Systemic treatment after sentinel lymph node biopsy in breast cancer: who, what, and why?

Efficacy and feasibility of the immunomagnetic separation based diagnosis for detecting sentinel lymph node metastasis from breast cancer

A purpose of this study was to establish a novel molecular diagnostic model and provide new insight into the intraoperative evaluation of the sentinel lymph node (SLN) metastasis in breast cancer. A total of 124 breast cancer patients who met the criteria of sentinel lymph node biopsy (SLNB) and underwent intraoperative biopsy were consecutively enrolled in this study. After the SLNs obtained from each patient were labeled, MOC-31 monoclonal antibody-mediated immunomagnetic separation (IMS) and flow cytometry were used to determine the expressions of breast cancer metastasis-related markers, including Mucin 1 (MUC1), CD44v6, and HER2. Alternatively, conventional intraoperative hematoxylin and eosin (HE) staining and cytokeratin immunohistochemistry (CK-IHC) were performed to detect potential SLN metastasis. The sensitivity, specificity, and false-negative rate of the three intraoperative diagnostic methods were compared and analyzed. A total of 55 positive-SLNs were found in 38 breast cancer patients using IMS, yielding a sensitivity of 86.4% (38/44), specificity of 94.7% (36/38), accuracy of 93.5% (116/124), false-positive rate of 2.5% (2/80), false-negative rate of 13.6% (6/44), positive predictive value of 95.5% (42/44), and negative predictive value of 93.0% (80/86). Patients with high expressions of CD44v6, MUC1, and HER2 in SLNs tended to have higher number of positive lymph nodes, among which the MUC1 and HER2 showed significant differences (P<0.05). Therefore, compared with conventional HE staining and CK-IHC, IMS technology has remarkably higher sensitivity and specificity and relative lower false-negative rate, thus making it an effective and feasible intraoperative detection method of SLN for breast cancer diagnosis to some extent.

Sentinel Lymph Node Biopsy in Breast Cancer

The axillary lymph node status is the most reliable prognostic indicator of recurrence and overall survival in patients with breast cancer. The current standard surgical procedure for the management of invasive breast cancer is the complete removal of the cancer with total axillary clearance. However, recently, selective sentinel lymph node mapping and biopsy is gaining acceptance as a useful and accurate staging procedure, as it is minimally invasive. The sentinel lymph node is the first node into which a primary cancer drains, and is thus the first node to be involved by metastases. Patients whose sentinel nodes are negative for breast cancer metastases, can be spared a more extensive axillary lymph node dissection, with reduction in the postoperative morbidity. Sentinel node mapping is usually performed by intradermal or peritumoral injection of a combination of blue dye and radiotracer. Sentinel node examination is sometimes done intraoperatively, by imprint cytology and frozen sections, for an immediate assessment, to plan the extent of surgery at a single sitting. Permanent sections of the sentinel node are studied by serial sectioning, and immunohistochemistry for cytokeratin is done to detect micrometastases which are frequently missed on hematoxylin and eosin (H&E)-stained sections. The various aspects of sentinel node examination, and its role to decide further management in patients with ductal carcinoma-in-situ, and in other clinical settings, are discussed in this review.

Sentinel node positive breast cancer patients who do not undergo axillary dissection: are they different?

BACKGROUND

Little data address outcome in patients with sentinel lymph node (SN) metastases without completion axillary lymph node dissection (CALND). This study was designed to assess locoregional recurrence in patients with positive SNs who did not undergo CALND.

METHODS

An IRB-approved, retrospective chart review was conducted on breast cancer patients with a positive SN. Follow-up information on outcomes was obtained via mailed questionnaires and chart review. Comparative analyses were performed between patients who did and did not undergo CALND after a positive sentinel lymph node biopsy.

