Sentinel lymph node biopsy in melanoma: our 8-year clinical experience in a single French institute (2002-2009)

Society of Surgical Oncology Consensus Statement: Assessing the Evidence for and Utility of Gene Expression Profiling of Primary Cutaneous Melanoma

INTRODUCTION

Gene expression profiling (GEP) of primary cutaneous melanoma aims to offer prognostic and predictive information to guide clinical care. Despite limited evidence of clinical utility, these tests are increasingly incorporated into clinical care.

METHODS

A panel of melanoma experts from the Society of Surgical Oncology convened to develop recommendations regarding the use of GEP to guide management of patients with melanoma. The use of currently available GEP tests were evaluated in three clinical scenarios: (1) the utility in patient selection for sentinel lymph node biopsy; (2) the utility to guide surveillance; and (3) the utility to inform adjuvant therapy. As a basis for these recommendations, the panel performed a systematic review of the literature, including articles published from January 2012 until August 2023.

RESULTS

After review of 137 articles, 50 met the inclusion criteria. These articles included evidence related to three available GEP tests: 31-GEP, CP-GEP, and 11-GEP. The consensus recommendations were finalized using a modified Delphi process. The panel found that current evidence often fails to account for known clinicopathologic risk factors and lacks high-level data. The panel recognizes that the study of GEP tests is still evolving. The integration of GEP into routine clinical practice for predicting sentinel lymph node status and patient prognosis in melanoma is therefore not currently recommended.

CONCLUSION

At present, GEP should be considered primarily an investigational tool, ideally used in the context of clinical trials or specialized research settings.

Lymphatic expression of the proliferation marker Ki67 is linked to sentinel node positivity, recurrence and mortality in primary cutaneous melanoma

Lymphangiogenesis is a precursor to lymphovascular invasion, and may therefore signal a higher risk of metastasis and mortality in primary cutaneous melanoma. This retrospective longitudinal study aimed to evaluate whether emergent lymphangiogenesis, as measured through co-expression of endothelial proteins with the proliferation marker Ki67, was associated with poorer prognosis in a cohort of patients with single primary cutaneous melanoma. We screened all patients with a single locally invasive primary cutaneous melanoma who received sentinel lymph node biopsy at a tertiary dermatology centre in Brisbane, Australia between 1994 and 2007. Primary melanoma sections were stained via Opal multiplex immunofluorescence, and categorized according to the presence of Ki67 within either CD31+ or D2-40+ endothelial cells. Multivariate Cox regression modelling was used to evaluate associations between endothelial Ki67 positivity and clinical outcomes, with adjustment for age, sex, Breslow depth, ulceration, and anatomical location. Overall, 264 patients were available for analysis, with a median follow-up duration of 7.1 years. The presence of D2-40+ /Ki67+ co-expression was associated with greater melanoma-specific mortality (adjusted hazard ratio [HR]: 2.03; 95% confidence interval [CI]: 1.33-3.10; p = 0.001) and recurrence (adjusted HR: 1.70; 95% CI: 1.33-3.10; p = 0.001) relative to absence. CD31+ /Ki67+ co-expression was not prognostic in this cohort. Lymphatic proliferation, as measured through D2-40+ /Ki67+ co-expression, predicted greater melanoma-specific mortality and recurrence in this cohort of primary cutaneous melanoma.

Clinical Utility of Melanoma Sentinel Lymph Node Biopsy Nomograms

BACKGROUND

For patients with melanoma, the decision to perform sentinel lymph node biopsy (SLNB) is based on the estimated risk of lymph node metastasis. We assessed 3 melanoma SLNB risk-prediction models' statistical performance and their ability to improve clinical decision making (clinical utility) on a cohort of melanoma SLNB cases.

STUDY DESIGN

Melanoma patients undergoing SLNB at a single center from 2003 to 2021 were identified. The predicted probabilities of sentinel lymph node positivity using the Melanoma Institute of Australia, Memorial Sloan Kettering Cancer Center (MSK), and Friedman nomograms were calculated. Receiver operating characteristic and calibration curves were generated. Clinical utility was assessed via decision curve analysis, calculating the net SLNBs that could have been avoided had a given model guided selection at different risk thresholds.

