Clinicopathologic predictors of sentinel lymph node metastasis in thin melanoma

Influence of regression, its extent and tumor-infiltrating lymphocytes on sentinel node status, relapse, and survival in a 10-year retrospective study of melanoma patients

This case-control study seeks to investigate the influence of histological findings, specifically regression, its extent and tumor-infiltrating lymphocyte (TILs), on result of sentinel lymph node (SLN) biopsy, 5-year melanoma-specific survival (MSS), and relapse-free survival (RFS). We included all patients with cutaneous melanoma who underwent SLN biopsy at the Melanoma Center of the University of Brescia, following the Italian Association of Medical Oncology National guidelines from January 2008 to August 2018. Regression and its extent (<75 or ≥75%) and the presence of TILs were reevaluated by a trained dermatopathologist, adhering to the 2017 College of American Pathologists Cancer Protocol for Skin Melanoma. These patients were followed up for 5 years. Our study uncovered significant associations between regression and male sex ( P  < 0.05), melanoma location on the trunk, upper limbs, and back ( P  = 0.001), ulceration ( P  < 0.05), lower Breslow thickness ( P  = 0.001), and the presence of lymphocytic infiltration (both brisk and nonbrisk) ( P  < 0.001). Regression and its extent, however, did not appear to affect SLN positivity ( P  = 0.315). Similarly, our data did not reveal a correlation between TILs and result of SLN biopsy ( P  = 0.256). When analyzing MSS and RFS in relation to the presence or absence of regression and TILs, no statistically significant differences were observed, thus precluding the need for logistic regression and Kaplan-Meier curve analysis. This study's findings underscore that regression and TILs do not appear to exert an influence on sentinel lymph node status,, MSS, or RFS in our cohort of patients.

Predictors of sentinel lymph node metastasis in very thin invasive melanomas

BACKGROUND

Melanomas < 0.8 mm in Breslow depth have less than a 5% risk for nodal positivity. Nonetheless, nodal positivity is prognostic for this group. Early identification of nodal positivity may improve the outcomes for these patients.

OBJECTIVES

To determine the degree to which ulceration and other high-risk features predict sentinel lymph node (SLN) positivity for very thin melanomas.

METHODS

The National Cancer Database was reviewed from 2012 to 2018 for patients with melanoma with Breslow thickness < 0.8 mm. Data were analysed from 7 July 2022 through to 25 February 2023. Patients were excluded if data regarding their ulceration status or SLN biopsy (SLNB) performance were unknown. We analysed patient, tumour and health system factors for their effect on SLN positivity. Data were analysed using χ2 tests and logistic regressions. Overall survival (OS) was compared by Kaplan-Meier analyses.

RESULTS

Positive nodal metastases were seen in 876 (5.0%) patients who underwent SLNB (17 692). Factors significantly associated with nodal positivity on multivariable analysis include lymphovascular invasion [odds ratio (OR) 4.5, P < 0.001], ulceration (OR 2.6, P < 0.001), mitoses (OR 2.1, P < 0.001) and nodular subtype (OR 2.1, P < 0.001). Five-year OS was 75% and 92% for patients with positive and negative SLN, respectively.

CONCLUSIONS

Nodal positivity has prognostic significance for very thin melanomas. In our cohort, the rate of nodal positivity was 5% overall in these patients who underwent SLNB. Specific tumour factors (e.g. lymphovascular invasion, ulceration, mitoses, nodular subtype) were associated with higher rates of SLN metastases and should be used to guide clinicians in choosing which patients will benefit from SLNB.

A Clinical Decision Tool to Calculate Pretest Probability of Sentinel Lymph Node Metastasis in Primary Cutaneous Melanoma

BACKGROUND

Although sentinel lymph node biopsy (SLNB) status is a strong prognostic indicator for cutaneous melanoma, unnecessary SLNBs have substantial cost and morbidity burden.

OBJECTIVE

This study was designed to develop, validate, and present a personalized, clinical, decision-making tool using nationally representative data with clinically actionable probability thresholds (Expected Lymphatic Metastasis Outcome [ELMO]).

METHODS

Data from the Surveillance, Epidemiology, and End Results (SEER) Registry from 2000 to 2017 and the National Cancer Database (NCDB) from 2004 to 2015 were used to develop and internally validate a logistic ridge regression predictive model for SLNB positivity. External validation was done with 1568 patients at a large tertiary referral center.

RESULTS

The development cohort included 134,809 patients, and the internal validation cohort included 38,518 patients. ELMO (AUC 0.85) resulted in a 29.54% SLNB reduction rate and greater sensitivity in predicting SLNB status for T1b, T2a, and T2b tumors than previous models. In external validation, ELMO had an accuracy of 0.7586 and AUC of 0.7218. Limitations of this study are potential miscoding, unaccounted confounders, and effect modification.

CONCLUSIONS

ELMO ( https://melanoma-sentinel.herokuapp.com/ ) has been developed and validated (internally and externally) by using the largest publicly available dataset of melanoma patients and was found to have high accuracy compared with other published models and gene expression tests. Individualized risk estimates for SLNB positivity are critical in facilitating thorough decision-making for healthcare providers and patients with melanoma.

99mTc-Rituximab sentinel lymph node mapping and biopsy, the effective technique avoids axillary dissection and predicts prognosis in 533 cutaneous melanoma

OBJECTIVE

To evaluate the efficiency of a novel lymph node radiotracer ^99mTc-rituximab in sentinel lymph node (SLN) lymphoscintigraphy and SLN biopsy (SLNB), and the influence of SLNB results on the prognosis of cutaneous malignant melanoma (CMM) patients.

METHODS

A retrospective study was performed on 533 patients with CMM who underwent lymphoscintigraphy and SLNB. All patients received a preoperative peritumoral injection of 11.1-18.5 MBq of ^99mTc-rituximab 0.5 to 1 h before lymphoscintigraphy and SLNB.

RESULTS

The detection rate of lymphoscintigraphy and SLNB was both 99.81% (532/533), and the average number of detected SLNs was 2.1 (range 1 to 8) and 2.7 (range 1 to 11) per patient, respectively. 12.1% SLNs and 22.2% patients were found metastatic, with an average of 1.5 (range 1 to 5) metastatic SLNs per patient. The SLN metastatic rates were different in patients with different Breslow thickness, Clark levels, ulceration, mitotic counts, and HMB45 expression (p < 0.05). Ninety patients were proceeded with the regional lymph node dissection (RLND) after SLNB, and the sensitivity, specificity and accuracy of SLNB in metastatic diagnosis is 97.4, 100 and 96.7%, respectively. And SLNs with metastases was an independent prognostic factor for OS and PFS by multivariate prognostic analyses (HR was 5.9 and 4.3, p < 0.001). For patients with metastatic SLNs, the non-SLNs with metastasis and non-SLNs without metastasis in RLND, and observation groups showed different mean PFS as 14.9, 24.8 and 25.5 months (p = 0.018), but no statistically significant difference existed in the OS.

CONCLUSION

The novel radiotracer ^99mTc-rituximab could identify SLNs specifically in SLN lymphoscintigraphy and SLNB in CMM patients, and the pathology obtained from SLNB rather than from RLND better indicated the staging and long-term prognosis.

