Results of Sentinel Lymph Node Biopsy in Patients With Thin Melanoma

Long-term outcomes and patterns of recurrence in patients with thin melanoma and a negative sentinel lymph node biopsy: a single-center experience

The majority of patients diagnosed with melanoma have thin melanomas (≤1 mm). Data on the rate and pattern of recurrence after a negative sentinel lymph node biopsy (SLNB) are sparse. We retrospectively searched our institutional database and retrieved the records of patients with thin melanomas who underwent an SLNB with negative results. We analyzed patterns of recurrence, time to recurrence, and mode of diagnosis. Thirteen of the 198 patients with thin melanomas and negative SLNB results had tumor recurrence (6.5%): two local in transit (15.4%), three regional (21.3%), and eight distant (61.5%). Distant recurrences tended to occur later than local or regional ones [median disease-free survival = 50 months (95% confidence interval: 36.1-63.9) vs. 34 and 15 months (95% confidence interval: 5.4-24.6), P = 0.005, respectively]. The percentage of patients with tumor thickness ≥0.8 mm was higher among those who sustained recurrence (84.6 vs. 64.9% for no recurrence, P = 0.04). The majority of patients with recurrence were not being followed up when diagnosed (69%), and they are presented because of clinical symptoms. Patients with recurrence had lower survival compared with those without recurrence (median: 118 months vs. ongoing survival, P < 0.001, respectively). Melanoma recurrence in patients with thin melanomas and negative SLNBs is rare, tends to be distant, and negatively affects prognosis. Recurrence tends to occur in patients with melanoma thickness ≥0.8 mm. Further studies are needed to identify patients with high recurrence risk and determine optimal follow-up protocols.

Fifty years of progress in surgical oncology: Melanoma

This paper outlines the scientific and clinical advances in the treatment of melanoma over the past 50 years. Among the highlights of progress, the dominant themes include evidence-based reduction in the extent and morbidity of surgical procedures in patients with local or regional melanoma without compromising end results, and the introduction of effective systemic therapy, specifically targeted therapy matched to patients based on specific tumor mutations, and immune checkpoint blockade. Management of advanced disease has also changed dramatically, due to improved understanding of the genomic variability of the disease as well as continuing improvements in imaging.

Clinical characteristics and prognosis of acral lentiginous melanoma: a single-center series of 211 cases in China

BACKGROUND

Acral lentiginous melanoma (ALM) is common in China with poor prognosis. However, there are only a few studies of ALM in the Asian population. We aimed to summarize and analyze the clinical characteristics, treatment strategy, treatment effect, and prognostic factors of ALM in a Chinese population.

METHODS

We included a total of 249 ALM patients (211 with follow-up data) from a single institution. Demographic, laboratory data, treatment strategy, and prognosis were analyzed.

RESULTS

The ratio of male and female was 1.3 ∶ 1.0. The median age was 58 years old. The majority of patients (70.3%) had lesions on the sole. Trauma history and irritation were associated with lesion size increase in some patients. The prognosis of patients in stage II-III undergoing standard operation was significantly better compared with those without surgical treatment. Patients who did not receive postoperative adjuvant treatment had shorter time to distant metastasis. In multivariable analysis, distant metastasis, duration of disease, LDH level, and Ki67 index were independently associated with survival.

CONCLUSIONS

Prognosis for ALM patients was poor in our study. Distant metastasis, duration of disease, LDH level, and Ki67 index were independently associated with prognosis.

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.

Early Melanoma Nodal Positivity and Biopsy Rates Before and After Implementation of the 7th Edition of the AJCC Cancer Staging Manual

Importance

There has been a continued increase in the incidence of newly diagnosed melanomas, most of which are T1 melanomas. The associations between changes in tumor staging, implemented with the 7th edition of the AJCC Cancer Staging Manual (AJCC 7), and sentinel lymph node biopsy rates and nodal positivity rates remain to be seen.

Objective

To evaluate the change that the implementation of the AJCC 7 had on staging criteria and the distribution of thin melanomas requiring nodal surgery and nodal positivity rates.

