Repeat sentinel lymph node surgery for locally recurrent breast cancer after prior mastectomy

BACKGROUND AND OBJECTIVES

Current NCCN guidelines discourage repeat sentinel lymph node (SLN) surgery in patients with local recurrence (LR) of breast cancer following prior mastectomy. This study addresses the feasibility and therapeutic impact of this approach.

METHODS

We identified 73 patients managed with repeat SLN surgery for post-mastectomy isolated LR. Lymphatic mapping was performed using radioisotope with or without lymphoscintigraphy and/or blue dye. Successful SLN surgery was defined as retrieval of ≥1 SLN.

RESULTS

SLN surgery was successful in 65/73 (89%), identifying a median of 2 (range 1-4) SLNs, with 10/65 (15%) SLN-positive. Among these, 5/10 (50%) proceeded to ALND. In unsuccessful cases, 1/8 (13%) proceeded to ALND. Seven of 10 SLN-positive patients and 50/55 SLN-negative patients received adjuvant radiotherapy. Chemotherapy was administered in 31 (42%) and endocrine therapy in 50 of 57 HR+ patients (88%). After 28 months median follow-up, eight patients relapsed with the first site local in two, distant in five, and synchronous local/distant in one. No nodal recurrences were observed.

CONCLUSIONS

SLN surgery for patients with LR post-mastectomy is feasible and informative. This approach appears oncologically sound, decreases axillary dissection rates and may be used to tailor adjuvant radiation target volumes and systemic therapies.

Ipsilateral breast tumor recurrence after breast-conserving surgery: insights into biology and treatment

Despite modern surgical and irradiation techniques, ipsilateral breast tumor recurrence (IBTR) accounts for 5-15% of all cancer recurrence in women treated with breast conservative treatment. Historically, this event has been treated definitively with salvage mastectomy and completion axillary clearance. However, many local recurrences are small and without nodal involvement at presentation. Thus, there has been an interest in performing a surgical de-escalation procedure in the breast and the axilla. The current guidelines do not provide detailed descriptions and treatment suggestions for these selected patients, resulting in inconsistent treatment strategies. Moreover, the methods to define true recurrence (TR) and new primary tumor (NP) for IBTR remain controversial. Most developed classification methods mainly rely on clinical and pathological criteria, limiting the accuracy of the discerption and causing misclassification. In this editorial, we will discuss the current trends in surgical de-escalation for patients with IBTR. Moreover, we will focus on recent IBTR innovations, highlighting molecular-integrated classification and multimodal staging methods for clinical practice and postoperative surveillance strategies.

Added value of repeat sentinel lymph node biopsy in FDG-PET/CT node-negative patients with ipsilateral breast cancer recurrence

PURPOSE

Repeat sentinel lymph node biopsy (rSLNB) has been suggested for axillary staging in clinically node-negative (cN0) patients with ipsilateral breast tumor recurrence (IBTR). Although rSLNB is technically feasible in this group of patients, the clinical value has not been established. We aimed to assess the added value of rSLNB in cN0 patients with IBTR who underwent optimal clinical staging with FDG-PET/CT.

METHODS

This retrospective single-center cohort study included 119 patients with IBTR-staged cT1-4N0M0 with FDG-PET/CT who underwent rSLNB between 2006 and 2020. Overall recurrence-free survival (RFS) and overall survival (OS) were calculated for subgroups with tumor-positive, tumor negative, and unsuccessful rSLNB.

RESULTS

rSLNB was successful in 79 (66%) of the 119 included patients, of whom 70 (59%) had a tumor negative and 9 (8%) a tumor-positive rSLNB; rSLNB was unsuccessful in the remaining 40 (34%) patients. Patients with a tumor-positive rSLNB had poorer overall 5-year RFS compared to patients with a tumor negative or unsuccessful rSLNB (44% vs. 86% vs. 90%, p = 0.004). Although patients with a tumor-positive rSLNB had worse RFS, the 10-year OS was comparable to a tumor negative or unsuccessful rSLNB (89% vs. 89% vs. 95%, p = 0.701).

CONCLUSION

The incidence of a tumor-positive rSLNB in patients with a negative FDG-PET/CT is low and does not change survival. Therefore, in cN0 patients with IBTR who underwent optimal clinical staging with FDG-PET/CT, we support a patient- and tumor-tailored treatment strategy in which rSLNB may be omitted.

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.

Does failed mapping predict sentinel lymph node metastasis in cN0 breast cancer?