The Evolution of the Sentinel Node Biopsy in Melanoma

The growing repertoire of approved immune-checkpoint inhibitors and targeted therapy has revolutionized the adjuvant treatment of melanoma. While the treatment of primary cutaneous melanoma remains wide local excision (WLE), the management of regional lymph nodes continues to evolve in light of practice-changing clinical trials and dramatically improved adjuvant therapy. With large multicenter studies reporting no benefit in overall survival for completion lymph node dissection (CLND) after a positive sentinel node biopsy (SLNB), controversy remains regarding patient selection and clinical decision-making. This review explores the evolution of the SLNB in cutaneous melanoma in the context of a rapidly changing adjuvant treatment landscape, summarizing the key clinical trials which shaped current practice guidelines.

Identifying the Transcriptional Drivers of Metastasis Embedded within Localized Melanoma

In melanoma, predicting which tumors will ultimately metastasize guides treatment decisions. Transcriptional signatures of primary tumors have been utilized to predict metastasis, but which among these are driver or passenger events remains unclear. We used data from the adjuvant AVAST-M trial to identify a predictive gene signature in localized tumors that ultimately metastasized. Using a zebrafish model of primary melanoma, we interrogated the top genes from the AVAST-M signature in vivo. This identified GRAMD1B, a cholesterol transfer protein, as a bona fide metastasis suppressor, with a majority of knockout animals rapidly developing metastasis. Mechanistically, excess free cholesterol or its metabolite 27-hydroxycholesterol promotes invasiveness via activation of an AP-1 program, which is associated with increased metastasis in humans. Our data demonstrate that the transcriptional seeds of metastasis are embedded within localized tumors, suggesting that early targeting of these programs can be used to prevent metastatic relapse.

SIGNIFICANCE

We analyzed human melanoma transcriptomics data to identify a gene signature predictive of metastasis. To rapidly test clinical signatures, we built a genetic metastasis platform in adult zebrafish and identified GRAMD1B as a suppressor of melanoma metastasis. GRAMD1B-associated cholesterol overload activates an AP-1 program to promote melanoma invasion. This article is highlighted in the In This Issue feature, p. 1.

Timing and necessity of staging imaging in clinical stage II cutaneous melanoma: Cost-effectiveness and clinical decision analysis

BACKGROUND

Preoperative imaging in clinical stage II melanoma is not indicated per National Comprehensive Cancer Network (NCCN) guidelines but remains common in clinical practice.

METHODS

Patients presenting with cutaneous clinical stage II melanoma from 2007 to 2019 were retrospectively reviewed. A clinical decision analysis with cost data was designed to understand ideal practice patterns in managing stage II melanoma, with pre-versus selective post-operative imaging as the initial decision node.

RESULTS

There were 277 subjects included, and 143 underwent preoperative imaging (49.5%). This changed management (i.e. no surgery) in one patient (0.4%). Overall, 16 patients had additional findings on imaging (5.8%). Upfront surgery with selective postoperative imaging was a more cost-effective strategy than routine performance of preoperative imaging, with savings of $1677 per patient.

CONCLUSION

Preoperative imaging is a low yield, costly approach for patients with clinical stage II melanoma with minimal impact on the decision to proceed with surgical management.

Surgical Management of Melanoma: Advances and Updates

PURPOSE OF REVIEW

To review and update surgeons about the evolving complexities in the surgical management of melanoma including lymph node staging and treatment.

RECENT FINDINGS

Primary resection with adequate margins continues to be the standard of care for localized cutaneous melanoma. Sentinel lymph node biopsy is confirmed to be a powerful tool due to its prognostic value and informative guidance for adjuvant treatments and surveillance. Due to the lack of benefit in melanoma-specific survival and distant metastasis-free survival, completion lymph node dissection is not performed routinely after a positive sentinel lymph node biopsy. Neoadjuvant systemic treatment approaches for advanced loco-regional disease show promise in phase I and II clinical trial data, and phase III studies. The surgical management of cutaneous melanoma continues to evolve with further de-escalation of the extent of excision of primary melanomas and the management of lymph node disease.

Melanoma: An immunotherapy journey from bench to bedside

Melanoma gave science a window into the role immune evasion plays in the development of malignancy. The entire spectrum of immune focused anti-cancer therapies has been subjected to clinical trials in this disease, with limited success until the immune checkpoint blockade era. That revolution launched first in melanoma, heralded a landscape change throughout cancer that continues to reverberate today.

Establishing a Prognostic Model Based on Ulceration and Immune Related Genes in Melanoma Patients and Identification of EIF3B as a Therapeutic Target

Ulceration and immune status are independent prognostic factors for survival in melanoma patients. Herein univariate Cox regression analysis revealed 53 ulcer-immunity-related DEGs. We performed consensus clustering to divide The Cancer Genome Atlas (TCGA) cohort (n = 467) into three subtypes with different prognosis and biological functions, followed by validation in three merged Gene Expression Omnibus (GEO) cohorts (n = 399). Multiomics approach was used to assess differences among the subtypes. Cluster 3 showed relatively lesser amplification and expression of immune checkpoint genes. Moreover, Cluster 3 lacked immune-related pathways and immune cell infiltration, and had higher proportion of non-responders to immunotherapy. We also constructed a prognostic model based on ulceration and immune related genes in melanoma. EIF3B was a hub gene in the intersection between genes specific to Cluster 3 and those pivotal for melanoma growth (DepMap, https://depmap.org/portal/download/). High EIF3B expression in TCGA and GEO datasets was related to worst prognosis. In vitro models revealed that EIF3B knockdown inhibited melanoma cell migration and invasion, and decreased TGF-β1 level in supernatant compared with si-NC cells. EIF3B expression was negatively correlated with immune-related signaling pathways, immune cell gene signatures, and immune checkpoint gene expression. Moreover, its low expression could predict partial response to anti-PD-1 immunotherapy. To summarize, we established a prognostic model for melanoma and identified the role of EIF3B in melanoma progression and immunotherapy resistance development.

Classification and Staging of Melanoma in the Head and Neck

The rates of melanoma continue to rise, with recent estimates have shown that 18% to 22% of new melanoma cases occur within the head and neck in the United States each year. The mainstay of treatment of nonmetastatic primary melanomas of the head and neck includes the surgical resection and management of regional disease as indicated. Thorough knowledge of the classification and staging of melanoma is paramount to evaluate prognosis, determine the appropriate surgical intervention, and assess eligibility for adjuvant therapy and clinic trials. The traditional clinicopathologic classification of melanoma is based on morphologic aspects of the growth phase and distinguishes 4 of the most common subtypes as defined by the World Health Organization: superficial spreading, nodular, acral lentiginous, and lentigo maligna melanoma. The data used to derive the AJCC TNM Categories are based on superficial spreading melanoma and nodular subtypes. Melanoma is diagnosed histopathologically following initial biopsy that will assist with classifying the tumor to guide treatment. Classification is based on tumor thickness and ulceration (T stage, Breslow Staging), Regional Lymph Node Involvement (N Stage), and presence of metastasis (M Stage). Tumor thickness (Breslow thickness) and ulceration are 2 independent prognostic factors that have been shown to be the strongest predictors of survival and outcome. Clark level of invasion and mitotic rate are no longer incorporated into the current AJCC staging system, but still have shown to be important prognostic factors for cutaneous melanoma. For patients with metastatic (Stage IV) disease Lactate Dehydrogenase remains an independent predictor of survival. The Maxillofacial surgeon must remain up to date on the most current management strategies in this patient population. Classification systems and staging provide the foundation for clinical decision making and prognostication for the Maxillofacial surgeon when caring for these patients.

