Improving the reproducibility of diagnosing micrometastases and isolated tumor cells

[Sentinel node biopsy in breast cancer: pathological analysis and interpretation]

This overview examines how the introduction of sentinel lymph node biopsy (SLNB) has changed the pathological staging of breast cancer. The more intensive analysis of the sentinel lymph nodes (gross slicing, step sections, immunohistological or molecular analysis) has lead to stage shifting in breast cancer. Regarding the rate of up-staging by positive results of SLNB, there are significant differences between institutes, some method-related, some related to the interpretation of results. Methodological differences should be reduced by means of reliable guidelines with the goal of systematically identifying metastases of a particular size (a macrometastasis over 2 mm being the minimum criterion). The next review of the TNM classification should result in a reduction in interobserver variability as a result of better definitions of staging categories for isolated tumor cells and micrometastases. In addition, a staging category is expected for metastases which have been identified by calibrated quantitative molecular tests only and which are larger than isolated tumors. Even in settings where nodal staging by SLNB is based on molecular tests at least a proportion of the lymph node should be investigated histologically.

Intraoperative consultation for axillary sentinel lymph node biopsy: an 8-year audit

To summarize the authors' 8-year institutional experience with intraoperative consultation via frozen section (FS) on sentinel lymph node biopsy (SLNB) in breast cancer patients we recorded the, complete operative procedure including additional surgery on the ipsilateral axilla and intraoperative consultation and permanent histopathologic processing for all cases with inoperative consultation on SLNB in breast cancer patients between the groups, chi(2) and Fisher's exact tests were used. Intraoperative consultation was positive in 116/706 cases (16.4%) and final pathology in 158/706 cases (22.4%); the false-negative rate was 26.6%, the false-positive rate was 0%, and the overall accuracy was 94%. False-negative rate was significantly associated with the size of metastasis (micro vs macrometastasis; P < .002) but not significantly associated with the histologic type (P = 0.76) or pathologist expertise (P = 0.08). The rate of spared second procedures was 92% when calculated exclusively for patients who ultimately underwent ALND. Intraoperative consultation via FS for SLNB is a safe practice that can reliably save clinically node-negative patients a second surgery.

Detection of disseminated tumor cells in bone marrow of gastric cancer using magnetic activated cell sorting and fluorescent activated cell sorting

BACKGROUND AND AIM

Magnetic activated cell sorting (MACS) and fluorescent activated cell sorting (FACS) were employed to enrich and detect the gastric cancer cells from a cell line in a model system, and to enrich and detect disseminated tumor cells (DTCs) from bone marrow (BM) of patients with gastric cancer.

METHODS

Fifteen patients with benign gastric lesions and 35 patients with gastric cancer who received curative operations between December 2002 and June 2003 were selected. Mononuclear cells were separated from their BM. Cells from cell line OCUM-2M were seeded with 10-grade ratio into mononuclear cells from patients with benign gastric lesion. After labeling by MACS minibeads conjugated with cytokeratin (CK) 7/8 antibodies, anti-CK-fluorescein isothiocyanate (FITC), and anti-CD45-perdinin chlorophyll protein (PerCP), the samples were enriched twice using an MS+/RS+ positive separation column. The FACS analysis was conducted on these samples before and after MACS enrichment. The results were analyzed using clinopathological parameters.

RESULTS

Disseminated tumor cells were detected in the BM of 25 (71.43%) patients with gastric cancer. The frequencies of DTCs were 1.38 x 10(-8)-2.40 x 10(-5), 2.19 x 10(-7)-3.70 x 10(-5), 4.01 x 10(-6)-8.57 x 10(-5) in patients with well, moderately, and poorly differentiated carcinoma, respectively (P = 0.026). Disseminated tumor cells in BM had close correlation with tumor tumor-node-metastasis (TNM) stage (P = 0.034) and cancer-free survival (P = 0.035).

CONCLUSION

Disseminated tumor cells are very common in the BM of gastric cancer patients. Poor histological differentiation and more advanced TNM stage have more DTCs in the BM of gastric cancer patients. Patients with DTCs tend to have a poor prognosis.

The prognostic impact of isolated tumor cells in lymph nodes of T2N0 gastric cancer: comparison of American and Japanese gastric cancer patients

BACKGROUND

The clinical significance of immunohistochemically detected isolated tumor cells (ITC) in lymph nodes of gastric cancer patients is controversial. This study examined the prognostic impact of ITC on patients with early-stage gastric cancer in two large volume centers in the United States and Japan.

METHODS

Fifty-seven patients with T2N0M0 gastric carcinoma who underwent gastric resection between January 1987 and January 1997 at Memorial Sloan-Kettering Cancer Center (MSKCC) in New York and 107 patients resected at National Cancer Center Hospital (NCCH) in Tokyo between January 1984 and December 1990 were studied. The sections were newly prepared from each lymph node for immunohistochemical staining for cytokeratin. Lymph nodes and original specimens from MSKCC were examined by pathologists in NCCH. The prognostic significance of the presence of ITC in lymph nodes was investigated in patients of both institutions.

RESULTS

ITC were identified in 30 of 57 patients (52.6%) at MSKCC and in 38 of 107 patients (35.5%) at NCCH. In both institutions, there was no significant difference in the prognosis of the studied patients with or without ITC (P= .22, .86 respectively).

CONCLUSIONS

The presence of ITC detected by immunohistochemistry in the regional lymph nodes did not affect the prognosis of American and Japanese patients with T2N0M0 gastric carcinoma who underwent gastrectomy with D2 lymph node dissection.