RESULTS

From November 1998 to June 2004, 625 breast cancer patients had a positive sentinel lymph node biopsy. One-hundred and eighteen patients with < or = 0.2 mm nodal metastases (N0i+) were excluded from the study. Of the remaining 507 patients, 421 underwent CALND and 86 did not. In comparison to patients who had CALND, patients who did not undergo CALND had smaller primary tumors (2 vs 2.6 cm, P = .0007) and were more likely to have a single positive sentinel node (92% vs 77%, P = .002). The metastasis size of the sentinel node was smaller compared to patients who underwent axillary dissection (1.7 vs 6.4 mm, P < .0001). Mean predicted probability of nonsentinel node metastasis in patients who did not undergo CALND was 20% compared to 47% in patients who did (P < .0001). During a median follow-up of 30 months, there were no axillary recurrences.

CONCLUSIONS

These data confirm that patients who have a positive sentinel node biopsy and do not undergo CALND have a lower risk profile for axillary disease. In this lower risk subset, axillary treatment may not be necessary.

Fluorodeoxyglucose positron emission tomography with sentinel lymph node biopsy for evaluation of axillary involvement in breast cancer

Background

This study analysed the value of [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) in detecting axillary lymph node involvement in women with breast cancer.

Methods

In the first 150 women in this prospective study, axillary lymph node dissection (ALND) was performed regardless of the PET results. In a second group (125 women) FDG-PET was complemented with sentinel lymph node biopsy (SLNB) only in those who did not have pathological axillary uptake.

Results

The sensitivity and specificity of FDG-PET in detecting axillary involvement was 84·5 and 98·5 per cent respectively in the whole series of 275 patients, with two false-positive and 22 false-negative results. False-negative results were associated with some intrinsic tumour characteristics. In 21 women, PET revealed pathological uptake, suggesting involvement of the internal mammary lymph node chain. Whole-body PET identified a second synchronous tumour in five asymptomatic patients and haematogenous metastases in two patients.

Conclusion

The high positive predictive value of PET (98·4 per cent) suggests that FDG uptake in the axilla could be an indication for full ALND without previous SLNB.

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.

Intraoperative Examination of Sentinel Nodes in Breast Cancer: Is the Glass Half Full or Half Empty?

BACKGROUND

Intraoperative identification of positive sentinel lymph nodes in patients with breast cancer may avoid a return to the operating room.

METHODS

In a group of 402 consecutive patients with primary breast cancer who underwent sentinel lymph node biopsy, an intraoperative examination (IE) was obtained in 236 cases either by frozen section (FS; n = 68) or by touch preparation cytology (TP; n = 168).

RESULTS

IE had an accuracy of 89% (209 of 236), but it identified only 52 of 77 positive cases (sensitivity, 68%). There were 25 false-negative cases (13.7%), of which 7 were macrometastases and 18 by micrometastases (P < .001). Six macrometastases were missed by TP and one by FS (P = .9). There were two false-positive cases (3.7%). Overall, 48 (20%) of 236 patients avoided a delayed return to the operating room for a completion lymphadenectomy because of IE findings. This occurred in 10% of patients with tumors <1 cm in diameter, in 20% of those with tumors between 1 and 2 cm, and in 34% of those with tumors >2 cm in diameter (P = .05). The cost savings for the Italian Health System amounted to 198,040 (US$223,794) in these patients.

CONCLUSIONS

IE has acceptable sensitivity for lymph node macrometastases, but it is a weak tool for diagnosing micrometastases. FS and TP are roughly equivalent. IE allows management changes, because approximately 20% of all patients are expected to undergo synchronous axillary dissection, and it is particularly helpful in T2 patients. This may allow substantial cost savings for the health-care system.