Predictive Values of Pathological and Clinical Risk Factors for Positivity of Sentinel Lymph Node Biopsy in Thin Melanoma: A Systematic Review and Meta-Analysis

Background

The indications for sentinel lymph node biopsy (SLNB) for thin melanoma are still unclear. This meta-analysis aims to determine the positive rate of SLNB in thin melanoma and to summarize the predictive value of different high-risk features for positive results of SLNB.

Methods

Four databases were searched for literature on SLNB performed in patients with thin melanoma published between January 2000 and December 2020. The overall positive rate and positive rate of each high-risk feature were calculated and obtained with 95% confidence intervals (CIs). Both unadjusted odds ratios (ORs) and adjusted ORs (AORs) of high-risk features were analyzed. Pooled effects were estimated using random-effects model meta-analyses.

Results

Sixty-six studies reporting 38,844 patients with thin melanoma who underwent SLNB met the inclusion criteria. The pooled positive rate of SLNB was 5.1% [95% confidence interval (CI) 4.9%-5.3%]. Features significantly predicted a positive result of SLNB were thickness≥0.8 mm [AOR 1.94 (95%CI 1.28-2.95); positive rate 7.0% (95%CI 6.0-8.0%)]; ulceration [AOR 3.09 (95%CI 1.75-5.44); positive rate 4.2% (95%CI 1.8-7.2%)]; mitosis rate >0/mm2 [AOR 1.63 (95%CI 1.13-2.36); positive rate 7.7% (95%CI 6.3-9.1%)]; microsatellites [OR 3.8 (95%CI 1.38-10.47); positive rate 16.6% (95%CI 2.4-36.6%)]; and vertical growth phase [OR 2.76 (95%CI 1.72-4.43); positive rate 8.1% (95%CI 6.3-10.1%)].

Conclusions

The overall positive rate of SLNB in thin melanoma was 5.1%. The strongest predictor for SLN positivity identified was microsatellites on unadjusted analysis and ulceration on adjusted analysis. Breslow thickness ≥0.8 mm and mitosis rate >0/mm² both predict SLN positivity in adjusted analysis and increase the positive rate to 7.0% and 7.7%. We suggest patients with thin melanoma with the above high-risk features should be considered for giving an SLNB.

The Impact of Hyaluronan on Tumor Progression in Cutaneous Melanoma

The incidence of cutaneous melanoma is rapidly increasing worldwide. Cutaneous melanoma is an aggressive type of skin cancer, which originates from malignant transformation of pigment producing melanocytes. The main risk factor for melanoma is ultraviolet (UV) radiation, and thus it often arises from highly sun-exposed skin areas and is characterized by a high mutational burden. In addition to melanoma-associated mutations such as BRAF, NRAS, PTEN and cell cycle regulators, the expansion of melanoma is affected by the extracellular matrix surrounding the tumor together with immune cells. In the early phases of the disease, hyaluronan is the major matrix component in cutaneous melanoma microenvironment. It is a high-molecular weight polysaccharide involved in several physiological and pathological processes. Hyaluronan is involved in the inflammatory reactions associated with UV radiation but its role in melanomagenesis is still unclear. Although abundant hyaluronan surrounds epidermal and dermal cells in normal skin and benign nevi, its content is further elevated in dysplastic lesions and local tumors. At this stage hyaluronan matrix may act as a protective barrier against melanoma progression, or alternatively against immune cell attack. While in advanced melanoma, the content of hyaluronan decreases due to altered synthesis and degradation, and this correlates with poor prognosis. This review focuses on hyaluronan matrix in cutaneous melanoma and how the changes in hyaluronan metabolism affect the progression of melanoma.

Sentinel Lymph Node Biopsy vs. Observation in Thin Melanoma: A Multicenter Propensity Score Matching Study

The therapeutic value of sentinel lymph node biopsy (SLNB) in thin melanoma remains controversial. The aim of this study is to determine the role of SLNB in the survival of thin melanomas (≤1 mm). A multicenter retrospective observational study was designed. A propensity score matching was performed to compare patients who underwent SLNB vs. observation. A multivariate Cox regression was used. A total of 1438 patients were matched by propensity score. There were no significant differences in melanoma-specific survival (MSS) between the SLNB and observation groups. Predictors of MSS in the multivariate model were age, tumor thickness, ulceration, and interferon treatment. Results were similar for disease-free survival and overall survival. The 5- and 10-year MSS rates for SLN-negative and -positive patients were 98.5% vs. 77.3% (p < 0.001) and 97.3% vs. 68.7% (p < 0.001), respectively. SLNB does not improve MSS in patients with thin melanoma. It also had no impact on DSF or OS. However, a considerable difference in MSS, DFS, and OS between SLN-positive and -negative patients exists, confirming its value as a prognostic procedure and therefore we recommend discussing the option of SLNB with patients.

Volar location and degree of pigmentation are associated with poor survival and first metastasis pattern in acral melanoma

The risk factors affecting acral melanoma metastasis and prognosis remain unclear. The study included 168 patients with invasive acral melanoma who were followed for ≥3 years. We evaluated patient demographics, stages, clinicopathological features, anatomic site of melanoma including nail versus volar surface, and degree of melanoma pigmentations, sentinel lymph node biopsy results, and the first metastasis sites. Of the 168 patients (mean age 64.5 years; 52.4% male), 43 (25.6%) had invasive melanoma without metastasis, 113 (67.3%) had invasive melanoma with a first lymph node metastasis, and 12 (7.1%) had invasive melanoma with invasive melanoma with a first distant metastasis. Advanced T stage, high mitotic rate, ulceration, and the degree of pigmentation were significant risk factors for metastasis. Amelanotic and mild pigmentation of acral melanoma was associated with first distant metastasis, whereas heavy pigmentation was associated with first lymph node metastasis. Advanced TNM stages, high mitotic rate, volar location (hazard ratio = 2.24, 95% confidence interval 1.18-4.26), and low-pigmentation (hazard ratio = 2.02, 95% confidence interval 1.17-3.49) were associated with melanoma-specific mortality.

More sentinel lymph node biopsies for thin melanomas after transition to AJCC 8th edition do not increase positivity rate: A Danish population-based study of 7148 patients

BACKGROUND

We evaluated the outcome of sentinel lymph node biopsies (SLNB) in patients with thin melanoma before and after the implementation of AJCC 8th edition (AJCC8) and identified predictors of positive sentinel lymph nodes (+SLN).

METHODS

Patients diagnosed with T1 melanomas (Breslow thickness ≤1 mm) during 2016-2017 as per AJCC 7th edition (AJCC7) (n = 3414) and 2018-2019 as per AJCC8 (n = 3734) were identified in the Danish Melanoma Database.

RESULTS

More SLNBs were performed in the AJCC8 cohort compared to the AJCC7 (22.2% vs. 16.2%, p < 0.001), with no significant difference in +SLN rates (4.7% vs. 6.7%, p = 0.118). In the AJCC7 + SLN subgroup, no melanomas were ulcerated, 94.6% had mitotic rate (MR) ≥ 1, 67.6% were ≥0.8 mm and 32.4% would be T1a according to AJCC8. In the AJCC8 + SLN subgroup, 10.3% were ulcerated, 74.4% had MR≥ 1, 97.4% were ≥0.8 mm and 23.1% would be T1a according to AJCC7. On multivariable analysis younger age and MR ≥ 1 were significant predictors of +SLN.

CONCLUSION

More SLNBs were performed in T1 melanomas after transition to AJCC8 without an increase in +SLN rate. None of the AJCC8 T1b criteria were significant predictors of +SLN. We suggest that mitosis and younger age should be considered as indications for SLNB in thin melanoma.

