The Role of Internal Mammary Lymph Node Metastases in the Management of Breast Cancer

A natural cuttlefish melanin nanoprobe for preoperative and intraoperative mapping of lymph nodes

Lymphatic metastasis plays an important role in malignant tumor invasion. Efficient identification of sentinel lymph node (SLN) is extremely significant for designing therapeutic strategies and assessing prognosis. In this work, we developed a natural cuttlefish melanin nanoprobe for the preoperative and intraoperative evaluation of lymphatic metastasis. The cuttlefish melanin nanoparticle could improve the water-solubility and biocompatibility of the near-infrared-II (NIR-II) dye, and extend the retention time of small molecule dye. The NIR-II imaging results verified that the nanoparticles have a high accumulation, high sensitivity, and high signal-to-noise ratio in the lymphatic system. Moreover, the nanoparticles have obvious naked-eye identification potential due to their natural brownish-black color. Additionally, the nanoparticles can combine with Gd ions to achieve preoperative lymphatic magnetic resonance imaging (MRI). The results of this study provide a unique approach to effectively identify and accurately remove lymph nodes before operation and during surgery, exhibiting tremendous potential in clinical translation.

Sentinel Node Biopsy in the Evaluation of the Internal Mammary Node Chain in Patients with Breast Cancer

Aims and Background

In patients with breast cancer the presence of internal mammary chain (IMC) metastases changes tumor staging, and the occurrence of IMC drainage is quite common in breast cancer. Nevertheless, IMC dissection is not a routine procedure in modern surgical approaches towards breast cancer. We therefore need minimally invasive techniques for accurate assessment of the IMC nodal basin. The aim of this study was to investigate whether sentinel node biopsy (SLNB) could offer a solution.

Methods and Study Design

From November 1997 to June 2001 143 female patients who were eligible for breast cancer surgery were included in the study. All patients had T1 breast cancer and clinically negative axillae. Patients were submitted to preoperative lymphoscintigraphy with subsequent SLNB. We used a 99m-technetium nanocolloid tracer (Nanocoll®) that was injected peritumorally so as to have about 10 MBq of radioactivity at the time of surgery. Scintigraphy was performed about 17 hours after tracer administration. During surgery, lymphoscintigraphic imaging and a gamma ray detection probe were used to locate the sentinel node. Histological examination after embedding in paraffin was usually requested and multilevel sectioning of the sentinel node (SLN) was performed, with hematoxylin and eosin staining and immunohistochemistry.

Results

Preoperative lymphoscintigraphy localized SLNs in the IMC basin in 27 of 143 patients (18.9%). Harvesting of IMC-SLNs based on lymphoscintigraphy results was successful in 20 of 27 patients (74.1 %). Histological examination revealed micrometastases in four of the 20 harvested nodes. One of these patients showed no axillary drainage and no axillary lymph node dissection was therefore performed. In the remaining three patients also axillary SLNs were harvested, which turned out be free from metastatic involvement.

Conclusions

In our experience lymphoscintigraphy with SLNB was an accurate method to detect IMC metastases in patients with breast cancer. We recommend peritumoral tracer injection and a reasonable interval between injection and scintigraphy. IMC-SLN biopsy did not result in any serious additional complications or morbidity. In our study this approach led to improved cancer staging: four of 20 harvested IMC-SLNs proved to be micrometastatic. None of these four patients had metastatic axillary SLNs. Exclusive drainage to the IMC is present in only a small number of breast cancer patients, and our results suggest that it is possible to avoid unnecessary axillary node dissection in such cases.

President’s Address

In breast cancer surgery, there has been a major shift toward less invasive local treatment: from extended or radical mastectomy to modified radical mastectomy, from modified radical mastectomy to breast conserving therapy, and from routine axillary lymph node dissection to sentinel lymph node biopsy. Many breast surgeons have experienced an evolutionary progression of surgical management of breast cancer. However, there is an increasing demand for minimally invasive and non-surgical treatment methods for patients with small breast cancer. Radiofrequency (RF) ablation is the most promising among non-surgical ablation techniques in the treatment of breast cancer, although it is still in the investigative stage. Nevertheless, surgery still plays an integral role in the treatment of breast cancer, because local therapy is important for enhancing survival in the presence of systemic therapy. In clinical practice, surgical oncologists must individualize treatments, selecting a surgical or non-surgical procedure that provides the best local control, does not compromise the chances of cure, and achieves the best cosmetic results.

Incidence of internal mammary node metastases after a sentinel lymph node technique in breast cancer and its implication in the radiotherapy plan

PURPOSE

To analyze the frequency in determining pathologically proven metastatic involvement of internal mammary nodes (IMN) after sentinel lymph node (SLN) technique in breast cancer and to evaluate the implications for radiotherapy (RT) management of patients.