Revision of breast cancer staging: the 6th edition of the TNM Classification

A Breast Task Force comprised of nationally known experts in the field of breast cancer treatment was charged with recommending additions and changes for the 6th edition of the TNM Classification that were based on published evidence and/or were consistent with widespread clinical consensus. Additions made to the staging system were designed to facilitate the uniform collection of clinically relevant information about new techniques for the detection of metastatic cells. These additions include quantitative criteria to distinguish micrometastases from isolated tumor cells, and specific identifiers to record the use of sentinel lymph node biopsy, immunohistochemical (IHC) staining, and molecular biology techniques. Revisions of the previous staging system are related to the number of affected axillary lymph nodes and to the classification of level III axillary lymph nodes and lymph nodes outside of the axilla.

Is it necessary to perform prospective randomized studies before sentinel node biopsy can replace routine axillary dissection?

BACKGROUND AND METHODS

Sentinel lymph node (SLN) biopsy is a useful way of assessing axillary nodal status in breast cancer patients. Recently, several surgeons have begun to abandon routine axillary dissection on the basis of negative SLN biopsy results. However, there is no long-term data comparing outcomes of SLN biopsy alone with those of axillary dissection. This paper reviews and discusses the significance of ongoing prospective randomized clinical trials aiming at the elimination of axillary dissection.

RESULTS

SLN biopsy is known to have a false-negative rate. It can thus be assumed that SLN biopsy alone may fail to remove the disease completely from the axilla in some patients. As a result, it is not known whether SLN biopsy alone will increase the axillary recurrence rate, particularly in patients with a high risk of axillary lymph node metastasis. Recently, moreover, locoregional control appears to be important for enhancing survival in conjunction with adjuvant systemic therapy. It is therefore still unclear to what extent the benefits of SLN biopsy outweigh the risks and, if so, for which patient groups.

CONCLUSION

Before SLN biopsy can replace routine axillary dissection, research using long-term regional controls and investigation of survival in a prospective randomized trial are essential. Except for clinical research studies, routine axillary dissection should not be abandoned until and unless there is documentation of extensive experience and a low false negative rate. Even with such evidence, however, patients undergoing SLN biopsy without concomitant axillary dissection should be informed of the risk of a false-negative result.

Staging system for breast cancer: revisions for the 6th edition of the AJCC Cancer Staging Manual

Since its inception, the AJCC staging system for breast cancer has been in an almost constant state of evolution, striving with each revision to reflect the most up-to-date clinical research as well as the widespread consensus among physicians about appropriate diagnostic and treatment standards. To date, these revisions have essentially represented a "fine-tuning" of the initial judgment that tumor size, lymph node status, and presence of distant metastases are the most significant prognostic factors for breast cancer. With the problems of standardization and reproducibility being resolved, it is likely that histologic grade will join this group of independent markers and be incorporated into the AJCC staging system in the near future. Over the last 15 years. considerable attention has been focused on the discovery of new markers visualized with immunohistochemistry and RT-PCR that may be validated as independent prognostic indicators (reviewed by Mirza et al). To date, the usefulness of many of these markers has been limited by lack of standardization in measurement techniques, but several show great promise for the future. By increasing the number of prognostic markers that can give independent information about patient outcome, physicians will be better able to determine optimal treatment approaches for individual patients.

Preliminary outcome analysis in patients with breast cancer and a positive sentinel lymph node who declined axillary dissection

BACKGROUND

This retrospective study was designed to provide a preliminary outcome analysis in patients with positive sentinel nodes who declined axillary dissection.

METHODS

A review was conducted of patients who underwent lumpectomy and sentinel lymph node excision for invasive disease between January 1998 and July 2000. Those who were found to have sentinel lymph node metastasis without completion axillary dissection were selected for evaluation. Follow-up included physical examination and mammography.

RESULTS

Thirty-one patients were identified who met inclusion criteria. Primary invasive cell types included infiltrating ductal carcinoma, infiltrating lobular carcinoma, and mixed cellularity. Most primary tumors were T1. Nodal metastases were identified by hematoxylin and eosin stain and immunohistochemistry. Twenty-seven of the metastases were microscopic (<2 mm), and the remaining four were macroscopic. All patients received adjuvant systemic therapy. With a mean follow-up of 30 months, there have been no patients with axillary recurrence on physical examination or mammographic evaluation.