RESULTS

Of 2,464 melanoma cases that underwent SLNB, 567 (23.0%) had a positive sentinel lymph node. The areas under the receiver operating characteristic curves for the Melanoma Institute of Australia, MSK, and Friedman models were 0.726 (95% CI, 0.702 to 0.750), 0.720 (95% CI, 0.697 to 0.744), and 0.721 (95% CI, 0.699 to 0.744), respectively. For all models, calibration was best at predicted positivity rates below 30%. The MSK model underpredicted risk. At a 10% risk threshold, only the Friedman model would correctly avoid a net of 6.2 SLNBs per 100 patients. The other models did not reduce net avoidable SLNBs at risk thresholds of ≤10%.

CONCLUSIONS

The tested nomograms had comparable performance in our cohort. The only model that achieved clinical utility at risk thresholds of ≤10% was the Friedman model.

Breslow thickness 2.0: Why gene expression profiling is a step toward better patient selection for sentinel lymph node biopsies

Risk-stratification of cutaneous melanoma is important. Patients want to know what to expect after diagnosis, and physicians need to decide on a treatment plan. Historically, melanoma that had spread beyond the skin and regional lymph nodes was largely incurable, and the only approach to preventing a bad outcome was surgery. Through the seminal work of Alexander Breslow and Donald Morton, a system was devised to carefully escalate surgery based on primary tumor thickness and sentinel lymph node status. Today, we know that prophylactic lymph node dissections do not improve survival, but we continue to appreciate the prognostic implications of a positive sentinel node and the benefits of removing nodal metastases, which facilitates locoregional disease control. However, the question arises whether we can better select patients for sentinel lymph node biopsies (SLNB) as, currently, 85% of these procedures are negative and non-therapeutic. Here, we argue that gene expression profiling (GEP) of the diagnostic biopsy is a valuable step toward better patient selection when combined with reliable clinicopathologic (CP) information such as patient age and Breslow thickness. Recently, a CP-GEP-based classifier of nodal metastasis risk, the Merlin Assay, has become commercially available. While CP-GEP is still being validated in prospective studies, preliminary data suggest that it is an independent predictor of nodal metastasis, outperforming clinicopathological variables. The hunt is on for Breslow thickness 2.0.

Improved Risk Prediction Calculator for Sentinel Node Positivity in Patients With Melanoma: The Melanoma Institute Australia Nomogram

PURPOSE

For patients with primary cutaneous melanoma, the risk of sentinel node (SN) metastasis varies according to several clinicopathologic parameters. Patient selection for SN biopsy can be assisted by National Comprehensive Cancer Network (NCCN) and ASCO/Society of Surgical Oncology (SSO) guidelines and the Memorial Sloan Kettering Cancer Center (MSKCC) online nomogram. We sought to develop an improved online risk calculator using alternative clinicopathologic parameters to more accurately predict SN positivity.

PATIENTS AND METHODS

Data from 3,477 patients with melanoma who underwent SN biopsy at Melanoma Institute Australia (MIA) were analyzed. A new nomogram was developed by replacing body site and Clark level from the MSKCC model with mitotic rate, melanoma subtype, and lymphovascular invasion. The predictive performance of the new nomogram was externally validated using data from The University of Texas MD Anderson Cancer Center (n = 3,496).

RESULTS

The MSKCC model receiver operating characteristic curve had a predictive accuracy of 67.7% (95% CI, 65.3% to 70.0%). The MIA model had a predictive accuracy of 73.9% (95% CI, 71.9% to 75.9%), a 9.2% increase in accuracy over the MSKCC model (P < .001). Among the 2,748 SN-negative patients, SN biopsy would not have been offered to 22.1%, 13.4%, and 12.4% based on the MIA model, the MSKCC model, and NCCN or ASCO/SSO criteria, respectively. External validation generated a C-statistic of 75.0% (95% CI, 73.2% to 76.7%).

CONCLUSION

A robust nomogram was developed that more accurately estimates the risk of SN positivity in patients with melanoma than currently available methods. The model only requires the input of 6 widely available clinicopathologic parameters. Importantly, the number of patients undergoing unnecessary SN biopsy would be significantly reduced compared with use of the MSKCC nomogram or the NCCN or ASCO/SSO guidelines, without losing sensitivity. An online calculator is available at www.melanomarisk.org.au.

Clinically node-negative head and neck mucosal melanoma: An analysis of current treatment guidelines & outcomes

OBJECTIVES

To analyze head and neck mucosal melanoma (MM) treatment patterns, and their association with survival, relative to National Comprehensive Cancer Network (NCCN) guidelines.

MATERIAL & METHODS

Adult head and neck MM patients with clinically-staged T3/4aN0 disease were identified in a retrospective analysis of the National Cancer Database (2010-2014) and stratified into sinonasal cavity (SN) and oral cavity, oropharynx, larynx, or hypopharynx (non-SN) cohorts.