Non-sentinel lymph node metastases associated with isolated breast cancer cells in the sentinel node

There are many reports on the frequency of non-sentinel lymph node involvement when isolated tumor cells are found in the sentinel node, but results and recommendations for the use of an axillary lymph node dissection differ among studies. This systematic review was conducted to give an overview of this issue and to provide recommendations for the use of an axillary lymph node dissection in these patients. We searched Medline, Embase, and Cochrane databases from January 1, 2002, through November 27, 2007, for articles on patients with invasive breast cancer who had isolated tumor cells in the sentinel lymph node (according to the sixth edition of the Cancer Staging Manual of the American Joint Committee on Cancer) and who also underwent axillary lymph node dissection. Of 411 selected articles, 29 (including 836 patients) were included in this review. These 29 studies were heterogeneous, reporting a wide range of non-sentinel lymph node involvement (defined as the presence of isolated tumor cells or micro- or macrometastases) associated with isolated tumor cells in the sentinel lymph node, with an overall pooled risk for such involvement of 12.3% (95% confidence interval = 9.5% to 15.7%). This pooled risk estimate was marginally higher than the risk of a false-negative sentinel lymph node biopsy examination (ie, 7%-8%) but marginally lower than the risk of non-sentinel lymph node metastases in patients with micrometastases (ie, approximately 20%) who are currently eligible for an axillary lymph node dissection. Because 36 (64%) of the 56 patients with isolated tumor cells in their sentinel lymph node also had non-sentinel lymph node macrometastases, those patients with isolated tumor cells in the sentinel lymph node without other indications for adjuvant systemic therapy might be candidates for axillary lymph node dissection.

Infrared micro-spectral imaging: distinction of tissue types in axillary lymph node histology

Background

Histopathologic evaluation of surgical specimens is a well established technique for disease identification, and has remained relatively unchanged since its clinical introduction. Although it is essential for clinical investigation, histopathologic identification of tissues remains a time consuming and subjective technique, with unsatisfactory levels of inter- and intra-observer discrepancy. A novel approach for histological recognition is to use Fourier Transform Infrared (FT-IR) micro-spectroscopy. This non-destructive optical technique can provide a rapid measurement of sample biochemistry and identify variations that occur between healthy and diseased tissues. The advantage of this method is that it is objective and provides reproducible diagnosis, independent of fatigue, experience and inter-observer variability.

Methods

We report a method for analysing excised lymph nodes that is based on spectral pathology. In spectral pathology, an unstained (fixed or snap frozen) tissue section is interrogated by a beam of infrared light that samples pixels of 25 μm × 25 μm in size. This beam is rastered over the sample, and up to 100,000 complete infrared spectra are acquired for a given tissue sample. These spectra are subsequently analysed by a diagnostic computer algorithm that is trained by correlating spectral and histopathological features.

Results

We illustrate the ability of infrared micro-spectral imaging, coupled with completely unsupervised methods of multivariate statistical analysis, to accurately reproduce the histological architecture of axillary lymph nodes. By correlating spectral and histopathological features, a diagnostic algorithm was trained that allowed both accurate and rapid classification of benign and malignant tissues composed within different lymph nodes. This approach was successfully applied to both deparaffinised and frozen tissues and indicates that both intra-operative and more conventional surgical specimens can be diagnosed by this technique.

Conclusion

This paper provides strong evidence that automated diagnosis by means of infrared micro-spectral imaging is possible. Recent investigations within the author's laboratory upon lymph nodes have also revealed that cancers from different primary tumours provide distinctly different spectral signatures. Thus poorly differentiated and hard-to-determine cases of metastatic invasion, such as micrometastases, may additionally be identified by this technique. Finally, we differentiate benign and malignant tissues composed within axillary lymph nodes by completely automated methods of spectral analysis.

Variations in sentinel node isolated tumour cells/micrometastasis and non-sentinel node involvement rates according to different interpretations of the TNM definitions

Breast cancers with nodal isolated tumour cells (ITC) and micrometastases are categorised as node-negative and node-positive, respectively, in the tumour node metastasis (TNM) classification. Two recently published interpretations of the TNM definitions were applied to cases of low-volume sentinel lymph node (SLN) involvement and their corresponding non-SLNs for reclassification as micrometastasis or ITC. Of the 517 cases reviewed, 82 had ITC and 435 had micrometastasis on the basis of one classification, and the number of ITC increased to 207 with 310 micrometastases on the basis of the other. Approximately 24% of the cases were discordantly categorised. The rates of non-SLN metastases associated with SLN ITCs were 8.5% and 13.5%, respectively. Although the second interpretation of low-volume nodal stage categories has better reproducibility, it may underestimate the rate of non-SLN involvement. The TNM definitions of low-volume nodal metastases need to be better formulated and supplemented with visual information in the form of multiple sample images.

The location of small tumor deposits in the SLN predicts Non-SLN macrometastases in breast cancer patients

AIMS

The extent to which the location of micrometastases (MIC) or isolated tumor cells (ITC) in sentinel lymph nodes (SLNs) is correlated with the risk of downstream metastases is still unknown. This study examined this issue and compared the impact of MIC/ITC location with other established risk factors.

METHODS

Paraffin slides of SLNs with MIC/ITC-involvement obtained from 68 breast cancer patients were evaluated for MIC/ITC location, lesion size, and various SLN morphologic features. These parameters, together with demographic data and primary tumor characteristics, were analyzed using univariate and multivariate analysis to determine their association with the presence of downstream macrometastases in Non-SLN.

RESULTS

Eighteen of 68 patients with MIC (n=37) or ITC (n=31) had Non-SLN metastases. After multivariate analysis, the location of MIC/ITC in the SLN (parenchyma vs. sinus/vessel) had the strongest association with the presence of Non-SLN macrometastases (p<0.0001), followed by the pT-category (p=0.008). Sixteen of 18 patients with parenchymal involvement but only 2 of 31 without parenchymal involvement had Non-SLN macrometastases. The metric size of the primary tumor and the estrogen receptor status were significantly associated only on univariate analysis (p=0.041, 0.034), whereas the correlation to the size classification for tumor cell deposits (MIC vs. ITC) was not significant (p=0.077).