Design, Setting, and Participants

Retrospective cross-sectional study from 2004 through 2013 of all adults (≥18 years) diagnosed with a T1 (Breslow depth ≤1.0 mm) melanoma using The National Cancer Database that captures 70% of all newly diagnosed cancers from accredited Commission on Cancer organizations, including both academic and community settings. Data were analyzed in May 2017.

Exposures

Patients were grouped together based on year of diagnosis, before and after 2009.

Main Outcomes and Measures

To determine the sentinel lymph node biopsy rate before and after the implementation of the AJCC 7.

Results

A total of 141 280 patients met inclusion criteria. Of 86 846 patients diagnosed from 2004 through 2009, 53.7% (49 644) were male and had a mean (SD) age of 57.7 (16.4) years. Of 54 434 patients diagnosed from 2010 through 2013, 54.3% (31 086) were male and had a mean (SD) age of 59.5 (15.9) years. After 2010, there was a 3.8% decrease in the number of nodal surgeries performed (32 485 of 86 846 patients [37.6%] vs 18 379 of 54 434 patients [33.8%]; P < .001). The nodal positivity rate decreased 1.0% from (9.8% [3166 of 86 846] to 8.8% [1618 of 54 434]) (P < .001). An increase in the proportion of T1b melanomas being evaluated, from 48.8% to 62.2%, was seen (P < .001). Of T1b melanomas that underwent nodal evaluation from 2004 through 2009, 74.0% had Clark level IV (invasion of the reticular dermis) or Clark level V (invasion of the deep, subcutaneous tissue) and 9.5% were ulcerated. From 2010 through 2013, of the T1b melanomas undergoing nodal evaluation, 82.6% had an elevated mitotic rate only, 3.7% were ulcerated, and 13.7% had both ulceration and an elevated mitotic rate.

Conclusions and Relevance

It appears that after the institution of AJCC 7, there was an overall decrease in the number of T1 melanomas undergoing nodal biopsy without a clinically relevant change in sentinel lymph node positivity, with an increase in the number of T1b melanomas undergoing nodal evaluation.

A nomogram to predict node positivity in patients with thin melanomas helps inform shared patient decision making

OBJECTIVE

To develop a nomogram to estimate the probability of positive sentinel lymph node (+SLN) for patients with thin melanoma and to characterize its potential impact on sentinel lymph node biopsy (SLNB) rates.

METHODS

Patients diagnosed with thin (0.5-1.0 mm) melanoma were identified from the National Cancer Database 2012 to 2015. A multivariable logistic regression model was used to examine factors associated with +SLN, and a nomogram to predict +SLN was constructed. Nomogram performance was evaluated and diagnostic test statistics were calculated.

RESULTS

Of the 21 971 patients included 10 108 (46.0%) underwent SLNB, with a 4.0% +SLN rate. On multivariable analysis, age, Breslow thickness, lymphovascular invasion, ulceration, and Clark level were significantly associated with SLN status. The area under the receiver operating curve was 0.67 (95% confidence interval, 0.65-0.70). While 15 249 (69.4%) patients had either T1b tumors or T1a tumors with at least one adverse feature, only 2846 (13.0%) had a nomogram predicted probability of a +SLN ≥5%. Using this cut-off, the indication for a SLNB in these patients would be reduced by 81.3% as compared to the American Joint Committee on Cancer 8th edition staging criteria.

CONCLUSIONS

The risk predictions obtained from the nomogram allow for more accurate selection of patients who could benefit from SLNB.