Integrating 31-Gene Expression Profiling With Clinicopathologic Features to Optimize Cutaneous Melanoma Sentinel Lymph Node Metastasis Prediction

National guidelines recommend sentinel lymph node biopsy (SLNB) be offered to patients with > 10% likelihood of sentinel lymph node (SLN) positivity. On the other hand, guidelines do not recommend SLNB for patients with T1a tumors without high-risk features who have < 5% likelihood of a positive SLN. However, the decision to perform SLNB is less certain for patients with higher-risk T1 melanomas in which a positive node is expected 5%-10% of the time. We hypothesized that integrating clinicopathologic features with the 31-gene expression profile (31-GEP) score using advanced artificial intelligence techniques would provide more precise SLN risk prediction.

TERT Promoter Mutational Status in the Management of Cutaneous Melanoma: Comparison with Sentinel Lymph Node Biopsy

BACKGROUND

While BRAF mutations seem important for early melanomagenesis, mutations in the TERT promoter (TERTp) are related to metastasis. Yet, in conventional melanoma management, risk stratification does not depend on molecular biomarkers that can indicate the stage of progression, but rather on clinical, pathological, sentinel lymph node (SLN), and radiologic evaluation. The aim of this work was to evaluate the frequency and prognostic impact of TERTp mutations, comparing their predictive value to those of conventional procedures in melanoma management.

METHODS

Mutational analysis of a series of 91 cases was performed. The correlations between TERTp and BRAF mutational status and clinicopathological features were assessed.

RESULTS

The mutation rate was 33% for TERTp and 30% for BRAF. There was 68% concordance between primary and metastatic samples for TERTp mutations and 92% for BRAF mutations. TERTp mutations are significantly associated with the presence of BRAF mutations, features of worse prognosis, and a reduced disease-free survival. Also, TERTp mutational status was similar to SLN biopsy as a predictive factor of cutaneous melanoma recurrence and metastasis.

CONCLUSIONS

The predictive value of TERTp mutations may be similar to that of SLN biopsy and its integration in the management algorithm of melanoma patients should be considered.

American Joint Committee on Cancer Staging and Other Platforms to Assess Prognosis and Risk

The eighth edition of the American Joint Committee on Cancer melanoma staging system relies on assessments of the primary tumor (T), regional lymph nodes (N), and distant metastatic sites (M). Its notable updates include tumor thickness measurements to the nearest 0.1 mm, revision of T1a and T1b definitions, re-evaluation of N category descriptors, increased number of stage III subgroupings, and incorporation of a new M1d designation, among others. These changes were based on analyses of a large contemporary international melanoma database. Ultimately, these revisions were made to improve staging and prognostication, risk stratification, and selection of patients for clinical trials.

Sentinel Lymph Node Biopsy: Indications and Technique

Sentinel lymph node biopsy is a key tool in the care of many patients with melanoma. The indications for the procedure have gradually become clearer over the 3 decades since the technique was developed. For appropriately selected patients, it carries enormous significance. Although it is a minimally invasive procedure, it does carry some risk. It is also a multidisciplinary procedure, requiring knowledge and experience from several specialties including nuclear medicine, surgery, and pathology.

Compliance with sentinel lymph node biopsy guidelines for invasive melanomas treated with Mohs micrographic surgery

BACKGROUND

Sentinel lymph node biopsy (SLNB) has not been studied for invasive melanomas treated with Mohs micrographic surgery using frozen-section MART-1 immunohistochemical stains (MMS-IHC). The primary objective of this study was to assess the accuracy and compliance with National Comprehensive Cancer Network (NCCN) guidelines for SLNB in a cohort of patients who had invasive melanoma treated with MMS-IHC.

METHODS

This retrospective cohort study included all patients who had primary, invasive, cutaneous melanomas treated with MMS-IHC at a single academic center between March 2006 and April 2018. The primary outcomes were the rates of documenting discussion and performing SLNB in patients who were eligible based on NCCN guidelines. Secondary outcomes were the rate of identifying the sentinel lymph node and the percentage of positive lymph nodes.

RESULTS

In total, 667 primary, invasive, cutaneous melanomas (American Joint Committee on Cancer T1a-T4b) were treated with MMS-IHC. The median patient age was 69 years (range, 25-101 years). Ninety-two percent of tumors were located on specialty sites (head and/or neck, hands and/or feet, pretibial leg). Discussion of SLNB was documented for 162 of 176 (92%) SLNB-eligible patients, including 127 of 127 (100%) who had melanomas with a Breslow depth >1 mm. SLNB was performed in 109 of 176 (62%) SLNB-eligible patients, including 102 of 158 melanomas (65%) that met NCCN criteria to discuss and offer SLNB and 7 of 18 melanomas (39%) that met criteria to discuss and consider SLNB. The sentinel lymph node was successfully identified in 98 of 109 patients (90%) and was positive in 6 of those 98 patients (6%).

CONCLUSIONS

Combining SLNB and MMS-IHC allows full pathologic staging and confirmation of clear microscopic margins before reconstruction of specialty site invasive melanomas. SLNB can be performed accurately and in compliance with consensus guidelines in patients with melanoma using MMS-IHC.

Fortuitous discovery of melanomas in the ENT Department - a histopathological and immunohistochemical study

The melanoma, having its origin in the melanocyte cells, is one of the most aggressive forms of skin cancer in the world with one of the highest rates of brain metastasis. The incidence of cutaneous melanoma in the Mediterranean countries varies from three to five cases/100 000 people/year. Its prognosis is based on an early diagnosis. Sinonasal mucosal melanoma (SNMM) is an extremely rare tumor, accounting for 0.3–2% of all melanomas. The non-specific symptomatology is often delaying the presentation of the patient at the hospital and therefore the diagnosis. The SNMM is a highly aggressive tumor, and the presence of metastasis at the diagnosis usually implies a poor prognosis. The management of the melanomas requires a precise pre-therapeutic assessment and a multidisciplinary approach for the diagnosis, with surgical treatment or radiotherapy required in order to ensure a better a quality of life. In this paper, we retrospectively analyzed two cases of mucosal melanoma and one case of cutaneous melanoma of the nose.

Regression is significantly associated with outcomes for patients with melanoma

BACKGROUND

The prognostic significance of regression in melanoma is debated. We present a large multicenter study correlating regression with sentinel lymph node metastasis and melanoma-specific survival.

METHODS

The Sentinel Lymph Node Working Group database was reviewed from 1993 to 2018. Patients with known regression and sentinel lymph node status were included. Clinicopathologic factors were correlated with regression, sentinel lymph node status, and melanoma-specific survival.

RESULTS

There were 4,790 patients; median follow-up was 39.6 months. Regression was present in 1,081 (22.6%) cases, and 798 (16.7%) patients had sentinel lymph node metastases. On multivariable analysis, male sex, truncal tumors, and decreasing thickness were significantly associated with regression (P < .05), whereas head/neck or leg tumors had lower rates of regression (P < .05). Regression was significantly correlated with a decreased risk of sentinel lymph node disease on multivariable analysis (odds ratio 0.68, 95% confidence interval 0.54-0.85; P = .0008). Multivariable analysis also showed that increasing age, male sex, increasing thickness, ulceration, lymphovascular invasion, microsatellitosis, and sentinel lymph node metastasis were significantly (P < .05) associated with worse melanoma-specific survival, while regression was significantly associated with better melanoma-specific survival (hazard ratio 0.75, 95% confidence interval 0.57-0.99; P = .043).

