases per 100,000 people, ranking it as the 11th among all cancers. Stage, grade and resection margin status are currently accepted as the most accurate pathologic variables predicting survival. All classification systems fail prognostically to distinguish between different stages. Even in patients with seemingly early tumours (T1, N0), the likelihood of relapse is high. This reflects the shortcomings of the pathologic staging to sufficiently discriminate patients with a high risk to develop tumour recurrence from those that carry a lower risk.

RESULTS

On the other hand, none of the currently used systems includes or takes into consideration the role of disseminated tumour cells neither in the lymph nodes nor in the bone marrow. Occult residual tumour disease is suggested when either bone marrow or lymph nodes, from which tumour relapse may originate, are affected by micrometastatic lesions undetectable by conventional histopathology. For detection, antibodies against tumour-associated targets can be used to detect individual epithelial tumour cells both in lymph nodes and in bone marrow. The clinical significance of these immunohistochemical analyses is still controversial. Various monoclonal antibodies are still in use for micrometastatic detection, thus contributing to the incongruity of data and validity of results. These assays have been rarely used in patients with pancreatic carcinoma.

CONCLUSION

The presence or absence of lymph-node metastases can predict the likelihood of survival for most, if not all, patients with pancreatic ductal adenocancer and the likelihood that metastases will develop at distant sites.

VEGF-D in association with VEGFR-3 promotes nodal metastasis in human invasive lobular breast cancer

We assessed the expression of vascular endothelial growth factors (VEGF-C and VEGF-D) in breast cancer cells and the density of lymph vessels and VEGF receptor-3 (VEGFR-3)-positive vessels in and around the tumor in invasive lobular breast cancer. We found significant correlation between peritumoral lymph vessel density and presence of lymph node metastases (P=.001) and the number of metastatic lymph nodes (P<.001). A significant correlation was detected between tumor cell VEGF-D expression and lymph node status (P=.001) and density of lymphatic vessel endothelial receptor (LYVE)-1-positive vessels (P=.035). VEGFR-3+/VEGF-D+ and VEGFR-3+/VEGF-C+ tumors had a significantly higher number of metastatic lymph nodes than tumors with other staining patterns (P<.001). Tumors positive for neither VEGF-D nor VEGFR-3 had a lower density of LYVE-1+ vessels than tumors with other staining patterns (P=.033). Our results indicate that peritumoral lymph vessel density is associated with lymph node metastases in invasive lobular breast cancer and that invasive lobular cancer producing VEGF-D, surrounded by VEGFR-3+ vessels, has a significantly higher peritumoral lymph vessel density and a higher number of metastatic lymph nodes.

The clinical significance of disseminated tumor cells in breast cancer

The presence of tumor cells in the bone marrow of primary breast cancer patients at surgery has been shown to be an independent prognostic indicator of relapse. Tumor cells have been detected either directly, using immunocytochemical staining, or indirectly, using reverse transcription-polymerase chain reaction (RT-PCR). Studies have been initiated to determine whether the presence of disseminated cells can be monitored during the therapy of patients with primary breast cancer, and thus potentially be used to predict relapse before overt metastases are detectable. Studies are also ongoing to improve methods of detection, such as immunobead enrichment followed by staining and real-time RT-PCR, and to find alternative markers for the disseminated cells. Studies of patients with overt metastases have shown that there is a large tumor load in the peripheral blood and that this predicts overall survival. This article reviews the published literature on studies carried out in both primary and metastatic breast cancer patients, the methodologies and markers used, and improvements in detection methodologies that are being investigated including real-time RT-PCR, novel markers, enrichment and automated image analysis.

Strong prognostic value of nodal and bone marrow micro-involvement in patients with pancreatic ductal carcinoma receiving no adjuvant chemotherapy

AIM: To study the prognostic value of adjuvant chemo-therapy in patients with pancreatic, ductal adenocar-cinoma.

METHODS: Lymph nodes from 106 patients with resectable pancreatic ductal adenocarcinoma were systematically sampled. A total of 318 lymph nodes classified histopathologically as tumor-free were examined using sensitive immunohistochemical assays. Forty-three (41%) of the 106 patients were staged as pT_1/2, 63 (59%) as pT_3/4, 51 (48%) as pN₀, and 55 (52%) as pN₁. The study population included 59 (56%) patients exhibiting G_1/2, and 47 (44%) patients with G₃ tumors. Patients received no adjuvant chemo- or radiation therapy and were followed up for a median of 12 (range: 3.5 to 139) mo.

RESULTS: Immunostaining with Ber-EP4 revealed nodal microinvolvement in lymph nodes classified as “tumor free” by conventional histopathology in 73 (69%) out of the 106 patients. Twenty-nine (57%) of 51 patients staged histopathologically as pN₀ had nodal microinvolvement. The five-year survival probability for pN0-patients was 54% for those without nodal microinvolvement and 0% for those with nodal microinvolvement. Cox-regression modeling revealed the independent prognostic effect of nodal microinvolvement on recurrence-free (relative risk 2.92, P = 0.005) and overall (relative risk 2.49, P = 0.009) survival.

