How Often Does Retrieval of a Clipped Lymph Node Change Adjuvant Therapy Recommendations? A Prospective, Consecutive, Patient Cohort Study

Targeted axillary dissection reduces residual nodal disease in clinically node- positive breast cancer after neoadjuvant chemotherapy

BACKGROUND

Any advantage of performing targeted axillary dissection (TAD) compared to sentinel lymph node (SLN) biopsy (SLNB) is under debate in clinically node-positive (cN+) patients diagnosed with breast cancer. Our objective was to assess the feasibility of the removal of the clipped node (RCN) with TAD or without imaging-guided localisation by SLNB to reduce the residual axillary disease in completion axillary lymph node dissection (cALND) in cN+ breast cancer.

METHODS

A combined analysis of two prospective cohorts, including 253 patients who underwent SLNB with/without TAD and with/without ALND following NAC, was performed. Finally, 222 patients (cT1-3N1/ycN0M0) with a clipped lymph node that was radiologically visible were analyzed.

RESULTS

Overall, the clipped node was successfully identified in 246 patients (97.2%) by imaging. Of 222 patients, the clipped lymph nodes were non-SLNs in 44 patients (19.8%). Of patients in cohort B (n=129) with TAD, the clipped node was successfully removed by preoperative image-guided localisation, or the clipped lymph node was removed as the SLN as detected on preoperative SPECT-CT. Among patients with ypSLN(+) (n=109), no significant difference was found in non-SLN positivity at cALND between patients with TAD and RCN (41.7% vs. 46.9%, p=0.581). In the subgroup with TAD with axillary lymph node dissection (ALND; n=60), however, patients with a lymph node (LN) ratio (LNR) less than 50% and one metastatic LN in the TAD specimen were found to have significantly decreased non-SLN positivity compared to others (27.6% vs. 54.8%, p=0.032, and 22.2% vs. 50%, p=0.046).

CONCLUSIONS

TAD by imaging-guided localisation is feasible with excellent identification rates of the clipped node. This approach has also been found to reduce the additional non-SLN positivity rate to encourage omitting ALND in patients with a low metastatic burden undergoing TAD.

Clipping a Positive Lymph Node Improves Accuracy of Nodal Staging After Neoadjuvant Chemotherapy for Breast Cancer Patients, but Does It Drive Management Changes?

BACKGROUND

Sentinel lymph node (SLN) biopsy for cN+ breast cancer patients after neoadjuvant chemotherapy (NAC) is controversial because the false-negative rate (FNR) is high. Identification of three or more SLNs with a dual tracer improves these results, and inclusion of a clipped lymph node (CLN) (targeted axillary dissection [TAD]) may be even more effective.

METHODS

A retrospective, single-institution analysis of consecutive cN+ patients undergoing NAC from 2019 to 2021 was performed. Patients routinely underwent placement of a clip in the positive lymph node before NAC, and TAD was performed after completion of therapy.

RESULTS

The study analyzed 73 patients, and the identification rate for CLN was 98.6% (72/73). A complete response in the lymph nodes was achieved for 43 (59%) of the 73 patients. Overall, the CLN was not a SLN in 18 (25%) of 73 cases, and for women who had one or two and those who had three or more SLNs identified, this occurred in 11 (32%) and 7 (21%) of 34 cases, respectively. Failure of SLN or TAD to identify a positive residual lymph node status after NAC occurred in 10 (15%) of 69 and 2 (3%) of 73 cases, respectively (p = 0.01). In four cases, a SLN was not retrieved (5.5%), and two of these cases had a positive CLN. In three cases, the CLN was the only positive node and did not match with a SLN, directing lymphadenectomy and oncologic management change in two cases. Therefore, 7 (10%) of 73 cases had a change in surgical or oncologic management with TAD.

CONCLUSIONS

For a conservative axillary treatment in this setting, TAD is an effective method. It is more accurate than SLN alone and allows management changes. Further studies are warranted.

Systematic review of targeted axillary dissection in node-positive breast cancer treated with neoadjuvant systemic therapy: variation in type of marker and timing of placement

BACKGROUND

In node-positive (cN+) breast cancer treated with neoadjuvant systemic therapy, combining sentinel lymph node biopsy and targeted lymph node excision, that is targeted axillary dissection, increases accuracy. Targeted axillary dissection procedures differ in terms of the targeted lymph node excision technique. This systematic review aimed to provide an overview of targeted axillary dissection procedures regarding definitive marker type and timing of placement: before neoadjuvant systemic therapy (1-step procedure) or after neoadjuvant systemic therapy adjacent to a clip placed before the neoadjuvant therapy (2-step procedure).

METHODS

PubMed and Embase were searched, to 4 July 2023, for RCTs, cohort studies, and case-control studies with at least 25 patients. Studies of targeted lymph node excision only (without sentinel lymph node biopsy), or where intraoperative localization of the targeted lymph node was not attempted, were excluded. For qualitative synthesis, studies were grouped by definitive marker and timing of placement. The targeted lymph node identification rate was reported. Study quality was assessed using a National Institutes of Health quality assessment tool.