RESULTS

We identified 353 SN and 79 non-SN MM cases. The majority of patients were treated with surgery (SN: 92.4%; non-SN 84.8%), within NCCN guidelines. Treatment within the non-SN MM NCCN recommendation of elective neck dissection (END) was approximately 26.6%. END is not recommended for SN MM and was not performed in 91.5% of cases. Radiotherapy (RT) is recommended in both SN and non-SN MM and was utilized in 63.5% of SN patients and 46.8% of non-SN patients. END was not independently associated with OS compared to surgery alone (SN HR: 1.350 [95% CI: 0.733-2.485]; non-SN HR: 3.460 [95% CI: 0.912-13.125]). RT was independently associated with improved OS in SN MM cases (HR: 0.679 [95% CI: 0.479-0.963]), but not in non-SN MM cases (HR: 0.824 [95% CI: 0.331-2.051]).

CONCLUSION

The majority of patients with head and neck MM are not treated within NCCN guidelines. The use of recommended END in non-SN patients is low. Similarly, adjuvant RT utilization is low. Our analysis shows that while greater use of RT may increase survival rates in this disease, the utility of END is unclear.

Clinical melanoma characteristics and survival-a single-center retrospective study between 2000 and 2010

The aim of this study was to characterize clinical, histological, and outcome features of primary melanoma in 1329 patients managed at a single-center institution between 2000 and 2010. Parameters included age at diagnosis, sex, tumor location, histology, stage, Breslow thickness, and sentinel lymph node status among others. The mean age at diagnosis was 59.1 ± 16.7 years. Women were significantly younger than men when diagnosed (57.2 vs. 61.0 years; p < 0.001). Most melanomas (83%) were diagnosed on typically sun-exposed skin areas. Superficial spreading melanoma (39.5%) was the most frequent histological subtype. The median Breslow thickness was significantly higher for men compared to women (1.10 mm vs. 0.90 mm; p = 0.018). 38.3% of patients with positive and 12.9% of patients with negative sentinel biopsies progressed. Five-year survival analysis for a sub-cohort of 577 patients showed better 5‑year overall survival for woman compared to men (75.8% vs. 63.6%; p = 0.025). Our findings indicate differences in patient characteristics between men and women, and underscore the importance of early melanoma detection to prevent disease progression.

Inter-observer variation in the histopathology reports of head and neck melanoma; a comparison between the seventh and eighth edition of the AJCC staging system

BACKGROUND

TNM staging of melanoma has recently been altered by the introduction of the 8th edition of the AJCC Cancer Staging manual. The purpose of this study is to analyze the inter-observer variation of histopathology reports and its effect on recommended treatment policy.

METHODS

We retrospectively analyzed 296 cases, diagnosed as primary cutaneous head and neck melanoma (2005-2016), referred to the Netherlands Cancer Institute (NCI) for treatment after prior diagnosis in another hospital (non-NCI). All reports were analyzed for patients demographics, tumor characteristics and histopathologic features.

RESULTS

In 53% and 40% of the cases, the histopathologic parameters were discordant, according to AJCC 7th and 8th edition, respectively. This indicated a perfect inter-observer agreement for the measurement of Breslow thickness (Intraclass correlation coefficient (ICC) = 0.981) and a substantial agreement for subtype (kappa statistic (κ) = 0.648) and ulceration (κ = 0.802), while only moderate for dermal mitotic activity (κ = 0.472). After NCI review, recommended treatment policies were changed in 13% and 11% of the patients when applying TNM 7 and TNM 8, respectively. Scheduling sentinel lymph node biopsy (SLNB) changed in 14 (5%) and 10 (3%) cases when using TNM 7 and TNM 8, respectively.

CONCLUSION

Review by a NCI pathologist of histopathologic parameters of primary cutaneous head and neck melanoma led to significant changes in treatment decision. Introduction of the AJCC 8th edition led to slightly less discordances between NCI and non-NCI reports and consequently smaller impact on treatment planning. Expert review remains indicated when a SLNB is considered for additional staging in selected cases.