CONCLUSION: The study reveals strong and independent prognostic significance of nodal microinvolvement in patients with pancreatic ductal adenocarcinoma who have received no adjuvant therapy. The addition of immunohistochemical findings to histopathology reports may help to improve risk stratification of patients with pancreatic cancer.

The value of cytokeratin immunohistochemistry in the evaluation of axillary sentinel lymph nodes in patients with lobular breast carcinoma

BACKGROUND

Cytokeratin immunohistochemistry (IHC) reveals a higher rate of occult lymph node metastases among lobular carcinomas than among ductal breast cancers. IHC is widely used but is seldom recommended for the evaluation of sentinel lymph nodes in breast cancer patients.

OBJECTIVE

To assess the value of cytokeratin IHC for the detection of metastases in sentinel lymph nodes of patients with invasive lobular carcinoma.

METHODS

The value of IHC, the types of metastasis found by this method, and the involvement of non-sentinel lymph nodes were analysed in a multi-institutional cohort of 449 patients with lobular breast carcinoma, staged by sentinel lymph node biopsy and routine assessment of the sentinel lymph nodes by IHC when multilevel haematoxylin and eosin staining revealed no metastasis.

RESULTS

189 patients (42%) had some type of sentinel node involvement, the frequency of this increasing with increasing tumour size. IHC was needed for identification of 65 of these cases: 17 of 19 isolated tumour cells, 40 of 64 micrometastases, and 8 of 106 larger metastases were detected by this means. Non-sentinel-node involvement was noted in 66 of 161 cases undergoing axillary dissection. Although isolated tumour cells were not associated with further lymph node involvement, sentinel node positivity detected by IHC was associated with further nodal metastases in 12 of 50 cases (0.24), a proportion that is higher than previously reported for breast cancer in general.

CONCLUSIONS

IHC is recommended for the evaluation of sentinel nodes from patients with lobular breast carcinoma, as the micrometastases or larger metastases demonstrated by this method are often associated with a further metastatic nodal load.

Intraoperative Imprint Cytology in Assessment of Sentinel Lymph Nodes and Lumpectomy Surgical Margins

Intraoperative imprint cytology (IIC) in the assessment of sentinel lymph nodes (SNs) allows immediate, cost-effective axillary lymph node dissection. IIC diagnosis is accurate in up to 100% of grossly abnormal SNs. Despite overall low sensitivity for grossly negative SNs, the benefits of immediate complete axillary lymph node dissection offset the increased risk of missing micrometastases or loss of isolated tumor cells (ITCs) by performing frozen section. IIC of the lumpectomy margins is rapid, accurate, and cost effective. It allows re-excision during initial surgery if needed with better cosmetic result. It is a useful adjunct to, and frequently a replacement for frozen section in many centers. Cytopathologists must familiarize themselves with both advantages and pitfalls of IIC to avoid errors.

Sentinel lymph node dissection provides axillary control equal to complete axillary node dissection in breast cancer patients with lobular histology and a negative sentinel node

OBJECTIVE

Invasive lobular carcinoma (ILC) presents special challenges to treating physicians because of the diffuse infiltrative growth pattern. As sentinel lymph node dissection (SLND) is rapidly replacing axillary lymph node dissection (ALND) in the management of patients with early-stage breast cancer, we sought to evaluate the safety of SLND in providing axillary control in breast cancer patients with lobular histology and a negative sentinel node.

METHODS

We identified 239 patients with T1-2,N0,M0 lobular breast cancer from the prospective databases of 2 institutions; all were treated between March 1994 and December 2003.

RESULTS

A total of 202 patients had SLND and 37 had SLND followed by ALND. There was no significant difference between the 2 groups with respect to tumor size, presence of lymphovascular invasion, estrogen receptor (ER)/progesterone receptor (PR) and HER-2/neu status, type of breast surgery, margin status, or nuclear grade. Use of chemotherapy, radiation, and hormonal therapy was not significantly different between groups. At a median follow-up of 48 months in the ALND group and 26 months in the SLND group (range 6 to 80 months), none of the 202 patients in the SLND group had experienced an axillary recurrence, while 2 (5.4%) of the 37 patients who underwent ALND had experienced an axillary recurrence.

CONCLUSIONS

SLND provided axillary control equivalent to that of ALND for patients with lobular breast cancer. SLND alone appears to be adequate axillary management of patients with lobular breast cancer and a negative sentinel node.