CONCLUSIONS

The results indicate that lesion location is an important predictor of Non-SLN-macrometastases. This finding may simplify the decision for axillary treatment in patients with small tumor deposits in the SLN.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Lymph node micrometastasis in node negative early gastric cancer

AIMS

The clinical significance of lymph node micrometastasis for histologically node negative gastric cancer is not well documented. This study was to assess the incidence and to clarify the risk factors of lymph node micrometastasis in patients with node negative early gastric cancer (EGC).

METHODS

We investigated the lymph node micrometastasis with using an anticytokeratin immunohistochemical stain in 90 patients with node negative EGC who underwent curative resection between 1991 and 2000.

RESULTS

Among 3526 nodes from 90 patients, there were 17 cytokeratin immunohistochemical stain positive nodes from nine patients. The incidence of micrometastasis was higher in patients with lymphatic invasion (p=0.012), venous invasion (p=0.026) and larger tumor (p=0.003). The independent risk factors for lymph node micrometastasis were lymphatic invasion (p=0.004, RR=22.915, 95% CI = 2.709 ~ 193.828) and tumor size (p=0.029, RR=1.493, 95% CI = 1.042 ~ 2.138). Although there were 10 deaths during the follow-up period of mean 67.6 months (1 month ~ 147 months), there was no death from a cancer recurrence.

CONCLUSIONS

The incidence of lymph node micrometastasis in patients with node negative early gastric cancer was 10%, and the independent risk factors for micrometastasis were lymphatic invasion and tumor size.

Minimal disease in sentinel nodes

Isolated tumor cells and micrometastases represent low-volume or minimal disease in the regional lymph nodes of breast cancer patients as compared to macrometastases. Sentinel lymph node biopsy is a functional selection and removal of the most likely site of regional metastasis, and gives pathologists the opportunity to concentrate detection techniques on a limited number of lymph nodes. Consequently, more lesions belonging in the two mentioned staging categories are discovered in sentinel lymph nodes. Despite some publications contradicting stochastic models of breast cancer, micrometastases seem to reflect a prognosis intermediate between the node-negative and macrometastatic nodal status, and they also reflect a risk of non-sentinel node involvement slightly higher than that associated with a node-negative status. Data are more contradictory as concerns isolated tumor cells. This minireview summarizes the definitions, their inconsistencies, pathological protocols aiming at the detection of minimal nodal disease, the prognostic impact and non-sentinel node involvement related risk of such nodal lesions, and their therapeutic consequences.

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

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

Factors predictive of nonsentinel lymph node involvement and clinical outcome in melanoma patients with metastatic sentinel lymph node

BACKGROUND

Identification of melanoma patients who need completion lymphadenectomy and adjuvant treatment after positive sentinel lymph node (SLN) biopsy would be a fundamental step forward toward personalized medicine. This study tested the hypothesis that the microscopic features of metastatic SLNs might predict not only nonsentinel lymph node (NSLN) status, but also patients' clinical outcomes.

METHODS

A retrospective analysis was performed on 96 consecutive melanoma patients who underwent completion lymphadenectomy after positive SLN biopsy. Patients' age and sex, primary tumor Breslow thickness, number of positive SLNs, the largest diameter and depth of invasion of metastatic deposits in the SLN, S stage, and pattern of nodal involvement were correlated with the presence of metastatic disease in NSLNs as well as with the likelihood of tumor recurrence and patient death.

RESULTS

At pathological examination, 20 patients (20.8%) had metastatic melanoma in the NSLN. Pattern of nodal involvement, depth of invasion of SLN by metastatic disease, and S stage were statistically significantly associated with the presence of metastatic disease in NSLN. Multivariate analysis revealed that only the SLN depth of invasion was an independent predictor of NSLN status (P = .0035). This parameter was also significantly associated with disease-free and overall survival, both by univariate (P < .0001 and P = .0006, respectively) and multivariate (P < .0001 and P = .0013, respectively) survival analysis.

CONCLUSIONS

These findings support further investigation of SLN depth of invasion as a predictive factor of potential clinical use to select patients as candidates for completion lymphadenectomy and adjuvant treatment.

Sentinel node biopsy: interpretation and management of patients with immunohistochemistry-positive sentinel nodes and those with micrometastases

The sentinel node procedure is an adequate tool to identify lymph node metastasis in breast cancer. Sentinel nodes are generally examined with greater attention mainly to exclude, as reliably as possible, lymph node metastasis. To achieve this, many protocols are used, resulting in different rates of micrometastasis or isolated tumor cells encountered. Since the prognostic significance of isolated tumor cells or micrometastasis in the sentinel nodes, and the risk of further axillary lymph node involvement in patients with isolated tumor cells, is uncertain and at most limited, these findings may pose difficulties for clinicians in clinical decision making. Protocols that identify lymph node metastasis, from which the clinical relevance is known, are warranted. Unnecessary lymph node dissections should be avoided.

The microanatomic location of metastatic breast cancer in sentinel lymph nodes predicts nonsentinel lymph node involvement

BACKGROUND

The majority of sentinel node (SN) positive breast cancer patients do not have additional non-SN involvement and may not benefit from axillary lymph node dissection (ALND). Previous studies in melanoma have suggested that microanatomic localization of SN metastases may predict non-SN involvement. The present study was designed to assess whether these criteria might also be used to be more restrictive in selecting breast cancer patients who would benefit from an ALND.

METHODS

A consecutive series of 357 patients with invasive breast cancer and a tumor-positive axillary SN, followed by an ALND, was reviewed. Microanatomic SN tumor features (subcapsular, combined subcapsular and parenchymal, parenchymal, extensive localization, multifocality, and the penetrative depth from the SN capsule) were evaluated for their predictive value for non-SN involvement.