CONCLUSIONS

We have presented patients with sentinel lymph nodes involved by cancer who did not undergo further axillary resection and remain free of disease at least 1 year later. This preliminary analysis supports the inclusion of patients with subclinical axillary disease in trials that randomize to observation alone.

Sentinel node biopsy after neoadjuvant chemotherapy for breast cancer

BACKGROUND

After neoadjuvant chemotherapy, while results of sentinel node biopsy (SNB) are encouraging, conditions that may affect sentinel node (SN) detection and false negative rates with respect to clinical and pathological tumor response after neoadjuvant therapy require investigation.

METHODS

Thirty-four patients with clinical stage I, II and IIIA invasive breast cancer underwent neoadjuvant chemotherapy with doxorubicin/cyclophosphamide or doxorubicin/cyclophosphamide and docetaxel/segmental resection, SNB, and axillary node dissection (AND).

RESULTS

SNs were found in 31 of 34 patients (91.2%). SNs were found in 20 of 21 patients (95.2%) with complete clinical tumor response, it was positive in 40% and no false negatives occurred. SNs were found in 11 of 13 patients (84.6%) with partial or no clinical tumor response; in four patients (33%) the SN was positive and no false negative nodes were found. Seven patients had complete pathological tumor response. SNs were found in six of these patients (85.7%). The SN was positive in 1 of 6 patients (16.7%) with no false negative. In 25 of 27 patients (92%) with partial or no pathological tumor response, the SN was identified. Eleven of these patients (44%) had positive nodes with no false negatives.

CONCLUSIONS

SN identification rate and accuracy after neoadjuvant chemotherapy for breast carcinoma were extremely good however there is potential for inaccuracy after less than complete pathological tumor response. Further evaluation of SNB in larger clinical trial is warranted prior to accepting this approach as a standard care.

Sentinel lymph node biopsy in breast cancer

The concept of sentinel lymph node (SLN) biopsy in breast cancer patients is simple, attractive and rapidly emerging as a new standard of care. Several aspects of the technique of lymphatic mapping, case selection, pathologic analysis and the finding of micrometastases, and the accuracy of the technique are important subjects of study and debate in the literature and will be discussed in this review. High identification rates can be attained by the use of both radioguided and blue dye lymphatic mapping. Intradermal injection of tracers has reported to be successful, suggesting that dermal and parenchymal lymphatics drain to the same SLN. Extra axillary drainage is only seen after peri- or intratumoural injection. SLN biopsy is most widely used for both palpable and non-palpable T1 and T2 tumours, and limited experience exists for other indications. Accuracy is high only in experienced hands. The impact of failure of the procedure on regional disease control and survival will be assessed in a trial of the NSABP (National Adjuvant Breast and Bowel Project). The influence of a positive SLN biopsy with and without axillary dissection on survival and local control will be studied in trials of the BASO (British Association of Surgical Oncology), ACOSOG (American College of Surgeons Oncology Group) and EORTC (European Organisation for Research and Treatment of Cancer). These phase III trials and related studies on the importance of micrometastases in the SLN will give new insights in the safety of the SLN procedure and in the importance of treatment of regional lymph nodes in relation to local disease control and survival.

Revision of the American Joint Committee on Cancer staging system for breast cancer

PURPOSE

To revise the American Joint Committee on Cancer staging system for breast carcinoma.

MATERIALS AND METHODS

A Breast Task Force submitted recommended changes and additions to the existing staging system that were (1) evidence-based and/or consistent with widespread clinical consensus about appropriate diagnostic and treatment standards and (2) useful for the uniform accrual of outcome information in national databases.