The melanoma antigen gene as a surveillance marker for the detection of circulating tumor cells in patients with breast carcinoma

BACKGROUND

Circulating occult tumors cells could be used for the surveillance of metastases after primary breast carcinoma therapy, but their detection is limited by the lack of specific molecular markers. Melanoma antigen genes (MAGEs), which are expressed in malignant tissues but not in normal tissues (except for placenta and testis), might provide such a marker. To date, however, the use of MAGEs in the detection of occult tumor cells using reverse transcription-polymerase chain reaction (RT-PCR) has been limited because of the heterogeneity and low expression of individual MAGEs in tumor tissues.

METHODS

We developed multiple MAGE-recognizing primers (MMRPs) that were capable of binding to the cyclic DNA of 6 MAGE-A gene subtypes (MAGE-A1-MAGE-A6). We assessed the ability of the MMRPs to detect the expression of MAGE-A gene subtypes in peripheral blood obtained from patients with benign or malignant breast disease.

RESULTS

MAGE-A gene expression was not detected in 32 patients with benign disease but was detected in 1 of 31 patients (3%) patients with negative lymph node breast carcinoma, in 10 of 52 patients (19%) with 1-3 positive lymph nodes, in 11 of 53 patients (21%) with > or = 4 positive lymph nodes, and in 20 of 52 patients (39%) with metastatic disease. The results were statistically significant (P < 0.0001; chi-square test for linear-by-linear association). The results also showed that the detection of MAGE-A gene expression in the blood predicted tumor progression or recurrence.

CONCLUSIONS

The results suggested that MAGE-A gene expression may be used for the surveillance of circulating breast carcinoma cells after primary therapy by RT-nested PCR using MMRPs.

Rapid immunohistochemistry enhances the intraoperative diagnosis of sentinel lymph node metastases in invasive lobular breast carcinoma

BACKGROUND

The sensitivity of the intraoperative diagnosis of sentinel lymph node (SLN) micrometastases and the metastases of invasive lobular carcinoma (ILC) is low. The goal of the current study was to assess whether the use of intraoperative, rapid immunohistochistochemistry (IHC) enhances the intraoperative detection of micrometastases and metastases of ILC.

METHODS

The sensitivity of the intraoperative diagnosis of SLN metastasis was evaluated in 438 patients when using rapid IHC with a cytokeratin biomarker. The results were compared with those obtained for 557 patients without rapid IHC but with conventional staining.

RESULTS

For patients with ILC, the sensitivity of the intraoperative diagnosis was 87% (45 of 52) in the IHC group and 66% (39 of 59) in the non-IHC group (P = 0.02). The sensitivity of the intraoperative diagnosis was similar for patients with other types of invasive cancer regardless of the use of rapid IHC. However, rapid IHC enhanced marginally the intraoperative diagnosis of the smallest micrometastases, isolated tumor cells (P = 0.06).

CONCLUSIONS

Rapid IHC with cytokeratin labeling enhanced the intraoperative diagnosis of SLN metastases in patients with ILC. It may also improve the intraoperative diagnosis of micrometastases.

The clinical significance of axillary lymph node micrometastases in breast cancer

OBJECTIVE

To evaluate the clinical significancer of axillary lymph-node micrometastases, in the era of sentinel lymph node (SLN) biopsy.

DATA SOURCES

Searches of MEDLINE (1966-2003) and an extensive manual review of journals were performed using the key search terms breast cancer, axillary lymph-node micrometastases, micrometastatic disease, and SLN biopsy.

STUDY SELECTION

All articles identified from the data sources were evaluated and all information deemed relevant was included for this review.

CONCLUSIONS

Axillary lymph-node micrometastases can be detected by serial sectioning, immunohistochemistry, or reverse transcriptase-polymerase chain reaction (RT-PCR). The presence of axillary SLN micrometastases is generally associated with a worse prognosis and is an indication for axillary lymph node dissection (ALND) and adjuvant therapy. The clinical significance of micrometastases identified by RT-PCR remains unknown and further research with longer follow-up is needed to ascertain the clinical implications of a positive result.

Mode of spread in the early phase of lymphatic metastasis in pancreatic ductal adenocarcinoma: prognostic significance of nodal microinvolvement

BACKGROUND

The aim of this study was to assess the prognostic significance of nodal microinvolvement as well as the mode of spread in the early phase of lymphatic metastasis in patients with node-negative pancreatic ductal adenocarcinoma.