RESULTS

Non-SN metastases were found in 136/357 cases (38%). Microanatomic location and penetrative depth of SN metastases were significant predictors for non-SN involvement (<0.001); limited penetrative depth was associated with a low frequency of non-SN involvement with a minimal of 10%.

CONCLUSIONS

Microanatomic location and penetrative depth of breast cancer SN metastases predict non-SN involvement. However, based on these features no subgroup of patients could be selected with less than 10% non-SN involvement.

Nodal Stage Classification for Breast Carcinoma: Improving Interobserver Reproducibility Through Standardized Histologic Criteria and Image-Based Training

Purpose

Reliable pathologic stage classification of axillary lymph nodes is an important determinant of prognosis and therapeutic decision making for patients with invasive breast cancer. Pathologists' distinction between micrometastasis (pN1mi) and isolated tumor cells [ITC; pN0(i+)] is variable using the American Joint Committee on Cancer (AJCC) Staging Manual (Sixth Edition). We sought to determine whether a set of clearly defined histologic criteria could lead to reproducible nodal classification by pathologists.

Patients and Methods

Digital images of sentinel lymph node biopsies from 56 patients with small-volume nodal metastases were examined by six experienced breast pathologists (MDs), first as a pre-test, and again as a post-test after studying a training program that outlined and illustrated the classification criteria.

Results

Post-test results, after study of the training program, were significantly improved. Compared with the reference MD, agreement improved from 76.2% (pre-test κ = 0.575; standard deviation [SD], 0.25) to 97.3% (post-test κ = 0.947; SD, 0.049). Multirater analysis of agreement among the six MDs improved from 71.5% (pre-test κ = 0.487; ASE, 0.039) to 95.7% (post-test κ = 0.915; ASE, 0.037). Agreement on lobular carcinoma metastasis classification improved from 55% (23 of 42; pre-test) to 100% (42 of 42; post-test) (P < .001), and agreement on ITC classification in nodal parenchyma improved from 67.6% (69 of 102; pre-test) to 98.0% (100 of 102; post-test; P < .001).

Conclusion

Application of current definitions for classification of small-volume nodal metastases are inconsistent, leading to variable classification of ITC and micrometastases. Reproducibility of pathologic nodal stage classification is achievable through study of a training set to clarify the AJCC criteria.

Anatomopathological analysis of sentinel and nonsentinel lymph nodes in breast cancer: hematoxylin-eosin versus immunohistochemistry

The authors compare the detection of metastases in sentinel lymph nodes (SLNs) and nonsentinel lymph nodes (NSLNs) using hematoxylin-eosin (HE) staining versus immunohistochemistry (IHC). Thirty-six patients with breast carcinoma undergo exeresis of the primary tumor and of 50 SLNs and 491 NSLNs. Sentinel lymph nodes are sectioned into transverse slices of 2- to 3-mm thickness, and a cytologic smear and a frozen section were obtained from each slice. The slices are completely cut into serial sections at 100-microm intervals. Two consecutive 4-microm-thick sections are then obtained from each level and were prepared for HE staining and IHC. Nonsentinel lymph nodes are evaluated similarly to SLNs. The authors obtain 4076 SLN sections and 32 012 NSLN sections, for a total of 36 088 sections. A comparison of HE staining versus IHC based on the total number of sections shows a sensitivity of 93.8%, a negative predictive value of 98.9%, and an accuracy of 99.1%. The values obtained by HE staining are similar to those obtained by IHC.

Diagnostic surgical pathology in lung cancer: ACCP evidence-based clinical practice guidelines (2nd edition)

OBJECTIVE

The objective of this study was to provide evidence-based background and recommendations for the development of American College of Chest Physicians guidelines for the diagnosis and management of lung cancer.

METHODS

A systematic search of the medical and scientific literature using MEDLINE, MDCONSULT, UpToDate, Cochrane Library, NCCN guidelines, and NCI/NIH search engines was performed for the years 1990 to 2006 to identify evidence-based and consensus guidelines. The search was limited to literature on humans and articles in the English language.

RESULTS

The pathologic assessment of lung cancers is based on a set of well-accepted findings, including histologic type, tumor size and location, involvement of visceral pleura, and extension to regional and distant lymph nodes and organs. Bronchial-based incipient neoplasia needs to be recognized both grossly and microscopically because these lesions may be multifocal and represent multistep carcinogenesis and may be amenable to therapy. Cytologic assessment of the individual with no symptoms is, as yet, of insufficient clinical benefit for screening of lung cancer. In challenging situations of pathologic differential diagnosis, additional studies may provide information that enables the separation of distinct tumor types. Pathobiological and molecular biological studies may yield prognostic and predictive information for clinical management and should be considered as part of protocol studies. Enhanced pathologic and molecular techniques may identify the presence of micrometastatic disease within lymph nodes; however, the clinical utility of these approaches is still unresolved. Intraoperative consultations have high diagnostic accuracy and may aid ongoing treatment and management decisions.

CONCLUSIONS

Pathologic assessment is a crucial component for the diagnosis, management, and prognosis of lung cancer. Selective diagnostic techniques and decision analysis will increase diagnostic accuracy. Cytologic screening, molecular characterization of tumors, and micrometastatic analysis are potential but not yet proved modalities for the evaluation of lung cancers.

The Prognostic Significance of Micrometastases in Breast Cancer: A SEER Population-Based Analysis

INTRODUCTION

The prognostic significance of lymph node micrometastases in breast cancer is controversial. We hypothesized that the survival of patients with solely micrometastatic disease (N1mi) would be intermediate to patients with 1-3 tumor-positive lymph nodes (N1) and those with no positive lymph nodes (N0).

