SENTINEL NODE BIOPSY IN LARGER OR MULTIFOCAL BREAST CANCERS: TO DO OR NOT TO DO

Sentinel lymph node biopsy validation for large tumors

BACKGROUND

Sentinel lymph node biopsy (SLNB) remains under discussion for large size tumors. The aim of this work has been to study the false negative rate (FNR) of SLNB for large tumors and predictive factors of false negative (FN).

MATERIALS AND METHODS

A study of a multicentric cohort, involved patients presenting N0 breast cancer with a SLNB eventually completed by complementary axillary lymph node dissection (cALND). The main criteria were the FNR and the predictive factors of FN.

RESULTS

12.415 patients were included: 748 with tumors ≥30 mm, 1101 with tumors >20 and < 30 mm and 10.566 with tumors ≤20 mm, with a cALND respectively for 501 patients (67%), 523 (62.1%) and 2775 (26.3%). The FNR were respectively: 3.05% (IC95%: 1.3-4.8) for tumors ≥30 mm*, 3.5% (1.8-5.2) for tumors >20 and < 30 mm*, 1.8% (1-2.4) for tumors ≤20 mm (p < 0.05) (*Not significant). At multivariate analysis, SN number harvested ≤2 (OR:2.0, p = 0.023) and tumor size >20 and < 30 mm (OR:2.07, p = 0.017) were significant predictive factors of FN, without significant value for tumor size ≥30 mm (OR:1.83, p = 0.073).

CONCLUSION

The FNR of SLNB was not higher amongst large size tumors compared to tumors of a smaller size. These results support the validation of SNLB for tumors up to 50 mm.

[Sentinel lymph node-multicentric and multifocal tumors: a valid technique?]

Sentinel node biopsy without complementary axillary lymph node dissection was validated for T1-2 N0 unifocal breast cancer without previous treatment since several years. In the situation of multifocal multicentric breast tumors, this procedure was considered as a contraindication. The aim of this work was to analyse literature results to determine if sentinel lymph node biopsy can be considered as a valid option without complementary axillary lymph node dissection for negative sentinel lymph node.

[Relevance of the sentinel lymph node biopsy in breast multifocal and multicentric cancer]

OBJECTIVES

The sentinel lymph node biopsy is a gold standard in the management of breast cancer. Its role in multifocal or multicentric tumors is still evolving. The aim of this study is to assess the feasibility and pertinence of sentinel lymph node biopsy in multifocal and multicentric tumors based on a systematic review of literature.

METHODS

A systematic review was conducted searching in the following electronic databases PubMed using "sentinel lymph node biopsy", "breast cancer", "multifocal tumor", "multicentric tumor" and "multiple tumor" as keywords. We included original articles published between 2000 and 2014, both French and English, studying feasibility of sentinel lymph node biopsy in invasive breast cancer, multicentric and/or multifocal tumors. The first end point was success rate and false negative rate.

RESULTS

Twenty-six articles were included in this literature review, with 2212 cases (782 multifocal, 737 multicentric and 693 multiple tumors). Percentage of tumors whose stage was higher than stage T2 ranged from 0 to 86.3%. Success rate average was 83.1%. False negative average was 8.2%. False negative rate was less than 10% in 15 articles. Mean of sentinel lymph node biopsy was 2 (1-9). The average rate of sentinel lymph node positive was 50.6%. Axillary recurrence rate was 0.5%.

CONCLUSION

Despite the methodological biases of the studies included in this review of literature, the false negative rate of sentinel node biopsy in multifocal and multicentric breast cancers are less than 10% with a low rate of axillary recurrence. Despite the lack of randomized study, this procedure can be routinely performed in accordance with rigorous technical process.

[Sentinel node biopsy in patients with multifocal and multicentric breast cancer: A 5-year follow-up]

OBJECTIVE

Sentinel lymph node biopsy (SLNB) as a staging procedure in multiple breast cancer is a controversial issue. We have aimed to evaluate the efficacy of sentinel node (SN) detection in patients with multifocal or multicentric breast cancer as well as the safety of its clinical application after a long follow-up.

MATERIAL AND METHODS

A prospective descriptive study was performed. Eighty-nine patients diagnosed of multiple breast cancer (73 multifocal; 16 multicentric) underwent SLNB. These patients were compared to those with unifocal neoplasia. Periareolar radiocolloid administration was performed in most of the patients. Evaluation was made at an average of 67.2 months of follow-up (32-126 months).

RESULTS

Scintigraphic and surgical SN localization in patients with multiple breast cancer were 95.5% and 92.1%, respectively. A higher percentage of extra-axillary nodes was observed than in the unifocal group (11.7% vs 5.4%) as well as a significantly higher number of SN per patient (1.70 vs 1.38). The rate of SN localization in multicentric cancer was slightly lower than in multifocal cancer (87.5% vs 93.1%), and the finding of extra-axillary drainages was higher (20% vs 10%). Number of SN per patient was significantly higher in multicentric breast cancer (2.33 vs 1.57). No axillary relapses have been demonstrated in the follow-up in multiple breast cancer patients group.

CONCLUSIONS

SLNB performed by periareolar injection is a reliable and accurate staging procedure of patients with multiple breast cancer, including those with multicentric processes.

Effectiveness and cost-effectiveness of sentinel lymph node biopsy compared with axillary node dissection in patients with early-stage breast cancer: a decision model analysis

Background:

Sentinel lymph node biopsy (SLNB) is less invasive than axillary lymph node dissection (ALND) for staging early breast cancer, and has a lower risk of arm lymphoedema and similar rates of locoregional recurrence up to 8 years. This study estimates the longer-term effectiveness and cost-effectiveness of SLNB.