METHODS

Lymph nodes from 48 node-negative patients with R0 resected pancreatic ductal adenocarcinoma were sampled from 3 different compartments: 1) distal hepatoduodenal ligament, 2) superior-anterior compartment, and 3) posterior-inferior. Tissue sections of 148 lymph nodes classified as tumor free by routine histopathology were examined, using a sensitive immunohistochemical assay with the antiepithelial monoclonal antibody Ber-EP4 for tumor cell detection. With regard to histopathologic tumor staging and grading, 26 (54.2%) of the patients were staged as pT1/pT2, 22 (45.8%) as pT3/pT4, while 31 (64.6%) as G1/G2 and 17 (35.4%) patients as G3. Of the 148 "tumor free" lymph nodes, 56 contained Ber-EP4-positive tumor cells. These 56 lymph nodes were from 28 of the 48 patients. The multivariate Cox regression analysis revealed the independent prognostic impact of nodal microinvolvement on relapse-free and overall survival. Analysis by compartment, from which the lymph nodes were collected, revealed that overall survival time (P = 0.006) and time to local recurrence (P = 0.015) depend on the presence of nodal microinvolvement in the superior-anterior compartment.

CONCLUSIONS

The influence of occult tumor cell dissemination in lymph nodes of patients with histologically proven pancreatic ductal adenocarcinoma supports the need for further tumor staging through immunohistochemistry. This could be a helpful tool in proper selection of patients for adjuvant chemotherapy.

Cytokeratin staining for intraoperative evaluation of sentinel lymph nodes in patients with invasive lobular carcinoma

BACKGROUND

Frozen section and intraoperative imprint cytology (IIC(N)) are 2 methods used for intraoperative pathologic assessment of sentinel lymph nodes (SLNs). The SLN evaluation of patients with invasive lobular carcinoma (ILC) results in a relatively high number of false-negative results using either of these methods. The purpose of this study was to evaluate the added benefits that intraoperative immunohistochemical-cytokeratin staining (I(CK-IHC)) can bring to IIC(N) in the evaluation of SLN in patients with ILC.

METHODS

A total of 59 breast cancer patients with ILC underwent an SLN biopsy evaluated by our standard IIC(N) assessment in addition to I(CK-IHC). The results of IIC(N) with I(CK-IHC) were compared with the final histopathologic assessment consisting of standard hematoxylin and eosin staining and additional cytokeratin staining of nodes.

RESULTS

Intraoperative evaluation of SLN using IIC(N) and I(CK-IHC) correctly diagnosed the nodal status in 45 of 59 (76.3%) patients. On final histopathologic assessment, 31 of 59 (52.5%) patients were found to have positive nodes. Using I(CK-IHC), 17 of these 31 positive cases (54.8%) were detected. Using IIC(N) alone, without the benefit of I(CK-IHC), only 13 of 31 (41.9%) positive cases were detected intraoperatively.

CONCLUSIONS

For patients with ILC, I(CK-IHC) staining in addition to IIC(N) improves accuracy over using IIC(N) alone. In this study, I(CK-IHC) staining demonstrated a 12.9% improvement in the detection of SLN metastases in patients with ILC. Cytopathologists should consider employing I(CK-IHC) staining to evaluate the touch-imprint slides of SLN in ILC patients.

Accuracy of axillary staging using sentinel node biopsy or diagnostic axillary lymph node dissection - a case-control study

We aimed to compare the accuracy of axillary staging in breast cancer between sentinel node biopsy (SNB) and axillary lymph node dissection (ALND). The prevalence of axillary metastases was studied in 166 breast cancer patients with SNB and pair-matched control patients with ALND. The matching factors included age of the patient and grade, histological type and histological size of the tumour. There were 37% of patients with axillary metastases in the SNB group and 31% in the ALND group. Altogether, 57 pairs were discordant in relation to axillary metastases. In 34 discordant pairs the SNB patient and in 23 the ALND patient had axillary metastases, p=ns. Among the 36 discordant pairs with invasive ductal carcinoma (IDC), axillary metastases were detected as often in the SNB and the ALND patients. In the 21 discordant pairs with other histological types, the SNB patient had axillary metastases in 16 pairs and the ALND patient in 5 pairs, p<0.03. SNB seems to be as accurate a method for axillary staging as ALND. However, SNB generated no upstaging effect in IDC, only in other histological tumour types.

Validation of axillary sentinel lymph node detection in the staging of early lobular invasive breast carcinoma

BACKGROUND

Previous reports have shown that regional lymph node involvement in patients with early-stage breast carcinoma can be evaluated by resection of axillary sentinel lymph nodes (ASLN). Axillary lymphadenectomy may be unnecessary in the absence of ASLN involvement. In the current study, the authors compared the results of ASLN resection in patients with lobular invasive carcinoma (LIC) with the results from patients with ductal invasive carcinoma (DIC) in terms of detection rates and false-negative rates.

METHODS

For ASLN detection, technetium 99m sulfur-colloid and patent blue were injected around the tumor. Each patient underwent both ASLN resection and complete axillary lymphadenectomy. Detection rates and false-negative rates were evaluated in patients with LIC and in patients with DIC.