Gamma probe and ultrasound guided fine needle aspiration cytology of the sentinel node (GULF) trial - overview of the literature, pilot and study protocol

BACKGROUND

Sentinel node (SN) biopsy (SNB) detects clinically occult metastases of breast cancer and melanoma in 20-30%. Wound infections, seroma and lymph edema occur in up to 10%. Targeted ultrasound (US) of the SN, (with fine needle aspiration cytology (FNAC) if appropriate) has been investigated as a minimally invasive alternative, but reported sensitivity rates are too low to replace SNB. Our hypothesis is that the use of a handheld gamma probe concomitant with US may improve sensitivity. Our aim is to provide an overview of the current literature on preoperative nodal staging of clinical N0 melanoma patients, report on a pilot, and present a study protocol for a minimally invasive alternative to the SNB: Gamma probe and Ultrasound guided Fine needle aspiration cytology of the sentinel node (GULF trial).

METHODS

The GULF trial is a multicenter open single arm observational trial. Newly diagnosed cT1b-4N0M0 cutaneous melanoma or cT1-3N0M0 breast cancer patients, aged >18 years, presenting for SNB are eligible. 120 patients will be included for preoperative targeted gamma probe guided US and FNAC of the SN. Afterwards all patients proceed to surgical SNB. Primary endpoint is the sensitivity of FNAC. Secondary endpoints include SN identification rate and the histopathological compatibility of Core Needle Biopsy and FNAC vs. SNB. Secondary endpoints were investigated in a pilot with 10 FNACs and marker placements, and 10 FNACs combined with Core Needle Biopsy.

RESULTS

A pilot in 20 patients showed that SN identification rate was 90%, supporting the feasibility of this technique.

DISCUSSION

There is broad experience with US (in combination with FNAC) prior to SNB, but sensitivity and specificity are too low to completely abandon SNB. Promising alternative techniques potentially will replace SNB in the future but more evidence is needed in the form of prospective studies. Accurate identification of the SN for US-FNAC has been proven feasible in our pilot. When adequate sensitivity can be reached, US-FNAC provides a minimally invasive alternative for the surgical SNB procedure.

TRIAL REGISTRATION

The GULF trial is registered in the Netherlands Trial Registry (NTR), ID: NRT5193 . May 1st 2015.

Implementation of the 7th edition AJCC staging system: Effects on staging and survival for pT1 melanoma. A Dutch population based study

In the 7^th edition of the AJCC staging system, the mitotic rate criterion replaced Clark level to increase correct classification of high-risk thin melanoma patients (pT1B). Additionally, sentinel node biopsy (SNB) was recommended for nodal staging of pT1B melanomas. The aim of this article was to evaluate the effects on pT1 substaging and clinical implications in the national pT1 melanoma population. All pT1 melanomas diagnosed in the Netherlands between 2003 and 2014 were selected from the Netherlands Cancer Registry (IKNL). Patients were stratified by cohort according to AJCC edition: (1) 2003-2009 (6^th ) and (2) 2010-2014 (7^th ). Relative survival was calculated to estimate melanoma-specific survival. A total of 29.546 pT1 melanoma patients were included. The pT1b proportion increased from 10.1% in Cohort 1 to 21.5% in Cohort 2. The proportion of performed SNBs per cohort increased: for pT1b melanomas alone from 4.5% to 13.0%. SNB positivity rate decreased from 10.5% to 8.8% for the entire pT1 population, and for pT1b melanomas from 11.3% to 8.6%. At 5 years, the relative survival rate was similar for pT1a and pT1b in both cohorts, namely, pT1a 100% vs pT1b 97% (Cohort 1), and pT1a 100% vs pT1b 98% (Cohort 2). The 7^th edition of the AJCC staging system has caused an increased number of patients to undergo SNB, without an increase in SNB positivity rate. Survival between pT1 subgroups remains similar. The mitotic rate criterion for pT1b classification and the recommendation to perform SNB for pT1b melanomas should be reconsidered.

Sentinel lymph node biopsy in early melanoma-comparison of two techniques for sentinel removal

BACKGROUND

Sentinel lymph node biopsy is an established technique for melanoma staging.

OBJECTIVE

There are no studies available comparing different techniques for the removal of sentinel lymph nodes related to safety and postsurgical complication rate.

METHODS

This is a retrospective single-center trial. We analyzed the postsurgical complications in 201 consecutive melanoma patients with ligature of lymphatic vessels by sutures (group A) and in 91 consecutive patients with occlusion of lymphatic vessels by bipolar tweezers (group B). We paid particular attention to complications related to disturbed lymphatic function, such as lymph edema, lymphatic fistula, and seroma.

RESULTS

The complication rate was 5.5 % (group A) and 9.6 % (group B) which is in the range of other published trials (p = 0.89). There was no increase of complications related to lymphatic vessels in group B, although the rate of patients with more than two sentinel lymph nodes removed was 5‑times higher than in group A.

