Clinical and biological prediction of axillary and internal mammary lymph node metastases in breast cancer

Predictors of axillary lymph node metastasis in breast cancer: A systematic review

AIMS

To review the established and emerging techniques in axillary lymph node prediction and explore their potential impact on clinical practice. To reliably identify patients in whom axillary lymph node surgery, including SLNB, can be safely omitted.

METHODS

Searches of PubMed were made using the search terms "axilla" (or "axillary"), "lymph", "node" and "predictor" (or "prediction"). Articles from abstracts and reports from meetings were included only when they related directly to previously published work.

FINDINGS

There are numerous studies in which the predictive utility of biomarkers as determinants of axillary lymph node status have been investigated. Few of these have specifically addressed the attributes of the primary tumour which could offer much potential for the prediction of tumour metastasis to the axillary lymph nodes.

CONCLUSIONS

Currently, no single marker is sufficiently accurate to obviate the need for formal axillary staging using SLNB or axillary clearance.

Implications of axillary sentinel lymph node biopsy in immediate autologous breast reconstruction

For patients with invasive breast cancer, if the results of an axillary sentinel node biopsy are determined to be positive after permanent pathologic examination, the current recommendation is to perform a complete axillary node dissection. Subsequent axillary surgery may compromise the blood supply to an immediate autologous breast reconstruction. The purpose of this study was to determine which clinicopathologic factors in clinically node-negative breast cancer patients may be associated with an increased risk of positive axillary nodes. Identification of these factors will allow surgeons to modify their approach to immediate autologous breast reconstruction in these high-risk patients. The relationship between presenting clinicopathologic characteristics and the incidence of axillary metastases was analyzed by chi-square test and multivariate analysis in 167 patients with invasive breast cancer and a clinically negative axilla who underwent modified radical mastectomy with an immediate free transverse rectus abdominis musculocutaneous (TRAM) flap reconstruction. Axillary nodal metastases were found in 35 percent of clinically node-negative breast cancer patients. Multivariate analysis showed that patient age of 50 years or younger (p = 0.019), T2 tumor stage or greater (p = 0.031), and presence of lymphovascular invasion on the initial biopsy specimen (p < 0.001) were independent predictors of axillary metastases in clinically node-negative patients. Based on these results, the authors propose an algorithm for decision making in clinically node-negative breast cancer patients who desire autologous breast reconstruction and sentinel lymph node biopsy. Options for immediate autologous breast reconstruction in patients undergoing mastectomy and axillary sentinel lymph node biopsy that may minimize the risk of vascular damage on reoperation include the use of the internal mammary artery and vein as recipient vessels for a free TRAM flap or a pedicled TRAM flap. If an axillary-based blood supply is used, the authors are considering the use of cadaveric dermis to isolate the pedicle of the flap away from the remaining axillary contents. New developments in breast cancer diagnosis and treatment necessitate a team approach, with increased communication between the breast surgeon and the plastic surgeon in planning surgery for these patients.

Clinical and pathologic factors predicting axillary lymph node involvement in breast cancer

The diagnosis of axillary disease remains a challenge in the management of breast cancer and is a subject of controversy. In 1998, the Japanese Breast Cancer Society conducted a study assessing axillary lymph node involvement in breast cancer. The study included (a) clinical assessment by pre-operative imaging modalities, (b) histologic assessment for peritumoral lymphatic invasion, (c) biologic assessment by gelatinolytic activity using film in situ zymography, and (d) sentinel lymph node (SLN) biopsy. Clinical assessments by CT, PET, and US as well as biologic assessment were limited in their ability to detect axillary lymph node disease, although these imaging techniques may be useful to exclude node-positive patients from the need for SLN biopsy. Histologic assessment for peritumoral lymphatic invasion was useful, particularly for detecting false-negative cases by SLN biopsy. Nevertheless, the utility of SLN biopsy in assessing axillary nodal status was confirmed. Axillary lymph node dissection (ALND) can be avoided in patients with a small tumor and a negative SLN. However, further studies will be required to investigate the value of SLN biopsy for predicting regional control and survival before it can replace routine ALND as the optimal staging procedure for operable breast cancer.

