Adriana J. G. Maaskant-Braat

Axillary staging in patients with locally recurrent breast cancer is important for obtaining locoregional control and predicting prognosis. The aim of the present study is to determine technical feasibility, validity, aberrant drainage patterns and clinical consequences of performing repeat sentinel node biopsy (SNB) in these patients. We performed a systematic review and meta-analysis of the literature and included all studies on repeat SNB in locally recurrent breast cancer. A total of 692 patients were described, 301 after a previous SNB, 361 after a previous axillary lymph node dissection (ALND), and 30 with no previous axillary surgery. Sentinel node identification was successful in 452 of the 692 patients (65.3 %), which was significantly higher in patients who had undergone previous SNB compared to previous ALND (81.0 vs. 52.2 %) (P < 0.0001). In 175 of 405 patients with successful lymphatic mapping aberrant drainage pathways were visualized (43.2 %), which were seen more frequently after previous ALND than after previous SNB (69.2 vs. 17.4 %) (P < 0.0001). In 19.2 % of the patients the sentinel node was tumor positive and 27.5 % of these metastases were found in aberrant lymph drainage basins. Overall, 213 patients could be spared an ALND and in 17.9 % of the patients the information derived from the repeat SNB led to a change in adjuvant radiotherapy or systemic treatment plans. The procedure had a false-negative rate of 0.2 %. Repeat SNB is technically feasible and accurate. Next to sparing patients an unnecessary ALND, the information can lead to a change in adjuvant treatment strategy.

Knowledge of regional lymph node involvement is important in patients with recurrent breast cancer for obtaining better locoregional control and predicting prognosis. To determine technical feasibility, validity, aberrant drainage rates, and clinical consequences of performing repeat sentinel node biopsy (SNB) in patients with locally recurrent breast cancer we conducted the “Sentinel Node and Recurrent Breast Cancer (SNARB)” study. A total of 150 patients with locally recurrent breast cancer underwent lymphatic mapping and SNB. In case of an intact axillary lymph node basin, ipsilateral axillary lymph node dissection (ALND) was performed subsequently. A total of 41 patients previously underwent breast conserving therapy (BCT) with SNB, 82 patients BCT with ALND, and 21 patients a mastectomy, of which 9 with SNB and 12 with ALND. In 95 patients (63.3 %) a sentinel node was identified and in 78 patients (52 %) the sentinel node was successfully removed. In 18 patients (22.8 %) a (micro)metastasis was found on pathologic examination. Confirmation ALND in 18 patients showed no axillary lymph node metastases. Aberrant drainage pathways were visualized in 58.9 % of the patients, significantly more frequently after a previous ALND (79.3 %) than after a previous SNB (25.0 %) (P < .0001). Overall, the result of this repeat SNB led to a change in the adjuvant treatment plan in 16.5 % of the patients with a successful repeat SNB. Repeat SNB is technically feasible and provides reliable results in patients with locally recurrent breast cancer, leading to change in management in 1 of 6 patients.

Sentinel node biopsy (SNB) for axillary staging in breast cancer allows the application of more extensive pathologic examination techniques. Micrometastases are being detected more often, however, coinciding with stage migration. Besides assessing the prognostic relevance of micrometastases and the need for administering adjuvant systemic and regional therapies, there still seems to be room for improvement. In a population-based analysis, we compared survival of patients with sentinel node micrometastases with those with node-negative and node-positive disease in the era after introduction of SNB. Data from the population-based Eindhoven Cancer Registry were used on all (n = 6803) women who underwent SNB for invasive breast cancer in the Southeast Region of The Netherlands in the period 1996–2006. In 451 patients (6.6%) a sentinel node micrometastasis (pN1mi) was detected and in 126 patients (1.9%) isolated tumor cells (pN0(i+)). Micrometastases or isolated tumor cells in the SNB did not convey any significant survival difference compared with node-negative disease. After adjustment for age, pT, and grade, still no survival difference emerged pN1mi: [HR 0.9 (95% CI, 0.6–1.3)] and pN0(i+): [HR 0.4 (95% CI, 0.14–1.3)] and neither was the case after additional adjustment for adjuvant systemic therapy. Our practice-based study showed that the presence of sentinel node micrometastases in breast cancer patients has hardly any impact on breast cancer overall survival during the first years after diagnosis.

Background Introduction of sentinel node biopsy (SNB) as an axillary staging procedure in breast cancer patients could have led to upstaging as well as downstaging of their disease. Intensified pathological processing could have led to upstaging due to presence of micrometastases, whereas the described false negative rate of 5% could be a cause of downstaging. We investigated whether or not the introduction of the sentinel node procedure has changed the incidence of axillary nodal micrometastases and induced stage migration on a population based level. Methods Data from the population based Eindhoven Cancer Registry were used on all (n = 17100) women diagnosed with invasive breast cancer in the South-East region of The Netherlands in the period 1994–2005. Results The percentage of patients staged with SNB increased from 0% in 1994 to 62% in 2005. The percentage of patients with micrometastases increased from 1.0% in 1994 to 4.3% in 2005 (P < 0.0001), whereas no significant increase was observed of the proportion of patients with positive axillary lymph nodes. After adjustment for tumor size, age at diagnosis and histology the probability of having a positive axillary lymph node status was 10% higher in period 2003–2005, as compared to period 1994–1996. Furthermore, women diagnosed in the period 2003–2005 had a 3.5 times higher risk of having micrometastases compared to women diagnosed in the period 1994–1996 (i.e., before the introduction of SNB). Conclusion The introduction of SNB in the Southeast region of The Netherlands has led to stage migration, as is reflected by the small but significant increase of the proportion of patients with positive axillary lymph nodes after adjustment for tumor size and age.