RESULTS

Of 277 unique records, 51 studies with a total of 4512 patients were included. Six definitive markers were identified: wire, 125I-labelled seed, 99mTc, (electro)magnetic/radiofrequency markers, black ink, and a clip. Fifteen studies evaluated one-step procedures, with the identification rate of the targeted lymph node at surgery varying from 8 of 13 to 47 of 47. Forty-one studies evaluated two-step procedures, with the identification rate of the clipped targeted lymph node on imaging after neoadjuvant systemic therapy varying from 49 to 100%, and the identification rate of the targeted lymph node at surgery from 17 of 24 to 100%. Most studies (40 of 51) were rated as being of fair quality.

CONCLUSION

Various targeted axillary dissection procedures are used in clinical practice. Owing to study heterogeneity, the optimal targeted lymph node excision technique in terms of identification rate and feasibility could not be determined. Two-step procedures are at risk of not identifying the clipped targeted lymph node on imaging after neoadjuvant systemic therapy.

Radiographic identification of a positive clipped axillary lymph node in a mastectomy specimen following neoadjuvant chemotherapy

Sentinel lymph node biopsies are recommended for staging in node-positive breast cancer patients who become clinically node-negative after neoadjuvant therapy. Current guidelines support the omission of an axillary lymph node dissection if 3 negative sentinel nodes are retrieved during surgery. Consequently, the utility of routine clip placement in biopsied nodes prior to neoadjuvant chemotherapy and the necessity of targeted removal of these clipped nodes is in question. There are various methods for retrieving clipped nodes. We describe a case in which an intraoperative radiograph of a mastectomy specimen identified a clipped node that had not been localized with targeted axillary dissection in a patient with breast cancer. Pathology revealed persistent nodal positivity after neoadjuvant therapy, resulting in an escalation in care and a complete axillary dissection. We review the current literature on nodal clipping, and discuss the importance of localizing clipped nodes and the impact it can have on management.

Nodal Positivity in Early-Stage Triple-Negative Breast Cancer: Implications for Preoperative Immunotherapy

BACKGROUND

Adding pembrolizumab to preoperative chemotherapy improves event-free survival in patients with early-stage triple-negative breast cancer (TNBC). However, owing to potential toxicities, the risk-benefit ratio of pembrolizumab must be considered. There is consensus that the addition of immunotherapy should be recommended in node-positive patients. This study is undertaken to determine nodal positivity rates in patients with TNBC presenting with cT1-2N0 disease undergoing upfront surgery and to evaluate the utility of axillary ultrasound and biopsy in the setting of a negative clinical examination.

PATIENTS AND METHODS

Patients with cT1-2N0 TNBC undergoing upfront surgery were identified from our institutional database (January 2016-February 2021; n = 343) and from the National Cancer Database (NCDB) (n = 46,015). Pathologic nodal status was determined. A second cohort of patients with cT1-T2 TNBC with a negative clinical examination was defined in our institutional database (n = 499), and utilization of axillary ultrasound was examined.

RESULTS

For patients undergoing upfront surgery, pathologically positive nodes were found in 14.6% patients of our institutional cohort: 9.4% cT1a/b, 14.9% cT1c, and 20.8% cT2 tumors. In the NCDB cohort, 13.7% patients were node positive: 4.9% cT1a/b, 11.4% cT1c, and 19.7% cT2 tumors. For patients with a normal clinical examination undergoing axillary ultrasound, 7.5% of cT1c and 8.7% of cT2 had suspicious nodes biopsied and confirmed positive for metastasis.

CONCLUSIONS

Pathologic node-positive disease is found in > 10 and 20% patients with cT1cN0 and cT2N0 TNBC, respectively. Axillary ultrasound can be used to identify patients presenting with a normal clinical examination for whom preoperative pembrolizumab should be considered.

Is Nodal Clipping Beneficial for Node-Positive Breast Cancer Patients Receiving Neoadjuvant Chemotherapy?

BACKGROUND

In cN1 patients rendered cN0 with neoadjuvant chemotherapy, the false-negative rate of sentinel lymph node biopsy (SLNB) is < 10% when ≥ 3 sentinel lymph nodes (SLNs) are removed. The added value of nodal clipping in this scenario is unknown. Here we determine how often the clipped node is a sentinel node when ≥ 3 SLNs are retrieved.

METHODS

We identified cT1-3N1 patients treated between 02/2018 and 10/2021 with a clipped lymph node at presentation. SLNB was performed with a standardized approach of dual-tracer mapping and retrieval of ≥ 3 SLNs. Clipped nodes were not localized; SLNs were X-rayed intraoperatively to determine clip location. Axillary lymph node dissection (ALND) was performed for any residual disease or retrieval of < 3 SLNs.

RESULTS

Of 269 patients, 251 (93%) had ≥ 3 SLNs. Median age was 51 years; the majority (92%) had ductal histology; 46% were HR+/HER2-. The median number of SLNs removed was 4 (IQR 3,5). The clipped node was an SLN in 88% (220/251) of cases. Of the 31 where the clipped node was not, 13 had a positive SLN mandating ALND, and the clip was identified in the ALND specimen. In the remaining 18, where ≥ 3 negative SLNs were retrieved and an ALND was not performed, the clip was not retrieved, with no axillary failures in this group (median follow-up: 55 months).

CONCLUSION

When the SLNB procedure is optimized with dual tracer and retrieval of ≥ 3 SLNs, the clipped node is an SLN in the majority of cases, suggesting that failure to retrieve the clipped node should not be an indication for ALND.