METHODS AND MATERIALS

Two hundred and twenty-five patients who underwent lymphatic mapping for early breast cancer treated with breast-conserving surgery and radiation (80%) or mastectomy (20%) were evaluated. There were two phases in the study: the validation phase (105 patients, 52 T1, 53 T2 < or = 4 cm), and the application phase (120 patients, 70 T1, 50 T2 < or = 2.5 cm). In the validation, if a drainage pathway to the IMN was identified, no biopsy was performed in this phase. In the application, if the study showed metastases in the IMNs, biopsy was performed. When histologically proven IMN metastases were detected, RT was included on the IMN chain planned with a 3D treatment system using conformal techniques. At the beginning of the study the injection site was subdermal and subsequently, the injection site was changed to peritumoral and intratumoral to search for IMN.

RESULTS

In 31 patients of 225 (14%) hot spots were observed in the internal mammary chain (11.5% and 17.2% in the validation and application phases, respectively). In the validation phase, in 11 cases (11.5%) IMN drainage was observed, and in the application phase, in 20 cases (17.2%). Sampling of the internal mammary basin based on lymphoscintigraphy results was successful in 69% of the cases (14 of 20) and revealed metastatic involvement in 14% (2 of 14). This represents incidence of only 1.7% (2 of 116) in early breast cancer patients with SLN study in the application phase. In both cases the axillary SLN was also positive. Both patients with metastatic involvement of the IMN area received RT on the IMN chain next to the remaining breast after conservative surgery.

CONCLUSIONS

We can conclude that 14% of the patients with intraoperative drainage into the IMN surgical examination of the lymph nodes had pathologically positive metastases. The percentage in pathologically proven metastatic involvement of IMN after the SLN technique in early breast cancer is low, but it is not negligible. Moreover, it is expected to increase since the international recommendations have established a 3-cm cutoff for practicing the SLN technique. Although the real value of IMN irradiation in early breast cancer is not known, including this chain in postoperative radiotherapy is not recommended unless pathologically proven IMNs have been produced by the SLN technique. To avoid overdosage or underdosage in the joint between the medial tangential and IMN fields, an individualized 3D dosimetry study is mandatory to enhance dose distribution and reduce the heart volume to lessen side effects.

Does regional treatment improve the survival in patients with operable breast cancer?

BACKGROUND

The impact of regional therapy on survival of patients with invasive breast cancer remains controversial. Regional therapies discussed include axillary lymph node dissection (ALND), internal mammary node dissection, and locoregional radiotherapy.

METHODS

Prospective randomized clinical studies of regional therapy were reviewed using, as a source, Medline, main review articles on the related topic, and statements from consensus conference.

RESULTS

Although a number of randomized clinical studies have failed to demonstrate the benefits of regional treatment for survival, it is still a matter of debate whether ALND or regional radiotherapy alone can have a small but significant beneficial effect on the survival of breast cancer patients. However, recent studies have suggested that survival can be enhanced by interaction of postmastectomy locoregional radiotherapy with adjuvant systemic therapy.

CONCLUSIONS

Locoregional control is important for enhancing survival in the presence of adjuvant systemic therapy. Although only a few randomized controlled trials show conclusively the survival benefit of local therapies, it is expected that in clinical practice, the node-positive or other high-risk breast cancer patients given systemic treatment will be more frequently treated with postmastectomy radiation.

Will early detection of non-axillary sentinel nodes affect treatment decisions?

Axillary lymph node involvement is the best prognostic factor for breast cancer survival. Staging breast cancers by axillary dissection remains standard management and is part of the UK national guidelines for breast cancer treatment. In the presence of involved axillary lymph nodes best treatment has been shown to be axillary clearance (Fentiman and Mansell, 1991), but clearly for women whose nodes are uninvolved avoidance of morbidity is optimal and this will be achieved by minimal dissection of the axilla. Thus, for node-negative women the introduction of the sentinel node biopsy technique may revolutionise the approach to the axilla. These will be women with mammographic screen detected small well and moderately differentiated tumours (Hadjiloucas and Bundred, 2000). The impact of sentinel node biopsy in women who have symptomatic large tumours is unproven, and around half of these women will require a second procedure to clear their axilla or radiotherapy as treatment. Even for those women found to have involved sentinel lymph nodes the ability to use early systemic chemotherapy followed by axillary clearance or radiotherapy may provide long-term survival gains. Sentinel node biopsy should not, however, become routine practice until randomised controlled trials have proven its benefit and safety in reducing morbidity. Several randomised controlled trials (including ALMANAC) are currently underway.

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.

Sentinel lymph node biopsy in breast cancer using blue dye with or without isotope localization

BACKGROUND

The purpose of this study was to determine the feasibility of sentinel lymph node (SLN) biopsy using blue dye with or without isotope localization to predict the presence of axillary and internal mammary lymph node (IMN) metastases in patients with breast cancer. We also investigated whether multiple sectioning of the SLN could improve the accuracy of frozen section examination.