CONCLUSION

This large study shows that regression is significantly associated with better outcomes in patients with melanoma and is correlated with a lower risk of sentinel lymph node metastasis and a better melanoma-specific survival.

Sentinel lymph node biopsy in melanoma: beyond histologic factors

Sentinel lymph node (SLN) biopsy should be performed with the technical expertise required to correctly identify the sentinel node, in the context of understanding both the likelihood of positivity in a given patient and the prognostic significance of a positive or negative result. National Comprehensive Cancer Network guidelines recommend SLN biopsy for all cutaneous melanoma patients with primary tumor thickness greater than 1 mm and in select patients with thickness between 0.8 and 1 mm, yet admit a lack of consistent clarity in its utility for prognosis and therapeutic value in tumors < 1 mm and leave the decision for undergoing the procedure up to the patient and treating physician. Recent studies have evaluated specific patient populations, tumor histopathologic characteristics, and gene expression profiling and their use in predicting SLN positivity. These data have given insight into improving the physician's ability to potentially predict SLN positivity, shedding light on if and when omission of SLN biopsy in specific patients based on clinicopathological characteristics might be appropriate. This review provides discussion and insight into these recent advancements.

Use and Costs of Sentinel Lymph Node Biopsy in Non-Ulcerated T1b Melanoma: Analysis of a Population-Based Registry

BACKGROUND

The utility of sentinel lymph node biopsy (SLNB) for non-ulcerated T1b melanoma is debated and associated costs are poorly characterized. Prior work using institutional registries may overestimate the incidence of nodal positivity in this population.

OBJECTIVE

The aim of this study was to estimate the use of SLNB, positivity prevalence, and procedural costs in patients with non-ulcerated T1b melanoma using a population-based registry.

METHODS

We identified patients with clinically node-negative, non-ulcerated melanoma 0.8-1.0 mm thick (T1b according to the 8th edition standard of the American Joint Committee on Cancer) in the Surveillance, Epidemiology, and End Results database from 2010 to 2016. The prevalence of SLNB procedures and positive sentinel nodes were calculated. Factors associated with SLNB and sentinel node positivity were assessed using logistic regression. Medicare reimbursement costs and patient out-of-pocket expenses for SLNB and wide local excision (WLE) versus WLE alone were estimated.

RESULTS

Among 7245 included patients, 3835(53%) underwent SLNB, 156 (4.1%, 95% confidence interval 3.5-4.7) of whom had a positive SLNB. Younger age, >1 mitosis per mm², female sex, and truncal tumor location were associated with higher odds of positivity. The estimated SLNB cost to identify one patient with stage III disease was $71,700 (range $54,648-$83,172). Out-of-pocket expenses for a Medicare patient were estimated to be $652 for a WLE and SLNB and $79 for a WLE alone.

CONCLUSIONS

In this population-based study, only 4% of selected non-ulcerated T1b patients had a positive SLNB, which is lower than prior reports. At the population level, SLNB is associated with high costs per prognostic information gained.

The role of FDG-PET-CT is limited in initial staging of nodal metastasis for thin cutaneous melanoma

INTRODUCTION

Positron emission tomography computed tomography (PET-CT) is often used to stage nodal metastases in thin cutaneous melanoma, with limited evidence.

METHODS

A retrospective review of patients with cutaneous malignant melanoma treated at our institution was performed from 2005 to 2015, identifying those who received a PET-CT prior to lymphadenectomy. Biopsy features, lymph node status, and PET-CT results were collected. We calculated the overall sensitivity, specificity, accuracy, likelihood ratios, and positive predictive value of PET-CT in identifying nodal metastases. Results were stratified by initial biopsy tumor depth.

RESULTS

We identified 367 cases; 95 obtained a PET-CT prior to lymphadenectomy. Overall, sensitivity and specificity of PET-CT was 34.6% and 95.4%, respectively. The positive likelihood ratio and negative likelihood ratio were 7.62 and 0.68, respectively. The accuracy was 78.2%. The positive predictive value for T3 and T4 melanomas were 100% and 81.4%, respectively. For thin melanomas, specificity and accuracy was 88.2% and 88.2%, respectively.

CONCLUSIONS

PET-CT has low specificity and its use alone is not recommended for initial staging of nodal metastases in thin cutaneous malignant melanoma.

Utility of a 31-gene expression profile for predicting outcomes in patients with primary cutaneous melanoma referred for sentinel node biopsy

BACKGROUND

A 31-gene genetic expression profile (31-GEP; Class 1 = low risk, Class 2 = high risk) developed to predict outcome in cutaneous melanoma (CM) has been validated by retrospective, industry-sponsored, or small series.

METHODS

Tumor features, sentinel node biopsy (SNB) results, and outcomes were extracted from a prospective database of 383 C M patients who underwent SNB and had a 31-GEP run on their primary tumor. Groups were compared by uni- and multi-variable analysis. Relapse-free and distant metastasis-free survival (RFS, DMFS) were estimated by Kaplan-Meier method.

RESULTS

Breslow thickness, T stage, and SNB positivity were significantly higher in Class 2 patients. Recurrence rates were higher for Class 2 vs Class 1 patients and highest in patients who were Class 2 and SNB positive. GEP class was predictive of RFS and DMFS and independently predicted relapse in AJCC "low risk" (stages IA-IIA) patients.

CONCLUSIONS

31-GEP adds prognostic information in CM patents undergoing SNB.

SEOM clinical guideline for the management of cutaneous melanoma (2020)

Melanoma affects about 6000 patients a year in Spain. A group of medical oncologists from Spanish Society of Medical Oncology (SEOM) and Spanish Multidisciplinary Melanoma Group (GEM) has designed these guidelines to homogenize the management of these patients. The diagnosis must be histological and determination of BRAF status has to be performed in patients with stage ≥ III. Stage I–III resectable melanomas will be treated surgically. In patients with stage III melanoma, adjuvant treatment with immunotherapy or targeted therapy is also recommended. Patients with unresectable or metastatic melanoma will receive treatment with immunotherapy or targeted therapy, the optimal sequence of these treatments remains unclear. Brain metastases require a separate consideration, since, in addition to systemic treatment, they may require local treatment. Patients must be followed up closely to receive or change treatment as soon as their previous clinical condition changes, since multiple therapeutic options are available.

Prognostic significance of acral lentiginous histologic type in T1 melanoma

Acral lentiginous melanoma (ALM) is a rare type of cutaneous melanoma with a poor prognosis. It is unclear whether the poor outcome of ALM is due to its inherent disease characteristics or advanced stage at initial diagnosis. To address this question, we retrospectively analyzed the clinicopathologic factors of 828 thin (T1; Breslow thickness ≤1.0 mm) melanomas [129 (15.6%) ALMs and 699 (84.4%) non-ALMs] and their nodal and distance metastases and local recurrence rates and determined their relationship with the disease-specific (DSS), overall (OS), and recurrence-free survivals (RFS) at the pathologic stages T1, T1a, and T1b with a median follow-up time of 84.5 months. With the exception of OS at T1b stage, ALM patients showed significantly lower 5- and 10-year DSS, OS, and RFS rates at every pathologic stage when compared with non-ALM. In multivariable analysis, ALM histologic type, SLN positivity, age, and the use of systemic therapy were detected as independent poor prognostic factors associated with significantly lower survival rates. ALM histologic type was associated with lower DSS and OS rates at T1 and T1a stages and lower RFS rates at T1b stage. SLN positivity was associated with lower DSS, OS, and RFS rates at T1, T1a, and T1b stages. Age was associated with lower OS rates at T1 and T1b stages. Whereas the use of systemic therapy was associated with lower DSS rates at T1a stage and RFS rates at T1b stage. In addition, the ALM group showed significantly older median age patients and higher rates of female sex, Hispanic ethnicity, nevoid cytology, non-brisk tumor-infiltrating lymphocytes, nodal metastasis, and local recurrence at every pathologic stage of thin melanoma. Our findings suggest that ALM is inherently more aggressive than other types of cutaneous melanoma. This information may be useful for prognostic stratification of patients with thin melanomas, especially to help guide the clinical decision-making for SLN biopsy and patients entering clinical trials.