Axillary lymph node dissection in breast cancer--current status and controversies, alternative strategies and future perspectives

Axillary lymph node dissection (ALND) has traditionally been considered as a standard procedure in the surgical management of patients with breast cancer. The goals of ALND in breast cancer surgery are: (a) to provide accurate prognostic information, (b) to maintain local control of the disease in the axilla and (c) to provide a rational basis for decisions about adjuvant therapy. Although controversial, ALND may also be associated with a small therapeutic benefit. Recently, the question of whether ALND is needed for every patient with invasive breast cancer has been the subject of ongoing debate in the literature. This is mainly due to the widespread use of adjuvant systemic therapy for patients with node-negative breast cancer and to the increasingly frequent detection of small invasive cancers by mammographic screening; the majority of these patients have negative axillae. Sentinel lymph node (SLN) biopsy is a new, promising, minimally invasive procedure, which accurately predicts nodal status with minimal morbidity, and reserves ALND for patients with positive SLN biopsies. However, this method is still investigational. Partial (levels I and II) ALND remains the gold standard in the surgical management of patients with breast cancer.

Sentinel Lymph Node Biopsy in Breast Cancer

One of the most important prognostic indicators in patients with breast cancer is axillary lymph node status. Sentinel lymph node (SLN) biopsy has emerged as a potential alternative to routine axillary dissection in clinically node-negative early breast cancer. This procedure requires a specialized but multidisciplinary approach utilizing the surgeon, nuclear radiologist and pathologist. SLN biopsy allows adequate assessment of the axillary nodal status in patients with early breast cancer, with minimal—if any—morbidity. Blue dye and lymphoscintigraphy are complementary techniques, and the success rate is maximized when the two methods are used together. Focused histopathologic examination on one or two lymph nodes most likely to contain metastases [SLN(s)], using serial sectioning and immunohistochemical techniques, allows an improved staging to be performed. Detection of metastases on SLN(s) is not only a prognostic indicator, but it also dictates whether the patient should receive further surgery and adjuvant chemotherapy. Until data regarding the long-term results of the SLN biopsy are available, this method should be considered investigational and be performed by surgeons experienced in this technique to achieve a failure rate of less than 2 per cent.

Role of sentinel lymph node dissection in breast cancer

The sentinel node concept is valid for penile cancer, melanoma, breast cancer and is probably also applicable to other solid malignancies. Sentinel nodes are the one or two initial nodes in the regional nodal drainage basin encountered by the lymphatic effluent from a tumour, which can be identified with an injection of vital dye or other lymphogogue. Sentinel lymph node dissection (SLND), a minimally invasive procedure with negligible morbidity, has therefore been utilized as an alternative to complete axillary lymph node dissection (ALND) for staging breast cancer. Examination of sentinel nodes provides a focused histopathological assessment of tissue most likely to harbour metastases, providing enhanced staging accuracy with a low false-negative rate. Tumour-free sentinel nodes are predictive of a tumour-free axilla, thereby allowing for the possibility of SLND without ALND and sparing patients the morbidity of ALND. Most of the experience from SLND has been obtained for axillary sentinel nodes. However, sentinel nodes have been identified in nonaxillary sites, such as the internal mammary nodes, but data on SLND for these regions is scarce. The ultimate role of SLND in breast cancer, which may be to identify sentinel-node-negative patients or even those with sentinel node metastases who can safely avoid ALND without sacrificing regional control and possibly gain a therapeutic benefit, cannot be defined before we have the results of large trials that are currently in progress.

Axillary clearance in operable breast cancer: still a necessity?