METHODS

We queried the surveillance, epidemiology and end results (SEER) database for all patients between 1992 and 2003 with invasive ductal or lobular breast cancer without distant metastases and < or = 3 axillary nodes with macroscopic disease. Patients were stratified by nodal involvement and compared using the Kaplan-Meier method. Cox proportional hazards regression was utilized to compare survival after adjusting for patient and tumor characteristics.

RESULTS

Between 1992 and 2003, N1mi diagnoses increased from 2.3% to 7% among the 209,720 study patients (p < 0.001). In a T-stage stratified univariate analysis, N1mi patients had a worse prognosis in T2 lesions. On multivariate analysis, N1mi remained a significant prognostic indicator across all patients (p < 0.0001) with a hazard ratio of 1.35 compared to N0 disease and 0.82 compared to N1 disease. Other negative prognostic factors included male gender, estrogen-receptor negativity, progesterone-receptor negativity, lobular histology, higher grade, older age, higher T-stage, and diagnosis in an earlier time period.

CONCLUSION

Nodal micrometastasis of breast cancer carries a prognosis intermediate to N0 and N1 disease, even after adjusting for tumor- and patient-related factors. Prospective study is warranted and the results of pending trials are highly anticipated. Until then adjuvant therapy trials should consider using N1mi as a stratification factor when determining nodal status.

Validation of clinical prediction rules for a low probability of nonsentinel and extensive lymph node involvement in breast cancer patients

BACKGROUND

Two recently developed clinical prediction rules aim to anticipate the lack of nonsentinel lymph node metastases and the involvement of less than 4 lymph nodes in breast cancer patients with positive sentinel lymph nodes (SLNs).

METHODS

The University of Louisville Breast SLN Study clinical prediction rules were validated on an independent set of SLN-positive patients with tumors < or = 15 mm.

RESULTS

The data on 475 and 473 patients, respectively, were used for the validation. The areas under the receiver operating characteristic curves were similar to the originals for both predictive tools (.70 and .76). The lowest score of 1 identified 5 of 7 patients with disease limited to the SLNs and 161 of 165 as having less than 4 involved lymph nodes.

CONCLUSIONS

A subset of patients with SLN-only involvement and less than 4 metastatic lymph nodes can probably be identified by means of the Louisville clinical prediction rules, but prediction of the lack of non-SLN metastasis seems less reliable.

Prognostic impact of PCR-based identification of isolated tumour cells in the peritoneal lavage fluid of gastric cancer patients who underwent a curative R0 resection

Identification of cancer cells in the peritoneal cavity could influence therapy and outcome of gastric carcinoma patients. The objective of this study was to evaluate the clinical impact of the real-time quantitative polymerase chain reaction-(PCR) based identification of isolated tumour cells in the peritoneal lavage fluid of gastric carcinoma. The peritoneal lavage fluid of 116 patients with gastric cancer was sampled at laparotomy. After RNA extraction and reverse transcription, real-time quantitative PCR was performed using the primers and probes for carcinoembryonic antigen (CEA) and cytokeratin-20 (CK20). When either the CEA mRNA or CK20 mRNA level of the sample was over the cutoff value, the sample was determined to be PCR-positive. Forty-six (40%) of the 116 patients were PCR-positive and 30 (65%) of the 46 PCR-positive patients died as a result of recurrent peritoneal dissemination. The prognosis of the 46 PCR-positive patients was significantly (P<0.001) worse than that of 70 PCR-negative patients. Furthermore, in 80 of the cases with a curative R0 resection, 15 of the patients with PCR-positive findings had a significantly (P<0.001) poorer prognosis than the 65 PCR-negative patients. The prognosis of the PCR-positive patients was significantly poorer than that of the PCR-negative patients in the T3 (P<0.0001) and T4 (P=0.048) subgroups. In a multivariate analysis of the 80 cases with a curative R0 resection, the real-time quantitative RT–PCR (CEA and/or CK20) levels indicated that they were independent prognostic factors. The real-time quantitative RT–PCR analysis of the CEA and/or CK20 transcripts in the peritoneal lavage fluid is useful for predicting the peritoneal recurrence in patients who are undergoing a curative resection for gastric cancer.

Proliferative activity of micrometastases in the lymph nodes of patients with gastric cancer

BACKGROUND

Immunohistochemically detectable isolated tumour clusters (ITCs) with a diameter of less than 0.2 mm have been regarded as non-metastatic lesions, because of a lack of proliferative activity. This study investigated the proliferative activities of ITCs.

METHODS

Three hundred and eight patients with primary gastric cancer diagnosed as pN0 by routine histological examination were studied. All patients underwent curative resection. Sections of lymph nodes were stained by double-immunostaining methods using anti-cytokeratin and anti-Ki-67 antibody (MIB-1).

RESULTS

ITCs were detected in 77 nodes from 37 patients, designated as having pN0(i+) lesions. Seventy of 77 lymph nodes with ITCs were detected in the N1 station, and seven were found in the N2 station. Of 25 single isolated cancer cells, 12 showed positive labelling with MIB-1, and 49 of 52 ITCs with clusters of cancer cells had positive MIB-1 labelling (mean(s.d.) 46.6(30.1) per cent). Five of the 37 patients with ITCs (pN0(i+)) versus one of the 271 patients with no evidence of ITCs (pN0(i-)) died from recurrence. Patients with ITCs had a significantly worse prognosis than those without (P = 0.014).

CONCLUSION

ITCs have a high proliferative activity and may have the potential to evolve into established lymph node metastasis.