RESULTS

Two hundred forty-three patients with invasive, early-stage breast carcinoma were enrolled in the study (208 patients with DIC and 35 patients with LIC). The median patient age, pathologic tumor size, hormone receptor status, and rates of involved lymph nodes were equivalent for both groups. ASLN detection and false-negative rates did not differ for patients with LIC and patients with DIC.

CONCLUSIONS

The ASLN detection rate was not dependent on the pathologic type of invasive carcinoma. Pathologic examination of ASLN in patients with LIC and in patients with DIC predicted axillary lymph node status with the same predictive value in terms of lymph node metastasis. For patients with LIC, ASLN examination overestimated the rate of micrometastasis as diagnosed by immunohistochemical techniques. These results will require confirmation in larger studies.

The feasibility of intraoperative diagnosis of sentinel lymph node metastases in breast cancer

BACKGROUND AND OBJECTIVES

The aim of the study was to analyse in detail the feasibility of intraoperative assessment of sentinel lymph nodes in breast cancer.

METHODS

Altogether 139 consecutive breast cancer patients with metastases in axillary sentinel nodes were included in a prospective study. A combination of imprint cytology and frozen section was used as the method of intraoperative diagnosis of sentinel node metastases. The definite postoperative evaluation of the sentinel nodes was taken as the gold standard.

RESULTS

The overall sensitivity of intraoperative diagnosis was 83%, reaching 81% if the intraoperative assessment had been limited to the two first retrieved sentinel nodes. False negative (FN) findings were more common in connection with invasive lobular carcinoma (28%) than with invasive ductal carcinoma (8%) (P < 0.01) as well as in connection with micro-metastases, in 38% of the cases, compared to the larger metastases, 6% (P < 0.00005).

CONCLUSIONS

Intraoperative examination of sentinel lymph nodes enables breast surgery, axillary staging, and treatment in the same operation in a substantial proportion of breast cancer patients. Hospital costs as well as workload in the pathology laboratory may be reduced, limiting the intraoperative assessment to the two first retrieved nodes.

Evaluation of immunohistochemistry and multiple-level sectioning in sentinel lymph nodes from patients with breast cancer

CONTEXT

Previous investigations on sentinel lymph node biopsies have demonstrated their importance in nodal staging of patients with breast cancer. However, sentinel node biopsy in breast cancer is currently a controversial procedure and continues to provoke debate.

OBJECTIVES

We designed our study to determine the usefulness of a standard protocol for evaluating sentinel lymph node metastases and to assess the value of sentinel node biopsy as the only procedure in nodal staging in breast cancer patients.

MATERIALS AND METHODS

A retrospective analysis of 84 breast cancer patients with sentinel node biopsies, who also underwent axillary dissection, was conducted using a standard protocol (3 levels of immunohistochemical stains for keratin and 2 levels of hematoxylin-eosin (HE) stains on the first 3 negative lymph nodes).

RESULTS

Hematoxylin-eosin staining identified 20 patients (23.8%) with sentinel node metastases. The remaining 64 negative patients (76.1%) were tumor free on sentinel lymph nodes at level 1 HE. Additional immunohistochemical stains for keratin and HE stains on specimens from these 64 patients showed an additional 5 patients (7.8%) to be positive for lymph node micrometastases (<2 mm). The total percentage of cases with sentinel lymph node metastases detected by HE staining and immunohistochemistry was 29.7%. Of the remaining 59 cases that were negative on HE and immunohistochemistry, axillary dissection revealed 3 cases that had metastases in the axillary lymph nodes. The false-negative rate was 10.7%. The concordance rate between sentinel lymph nodes and axillary lymph nodes was 96.4%. The sensitivity was 89% and specificity was 100%.

CONCLUSION

Immunohistochemistry and multiple-level sectioning increased detection of metastases by 7.8% in sentinel lymph nodes. Caution should be used in accepting sentinel node biopsy alone as the only procedure for staging due to a high false-negative rate (10.7%). A predictive value of 96.4% confirms that sentinel lymph node biopsy is most likely to contain metastatic carcinoma. Sentinel lymph node examination with the protocol we describe, combined with axillary dissection, increased the yield of metastatic disease by identifying 8 additional cases of nodal metastatic disease (an increase of 28%), as compared to standard axillary nodal dissection and single-section sentinel lymph node examination alone.

Stage migration in breast cancer: surgical decisions concerning isolated tumour cells and micro-metastases in the sentinel lymph node

AIMS

Sentinel lymph node biopsy has replaced the axillary lymph node dissection (ALND) in primary surgery for breast cancer in many hospitals and is expected to become the standard of care in due time. Since the sentinel lymph node is subjected to more extensive pathologic examination than the lymph nodes in the axillary dissection specimen, more patients are found to be node positive (N+); however many of them contain micro-metastases (<or=2mm). The consequence may be an overshoot of therapy: additional surgery for non-metastatic lymph nodes or systemic adjuvant therapy.