Complete axillary dissection, as part of radical mastectomy, was the standard of care for the first three-quarters of this century. Long-term follow-up of these patients showed substantial cure rates for positive-node patients before systemic therapy was available, indicating a therapeutic value to nodal dissection. There was also good control of the axilla; axillary recurrence after removal of positive nodes was quite low. Even today, in patients with positive nodes, complete axillary clearance as part of a modified radical mastectomy or a breast conservation approach with lumpectomy leads to control of the axilla and complete axillary staging, allowing medical oncologists to tailor their systemic treatment to the total number of nodes involved. Today, due to a combination of factors including patient awareness and the ability of mammography to detect smaller lesions, many women present with small cancers that carry a much lower risk of axillary involvement. Whereas a complete dissection is indicated for patients with clinically involved nodes, a level I-II dissection is the standard in most centers for patients with clinically negative nodes. In those patients with very small (T1a, T1b) cancers, the role of sentinel lymphadenectomy is being explored; it may spare these patients the morbidity of complete axillary dissection.

Sentinel Lymphadenectomy in Breast Cancer: An Alternative to Routine Axillary Dissection

We reviewed the literature concerning sentinel lymphadenectomy in breast cancer and reached the following conclusions: (a) A combination of lymphoscintigraphy and dye-guided and/or gamma probe-guided techniques are superior to either technique alone for identifying the sentinel lymph node. (b) lmmediate and reliable intraoperative information on the sentinel node is vital for the technique's success. However, the reliability of sentinel node diagnosis using frozen sections is questionable, because micrometastatic foci cannot be identified. (c) A reverse transcriptase-polymerase chain reaction(RT-PCR)method is more sensitive than immunohistochemistry for the detection of micrometastasis in the sentinel node. (d) Until there are new tumor markers or new imaging techniques to identify axillary metastasis without operative intervention, sentinel lymphadenectomy is a highly accurate, minimally invasive way to assess disease extent. Before sentinel lymphadenectomy gains general acceptance for patients with primary breast cancer, however, a large clinical trial will be essential to verify the value of this technology.

Axillary lymphadenectomy: a diagnostic and therapeutic procedure

Axillary dissection for primary operable cancer follows the basic tenants of surgical oncology and achieves the stated goals. Local control is excellent with failure rates in the 0-2% range. Long-term and disease-free survival is improved with axillary dissection. It is often stated that axillary dissection is not required for the smallest of lesions, but the 15% risk of axillary disease with the T1A lesion would suggest otherwise. Axillary sampling would not achieve the stated goals because of the high probability of retained, potentially resectable disease in the node positive group. Axillary recurrence is associated with an unacceptably high morbidity and mortality. Although the survival is similar in the three treatment groups of NSABP B-04, the inordinately high systemic failure rate with axillary recurrence would suggest that more aggressive local control could prevent many of these failures. After all, long-term survival free of disease is reported in many series even in patients with multiple involved nodes. Axillary dissection also generates the most accurate prognostic variable upon which further therapeutic interventions are predicated. At present there is no other diagnostic or therapeutic approach that achieves all of these goals. In summary the value of the axillary dissection is to provide accurate prognostic information as well as excellent local control and to improve the survival rate in the node positive group. It is hoped that in the future a diagnostic test such as PET scanning or sentinel node mapping may predict those patients with a clear axilla and therefore not require an axillary dissection. Finally, there has yet to be a primary operable carcinoma that benefits from preservation of potentially fully resectable disease.

Diagnosis of axillary lymph node metastases in patients with breast cancer

The diagnosis of axillary (AX) metastases remains a challenge in the management of breast cancer and is a subject of controversy. Clinical node staging clearly is limited in the assessment of AX lymph nodes. AX mammography, ultrasonography, and computed tomography (CT) do not provide histologic information. Although nuclear magnetic resonance imaging may have considerable value in the diagnosis of AX metastases, it does not detect micrometastases. The use of biologic markers in the assessment of AX metastases remains a subject of investigation. On the other hand, biopsy of selected AX nodes or tissue with examination of histology or cytology generally would not identify a significant percentage of patients with AX node involvement. Sentinel lymph node biopsy, however, might be potentially useful for assessing AX metastases, although it remains investigational. In order to simplify diagnosis and reduce morbidity and mortality, alternatives to AX dissection must be sought and imaging and staging modalities refined. We present a review of the literature pertaining to the diagnosis of AX metastases in patients with breast cancer and a discussion of some current areas of controversy.