Methods:

A Markov decision model was developed to estimate the incremental quality-adjusted life years (QALYs) and costs of an SLNB-based staging and management strategy compared with ALND over 20 years’ follow-up. The probability and quality-of-life weighting (utility) of outcomes were estimated from published data and population statistics. Costs were estimated from the perspective of the Australian health care system. The model was used to identify key factors affecting treatment decisions.

Results:

The SLNB was more effective and less costly than the ALND over 20 years, with 8 QALYs gained and $883 000 saved per 1000 patients. The SLNB was less effective when: SLNB false negative (FN) rate >13% 5-year incidence of axillary recurrence after an SLNB FN>19% risk of an SLNB-positive result >48% lymphoedema prevalence after ALND <14% or lymphoedema utility decrement <0.012.

Conclusion:

The long-term advantage of SLNB over ALND was modest and sensitive to variations in key assumptions, indicating a need for reliable information on lymphoedema incidence and disutility following SLNB. In addition to awaiting longer-term trial data, risk models to better identify patients at high risk of axillary metastasis will be valuable to inform decision-making.

Accuracy of sentinel lymph node biopsy in large and multifocal/multicentric breast carcinoma--a systematic review

BACKGROUND

While sentinel lymph node biopsy (SLNB) is established in the management of small unifocal breast cancer its role in management of multifocal (MF), multicentric (MC) and larger tumors is still evolving.

METHODS

Medline was searched; studies meeting pre-determined criteria were included. Data were extracted and entered into evidence tables.

RESULTS

Twenty six studies met inclusion criteria and reported data on accuracy; no randomized trials were identified. For MF cancers (n = 314 cases), success rate for identification of an SLN was 86-94%, SLN positivity rate 42-59%, false negative rate (FNR) 0-33% and overall accuracy 78-100%. For MC (n = 294 cases): success rate 92-100%, SLN positivity rate 25-61%, FNR 4-8% and accuracy 96-100%. For 'multiple breast cancer' (studies combining MF/MC cases; n = 996 cases): success rate 92-100%, SLN positivity rate 12-63%, FNR 0-25%, and accuracy 82-100%. For larger tumors (n = 1912 cases): success rate 86-100%, SLN positivity rate 49-77%, FNR 3-18% and accuracy 85-98%. For MC/MF and larger cancers overall non-SLN positivity rates were up to 82%; axillary recurrence rates were low but seldom reported.

CONCLUSION

There are no randomized trials evaluating the safety of SLNB in MF/MC and larger breast cancers. Based on limited evidence, success rate and FNR appear to be similar to those for small unifocal cancers, however node positivity rates are higher and rates of non-SLN positivity are very high. Awareness of these issues is essential when recommending SLNB based axillary management for these higher-risk tumors.

Lymphangiogenesis and lymphatic metastasis in breast cancer

Lymphatic metastasis is the main prognostic factor for survival of patients with breast cancer and other epithelial malignancies. Mounting clinical and experimental data suggest that migration of tumor cells into the lymph nodes is greatly facilitated by lymphangiogenesis, a process that generates new lymphatic vessels from pre-existing lymphatics with the aid of circulating lymphatic endothelial progenitor cells. The key protein that induces lymphangiogenesis is vascular endothelial growth factor receptor-3 (VEGFR-3), which is activated by vascular endothelial growth factor-C and -D (VEGF-C and VEGF-D). These lymphangiogenic factors are commonly expressed in malignant, tumor-infiltrating and stromal cells, creating a favorable environment for generation of new lymphatic vessels. Clinical evidence demonstrates that increased lymphatic vessel density in and around tumors is associated with lymphatic metastasis and reduced patient survival. Recent evidence shows that breast cancers induce remodeling of the local lymphatic vessels and the regional lymphatic network in the sentinel and distal lymph nodes. These changes include an increase in number and diameter of tumor-draining lymphatic vessels. Consequently, lymph flow away from the tumor is increased, which significantly increases tumor cell metastasis to draining lymph nodes and may contribute to systemic spread. Collectively, recent advances in the biology of tumor-induced lymphangiogenesis suggest that chemical inhibitors of this process may be an attractive target for inhibiting tumor metastasis and cancer-related death. Nevertheless, this is a relatively new field of study and much remains to be established before the concept of tumor-induced lymphangiogenesis is accepted as a viable anti-metastatic target. This review summarizes the current concepts related to breast cancer lymphangiogenesis and lymphatic metastasis while highlighting controversies and unanswered questions.

Synchronous multiple ipsilateral breast cancers: implications for patient management

Interest in the presence and management of synchronous multiple ipsilateral breast cancer has been reported since the early 1920s. The demonstration of multiple foci of breast cancer has been reported in 9-75% of breast cancer related specimens. The large difference in reported incidence is multifactorial and related to the definitions applied, mode of detection and pathological assessment. However, randomised clinical trials comparing total mastectomy and segmental mastectomy with or without radiation over many years have shown no difference in distant disease-free survival or overall survival in patients with synchronous multiple ipsilateral breast cancer compared with unifocal breast cancer. This review examines the current definitions, incidence, pathological assessment, staging and surgical options of synchronous multiple ipsilateral breast cancer.

The sentinel node in breast cancer

Biopsy of the sentinel lymph node now forms part of routine management in many centres dealing with early stage breast cancer. This article seeks to discuss developments over the past number of years and to summarise current practice.