CONCLUSIONS

Removal of sentinel lymph nodes with the use of bipolar tweezers does not increase the risk of postsurgical complications, and in particular it is not associated with a higher rate of complications related to lymphatic vessel dysfunction.

Analysis of melanoma recurrence following a negative sentinel lymph node biopsy

Little attention has been paid to the characteristics and outcomes of patients who experience distant, local or regional recurrence of melanoma following a negative sentinel lymph node biopsy. This article aims to review the published literature on the topic and presents some general summaries regarding this patient population. Patients who experience a disease recurrence following a negative sentinel lymph node biopsy have a worse overall survival compared with patients with a positive sentinel lymph node biopsy. The implications and possible explanations for these findings are discussed in order to both underscore the need for in-depth investigation of local, regional or distant melanoma recurrence among patients following a true negative sentinel lymph node biopsy, as well as increased efforts to minimize the rate of false negative sentinel lymph node biopsies.

[Sentinel lymph node biopsy in melanoma: our experience over 8 years in a universitary hospital]

BACKGROUND

Since the introduction of sentinel lymph node biopsy, its use as a standard of care for patients with clinically node-negative cutaneous melanoma remains controversial. Our experience of sentinel lymph node biopsy for melanoma is presented and evaluated.

MATERIAL AND METHODS

A cohort study was conducted on 69 patients with a primary cutaneous melanoma and with no clinical evidence of metastasis, who had sentinel lymph node biopsy from October-2005 to December-2013. Sentinel lymph node biopsy was identified using preoperative lymphoscintigraphy and subsequent intraoperative detection with gamma probe.

RESULTS

The sentinel lymph node biopsy identification rate was 98.5%. The sentinel lymph node biopsy was positive for metastases in 23 patients (33.8%). Postoperative complications after sentinel lymph node biopsy were observed in 4.4% compared to 38% of complications in patients who had complete lymphadenectomy.

CONCLUSION

The sentinel lymph node biopsy in melanoma offers useful information about the lymphatic dissemination of melanoma and allows an approximation to the regional staging, sparing the secondary effects of lymphadenectomy. More studies with larger number of patients and long term follow-up will be necessary to confirm the validity of sentinel lymph node biopsy in melanoma patients, and especially of lymphadenectomy in patients with positive sentinel lymph node biopsy.

Ultrasound-guided fine needle aspiration cytology as an addendum to sentinel lymph node biopsy can perfect the staging strategy in melanoma patients

BACKGROUND

Ultrasound guided fine needle aspiration cytology (US-guided FNAC) can identify microscopic involvement of lymph nodes as in breast cancer and avoid surgical sentinel node (SN). Its utility in melanoma patients is controversial and subject of this study.

METHODS

Between 2001 and 2010 over 1000 stage I/II consecutive melanoma patients prospectively underwent US-FNAC prior to SN biopsy. All patients underwent lymphoscintigraphy prior to US-FNAC. The Berlin US morphology criteria: Peripheral perfusion (PP), loss of central echoes (LCE) and balloon shaped (BS) were registered. FNAC was performed in case of presence of any of these factors. SN tumour burden was measured according to the Rotterdam criteria. All patients underwent SN or lymph node dissection (LND) in case of positive FNAC.

FINDINGS

Mean/median Breslow thickness was 2.58/1.57 mm. Mean/median follow-up was 56/53 months (1-132). SN positivity rate was 21%. US-FNAC Sensitivity was 71% (US only) and 51% (US-FNAC). Sensitivity of US-FNAC was highest for T4 (76%) and ulcerated melanomas (63%). PP, LCE and BS had sensitivity of 69%, 24% and 24% respectively. Sensitivity of US-FNAC increased with increasing SN tumour burden. PP was an early sign of metastasis (58% in <0.1mm metastases). Threshold size of a metastasis for FNAC was 0.3mm. Five-year survival correlated to US-FNAC status (95% in negative and 59% in positive).

INTERPRETATION

Ultrasound guided FNAC (US-FNAC) according to the Berlin morphology criteria could correctly identify at least half of all tumour positive sentinel nodes, prior to the surgical SN procedure. Peripheral perfusion is an early sign of metastasis, which is very sensitive, but with lower positive predictive value (PPV). It is responsible for the sensitivity of the procedure. Balloon shape is a sign of advanced metastases, with lower sensitivity, but high PPV. US-FNAC sensitivity correlated with increasing T-stage, ulceration of the primary and increasing SN tumour burden. US-FNAC status accurately predicts survival.