Melanoma Sentinel-Node Metastasis

Nodal and systemic recurrence following observation of a positive sentinel lymph node in melanoma

BACKGROUND

Two RCTs found no survival benefit for completion lymphadenectomy after positive sentinel lymph node biopsy compared with observation with ultrasound in patients with melanoma. Recurrence patterns and regional control are not well described for patients undergoing observation alone.

METHODS

All patients with a positive sentinel node biopsy who did not have immediate completion lymphadenectomy were identified from a single-institution database (1995-2018). First recurrences were classified as node only, local and in-transit (LCIT) only, LCIT and nodal, or systemic. Regional control and factors associated with recurrence survival were analysed.

RESULTS

Median follow-up was 33 months. Of 370 patients, 158 (42·7 per cent) had a recurrence. The sites of first recurrence were node only (13·2 per cent), LCIT only (11·9 per cent), LCIT and nodal (3·5 per cent), and systemic (13·8 per cent). The 3-year postrecurrence melanoma-specific survival rate was 73 (95 per cent c.i. 54 to 86) per cent for patients with node-only first recurrence, and 51 (31 to 68) per cent for those with initial systemic recurrence. In multivariable analysis, ulceration in the primary lesion (hazard ratio (HR) 2·53, 95 per cent c.i. 1·27 to 5·04), disease-free interval 12 months or less (HR 2·38, 1·28 to 4·35), and systemic (HR 2·57, 1·16 to 5·65) or LCIT and nodal (HR 2·94, 1·11 to 7·79) first recurrence were associated significantly with decreased postrecurrence survival. Maintenance of regional control required therapeutic lymphadenectomy in 13·0 per cent of patients during follow-up.

CONCLUSION

Observation after a positive sentinel lymph node biopsy is associated with good regional control, permits assessment of the time to and pattern of recurrence, and spares lymphadenectomy-related morbidity in patients with melanoma.

Does the time interval between sentinel lymph node biopsy and completion lymph node dissection affect outcome in malignant melanoma? A retrospective cohort study

Nodal clearance was recommended after positive sentinel lymph node biopsy (SLNB) despite further metastases to the regional lymph node basin being found in only 6-21% in the literature. This retrospective study was conducted to determine the role of the time interval between excision of primary melanoma and confirmed metastasis in the sentinel lymph node biopsy as well as the one between positive sentinel lymph node biopsy (SLNB-positive patients) and subsequent completion lymph node dissection (CLND) on the presence of metastases. The monocentric analysis included 121 patients with a history of completion lymph node dissection after positive SLNB from January 2005 to October 2013. Additional metastases in the regional lymph node basin (non-sentinels) were found in 14.05% (n = 17). Significant risk factors for the presence of metastases in CLND were the time between confirmed primary tumour to metastasis in sentinel lymph nodes (SLN) (p = 0.0034), N-category of TNM-classification (p = 0.0066) and independent of thickness of primary tumour (p = 0.11). If SLNB was performed up to forty-three days after confirmed primary melanoma, subsequent lymph node dissection was positive in less than 9.1%. When SLNB was performed with a delay of more than 80 days, all patients had metastases in the CLND specimens. Our data analysis suggests that delays in subsequent procedures of SLNB after diagnosis of primary melanoma may have a greater impact on positivity of non-sentinel lymph nodes than previously assumed. Our retrospective analysis may indicate the reconsideration of time schedule in the management of primary melanoma to potentially avoid local relapse in the draining lymph node region after positive SLNB.

[Stage III melanoma: Sentinel node biopsy, completion lymph node dissection and prospects of adjuvant therapy. A French national survey on current and envisaged practices]

BACKGROUND

The recent publication of randomized trials investigating the efficacy of adjuvant therapy and completion lymph node dissection at microscopic stage III melanoma calls for a reappraisal of melanoma management from different angles: indications for sentinel lymph node biopsy, indications for completion lymph node dissection in microscopic-stage disease, and adjuvant therapies. Our objective was to evaluate current practices and to question French onco-dermatologists about any changes they envisaged in their practices in the light of recent publications.

METHODS

We conducted a national survey among members of the Cutaneous Oncology Group of the French Society of Dermatology in October 2017.

RESULTS

Forty French health centers were included, and 53 individual responses were collected. Sentinel lymph node biopsy for melanoma was performed at 75 % of the centers. Before the summer of 2017 and the publication of MSLT-II (proving the absence of any therapeutic benefits for complete lymph node dissection in microscopic stage III melanoma), when a positive sentinel lymph node was diagnosed, immediate completion lymph node dissection was performed at 90 % of the centers. After the publication of MSLT-II, 45 % of the respondents considered stopping this practice. The risk-benefit ratio prompted prescription of nivolumab and of combined dabrafenib+trametinib as adjuvant therapy by respectively 96 % and 79 % of respondents, while the corresponding rates for interferon and ipilimumab were only 21 % and 15 %.