METHOD

One-hundred twenty-six patients underwent dye-guided or dye- and gamma probe-guided SLN biopsy followed by complete axillary lymph node dissection (ALND). No ALND was performed in the 14 patients with small tumors and a negative SLN. In addition, 69 patients underwent IMN biopsy.

RESULTS

The axillary SLN was identified in 123 of 140 (88%) patients. An accuracy rate of 90% was obtained by frozen section examination of the SLN, which increased to 100% in patients examined with a greater number of sections. Lymphatic flow to the IMN and/or a radioactive hot spot in the IMN was found in 9 of 102 (9%) patients, while a hot node was detected using a gamma probe in only 2 of these patients. No involvement of the IMNs was found histologically in these 9 patients. IMN involvement was found in 7 of 61 (11%) patients without lymphatic flow to the IMNs or a hot spot by lymphoscintigraphy or who did not undergo lymphoscintigraphy.

CONCLUSION

ALND can be avoided in patients with small breast cancers and a negative SLN. SLN biopsy guided by lymphatic mapping is unreliable for identifying metastases to IMNs.

Internal mammary chain sentinel lymph node identification in breast cancer

BACKGROUND AND OBJECTIVES

Sentinel lymph node (SLN) biopsy is not usually performed with respect to the internal mammary lymph node chain. However, the SLN may be located in the internal mammary chain, particularly with medial lesions. We carried out this study to investigate whether lymphatic mapping and SLN biopsy can detect internal mammary involvement in patients with breast cancer.

METHODS

A dye- and gamma probe-guided SLN biopsy was performed in a consecutive series of 41 patients with tumor in situ or clinical stage I or II breast cancer. After the biopsy, these patients underwent either a modified radical mastectomy or breast-conserving surgery including axillary lymph node dissection. Biopsy of internal mammary lymph nodes was performed in 19 of these patients.

RESULTS

No involvement of internal mammary lymph nodes was found histologically in 5 patients in whom lymphatic flow or a "hot nodule" in the internal mammary chain was found using lymphoscintigraphy. Nodal involvement was demonstrated histologically in only 1 of 5 cases where lymphatic vessels showed dye staining or faintly stained nodes. Internal mammary lymph node biopsy also was performed in 14 of 36 patients with neither stained lymphatic vessels or nodes, nor with lymphatic flow or a hot nodule by lymphoscintigraphy. Nodal involvement was found histologically in 1 of these patients.

CONCLUSION

SLN biopsy guided by lymphatic mapping is unreliable for identifying metastases to internal mammary lymph nodes.

Staging efficacy of breast cancer with sentinel lymphadenectomy

Seventy-two patients underwent dye-guided or dye- and gamma probe-guided sentinel lymphadenectomy (SLND) followed by complete axillary lymph node dissection (ALND). The results of imprint cytology, frozen sections, and permanent sections of the sentinel lymph node (SLN) were compared to each other and to the histologic findings in the nonsentinel nodes. The SLN was identified in 62 (88%) of 72 patients. Evaluation of the SLN on the permanent sections yielded a diagnostic accuracy of 95%, a sensitivity of 89%, and a specificity of 100%, although the reliability of SLN diagnosis using frozen sections or imprint cytology is limited. Therefore, it may be concluded that SLND with multiple sectioning and histopathologic examination of the SLNs can predict the presence or absence of axillary-node metastases in patients with breast cancer. However, further studies will be needed to investigate the value of SLND in respect to the long-term regional control and any possible detriment or benefit to survival, before it can replace routine ALND as the preferred staging operation for operable breast cancer.

Sentinel lymphadenectomy in breast cancer: identification of sentinel lymph node and detection of metastases

Sentinel lymphadenectomy is a useful way of assessing axillary status and obviating axillary dissection in patients with node-negative breast cancer. However, controversies remain concerning the optimal method to identify the sentinel lymph node (SLN) and detect micrometastases in this lymph node. We reviewed the literature concerning sentinel lymphadenectomy in breast cancer and reached the following conclusions: (a) A combination of preoperative lymphoscintigraphy with intraoperative dye-guided and gamma probe-guided methods achieves a higher rate of identification of SLN than any of these techniques alone. (b) Immediate and reliable intraoperative assessment of sentinel node status is vital to the technique's success. However, the reliability of sentinel node diagnosis using frozen sections is questionable, because micrometastatic foci cannot always be identified. (c) Hematoxylin and eosin (H&E) staining and/or immunohistochemistry on permanent sections are useful for the detection of micrometastases in the sentinel node. Although a reverse transcriptase-polymerase chain reaction (RT-PCR) method is more sensitive than H&E staining and immunohistochemistry, it would not distinguish benign from malignant epithelial cells in the SLN. Therefore, further study is required before sentinel lymphadenectomy gains general acceptance for patients with primary breast cancer.