Sentinel lymph node biopsy and aberrant lymphatic drainage in recurrent breast cancer: Findings likely to change treatment decisions

Personalizing Locoregional Therapy in Patients With Breast Cancer in 2024: Tailoring Axillary Surgery, Escalating Lymphatic Surgery, and Implementing Evidence-Based Hypofractionated Radiotherapy

The management of axillary lymph nodes in breast cancer is continually evolving. Recent data now support omitting axillary lymph node dissection (ALND) in most patients with metastases in up to two sentinel lymph nodes (SLNs) during upfront surgery and those with residual isolated tumor cells after neoadjuvant chemotherapy (NACT). In the upfront surgery setting, ALND is still indicated, however, in patients with clinically node-positive breast cancer or more than two positive SLNs and, after NACT, in case of residual micrometastases and macrometastases. Omission of the sentinel lymph node biopsy (SLNB) can be considered in many postmenopausal patients with small luminal breast cancer, particularly when axillary ultrasound is negative. Several randomized controlled trials (RCTs) are currently aiming at eliminating the remaining indications for ALND and also establishing omission of SLNB in a broader patient population. The movement to deescalate axillary staging is in part because of the association between ALND and lymphedema, which is swelling of an extremity because of lymphatic damage and obstructed lymphatic drainage. To reduce the risk of developing this condition, patients undergoing ALND can undergo reverse mapping of the axilla and immediate reconstruction or bypass of the lymphatics from the involved extremity. Decongestion and compression are the foundation of conservative treatment for established lymphedema, while lymphovenous bypass and lymph node transfer are surgical procedures to address the physiologic dysfunction. Radiotherapy is an essential component of breast locoregional therapy: more than three decades of radiation research has optimized treatment according to patient's risk of local recurrence while substantially reducing the number of treatment visits. High-quality RCTs have shown the efficacy and safety of hypofractionation-more than 2Gy radiation dose per treatment (fraction)-significantly reducing the burden of radiotherapy treatment for many patients with breast cancer. In 2024, guidelines recommend no more than 15-16 fractions for whole-breast and nodal radiotherapy, with some recommending five fractions for whole-breast radiotherapy. In addition, simultaneous integrated boost (SIB) has been shown to be noninferior to sequential boost with regards to ipsilateral breast tumor recurrence with similar or reduced long-term side effects, also reducing overall treatment length. Further RCTs are underway investigating other indications for five fractions, including SIB and regional node irradiation, such that, in future, it may be possible for the majority of breast radiotherapy patients to be treated with a 1-week course. This manuscript serves to outline the latest updates on axillary surgical staging, lymphatic surgery, and evidence-based radiotherapy in the treatment of breast cancer.

Prognostic value and management of regional lymph nodes in locoregional breast cancer recurrence: a systematic review of the literature

PURPOSE

Management of regional lymph nodes in breast cancer recurrence has been heterogeneous. To facilitate clinical practice, this review aims to give an overview on the prognosis, staging and operative management of (inapparent) regional lymph nodes.

METHODS

Current national and international guidelines are reviewed and a structured search of the literature between Jan 1, 1999 and Feb 1, 2021 on the repeat sentinel node biopsy (re-SNB) procedure was performed.

RESULTS

Positive regional lymph nodes in recurrent breast cancer indicate a poorer outcome with axillary recurrences being the most favorable tumor site among all nodal regions. Most preferred staging method is ultrasound ± guided biopsy. PET-CT, scintimammography, SPECT-CT may improve visualization of affected lymph nodes outside the axilla. Concerning operative management 30 articles on re-SNB were identified with a mean harvesting rate of 66.4%, aberrant drainage and aberrant metastasis in 1/3 of the cases. Total rate of metastasis is 17.9%. After previous axillary dissection (ALND) the re-SNB has a significantly lower harvesting rate and higher aberrant drainage and aberrant metastasis rate. The prognostic outcome after re-SNB has been favorable.

CONCLUSION

Nodal status in recurrent disease has prognostic value. The choice of operative management of clinically inapparent regional lymph nodes during local recurrence should be based on the previous nodal staging method. Patients with previous ALND should be spared a second systematic ALND. Re-SNB or no axillary surgery at all are possible alternatives. Lymphoscintigraphy may be performed to identify extraaxillary drainage. However, for definite recommendations randomized controlled studies are heavily needed.

Repeat Sentinel Lymph Node Biopsy for Ipsilateral Breast Tumor Recurrence After Breast Conserving Surgery With Sentinel Lymph Node Biopsy: Pooled Analysis Using Data From a Systematic Review and Two Institutions

Introduction: Best surgical approach of axillary staging remains controversial in locally recurrent breast cancer. We evaluated the reliability of repeat sentinel lymph node biopsy (reSLNB) in patients with ipsilateral breast tumor recurrence (IBTR) after breast conserving surgery (BCS) with sentinel lymph node biopsy (SLNB) in terms of identification rate (IR) and false negative rate (FNR). To address the FNR, we identified patients who underwent sequential axillary lymph node dissection (ALND) after reSLNB.