Discordance in Diagnosis of Melanocytic Lesions and Its Impact on Clinical Management

CONTEXT.—

Accurate diagnosis of melanocytic lesions is fundamental for appropriate clinical management.

OBJECTIVE.—

To evaluate the degree of discordance, if any, between histopathologic diagnoses of melanocytic lesions at referring institutions and at a tertiary referral cancer center and the potential impact of such discordance on clinical management.

DESIGN.—

We retrospectively identified all patients referred to our comprehensive cancer center for evaluation of a melanocytic lesion from January 2010 to January 2011. For each patient, the histopathologic diagnosis from the referring institution was compared with the histopathologic diagnosis from a dermatopathologist at our center. Discordances were classified as major if they resulted in a change in clinical management and minor if they did not.

RESULTS.—

A total of 1521 cases were included. The concordance rates were 72.2% (52 of 72) for dysplastic nevus, 75.0% (15 of 20) for all other types of nevi, 91.1% (143 of 157) for melanoma in situ, 96.1% (758 of 789) for invasive melanoma, and 99.6% (478 of 480) for metastatic melanoma. Major discordances were found in 20.2% of cases (307 of 1521), and minor discordances were found in 48.8% of cases (742 of 1521). Compared with the guideline-based treatment recommendation based on the referring-institution diagnosis, the guideline-based treatment recommendation based on the cancer center diagnosis was more extensive in 5.9% (89 of 1521) of patients and less extensive in 5.0% (76 of 1521) of patients.

CONCLUSIONS.—

Our findings underscore the importance of secondary histopathologic review of melanocytic lesions by expert dermatopathologists because significant changes in the diagnosis, tumor classification, and/or staging may be identified; thus, resulting in critical changes in recommendations for clinical management.

Re-evaluation of Sentinel Lymph Node Biopsy for Melanoma

OPINION STATEMENT

The vast majority of patients newly diagnosed with melanoma present with clinically localized disease, and sentinel lymph node biopsy (SLNB) is a standard of care in the management of these patients, particularly in intermediate thickness cases, in order to provide important prognostic data. However, SLNB also has an important role in the management of patients with other subtypes of melanoma such as thick melanomas, certain thin melanomas, and specific histologic variants of melanoma such as desmoplastic melanoma. Furthermore, there have been technical advances in the SLNB technique, such as the development of newer radiotracers and use of SPECT/CT, and there is some data to suggest performing a SLNB may be therapeutic. Finally, the management of patients with a positive sentinel lymph node (SLN) has undergone dramatic changes over the past several years based on the results of recent important clinical trials. Treatment options for patients with SLN metastases now include surveillance, completion lymph node dissection, and adjuvant therapy with checkpoint inhibitors and targeted therapy. SLNB continues to play a crucial role in the management of patients with melanoma, allowing for risk stratification, potential regional disease control, and further treatment options for patients with a positive SLN.

Sentinel lymph node biopsy in acral melanoma: A Korean single-center experience with 107 patients (2006-2018)

BACKGROUND

Sentinel lymph node biopsy (SLNB) of primary cutaneous melanoma as an important staging method has not been popularly undertaken in Korea and only a few studies with small patient numbers have been published.

AIM

We examined the clinical feasibility and overall outcomes of SLNB in acral melanoma (AM) of Korean in Kyungpook National University Hospital (KNUH) over the past 13 years.

METHODS

SLNB in AM patients during 2006-2018 were analyzed retrospectively for sentinel lymph node (SLN) harvesting rate, positivity rate, positivity-relevant overall survival (OS) and disease-free survival (DFS), and its side effects.

RESULTS

A total of 109 AM patients who underwent SLNB were enrolled. Harvested nodes were identified from 107 patients and SLN harvesting rate was 98.2%. The mean Breslow thickness (±standard deviation) was 3.38 ± 3.03 mm, and the proportion of ulcerated melanomas was 64%. Twenty-two (20.6%) had a tumor-positive SLN and, among them, 82% (18/22) underwent immediate complete lymph node dissection (CLND). The metastasis-positive nodal basin after CLND was detected in 16.7% of cases (3/18). Tumor-negative SLN cohorts showed significantly better OS and DFS than tumor-positive ones (P = 0.006 and P < 0.001 for each). Two side effects, one seroma and one lymphocele, were observed without major sequelae.

CONCLUSION

SLNB, crucial management of melanoma, proved its efficacy to predict patients' prognosis and could be performed successfully and safely in Korean AM patients by interdisciplinary cooperation between dermatology and other surgical departments. SLN(-) showed significantly better OS and DFS than SLN(+). Significant risk factors for DFS were Breslow thickness, the presence of ulceration and the presence of SLN metastasis. SLNB should be encouraged in order to stage melanoma accurately and direct the proper management in Korean AM.

Differences in cutaneous melanoma survival between the 7th and 8th edition of the American Joint Committee on Cancer (AJCC). A multicentric population-based study

BACKGROUND

The 8th edition of the AJCC manual for melanoma includes many changes leading to major substage migrations, which could lead to important clinical reassessments.

OBJECTIVES

To evaluate the differences and prognostic value of the 8th AJCC classification in comparison with the 7th edition.

METHODS

Clinical and histopathological data were retrieved from five melanoma referral centers including 7815 melanoma patients diagnosed between January 1998 and December 2018. All patients were reclassified and compared using the 7th and 8th classifications of the AJCC. Sankey plots were used to evaluate the migration of patients between the different versions. The primary outcome was overall survival (OS), and curves based on the Kaplan-Meier method were used to investigate survival differences between the 7th and 8th editions.

RESULTS

The number of patients classified as stages IB, IIIA, and IIIB decreased while the patients classified as stages IA and IIIC increased notably. Migration analysis showed that many patients in group I were understaged whereas a significant percentage of patients in group III were upstaged. Indirect OS analysis showed a loss in the linearity in the AJCC 8th edition and the groups tended to overlap. Direct OS analysis between groups and versions of the AJCC showed a better prognosis within the new stage III patients, with no effect on those in stages I and II.

CONCLUSION

The 8th AJCC edition represents an important change in the classification of patients. We observe that the main migratory changes occur in stage I and III, that severity linearity is lost and groups overlap, and that a more advanced stage does not mean a worse prognosis.

Prognostic significance of regression and mitotic rate in head and neck cutaneous melanoma

Importance

While regression is a commonly reported microscopic feature of melanoma, its prognostic significance is unclear.

Objective

To examine the impact of regression on sentinel node status and the likelihood of recurrence in primary cutaneous melanoma of the head and neck.

Design

Retrospective analysis of 191 adults who underwent surgical management for primary cutaneous melanoma of the head and neck between May 2002 and March 2019.

Setting

Tertiary academic center.