METHODS

We examined 34 (out of a series of 38) clinically T1 (cT1) patients who had a SLN biopsy with or without ALND and compared them to a matched historical control group.

RESULTS

Twenty-one of 34 (62%) patients showed tumour cells in their SLN's. From these 21 patients in 13 (62%) the SLNs contained isolated tumour cells, of which 10 (77%) were detected only by immunohistochemistry (IHC), in four (19%) the SLNs contained micrometastases, and in four (19%) macrometastases. From 16 patients with isolated tumour cells or micrometastases in the SLN who underwent a regular ALND one had an H&E detected isolated tumour cell in a non-SLN and one patient with isolated tumour cells in the SLN who did not get a regular ALND developed an axillary recurrence 11 months after the primary treatment. On the other hand, three of four (75%) patients with macrometastases in the SLN had pathologically involved non-SLNs. In the majority (70%) of patients of the historical control group no lymph node involvement was seen. The percentage of macrometastases staged as lymph node positive in the control group was the same as in the studied group.

CONCLUSION

Most patients with cT1 breast cancer with isolated tumour cells or micrometastases in the SLN will not benefit from additional axillary dissection; 88% had a negative ALND. Since we cannot select the group that will benefit from ALND, this is still indicated in case of isolated tumour cells or micrometastases in the SLN. Since most of the affected SLNs show isolated tumour cells and are classified as pN0(i+), stage migration due to more meticulous pathologic examination does not occur according to the TNM classification. However some patients do not benefit from the introduction of the SLN, due to the high incidence of isolated tumour cells or micrometastases in the SLN. Many more patients than expected still end up with an ALND.

Cytokeratin staining and other sentinel node controversies

Sentinel lymph node (SLN) biopsy for breast cancer staging has been widely accepted because it is more sensitive and less morbid than axillary dissection. Sentinel nodes can be thoroughly scrutinized using a variety of techniques increasing the detection of micrometastases; however, the clinical relevance of micrometastases has been challenged. The available data suggest that the prognostic significance of axillary metastases is related to the size of the metastases, and the best data suggest that outcome for patients with metastases < 0.2 mm is similar to patients with node-negative disease. This would argue against the use of ultrasensitive tests such as reverse transcriptase polymerase chain reaction. Immunohistochemistry upstages 2%-20% of hematoxylin and eosin-negative sentinel nodes, and additional nodal metastases are identified in approximately 10% of completion axillary dissections prompted by an immunohistochemistry (IHC)-positive sentinel node. This would appear to be a good reason to perform IHC and act on the results. Because micrometastases can be artifactual, SLN biopsy in ductal carcinoma in situ can lead to harmful overtreatment and is best performed in the context of clinical trials. Lymphoscintigraphy has allowed the detection of alternate drainage patterns to internal mammary, infraclavicular, and supraclavicular lymph nodes. Although patients are occasionally identified who have metastases to these basins but not the axilla, this information will not impact the decision for chemotherapy in most cases. Internal mammary SLN biopsy may have value in patients with tumors < 1 cm, but requires additional evaluation in clinical trials.

Tumor characteristics predictive of sentinel node metastases in 105 consecutive patients with invasive lobular carcinoma

BACKGROUND

Identification of nodal metastases in invasive lobular carcinoma (ILC) is difficult. Sentinel node (SN) biopsy offers a potential advantage. This study reports the feasibility of SN identification and predictors of SN metastases for ILC.

METHODS

All cases of ILC undergoing sentinel lymphadenectomy between October 1991 and May 2001 were evaluated. Patients enrolled in ACOSOG Z0010/Z0011 were excluded. Presentation, surgical treatment, tumor characteristics, and prognostic factors were analyzed for statistical significance.

RESULTS

SN mapping was performed in 105 patients with 106 cases of ILC. SN identification was 97%, accuracy 100%, and positivity 50% with 45% macrometastases, 16% micrometastases, and 39% immunometastases. There are no axillary recurrences at 43.73 months. Palpable tumor, increasing tumor size, and angiolymphatic invasion are statistically significant for SN-positive status.

CONCLUSIONS

SN staging for ILC is feasible and accurate. Receptor status and proliferative indices are not useful markers for metastases. However, large tumor size and presence of angiolymphatic invasion are positive predictors.

Immunocytochemical analysis of breast cells obtained by ductal lavage

BACKGROUND

Intraductal breast fluids containing exfoliated mammary epithelial cells can be harvested from the breast by ductal lavage to screen for disease-associated cytologic abnormalities. In addition to epithelial cells, breast fluids contain large numbers of mammary foam cells, and the tissue of origin of these foam cells has been the subject of controversy for many years. Immunocytochemical, morphologic, and molecular studies variously have supported a mammary epithelial origin versus a histiocytic origin for this cell type. In the current study, the authors performed immunocytochemical analysis with epithelial specific and macrophage specific antibodies to characterize and quantify breast cells obtained by ductal lavage.