Methods: A systematic search of PubMed, EMBASE, and Cochrane Library were conducted to identify patient-level data from articles. We searched for data of patients who underwent BCS with SLNB for primary breast cancer and who underwent sequential ALND after reSLNB due to local recurrence. Patients data was also identified by the same criteria at two institutions.

Results: In total, 197 peer-reviewed publications were obtained, of which 20 included patients who met the eligibility criteria. Data from 464 patients were collected. From the two institutions, 31 patients were identified. A total of 495 patients were pooled. The IR of reSLNB was 71.9% (356/495). To address the FNR of reSLNB, 171 patients who underwent ALND after reSLNB were identified. The FNR and accuracy of reSLNB were 9.4% (5/53) and 97.1% (165/170), respectively.

Conclusion: Our pooled data analysis showed that the FNR of reSLNB is lower than 10%, indicating that this operation is a reliable axillary surgery in patients with IBTR after they underwent BCS.

Altered lymphatic drainage patterns in re-operative sentinel lymph node biopsy for ipsilateral breast tumor recurrence

Background

This study aimed to evaluate the impact of previous local treatment on lymphatic drainage patterns in ipsilateral breast tumor recurrence (IBTR) based on our data on re-operative sentinel lymph node biopsy (re-SLNB) for IBTR.

Methods

Between April 2005 and December 2016, re-SLNB using lymphoscintigraphy with Tc-99 m phytate was performed in 136 patients with cN0 IBTR. Patients were categorized into two groups: the AX group included 55 patients with previous axillary lymph node dissection; the non-AX group included 69 patients with previous SLNB and 12 patients with no axillary surgery. The whole breast irradiation (RT) after initial surgery had performed in 17 patients in the AX group and 27 patients in the non-AX group.

Results

Lymphatic drainage was visualized in 80% of the AX group and 95% of the non-AX group (P < 0.01). The visualization rate of lymphatic drainage was associated with the number of removed lymph nodes in prior surgery. In the non-AX group, lymphatic drainage was visualized in 96% of patients without RT and 93% with RT. Lymphatic drainage was observed at the ipsilateral axilla in 98% of patients without RT and in 64% with RT (P < 0.0001). Aberrant drainage was significantly more common in patients with RT than without RT (60% vs. 19%, P < 0.001); it was observed mostly to the contralateral axilla (52% vs. 2%, P < 0.0001). In the AX group, patients with previous RT showed decreased lymphatic drainage to the ipsilateral axilla compared to those without RT (29% vs. 63%, P < 0.05) and increased aberrant drainage to the contralateral axilla (64% vs. 5%, P < 0.0001).

Conclusion

Lymphatic drainage patterns altered in re-SLNB in patients with IBTR and previous ALND and RT were associated with alterations in lymphatic drainage patterns.

Risk of Regional Recurrence After Negative Repeat Sentinel Lymph Node Biopsy in Patients with Ipsilateral Breast Tumor Recurrence

Background

Repeat sentinel lymph node biopsy (rSLNB) has increasingly been used in patients with ipsilateral breast tumor recurrence (IBTR). The safety in terms of regional disease control after this procedure remains unclear. This study evaluates occurrence of regional recurrence as first event in patients with IBTR and negative rSLNB, treated without additional lymph node dissection.

Patients and Methods

Data were obtained from the Sentinel Node and Recurrent Breast Cancer (SNARB) study. In 201 patients, tumor-negative rSLNB was obtained without performing additional lymph node dissections.

Results

With median follow-up of 4.7 (range 0.9–12.7) years, regional recurrence occurred after median time of 3.0 (range 0.4–6.7) years in 4.5% (N = 9) of patients as first event after IBTR and rSLNB. In four of these nine patients, the site of recurrence was in concordance with the anatomical location of rSLNB. Two of the nine recurrences were reported in the ipsilateral axilla, resulting in an ipsilateral axillary regional recurrence rate of 1.0%. In the other seven patients, regional recurrence occurred in aberrant basins. Univariable analysis showed that triple-negative IBTR and lower amount of radioactive-labeled tracer (^99mtechnetium) used during rSLNB were associated with developing regional recurrence as first event after negative rSLNB (P < 0.05).

Conclusions

The risk of developing regional recurrence after negative rSLNB is low. The low relapse rate supports the safety of rSLNB as primary nodal staging tool in IBTR. The time has come for clinical guidelines to adopt rSLNB as axillary staging tool in patients with IBTR.

Electronic supplementary material

The online version of this article (10.1245/s10434-018-6384-y) contains supplementary material, which is available to authorized users.