Participants

Patients appropriate for the study were identified by the Academic Health Center Information Exchange using a list of current procedural terminology codes. One hundred and ninety‐one cases of invasive melanoma of the head and neck were included from 830 patients identified. Clinical features assessed for each patient included age, sex, location of primary lesion, date of diagnosis, and current disease status (alive with or without disease). Histologic features assessed were histological melanoma subtype (nodular vs non‐nodular), Breslow thickness, Clark level, presence/absence of ulceration, mitotic rate per square millimeter, and regression. If applicable, sentinel lymph node biopsy (SLNB) status, date of recurrence, interval treatments, and date of death related to melanoma were recorded. Exclusion criteria included melanoma outside the anatomic parameters of head and neck, ocular or choroidal melanoma, mucosal melanoma, metastatic melanoma to the head or neck with no known primary tumor, melanoma of the head or neck with no surgical intervention, and non‐melanoma skin cancers of the head and neck.

Intervention/Exposure

Surgery for cutaneous melanoma of the head and neck.

Main Outcome(s) and Measure(s)

The association between presence of regression and Breslow thickness, sentinel node status, and recurrence.

Results

Of the 191 patients identified, 30.9% were female and 69.1% were male with a mean age at diagnosis of 62.6 (range 20‐97) years. Mean Breslow thickness was 1.2 mm in those with regression and 2.0 mm in those without regression. In patients with regression, 17.6% had a positive sentinel node, and 13.0% experienced a recurrence. In patients without regression, 26.5% had a positive sentinel node, and 31.4% experienced a recurrence. When adjusted for other factors above, regression was not associated with positive sentinel node (odds ratio [OR] = 0.59, 95% confidence interval [CI] = 0.13‐2.00) or recurrence (OR = 0.33, CI = 0.07‐1.01). Mitotic rate >2 was associated with recurrence (OR = 2.71, CI = 1.11‐6.75, P = .03).

Conclusions and Relevance

Patients with presence of regression had thinner melanomas and trended toward decreased rates of sentinel node positivity and recurrence, suggesting regression may not be a negative prognostic indicator in patients with cutaneous melanoma of the head and neck.

The Devil's in the Details: Discrepancy Between Biopsy Thickness and Final Pathology in Acral Melanoma

PURPOSE

We hypothesized that initial biopsy may understage acral lentiginous melanoma (ALM) and lead to undertreatment or incomplete staging. Understanding this possibility can potentially aid surgical planning and improve primary tumor staging.

METHODS

A retrospective review of primary ALMs treated from 2000 to 2017 in the US Melanoma Consortium database was performed. We reviewed pathology characteristics of initial biopsy, final excision specimens, surgical margins, and sentinel lymph node biopsy (SLNB).

RESULTS

We identified 418 primary ALMs (321 plantar, 34 palmar, 63 subungual) with initial biopsy and final pathology results. Median final thickness was 1.8 mm (range 0.0-19.0). There was a discrepancy between initial biopsy and final pathology thickness in 180 (43%) patients with a median difference of 1.6 mm (range 0.1-16.4). Final T category was increased in 132 patients (32%), including 47% of initially in situ, 32% of T1, 39% of T2, and 28% of T3 lesions. T category was more likely to be increased in subungual (46%) and palmar (38%) melanomas than plantar (28%, p = 0.01). Among patients upstaged to T2 or higher, 71% had ≤ 1-cm margins taken. Among the 27 patients upstaged to T1b or higher, 8 (30%) did not have a SLNB performed, resulting in incomplete initial staging.

CONCLUSIONS

In this large series of ALMs, final T category was frequently increased on final pathology. A high index of suspicion is necessary for lesions initially in situ or T1 and consideration should be given to performing additional punch biopsies, wider margin excisions, and/or SLNB.

Validation of a clinicopathological and gene expression profile model for sentinel lymph node metastasis in primary cutaneous melanoma

BACKGROUND

The Clinicopathological and Gene Expression Profile (CP-GEP) model was developed to accurately identify patients with T1-T3 primary cutaneous melanoma at low risk for nodal metastasis.

OBJECTIVES

To validate the CP-GEP model in an independent Dutch cohort of patients with melanoma.

METHODS

Patients (aged ≥ 18 years) with primary cutaneous melanoma who underwent sentinel lymph node biopsy (SLNB) between 2007 and 2017 at the Erasmus Medical Centre Cancer Institute were eligible. The CP-GEP model combines clinicopathological features (age and Breslow thickness) with the expression of eight target genes involved in melanoma metastasis (ITGB3, PLAT, SERPINE2, GDF15, TGFBR1, LOXL4, CXCL8 and MLANA). Using the pathology result of SLNB as the gold standard, performance measures of the CP-GEP model were calculated, resulting in CP-GEP high risk or low risk for nodal metastasis.

RESULTS

In total, 210 patients were included in the study. Most patients presented with T2 (n = 94, 45%) or T3 (n = 70, 33%) melanoma. Of all patients, 27% (n = 56) had a positive SLNB, with nodal metastasis in 0%, 30%, 54% and 16% of patients with T1, T2, T3 and T4 melanoma, respectively. Overall, the CP-GEP model had a negative predictive value (NPV) of 90·5% [95% confidence interval (CI) 77·9-96.2], with an NPV of 100% (95% CI 72·2-100) in T1, 89·3% (95% CI 72·8-96·3) in T2 and 75·0% (95% CI 30·1-95·4) in T3 melanomas. The CP-GEP indicated high risk in all T4 melanomas.

CONCLUSIONS

The CP-GEP model is a noninvasive and validated tool that accurately identified patients with primary cutaneous melanoma at low risk for nodal metastasis. In this validation cohort, the CP-GEP model has shown the potential to reduce SLNB procedures in patients with melanoma.

Sentinel lymph node biopsy is associated with increased cost in higher risk thin melanoma

INTRODUCTION

National Comprehensive Cancer Network guidelines recommend that sentinel lymph node biopsy (SLNB) be discussed with patients with thin melanoma at higher risk for lymph node metastasis (T1b or T1a with positive deep margins, lymphovascular invasion, or high mitotic index). We examined the association between SLNB and resource utilization in this cohort.

METHODS

We conducted a retrospective cohort study of patients that underwent wide local excision for higher risk thin melanomas from 2009 to 2018 at a tertiary care center. Patients who underwent SLNB were compared to those who did not undergo SLNB with regard to resource utilization, including total hospital cost.

RESULTS

A total of 70 patients were included in the analysis and 50 patients (71.4%) underwent SLNB. SLNB was associated with increased hospital costs ($6700 vs. $3767; p < .01) and increased operative time (68.5 vs. 36.0 min; p < .01). This cost difference persisted in multivariable regression (p < .01). Of patients who underwent successful SLN mapping, 3 out of 49 patients had a positive SLN (6.1%). The cost to identify a single positive sentinel lymph node (SLN) was $47,906.

CONCLUSION

In patients with a higher risk of thin melanoma, SLNB is associated with increased cost despite a low likelihood of SLN positivity. These data better inform patient-provider discussions as the role of SLNB in thin melanoma evolves.