Sentinel lymph node biopsy and non-sentinel node involvement in special type breast carcinomas with a good prognosis

This study aimed at identifying factors related to sentinel lymph node (SLN) involvement in patients with tubular, cribriform, mucinous or papillary breast carcinoma and those related to non-SLN metastases if an SLN was positive. Multivariate analyses involved logistic and stepwise regressions. The SLNs harboured metastases in 85 of 572 cases, 78 of whom underwent axillary dissection; 19 presented non-SLN positive disease. Lack of lymphovascular invasion, a tumour size < or = 10 mm and a single SLN removed were the factors predicting an SLN metastasis rate <10%, and patients with these features could be candidates for no surgical axillary staging. A positive SLN proportion of < or = 50% and no lymphovascular invasion were associated with a <10% rate of non-SLN invasion; patients with a positive SLN and these features could be candidates for the omission of completion axillary dissection. The opposite presentation of these factors would mandate SLN biopsy and axillary dissection, respectively.

Management of the axilla in women with breast cancer

The approach towards axillary surgery should be selective and flexible, with its management tailored to patient choice and tumour characteristics, and concordant with local practice guidelines and available resources. Sentinel-lymph-node biopsy has been embraced as a standard of care in many centres around the world and has revolutionised management of the axilla during the past decade. Nonetheless, data for long-term outcomes remain scarce, and there are persistent variations in practice and inconsistencies in methodology. An international perspective has been sought on important issues relating to management of the axilla, which includes not only the indications and techniques for sentinel-lymph-node biopsy, but also lymph-node sampling, axillary-lymph-node dissection, and observation alone. In this Review, we initially present an overview, which focuses on biological models of lymphatic networks within the breast and patterns of tumour dissemination. A set of key questions are posed with preliminary comments from the authors, followed by a series of collective viewpoints from experts within several different countries.

What is a positive sentinel lymph node in a breast cancer patient? A practical approach

Sentinel lymph node (SN) biopsy has become increasingly used for the staging of breast carcinoma, resulting in the upstaging of this disease, and this has led to concerns with regard to what should be considered a positive SN. Factors influencing the positive staging of an SN include metastasis size, the method used for metastasis detection, the definition of metastasis and the individual pathologist. Until evidence to the contrary emerges, an SN should be considered positive if metastases (nodal involvement >0.2mm in the largest dimension) are detected in it by histology. A target size should be identified, and SNs, as the most likely sites of nodal metastases, should be searched systematically to find (nearly) all of the targeted metastases. The European guidelines for SN assessment have set two such target sizes: as a minimum, all metastases >2mm should be identified, and optimally all micrometastases should also be sought.

Sentinel lymph node biopsy in staging small (up to 15 mm) breast carcinomas. Results from a European multi-institutional study

Sentinel lymph node (SLN) biopsy has become the preferred method for the nodal staging of early breast cancer, but controversy exists regarding its universal use and consequences in small tumors. 2929 cases of breast carcinomas not larger than 15 mm and staged with SLN biopsy with or without axillary dissection were collected from the authors' institutions. The pathology of the SLNs included multilevel hematoxylin and eosin (HE) staining. Cytokeratin immunohistochemistry (IHC) was commonly used for cases negative with HE staining. Variables influencing SLN involvement and non-SLN involvement were studied with logistic regression. Factors that influenced SLN involvement included tumor size, multifocality, grade and age. Small tumors up to 4 mm (including in situ and microinvasive carcinomas) seem to have SLN involvement in less than 10%. Non-SLN metastases were associated with tumor grade, the ratio of involved SLNs and SLN involvement type. Isolated tumor cells were not likely to be associated with further nodal load, whereas micrometastases had some subsets with low risk of non-SLN involvement and subsets with higher proportion of further nodal spread. In situ and microinvasive carcinomas have a very low risk of SLN involvement, therefore, these tumors might not need SLN biopsy for staging, and this may be the approach used for very small invasive carcinomas. If an SLN is involved, isolated tumor cells are rarely if ever associated with non-SLN metastases, and subsets of micrometastatic SLN involvement may be approached similarly. With macrometastases the risk of non-SLN involvement increases, and further axillary treatment should be generally indicated.

Sentinel lymph node biopsy as the new standard of care in the surgical treatment for breast cancer

During the recent years, based on the results of validation studies, the sentinel lymph node biopsy has replaced routine axillary dissection as the new standard of care in early breast cancer. The technique represents a minimally invasive, highly accurate method for axillary staging, which could spare approximately 65-70% of patients unnecessary axillary dissection and its related morbidity. Several technical and clinical controversies have been raised during the development of this new technique; the authors review the most important issues, some questions have already been answered and others are still under debate. As far as the technical aspects are concerned, mapping techniques, appropriate surgical training, options for pathological examination of sentinel lymph nodes and the issue of nonaxillary sentinel lymph nodes are discussed. An update on clinical controversies demonstrates that factors such as large tumor size, palpable axillary nodes, multifocality and multicentricity, previous breast and axillary surgery, and pregnancy are no longer regarded as absolute contraindications for sentinel lymph node biopsy. Feasibility, accuracy and timing of sentinel lymph node biopsy in patients undergoing neoadjuvant chemotherapy remain unsolved issues, as well as the indication of the technique for some subgroups of in situ lesions. Finally, one of the most attractive open forums for debate will be discussed: whether or not completion of axillary dissection in the case of positive SLN is always required.

Pathological Evaluation of Sentinel Lymph Nodes

The sentinel lymph nodes are the most likely site of nodal metastasis. Their focused analysis results in upstaging cancers, although the extra yield from a more intensive work-up is generally dominated by micrometastases and isolated tumor cells. Nodal staging is generally done to reflect systemic spread of solid tumors and guide treatment accordingly. However, in general, the two processes of haematogenous and lymphogenic spread are not causally interrelated, and the extrapolation from low-volume nodal involvement to systemic involvement and therapeutic consequences of this extrapolation are still under investigation.

Le système TNM: 3 lettres pour un langage riche mais parfois ambigu

The T (tumor), N (node) and M (metastasis) staging system classifies tumors according to the anatomic extent. Since its first publication in 1940, the TNM classification has been periodically updated. This article reviews the main changes of the last edition and potential practical difficulties in interpretation of pN0 status, residual tumor, definition and classification of micrometastases and isolated tumoral cells, yTNM, use of X classification.