CONCLUSION

Early melanoma management stands on the verge of major changes thanks to the arrival of efficient adjuvant therapies and a decrease in immediate completion lymph node dissections for patients with microscopic stage III is also anticipated.

Sentinel Lymph Node Biopsy and Complete Lymph Node Dissection for Melanoma

PURPOSE OF REVIEW

The main surgical treatment for invasive malignant melanoma consists of wide surgical and examination of the sentinel node and in selected cases complete lymph node dissection. The aim of this review is to present data for the optimal surgical management of patients with malignant melanoma.

RECENT FINDINGS

A surgical excision margin of 1-2 cm is recommended for invasive melanoma depending on the thickness of the melanoma. Sentinel node biopsy may be considered for patients with at least T1b melanomas thickness 0.8 to 1.0 mm or less than 0.8 mm Breslow thickness with ulceration, classified as T1b lesion, per recent AJCC guidelines. Two randomized controlled trials have been published-DeCOG (German Dermatologic Cooperative Oncology Group Selective Lymphadenectomy) and MSLT-2 (Multicenter Selective Lymphadenectomy Trial) comparing the complete lymph node dissection (CLND) with observation after positive sentinel node biopsy. In the MSLT-2 study, the disease control rate was improved in the immediate CLND group compared with observation but there was no difference in 3-year melanoma specific survival (86% ± 1.3% and 86% ± 1.2%, respectively; p = 0.42). Isolated limb perfusion (ILP) or isolated limb infusion (ILI) with melphalan and actinomycin D is recommended for large and multiple in-transit metastases and satellite metastases in the extremities when local excision is considered ineffective or too extensive. In light of new adjuvant treatment options and new indications for checkpoint inhibitors, and the lack of survival benefit after CLND, we can expect open surgery to decrease in melanoma disease.

Current management of regional lymph nodes in patients with melanoma

The publication of recent randomized trials has prompted a significant shift in both our understanding and the management of patients with melanoma. Here, the current management of the regional lymph nodes in patients with melanoma is discussed. This review focuses on selection for sentinel lymph node biopsy, management of the positive sentinel node, management of the clinically positive node, and the controversy over the therapeutic value of early nodal intervention.

Routine retrieval of pelvic sentinel lymph nodes for melanoma rarely adds prognostic information or alters management

Pelvic sentinel lymph nodes (SLNs) are commonly identified during inguinal SLN biopsy for melanoma, but retrieval is not uniform among surgeons/centers. Few studies have assessed rates of micrometastases in pelvic versus superficial inguinal SLNs. Previous studies suggested that presence of pelvic SLNs was predicted by aggressive pathologic features and that their presence portended a worse prognosis. The objectives of this study were to examine presurgical predictors of pelvic SLNs among patients undergoing inguinal SLN biopsy, assess rates of micrometastases in superficial inguinal versus pelvic SLNs, and determine whether presence of pelvic SLNs was associated with long-term outcomes. Multivariable regression was used to assess presurgical factors associated with presence of pelvic SLNs. Rates of micrometastases in superficial inguinal versus pelvic SLNs in patients who had a pelvic SLN were compared with McNemar's test. Groin recurrence, disease-free survival (DFS), and disease-specific survival were analyzed by Kaplan-Meier method. A multivariable Cox model for DFS was performed. Pelvic SLNs were retrieved in 100/537 (18.6%) superficial inguinal SLN biopsies and no preoperative factors predicted their presence. In patients with a pelvic SLN, micrometastases were present in 3.0% of pelvic versus 34.0% of superficial inguinal SLN biopsies (P<0.001). There were no differences in groin recurrence, DFS, and disease-specific survival for patients with/without pelvic SLNs in univariate analyses (all P>0.2) or in the multivariable Cox model for DFS (hazard ratio: 1.1, 95% confidence interval: 0.6-2.1). In conclusion, pelvic SLNs harbor micrometastases less frequently than superficial inguinal SLNs do, suggesting that omission of pelvic SLN biopsy may be reasonable.

Essential Components of Melanoma Histopathological Reporting: The Surgical Oncologist's Perspective

Histopathological reporting plays a critical role in guiding the surgical oncologist's management plan in treatment of primary cutaneous melanoma. The International Collaboration on Cancer Reporting (ICCR) espouses various components of structured histopathological reporting as "essential" or "recommended." From a surgical oncologist's perspective, we discuss the clinical relevance of each essential component, as well as prognostic and treatment implications with regard to treatment planning.