Aims: The clinical significance of nonvisualized sentinel lymph nodes (non-vSLNs) is unknown. The authors sought to determine the incidence of non-vSLNs on lymphoscintigraphy, the identification rate during surgery, factors associated with non-vSLNs and related axillary management. Patients & methods: A total of 30,508 consecutive SLN procedures performed at a single institution from 2000 to 2017 were retrospectively studied. Associations between clinicopathological factors and the identification of SLNs during surgery were assessed. Results: Non-vSLN occurred in 525 of the procedures (1.7%). In 73.3%, at least one SLN was identified intraoperatively. Nodal involvement was only significantly associated with SLN nonidentification (p < 0.001). Conclusion: Patients with non-vSLN had an increased risk for SLN metastasis. The detection rate during surgery was consistent, reducing the amount of unnecessary axillary dissection.

How to Perform Repeat Sentinel Node Biopsy Safely After a Previous Mastectomy: Technical Features and Oncologic Outcomes

BACKGROUND

The latest National Comprehensive Cancer Network Breast Cancer Guidelines still discourage repeat sentinel node biopsy (SNB) after mastectomy, and the largest multicentric study available reports only 35 cases in the absence of previous axillary dissection (AD).

METHODS

From January 2003 to November 2018, 89 patients of the European Institute of Oncology with local recurrence of breast cancer after mastectomy, free of distant metastases, with a clinically negative axilla and a negative axillary ultrasound, in absence of AD, underwent lymphatic mapping before wide local excision.

RESULTS

During surgery, SNB was successful for 99% of the patients, with 14% being metastatic. Additional metastatic nodes removed by AD after a positive sentinel node occurred in 82% of cases. After a medium follow-up period of 3.7 years, the overall survival rate was 96.7%, and the disease-free survival rate was 84.4%. No axillary relapse after AD was recorded. One patient who refused human epidermal growth factor receptor 2 (HER2)-targeted treatment experienced ipsilateral axillary recurrence after a negative repeat SNB. The first axillary level was never directly irradiated because all the patients with positive repeat SNB underwent AD. For invasive luminal-like HER2-negative recurrences, the metastatic sentinel node was significantly associated with the choice to prescribe adjuvant chemotherapy (p = 0.003).

CONCLUSIONS

In specialized centers, repeat axillary SNB for patients with local recurrence after mastectomy in the absence of previous AD can represent a safe option for detection and removal of occult axillary disease that would otherwise not be excised/irradiated to achieve better local control and could possibly influence the choice of adjuvant treatments.

Radiotherapy biobanking: current landscape, opportunities, challenges, and future aspirations

Half of all cancer patients receive radiotherapy, which makes a substantial contribution to their long‐term disease control/cure. There are significant inter‐patient differences in response, both in terms of efficacy and toxicity (frequently delayed onset) which are difficult to predict. With the introduction of technological improvements (e.g. stereotactic body radiotherapy and proton therapy) and development of combination therapies (e.g. radiotherapy and immune checkpoint inhibition), predictive biomarkers are needed even more. Whilst genomic studies have contributed significantly to predictions of response to anticancer therapy, there is no doubt that more information can be gathered from patient tissue samples. Patients are willing to donate their tissues to biobanks and wish them to be used as widely as possible for high‐quality research. We report here a survey of the current practices in the UK from several groups collecting material from patients in radiotherapy trials and have identified barriers to collecting and sharing data and samples. We believe the current situation represents a significant missed opportunity to improve the personalisation of radiotherapy. We propose a greater involvement of patients and/or their advocates, a standardisation of the patient information leaflet, consent form content and data set, with easy linkage to clinical data, which would facilitate widespread sample and data discovery and availability to other researchers. The greater sharing of data and samples, nationally and internationally, would facilitate robust multicentre studies and avoid duplication of effort.

Where does subcutaneous lymph from the chest wall flow into after mastectomy?

BACKGROUND

Changes of the lymph flow from the chest wall after mastectomy and sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (Ax) has yet to be understood. This study aimed to investigate the effect of axillary surgery on lymphatic flow from the chest wall in patients who have undergone mastectomy, including those have undergone breast reconstruction and vascularized lymph node transfer (VLNT).

METHODS

Following mastectomy in 100 breasts, the directions of lymph flow from the chest wall was compared between the SLNB omission, SLNB, Ax, and Ax followed by VLNT groups using indocyanine green (ICG) lymphography in cross-sectional study. Lymph flow on the deep epigastric artery perforator (DIEP) flap was also investigated.

RESULTS

Lymph flow directing to the ipsilateral axilla was observed more frequently after SLNB than Ax (48% vs. 12.5%; p = 0.005); however, no significant difference was observed in the frequency of contralateral axillary route adoption between them (8% vs. 15%; p = 0.65). In the VLNT group, lymph flow to the ipsilateral axilla was not observed at a significantly higher frequency than in the Ax group (12.5% vs. 12.5%, p = 1.00). On the transferred DIEP flap, the lymph flowed anterograde or retrograde parallel to the anatomic course of the lymphatic vessels.