Maladie micrométastatique et maladie résiduelle axillaire. Exemple du cancer du sein

The knowledge of the axillary involvement is a major prognosis factor for breast cancer and an important parameter for treatment decision. Nevertheless, two recent current medical situations have occurred in breast cancer, changing our management. First, with the development of mass screening and sentinel lymph nodes biopsies, we have to take treatment decisions based upon minimal lymph node involvement, with a clinical significance still poorly understood. Second, for the large tumors, potentially with lymph node involvement, we have to deal with tumor and lymph node under staging, after induction chemotherapy. We have to learn how to evaluate accurately those new parameters to treat the best way our patients.

Seeding of epithelial cells into circulation during surgery for breast cancer: the fate of malignant and benign mobilized cells

Background

Surgery of malignant tumors has long been suspected to be the reason for enhancement of growth of metastases with fatal outcome. This often prevented surgeons from touching the tumor if not absolutely necessary. We have shown in lung cancer patients that surgery, itself, leads to mobilization of tumor cells into peripheral blood. Some of the mobilized cells finding an appropriate niche might grow to form early metastases. Monitoring of tumor cell release during and the fate of such cells after surgery for breast cancer may help to reveal how metastases develop after surgery.

Method

We used the MAINTRAC^® analysis, a new tool for online observation of circulating epithelial cells, to monitor the number of epithelial cells before, 30 min, 60 min, three and seven days after surgery and during subsequent variable follow up in breast cancer patients.

Results

Circulating epithelial cells were already present before surgery in all patients. During the first 30–60 min after surgery values did not change immediately. They started increasing during the following 3 to 4 days up to thousand fold in 85% of treated patients in spite of complete resection of the tumor with tumor free margins in all patients. There was a subsequent re-decrease, with cell numbers remaining above pre-surgery values in 58% of cases until onset of chemotherapy. In a few cases, where no further therapy or only hormone treatment was given due to low risk stage, cell numbers were monitored for up to three years. They remained elevated with no or a slow decrease over time. This was in contrast to the observation in a patient where surgery was performed for benign condition. She was monitored before surgery with no cells detectable. Epithelial cells increased up to more than 50 000 after surgery but followed by a complete reduction to below the threshold of detection.

Conclusion

Frequently before but regularly during surgery of breast cancer, epithelial cells are mobilized into circulation. Part of these cells, most probably normal or apoptotic cells, are cleared from the circulation as also shown to occur in benign conditions. After resection even if complete and of small tumors, cells can remain in the circulation over long times. Such cells may remain "dormant" but might settle and grow into metastases, if they find appropriate conditions, even after years.

Histopathologic Examination of the Sentinel Lymph Nodes

Sentinel lymph nodes (SLNs) are the most likely site of regional metastasis. Their step sectioning and cytokeratin immunohistochemistry (IHC) result in the upstaging of breast cancer. The heterogeneity of histologic methods is partially responsible for differences in nodal upstaging of the disease in different reports. Intraoperative assessment might be done by both frozen sections and imprint cytology; both methods have advantages and disadvantages. Several guidelines relating to the histopathology of sentinel nodes, including the recent European Working Group for Breast Screening Pathology guidelines, are briefly summarized. These latter advocate multilevel assessment of grossly or intraoperatively negative sentinel nodes with levels separated by a maximum of 1 mm and allow IHC in their assessment, although this latter method is not mandatory. Both methods of intraoperative evaluation are allowable. There are also minimum requirements for the reports on sentinel node histology. For example, the reports should include the extent of nodal involvement, the method used for their identification, and preferably the method used for investigating the sentinel nodes, even if the results are negative. These guidelines are intended to form the basis for national guidelines in European countries.

Minimal metastatic disease in sentinel lymph nodes in breast carcinoma: some modest proposals to refine criteria for "isolated tumor cells"

Axillary lymph node status is one of the most important prognostic factors in breast carcinoma. The weight of cumulative evidence suggests that the development of the sentinel lymph node (SLN) biopsy procedure has not only allowed for accurate lymph node-staging but has also helped avoid the morbidity of a full axillary dissection in those patients who are unlikely to have metastatic tumor in that location. The detection of metastases in SLNs is facilitated by the, now relatively routine, enhanced histopathologic examination via step-sectioning and immunohistochemistry. In clinical terms, the finding of a metastatic deposit that measures between 0.2 and 2 mm, that is, "micrometastasis" in a SLN is largely noncontroversial; however, the presence of smaller metastatic foci detected either by routine hematoxylin and eosin stain or by cytokeratin immunostain [<0.2 mm, ie, so-called "isolated tumor cells (ITCs)"] has remained problematic since the advent of the SLN biopsy. In this communication, attention is drawn to the broad morphologic range of metastatic disease in SLN that may be placed in the category of so-called ITC. To facilitate the reproducible classification of the various strata of minimal metastasis in sentinel lymph nodes, we recommend the following: (1) the term "isolated tumor cell" (note singular form) be restricted to cases that show the presence of only a single tumor cell. (2) In situations where there are multiple isolated single cells and/or cell cluster(s) present and each cluster measures<0.2 mm, the term "submicroscopic metastasis" be adopted and an actual count of tumor cells present may be given. (3) Restrict the use of the term micrometastasis to cases wherein the largest metastatic focus is larger than 0.2 mm but smaller than 2.0 mm.