RESULTS

Major changes included the following: size-based discrimination between micrometastases and isolated tumor cells; identifiers to indicate usage of innovative technical approaches; classification of lymph node status by number of involved axillary lymph nodes; and new classifications for metastasis to the infraclavicular, internal mammary, and supraclavicular lymph nodes.

CONCLUSION

This revised staging system will be officially adopted for use in tumor registries in January 2003.

Minimally invasive surgery in breast cancer treatment

As genetic and biological treatment modalities are developed that can be custom-designed for individual patients, the possibility that breast cancer can be managed as a chronic long-term disease becomes more real, and the requirement for minimally invasive surgical intervention used as part of a multidisciplinary treatment approach becomes more pressing. Rather than fearing that they will be replaced, surgeons should enthusiastically move into this dynamic phase in the development of new surgical techniques for the treatment of breast cancer. This article will discuss such techniques in three evolving areas: 1) management of the axilla after neoadjuvant chemotherapy; 2) sentinel node dissection; and 3) radiofrequency ablation of primary tumors of the breast.

Sentinel lymph node biopsy for breast cancer

Sentinel lymph node biopsy (SLNB) is an emerging surgical technique to improve lymph node staging for breast cancer. Despite the rapid development of this technique, there remain aspects of SLNB that need to be further defined to provide a standardized approach. Variables, including patient selection, technical details for the performance of SLNB, extent of pathologic evaluation of the sentinel lymph node, and the impact of micrometastases, are areas of controversy. This paper reviews the controversies and discusses available data as well as personal experience and opinion.

Neoadjuvant chemotherapy in the treatment of stage II and III breast cancer

The current attractiveness of neoadjuvant chemotherapy lies in its ability to downstage both the primary tumor and the axilla, making many patients good candidates for breast-conserving surgical techniques. This has been an important achievement in a patient group whose tumors are often considered inoperable. Attention has more recently turned to the use of neoadjuvant chemotherapy in patients with operable tumors. In patients with resectable stage II and III breast tumors, neoadjuvant chemotherapy has been demonstrated to provide effective downstaging of the primary tumor, and subsequent breast-conserving surgery results in excellent local control. In addition, neoadjuvant chemotherapy has been shown to downstage axillary lymph nodes from positive to negative in a significant number of cases. This raises the question of whether patients who have clinically negative axillae after neoadjuvant chemotherapy need to risk the morbidity associated with axillary lymph node dissection. Axillary irradiation may provide adequate regional control in patients who are clinically node negative. In addition, sentinel lymph node dissection has been shown to provide accurate assessment of the axilla in patients who have received neoadjuvant chemotherapy. An important ramification of the concept of neoadjuvant chemotherapy is that surgery that takes place after the completion of systemic therapy can become minimally invasive, accomplished in an outpatient setting without the need for an operating room suite.

Observation of the breast cancer patient with a tumor-positive sentinel node: implications of the ACOSOG Z0011 trial

Axillary lymph node status has been the most important prognostic factor for breast cancer throughout the past century. During the past decade, intraoperative lymphatic mapping with sentinel lymph node dissection (SLND) has been investigated as an alternative staging modality. This technique may be as accurate as ALND, and certainly is less invasive. Adjuvant treatment recommendations, which historically were made on the basis of lymph node status alone, now take into account primary tumor features, molecular markers, and patient characteristics. This evolution of current treatment patterns is driven in part by the diminishing size of tumors, the simultaneous decrease in the presence of axillary metastases, and a better understanding of tumor-specific risk factors. How do these trends affect the interpretation of a tumor-positive sentinel node (SN)? Can an axilla with a positive SN be observed? Should it be observed? This review examines the implications of a positive SN in the context of smaller tumor size, decreased nodal disease, and increased reliance on alternative prognostic factors for treatment decisions. The historical data comparing ALND to no ALND in clinically node-negative patients is reviewed and discussed in the context of observation for a positive SN. These are the issues underlying the ACOSOG Z0010 and Z0011 trials.