CONCLUSION

To visualize the direction of lymph flow of the chest following mastectomy, ICG lymphography may be useful to discern the direction in which malignant neoplasms, including lymphoma, are transported and to plan for lymph flow restoration.

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.

Aberrant Lymphatic Drainage in the Contralateral Axilla in Patients with Isolated Ipsilateral Breast Tumor Recurrence

The management and implications of aberrant lymphatic drainage in the contralateral axilla during repeat sentinel lymph node biopsy (SLNB) in patients with isolated ipsilateral breast tumor recurrence (IBTR) are not well understood. We analyzed the outcomes of contralateral SLNB in cases of isolated IBTR compared to ipsilateral SLNB. We conducted a retrospective review of cases reported at Samsung Medical Center between 1995 and 2015. All patients with isolated IBTR that underwent ipsilateral and contralateral SLNB with clinically negative lymph nodes but lymphatic drainage on the ipsilateral or contralateral axilla were included. Among 233 patients with isolated IBTR, 31 patients underwent repeat SLNB, 11 underwent ipsilateral SLNB, and nine underwent contralateral SLNB. None of the patients showed contralateral axillary metastasis in cases with isolated IBTR in the absence of clinically suspicious drainage on the contralateral axilla. Contralateral drainage was associated with a longer interval to IBTR (68.4 vs.18.6 months, p = 0.001) and the overall median follow-up duration (102.6 vs. 45.4 months, p = 0.002). There was no significant difference in the recurrence after the second operation (1 of 11 vs. 1 of 9, p = 1.000). Only one patient in both groups experienced recurrence after the second operation. Two patients (22.2%) who underwent contralateral SLNB had lymphedema. We demonstrate that no patient had contralateral metastasis in patients with isolated IBTR in the absence of clinically suspicious drainage in the contralateral axilla. Further study is warranted to better understand and optimize the management of these rare and challenging cases.

Prognostic impact of repeat sentinel lymph node biopsy in patients with ipsilateral breast tumour recurrence

BACKGROUND

Ipsilateral breast tumour recurrence (IBTR) has an unfavourable prognosis, with a significant subsequent risk of distant recurrence. Repeat sentinel lymph node biopsy (rSLNB) has recently been demonstrated to be technically feasible and useful in tailoring adjuvant treatment plans in patients with IBTR. The prognostic impact of rSLNB in patients with IBTR remains unclear. This study analysed the risk of distant recurrence after IBTR, and evaluated the prognostic impact of rSLNB and other patient and tumour characteristics on distant recurrence-free survival.

METHODS

Data were obtained from the SNARB (Sentinel Node and Recurrent Breast Cancer) study. Cox proportional hazards analyses were performed to assess the prognostic effect of tumour, patient and treatment factors on distant recurrence-free survival.

RESULTS

Of the 515 included patients, 230 (44·7 per cent) had a tumour-negative rSLNB and 46 (8·9 per cent) a tumour-positive rSLNB. In 239 patients (46·4 per cent) the rSLNB procedure was unsuccessful. After a median follow-up of 5·1 years, 115 patients (22·3 per cent) had developed a recurrence. The overall 5-year distant recurrence-free survival rate was 84·2 (95 per cent c.i. 80·7 to 87·7) per cent. An interval of less than 2 years between primary breast cancer treatment and ipsilateral recurrence (P = 0·018), triple-negative IBTR (P = 0·045) and absence of adjuvant chemotherapy after IBTR (P = 0·010) were independently associated with poor distant recurrence-free survival. The association between the outcome of rSLNB and distant recurrence-free survival was not statistically significant (P = 0·682).

CONCLUSION

The outcome of rSLNB is not an important prognostic factor for distant recurrence, and its value as a staging tool in patients with IBTR seems disputable.

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.

Low Risk of Development of a Regional Recurrence After an Unsuccessful Repeat Sentinel Lymph Node Biopsy in Patients with Ipsilateral Breast Tumor Recurrence

BACKGROUND

Unlike sentinel lymph node biopsy (SLNB) in the primary setting, the repeat SLNB (rSLNB) in patients with ipsilateral breast tumor recurrence (IBTR) is challenging, because it is difficult to visualize and/or harvest a sentinel lymph node in every patient. Regional treatments options and safety in terms of regional disease control after such an unsuccessful rSLNB remain unclear. This study assesses factors associated with the performance of axillary lymph node dissection (ALND) after unsuccessful rSLNB and evaluates the occurrence of regional recurrences.

METHODS

Data were obtained from the Sentinel Node and Recurrent Breast Cancer (SNARB) study. In 239 patients, the rSLNB was unsuccessful, of whom 60 patients underwent ipsilateral ALND.