Features associated with melanoma metastasis in Latvia

Cutaneous melanoma (CM) is the most aggressive form of skin cancer, exhibits an increasing incidence worldwide and has a high potential to develop metastasis. The current study aimed to identify a set of parameters that may aid in predicting the probability and timing of the onset of CM metastasis. A retrospective analysis was performed using the archive data of 2,026 patients with CM that were treated at the Riga East University Hospital Latvian Oncology Centre, which is the largest oncological hospital in the country, between 1998 and 2015. A case-control study design was employed, where patients with metastasis (n=278) were used as the cases and patients without metastasis were used as the controls. The present study examined the associations between metastasis and potential risk factors and constructed multivariate models of features that predicted metastasis using stepwise regression. Time until metastasis was analyzed using negative binomial regression models. The results of the present study indicated an increase in the number of melanomas that developed metastases during 1998–2015. Tumor Breslow thickness was demonstrated to be significantly larger in patients with metastasis compared with those without (P=0.012). The presence of ulceration significantly increased the risk of metastases [odds ratio (OR), 1.66; 95% CI, 1.07-2.59; P=0.033]. The absence of pigment in melanoma tissues was indicated to lead to a greater likelihood of metastasis (OR, 2.14; 95% CI, 1.10-4.19; P=0.035). Shorter times from diagnosis until the onset of metastases were observed in older patients (incident rate ratio (IRR), 6.85; 95% CI, 2.43-19.30; P=2.78×10⁻⁴), and a borderline significant association was observed in those with ulcerated tumors (IRR, 1.33; 95% CI, 0.98-1.80; P=0.064). Therefore, the main features associated with the development of melanoma metastasis in Latvia were indicated to be tumor ulceration, absence of pigment and Breslow thickness.

ESMO consensus conference recommendations on the management of locoregional melanoma: under the auspices of the ESMO Guidelines Committee

The European Society for Medical Oncology (ESMO) held a consensus conference on melanoma on 5-7 September 2019 in Amsterdam, The Netherlands. The conference included a multidisciplinary panel of 32 leading experts in the management of melanoma. The aim of the conference was to develop recommendations on topics that are not covered in detail in the current ESMO Clinical Practice Guideline and where available evidence is either limited or conflicting. The main topics identified for discussion were: (i) the management of locoregional disease; (ii) targeted versus immunotherapies in the adjuvant setting; (iii) targeted versus immunotherapies for the first-line treatment of metastatic melanoma; (iv) when to stop immunotherapy or targeted therapy in the metastatic setting; and (v) systemic versus local treatment of brain metastases. The expert panel was divided into five working groups in order to each address questions relating to one of the five topics outlined above. Relevant scientific literature was reviewed in advance. Recommendations were developed by the working groups and then presented to the entire panel for further discussion and amendment before voting. This manuscript presents the results relating to the management of locoregional melanoma, including findings from the expert panel discussions, consensus recommendations and a summary of evidence supporting each recommendation. All participants approved the final manuscript.

High Mitotic Rate Predicts Sentinel Lymph Node Involvement in Thin Melanomas

BACKGROUND

Indications for sentinel lymph node (SLN) biopsy in the population with thin melanoma have frequently changed over time. The objective of our study was to evaluate T1 melanoma pathologic features predictive of SLN positivity with a primary focus on identifying a specific mitotic value that is most predictive of lymph node disease. Further detailed predictive features would help physicians select patients with thin melanoma for SLN biopsy.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for all patients diagnosed with trunk or extremity cutaneous melanoma with ≤1 mm depth who underwent SLN biopsy between the years of 2010 and 2013. Patient demographics and tumor characteristics including depth, mitotic rate (MR), ulceration, and tumor location were evaluated. MR was dichotomized at multiple cut points to identify the ideal number of mitosis for MR as a predictor of SLN status. Multivariable logistic regression analyses were performed to identify the factors affecting nodal positivity and the impact of MR threshold. Kaplan-Meir curves were used for overall survival (OS) analysis.

RESULTS

Factors significantly associated with SLN positivity in the entire cohort included MR (P < 0.001, OR 1.24, 95% CI 1.18-1.31), tumor location (P = 0.017, OR 1.48, 95% CI 1.07-2.05), and ulceration (P < 0.001, OR 2.01, 95% CI 1.39-2.93,). An MR ≥ 4 was significant for SLN positivity (P = 0.049, OR 1.08, 95% CI 1.01-1.38). Mean OS was 46.7 mo for MR < 4 compared with 43.2 mo for MR ≥ 4 (P < 0.001).

CONCLUSIONS

MR ≥ 4 was significant and associated with SLN positivity in thin melanomas and asulceration. Thus, MR ≥ 4 should be considered as an indication for SLN biopsy in thin melanoma.

Is it Necessary to Perform Sentinel Lymph Node Biopsy in Thin Melanoma? A Retrospective Single Center Analysis

Sentinel lymph node biopsy (SLNB) is a standard procedure for regional lymph node staging and still has the most important prognostic value for the outcome of patients with thin melanoma. In addition to ulceration, SLNB had to be considered even for a single mitotic figure in thin (<1 mm) melanoma according to AJCC7th guideline, therefore, a retrospective review was conducted involving 403 pT1 melanoma patients. Among them, 152 patients suffered from pT1b ulcerated or mitotic rate ≥ 1/ mm2 melanomas according to the AJCC7th staging system. SLNB was performed in 78 cases, of which nine (11.5%) showed SLN positivity. From them, interestingly, we found a relatively high positive sentinel rate (6/78-8%) in the case of thin primary melanomas ˂0.8 mm. Moreover, the presence of regression increased the probability of sentinel positivity by 5.796 fold. After reassessing pT stage based on the new AJCC8th, 37 pT1b cases were reordered into pT1a category. There was no significant relation between other characteristics examined (age, gender, Breslow, Clark level, and mitosis index) and sentinel node positivity. Based on our data, we suggest that mitotic rate alone is not a sufficiently powerful predictor of SLN status in thin melanomas. If strict histopathological definition criteria are applied, regression might be an additional adverse feature that aids in identifying T1 patients most likely to be SLN-positive. After reassessing of pT1b cases according to AJCC8th regression proved to be independent prognostic factor on sentinel lymph node positivity. Our results propose that sentinel lymph node biopsy might also be considered at patients with regressive thin (˂0.8 mm) melanomas.

Sentinel Lymph Node Biopsy for T1b Melanoma: Balancing Prognostic Value and Cost

BACKGROUND

The purpose of this study is to report the additional prognostic information and cost associated with sentinel lymph node biopsy (SLNB) for patients with T1b melanoma.

PATIENTS AND METHODS

An institutional database was queried for patients with T1b melanoma (0.8-1.0 mm or < 0.8 mm with ulceration) with at least 5 years of follow-up. Results of SLNB, completion lymphadenectomy (CLND), recurrence, and melanoma-specific survival (MSS) were assessed. Institutional costs of melanoma care were converted to Medicare proportional dollars. A Markov model was created to estimate long-term costs.

RESULTS

Among the total 392 patients, 238 underwent SLNB. Median follow-up was 10.5 years. SLNB was positive in 19 patients (8.0%). Patients who underwent SLNB had higher 10-year nodal recurrence-free survival (98.6% vs. 91.2%, p < 0.001) but not MSS (94.4% vs. 93.2%, p = 0.55). Ulceration (HR 4.7, p = 0.022) and positive sentinel node (HR 11.5, p < 0.001) were associated with worse MSS. Estimates for 5-year costs reflect a fourfold increase in total costs of care associated with SLNB. However, a treatment plan that forgoes adjuvant therapy for resected stage IIIA melanoma but offers systemic therapy for a node-basin recurrence would nullify the additional cost of SLNB.

CONCLUSIONS

SLNB is prognostic for T1b melanoma. Its impact on the overall cost of melanoma care is intimately tied to systemic therapy in the adjuvant and recurrent settings.