Breast-conserving treatment: controversies and consensus

Although breast-conserving therapy (BCT) is an accepted alternative for the treatment of breast cancer, numerous controversies surround the selection criteria and the treatment details. A review of the literature revealed that patient selection is of critical importance. However, there is disagreement over the relative importance of some of the criteria for patient selection. A wide excision is preferable to a less complete excision (tumorectomy) or a more radical excision (quadrantectomy). Accurate assessment of surgical margins is important. The risk of local recurrence may be diminished if a re-excision is performed to obtain tumor-free margins. However, the suitability and practicality of the techniques used to assess the resection margins have been questioned. Radiotherapy is an integral part of BCT. Surgery alone remains an investigational approach. Axillary dissection remains a reliable method of assessing nodal status and treating regional disease.

Intraoperative assessment of axillary lymph node metastases in operable breast cancer

The diagnostic value of intraoperative histologic examination of frozen sections of axillary lymph nodes was investigated in 243 patients with operable breast cancer. One to six hard or enlarged axillary nodes were sampled from the axillary pad which was derived from a partial axillary dissection (including level 1 and 2 nodes). Half of these nodes were histologically examined using frozen sections during surgery. After a total axillary dissection, both the axillary nodes in the partial axillary dissection and the nodes dissected at level 3 were histologically examined on permanent section. A mean of four nodes were sampled (range: 1 to 6). Axillary dissection yielded a mean of 22 nodes (range: 6 to 60). Axillary sampling detected the presence of metastases in 65 of 84 (77%) patients with positive axillary lymph nodes. In the patients in whom the axillary involvement was not identified by axillary sampling, however, the extent of axillary involvement was limited to levels 1 and 2. Therefore, a partial axillary dissection may be justified for patients in whom axillary involvement is not found on frozen section of nodes from axillary sampling, whereas a total axillary dissection should be performed for patients in whom axillary involvement is found by these procedures.

Intraoperative histologic assessment of surgical margins and lymph node metastasis in breast-conserving surgery

The diagnostic value of intraoperative histologic examination of frozen sections of surgical margins and axillary lymph nodes (AX) was investigated in 95 patients with breast cancer who underwent breast-conserving surgery. The periphery of the excised breast tissue was peeled like an orange and examined histologically by frozen section. The results were compared with examination by permanent section. Evaluation of surgical margins by frozen section resulted in a diagnostic accuracy of 87%, a sensitivity of 96%, and a specificity of 84%. Enlarged or hardened AXs were sampled from the axillary pad which was derived from a complete AX dissection. Histologic examination using frozen section was performed during surgery. After the operation, the remaining AXs were removed from the axillary pad by hand dissection and histologically examined on permanent section. A diagnostic accuracy of 97%, a sensitivity of 77%, and a specificity of 100% were achieved in the diagnosis of AX involvement on frozen section. It was therefore concluded that intraoperative histologic examination of frozen sections may be useful in the determination of involvement of the surgical margins and the AXs in patients with breast cancer.

Typing and grading breast carcinoma on fine-needle aspiration: is this clinically useful information?

The ability of fine-needle aspiration (FNA) to diagnose breast cancer is beyond question. The established role of cytopathology is to maintain a low benign to malignant biopsy ratio by reducing the number of benign lesions excised. Both typing and grading of breast cancers on FNA have received attention in the cytology literature but how this knowledge can influence management has not been fully explored. Recently we described a method for the cytological grading of breast cancer that compares well with the established Bloom and Richardson grades. In this paper we present our experience of 1,387 breast cancer FNAs reported by us with histological verification. We show that cytologically typing and grading breast cancers are valid exercises that can predict the true nature of the neoplasm. This information may assist in the clinical approach to the malignant breast.