RESULTS

A shorter time interval between primary treatment and IBTR, and a primary negative SLNB were significantly associated with a higher probability to be treated with ALND after unsuccessful rSLNB (P < 0.001). The 5-year regional-recurrence rate was 0.0% in the ALND group compared with 3.7% in the group treated without ALND (P = 0.113). Of the 179 patients treated without ALND, after a median follow-up of 5.1 years (range 0.3-13.2), 7 (3.9%) developed a regional recurrence as first event after unsuccessful rSLNB. None of the seven recurrences occurred in the ipsilateral axilla. Univariable analysis showed no factors associated with regional recurrence as first event after unsuccessful rSLNB (P > 0.05).

CONCLUSIONS

The present study demonstrates that the risk of regional recurrence in patients with an IBTR and an unsuccessful rSLNB is negligible, irrespective of the use of ALND. This suggests that there is no need for additional treatment of the axilla after an unsuccessful rSLNB.

Management of In-Breast Tumor Recurrence

The management of isolated in-breast tumor recurrence is complex, requiring careful consideration of prior local therapies to plan future multimodality treatment. Options for surgical management have evolved from standard salvage mastectomy with axillary clearance and now include repeat breast conservation with axillary staging in select patients. Reattempting sentinel lymph node biopsy may avoid the morbidity of extensive axillary surgery and has been shown to be feasible in clinically node-negative patients with oncologically safe outcomes. In the adjuvant setting, partial breast irradiation has emerged as a valuable means to improve local control rates with limited associated toxicity and acceptable overall cosmesis. Furthermore, results from prospective trials are now available to support the use of chemotherapy in hormone-receptor negative subgroups, which is associated with improvements in long-term, disease-free, and overall survival.

Feasibility and oncological safety of sentinel node biopsy in breast cancer patients with a local recurrence

OBJECTIVES

To investigate the role and feasibility of sentinel lymph node biopsy (SLNB) in breast cancer patients with a local recurrence and no clinically positive axillary lymph nodes.

MATERIALS AND METHODS

A total of 71 patients underwent SLNB for breast cancer recurrence. At first surgery, they had received SLNB (46.5%), axillary lymph node dissection (ALND) (36.6%) or no axillary surgery (16.9%).

RESULTS

Lymphatic migration was successful in 53 out of 71 patients (74.6%) and was significantly higher in patients with previous SLNB or no axillary surgery than in those with previous ALND (87.9% vs. 53.8%; p = 0.009). Aberrant lymphatic migration pathways were observed in 7 patients (13.2%). The surgical SLNB was successfully performed in 51 patients (71.8%). In 46 patients (90.2%) the SLN was histologically negative, in 3 patients (5.9%) micrometastastatic and in 2 patients (3.9%) macrometastatic. The 2 patients with a macrometastates in SLN underwent ALND, In 4 out of the 18 patients with failure of tracer migration ALND, performed as surgeon's choice, did not find any metastatic node. After a median follow-up period of 39 months (range: 2-182 months), no axillary recurrence has been diagnosed.

CONCLUSION

A SLNB in patients with locally recurrent breast cancer, no previous ALND and negative axillary lymph nodes is technically feasible and impacts on the ALND rate. In patients who at primary surgery received ALND, migration rate is significantly lower, aberrant migration is frequent and no clinically useful information has been obtained.

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.

Can Locoregionally Recurrent Breast Cancer Be Cured?

Locoregional recurrence (LRR) of breast cancer can occur after multidisciplinary treatment of a primary breast cancer. With modern multidisciplinary breast cancer treatment, the incidence of isolated LRR is decreasing. Improvements in systemic therapy are driving the decrease in LRR. LRR does still occur, however. LRR reflects biology of the cancer, as does systemic recurrence. LRR of breast cancer is frequently associated with systemic disease recurrence and poor prognosis. Given this associated poor prognosis, historically, it has been unclear whether patients with LRR would benefit from aggressive therapy with curative intent. Findings in retrospective studies suggest that prognosis for patients with LRR is not universally poor, and some patients may benefit from aggressive locoregional and systemic therapy. The challenge remains to assess prognosis and appropriately treat patients with locoregional breast cancer recurrence.

Three Different Locations of a Sentinel Node Highlight the Importance of Performing a Sentinel Node Biopsy in Breast Cancer Recurrence

A local breast cancer recurrence or a new breast cancer in the previously treated breast is a staging challenge. Staging is important to tailor the local and the systemic treatment. Earlier treatment(s) can disrupt the primary lymphatic drainage. After the disruption, new lymphatic drainage pathways are often created. The identification of these new pathways together with their sentinel node(s) (SN) is important for retreatment. A fluorodeoxyglucose positron emission tomography-computerized tomography could be useful to identify the involved node(s), but, unfortunately, there is no evidence to support this. Ideally, in the case of a recurrence, an SN biopsy should be performed in order to identify the “new” draining lymph node(s). This new draining SN(s) can be located in unexpected places, and tumor invasion will lead to a change in the management.