METHODS

Breast fluids were harvested from 19 individual breast ducts in 15 female patients by ductal lavage. Cells from each specimen were processed for immunocytochemical staining using the AE1/AE3 multicytokeratin and CD68 (clone KP1) monoclonal antibodies. Cells were classified as mammary epithelial cells or mammary foam cells on the basis of morphologic criteria, and the cells were counted and evaluated for immunoreactivity with epithelial specific and macrophage specific antibodies.

RESULTS

The CD68 macrophage specific antibody stained all ductal lavage cells that exhibited foam cell morphology. The AE1/AE3 multicytokeratin antibody demonstrated strong, positive staining of cells that exhibited epithelial morphology but failed to demonstrate significant staining of mammary foam cells. The lavage specimens contained a range of 3040-278,850 epithelial cells and 2230-90,480 foam cells. The median numbers of epithelial cells and foam cells per lavage sample were 15,680 and 29,200, respectively. The ratio of epithelial cells to foam cells varied among specimens ranging from 3.4 to 0.09 (median, 0.8). Seven of 19 lavage specimens contained more epithelial cells than foam cells, whereas 12 samples contained a greater proportion of foam cells.

CONCLUSIONS

Immunocytochemical analysis using the AE1/AE3 multicytokeratin and CD68 antibodies supports a histiocytic origin for the majority of mammary foam cells harvested from the ductal system of the human breast by ductal lavage. Although mammary foam cells constitute a significant proportion of the cellular population obtained by ductal lavage, thousands of epithelial cells also are harvested.

Detection and Significance of Occult Axillary Metastatic Disease in Breast Cancer Patients

After clinical staging, the single most important prognostic factor for patients with newly diagnosed primary breast cancer is the presence or absence of detectable metastases to axillary lymph nodes when examined by conventional light microscopy. More sensitive methods of determination of lymph node status, such as evaluation of serial sections, immunohistochemical staining, and use of molecular biological assays increase the rate of detection of micrometastases. Although the feasibility of enhanced detection of occult axillary metastatic disease is well established, the prognostic significance of such detection is only recently starting to emerge. Furthermore, the enormous recent interest in the application of sentinel lymph node biopsy as an alternative to the evaluation of the entire axilla in patients with breast cancer makes the first-time detailed evaluation for micrometastases practically feasible. In this review the different methods of detecting micrometastatic disease in the axilla and the significance of such findings are discussed.

Importance of missed axillary micrometastases in breast cancer patients

Axillary lymph node metastases dramatically worsen the prognosis of patients with breast cancer. Despite this prognostic significance, routine histologic examination of axillary lymph nodes examines less than 1% of the submitted material. It is therefore obvious that micrometastatic disease is missed with this rather cursory examination, and the question arises as to the significance of this missed disease. Most lines of evidence suggest that missed axillary micrometastases exist and contribute to patient mortality. Most large studies of breast cancer micrometastases have suggested that undetected axillary micrometastases can be identified with more detailed examinations of the regional lymph nodes and that this group of patients has a poorer prognosis than those with no metastases identified. In addition, small-volume nodal disease, too small to be detected by traditional hematoxylin and eosin staining, has been shown to be capable of producing tumors in animal models. Finally, micrometastases have been shown to be of significance in other diseases. This article reviews the lines of evidence and the ongoing studies that are attempting to clarify the significance of micrometastatic disease in patients with breast cancer.

Clinical significance of occult metastatic cells in bone marrow of breast cancer patients

The early and clinically occult spread of viable tumor cells to the organism is increasingly considered a hallmark in cancer progression, as emerging data suggest that these cells are precursors of subsequent distant relapse. Using monoclonal antibodies to epithelial cytokeratins or tumor-associated cell membrane glycoproteins, individual carcinoma cells can be detected on cytologic bone marrow preparations at frequencies of 10(-5) to 10(-6). Prospective clinical studies have shown that the presence of these immunostained cells in bone marrow, as a frequent site of overt metastases, is prognostically relevant with regard to relapse-free and overall survival. This screening approach may be, therefore, used to improve tumor staging and guide the stratification of patients for adjuvant therapy in clinical trials. Another promising application is monitoring the response of micrometastatic cells to adjuvant therapies, which, at present, can only be assessed retrospectively after an extended period of clinical follow-up. The present review summarizes the current data on the clinical significance of occult metastatic breast cancer cells in bone marrow.

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.