Discriminating between micrometastases and isolated tumor cells in a regional and institutional setting

The reproducibility of diagnosing isolated tumor cells (ITC) and micrometastases has been recently tested by expert breast pathologists, but might be different in a community setting. Digital images of 50 cases of low volume nodal involvement were circulated among pathologists from the Piedmont region (Italy) and from the Helios Medical Center in Berlin. Participants were asked to categorize the lesions into micrometastasis, ITC or others. The test was performed on the basis of a previous consensus statement. Kappa statistics were used for the assessment of interobserver variability. The kappa values for the consistency of categorizing cases were 0.47 and 0.57 for the regional and the institutional tests, respectively. Our study suggests that the reproducibility of diagnosing micrometastases and ITC in a community setting may reach that of experts, but is in the moderate range, and this may interfere with studies trying to solve the prognostic significance of these diagnostic categories.

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.

Comprehensive examination of sentinel lymph node in breast cancer: a solution without a problem?

Although several methods have been devised to examine sentinel lymph node (SLN) specimens in breast cancer, the extent of examination and whether it should routinely include multilevel sectioning to detect micrometastases (MM) (<2.0 mm) is still debated. In this study all "positive'' SLN biopsies from 67 consecutive patients with breast carcinoma and evaluated by means of an extended protocol were reviewed. Abnormal findings included micrometastases (MM) between 0.2 and 1.0 mm (14 cases), (MM) between 1.0 and 2.0 mm (8 cases), metastases>2.0 mm (22 cases), and isolated tumor cells (ITCs) (23 cases). The likelihood of finding metastatic deposits was comparable if sections were carried out at 100-, 150-, 200-, 250-, and 500-microm intervals. No metastatic foci>2.0 mm would have been missed. 1 MM (1.1 mm focus) was missed within the 250- and 500-microm levels on hematoxylin-eosin, but not complementary cytokeratin staining. Our data show that SLN step sectioning does not add significant yield if compared to standard examination carried on initial levels, if the minimal target of 1.0 mm micrometastatic deposit is sought.

Analysis of micrometastatic disease in sentinel lymph nodes from resectable colon cancer: results of Cancer and Leukemia Group B Trial 80001

PURPOSE

To determine whether sentinel lymph node (LN) sampling (SLNS) could reduce the number of nodes required to characterize micrometastatic disease (MMD) in patients with potentially curable colon cancer.

PATIENTS AND METHODS

Cancer and Leukemia Group B 80001 was a study to determine whether SLNS could identify a subset of LNs that predicted the status of the nodal basin for resectable colon cancer and, therefore, could be extensively evaluated for the presence of micrometastases. Patients enrolled onto this study underwent SLNS after injection of 1% isosulfan blue, and both sentinel nodes (SNs) and non-SNs obtained during primary tumor resection were sectioned at multiple levels and stained using anti-carcinoembryonic antigen and anticytokeratin antibodies.

RESULTS

Using standard histopathology, SNs failed to predict the presence of nodal disease in 13 (54%) of 24 node-positive patients. Immunostains were performed for patients whose LNs were negative by standard histopathology. Depending on the immunohistochemical criteria used to assign LN positivity, SN examination resulted in either an unacceptably high false-positive rate (20%) or a low sensitivity for detection of MMD (40%).

CONCLUSION

By examining both SNs and non-SNs, this multi-institutional study showed that SNs did not accurately predict the presence of either conventionally defined nodal metastases or MMD. As a result, SLNS is not a useful technique for the study of MMD in patients with colon cancer.

Prospective validation of quantitative CEA mRNA detection in peritoneal washes in gastric carcinoma patients

Prediction of peritoneal relapse is extremely important for gastric cancer patients after curative surgery. The present study prospectively validates the prognostic ability of quantifying carcinoembryonic antigen (CEA) mRNA in peritoneal washes by real-time reverse transcriptase-polymerase chain reaction. Based on a retrospective study of 197 curatively resected gastric cancer patients (training set), we determined a cutoff value of CEA mRNA using receiver-operating characteristic curve. We used this cutoff value to validate the risk of peritoneal recurrence in a new cohort of 86 gastric cancer patients (validation set) between July 2000 and December 2002 in a prospective study. During the median 30 months of postoperative surveillance, 20 of the 86 patients died, and 13 of the 20 developed peritoneal metastases. Peritoneal recurrence-free survival as well as overall survival was significantly worse in patients with positive CEA mRNA (P<0.0001). Multivariate analysis with the Cox proportional hazards model showed that positive CEA mRNA was a significant independent risk factor with both survival (P=0.0130) and peritoneal recurrence-free survival (P=0.0006) as end points. These results indicate that quantitation of CEA mRNA in peritoneal washes is a reliable prognostic indicator of peritoneal recurrence in the clinical setting.

Implications of the sentinel lymph node procedure for local and systemic adjuvant treatment

PURPOSE OF REVIEW

The objective of the sentinel lymph node procedure in breast cancer is to perform an accurate axillary staging and provide good local control, while sparing the patients the morbidity of an axillary lymph node dissection. Since its routine clinical use, questions were raised concerning the implications for local and systemic adjuvant treatment. This review provides an update of the recent literature.

RECENT FINDINGS

As a result of a more detailed histopathologic work-up of the sentinel lymph node, higher rates of lymph node metastases are detected. This leads to an upstaging of a subset of node-negative patients and an increase in the overall percentage of node-positive patients. However, the clinical implications of micrometastases and isolated tumor cells remain unclear. Furthermore, sentinel lymph nodes may be found in the internal mammary lymph node chain but the treatment of these nodes is subject of debate.

SUMMARY

Current guidelines recommend axillary lymph node dissection in patients with a positive sentinel node. The surgical removal of the internal mammary lymph node is only indicated in the context of a clinical trial. Radiation therapy of the axilla is an acceptable alternative for patients who refuse an axillary lymph node dissection (clinical trial). The value of radiotherapy to the internal mammary lymph node has never been established. Systemic treatment decisions in patients with a macrometastasis or micrometastasis in the sentinel lymph node follow the guidelines of node-positive patients, whereas in patients with isolated tumor cells only, guidelines for node-negative patients are followed. The results of ongoing clinical trials will be important for the development of further guidelines.