Implications of occult metastatic cells for systemic cancer treatment in patients with breast or gastrointestinal cancer

The early and clinically occult spread of viable tumour cells to the organism is becoming acknowledged as a hallmark in cancer progression, since abundant clinical and experimental data suggest that these cells are precursors of subsequent distant relapse. Using monoclonal antibodies against epithelial cytokeratins or tumour-associated cell membrane glycoproteins, individual carcinoma cells can be detected in cytological bone marrow preparations at frequencies of 10(-5) to 10(-6). Prospective clinical studies have shown that the presence of such immunostained cells in bone marrow is prognostically relevant with regard to relapse-free and overall survival, even in malignancies that do not preferentially metastasise to bone. As current treatment strategies have resulted in a substantial improvement of cancer mortality rates, it is noteworthy to consider the intriguing options of immunocytochemical screening of bone marrow aspirates for occult metastatic cells. Besides improved tumour staging, such screening offers opportunities for guiding patient stratification for adjuvant therapy trials, monitoring response to adjuvant therapies (which, at present, can only be assessed retrospectively after an extended period of clinical follow-up), and specifically targeting tumour-biological therapies against disseminated tumour cells. The present review summarises the current data on the clinical significance of occult metastatic cancer cells in bone marrow.

Occult metastasis

The most important factor affecting the outcome of patients with invasive cancers 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 methods routinely employed (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 [1]. 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.

Comparative analysis of micrometastasis to the bone marrow and lymph nodes of node-negative breast cancer patients receiving no adjuvant therapy

PURPOSE

In node-negative patients, of whom up to 30% will recur within 5 years after diagnosis, markers are still needed that identify patients at high enough risk to warrant further adjuvant treatment. In the present study we analyzed whether a correlation exists between microscopic tumor cell spread to bone marrow and to lymph nodes and attempted to determine which route is clinically more important.

PATIENTS AND METHODS

According to a prospective design, bone marrow aspirates and axillary lymph nodes of level I (n = 1,590) from 150 node-negative patients with stage I or II breast cancer were analyzed immunocytochemically with monoclonal anticytokeratin (CK) antibodies. We investigated associations with prognostic factors and the effect of micrometastasis on patients' prognosis.

RESULTS

CK-positive cells in bone marrow aspirates were present in 44 (29%) of 150 breast cancer patients, whereas only 13 patients (9%) had such positive findings in lymph nodes; simultaneous microdissemination to bone marrow and lymph nodes was seen in merely two patients. No correlation of bone marrow micrometastases with other risk factors was assessed. Reduced 4-year distant disease-free and overall survival were each associated with a positive bone marrow finding (P =.032 and P =.014, respectively) but not with lymph node micrometastasis. Multivariate analysis revealed an independent prognostic effect of bone marrow micrometastasis on survival, with a hazards ratio of 6.1 (95% confidence interval, 1.2 to 31.3) for cancer-related death (P =.031) in our series.

CONCLUSION

Immunocytochemical detection of micrometastatic cells in bone marrow but not in lymph nodes is an independent prognostic risk factor in node-negative breast cancer that may have implications for surgery and stratification into adjuvant therapy trials.

The immunohistochemical assessment of occult regional lymph node metastases in patients with T3pN0M0 prostate cancer before definitive radiotherapy

OBJECTIVE

To detect occult regional lymph node metastases in patients with T3pN0M0 prostate cancer not recognized by routine haematoxylin and eosin staining, and to evaluate the clinical relevance of this finding.

PATIENTS AND METHODS

Formalin-fixed and paraffin-embedded pelvic lymph nodes (1118) from 92 patients were evaluated by immunohistochemistry using antibodies for prostate specific antigen (PSA) and pancytokeratin (AE1/AE3). Of the tumours, 14% were well, 69% moderately and 17% poorly differentiated. The extent of tumour was categorized as T3pN0M0 in all patients, who were referred for definitive radiotherapy after pelvic staging lymphadenectomy. The median (range) serum PSA value before treatment was 18.5 (0.4-342) microg/L. After radiotherapy, the patients were followed by assessing biochemical progression, pelvic recurrence and/or development of distant metastases. The median (range) observation time for all patients was 61 (16-136) months.

RESULTS

Occult lymph node metastases were detected in four (4.4%) of the 92 patients. Patients with or without occult metastases had similar serum PSA levels and histological grades. None of the four patients with occult metastases progressed, compared with 37 of the 88 (42%) with no such metastases.

CONCLUSION

Using immunohistochemistry the detection rate of occult lymph node metastases in patients with T3pN0M0 prostate cancer is low. The occurrence of such metastases is probably unrelated to the serum PSA value before treatment. The short-term outcome of patients subsequently treated with definitive radiotherapy does not seem to be associated with the finding of occult lymph node metastases, but long-term follow-up is needed. So far, the results do not justify the search for occult lymph node metastases as a routine procedure in these patients

Micrometastases: have they an impact on prognosis?

Current routine histopathologic methods may fail in detecting lymph node micrometastases, while the introduction of newer, sensitive techniques, such as immunohistochemistry and molecular analysis, can improve their detection. The literature reveals that the presence of micrometastases has clinical and prognostic implications.