Survival analysis and sentinel lymph node status in thin cutaneous melanoma: A multicenter observational study

Mitotic rate is no longer considered a staging criterion for thin melanoma in the 8th edition of the American Joint Committee on Cancer Staging Manual. The aim of this observational study was to identify prognostic factors for thin melanoma and predictors and prognostic significance of sentinel lymph node (SLN) involvement in a large multicenter cohort of patients with melanoma from nine tertiary care hospitals. A total of 4249 consecutive patients with thin melanoma diagnosed from January 1, 1998 to December 31, 2016 were included. The main outcomes were disease-free interval and melanoma-specific survival for the overall population and predictors of SLN metastasis (n = 1083). Associations between survival and SLN status and different clinical and pathologic variables (sex, age, tumor location, mitosis, ulceration, regression, lymphovascular invasion, histologic subtype, Clark level, and Breslow thickness) were analyzed by Cox proportional hazards regression and logistic regression. SLN status was the most important prognostic factor for melanoma-specific survival (hazard ratio, 13.8; 95% CI, 6.1-31.2; P < 0.001), followed by sex, ulceration, and Clark level for patients who underwent SLNB. A mitotic rate of >2 mitoses/mm2 was the only factor associated with a positive SLN biopsy (odds ratio, 2.9; 95% CI, 1.22-7; P = 0.01. SLN status is the most important prognostic factor in thin melanoma. A high mitotic rate is associated with metastatic SLN involvement. SLN biopsy should be discussed and recommended in patients with thin melanoma and a high mitotic rate.

BRAF immunohistochemistry predicts sentinel lymph node involvement in intermediate thickness melanomas

Background

Sentinel node biopsy (SNB) is an important step in melanoma staging and prognostication. It is commonly performed for patients with intermediate thickness melanomas, based on clinicopathological features. However, only 20–25% of patients eventually demonstrate nodal involvement. The aim of this study was to evaluate whether tissue biomarkers with links to melanoma biology, together with clinicopathological parameters, could aid in the prediction of sentinel node involvement and improve selection of patients for SNB. In addition, we examined the role of these clinical or biological markers in disease outcome.

Methods

We collected a case-control cohort of 140 intermediate thickness (Breslow 0,9–4,0mm) melanoma patients with or without SNB involvement matched for age, gender, Breslow thickness and location. From this cohort, we tested the predictive value of common clinicopathological parameters (ulceration, mitotic count and tumor regression) and FMNL-2, ezrin and BRAF V600E immunoreactivity, for sentinel node involvement and survival. We further analyzed the correlations in the superficial spreading melanoma subtype.

Results

Based on our case control analysis, of the markers, BRAF V600E status (p = 0.010) and mitotic count (p = 0.036) correlated with SNB involvement. SNB status was a strong independent prognosticator for recurrence free survival (RFS p<0.001), melanoma specific survival (MSS p = 0.000) and overall survival (OS p = 0.029). In the superficially spreading melanoma subgroup, BRAF V600E positivity indicated poorer RFS (p = 0.039) and OS (p = 0.012). By combining the Breslow thickness, mitotic count and BRAF immunohistochemistry, we identified a group of superficially spreading melanomas with an excellent survival probability independent of SNB status.

Conclusions

These results demonstrate that BRAF immunohistochemistry could serve as a useful addition to a marker panel for selecting intermediate thickness melanoma patients for SNB.

Predictors of sentinel lymph node positivity in thin melanoma using the National Cancer Database

BACKGROUND

Sentinel lymph node biopsy (SLNB) specimens are often obtained from patients for further staging after these patients have undergone melanoma excision. Limited data regarding predictors of SLNB positivity in thin melanoma are available.

OBJECTIVE

We sought to evaluate predictors of SLNB positivity in thin melanoma.

METHODS

Patients with cutaneous melanoma with a Breslow thickness ≤1.00 mm who received a SLNB were identified from the National Cancer Database between 2004 and 2014 (n = 9186). Predictors of SLNB positivity were analyzed using logistic regression.

RESULTS

In a multivariate analysis, patients <60 years of age (P < .001) and Breslow thickness >0.8 mm (P = .03) were at increased risk for positive sentinel lymph node (SLN). Moreover, on multivariate analysis, the presence of dermal mitoses increased the odds of SLN positivity by 95% (odds ratio [OR] 1.95 [95% confidence interval {CI} 1.53-2.5], P < .001), ulceration by 63% (OR 1.63 [95% CI 1.21-2.18], P < .001), and Clark level IV to V by 48% (OR 1.48 [95% CI 1.19-1.85]). Patients without ulceration but with dermal mitoses had 92% (OR 1.92 [95% CI 1.5-2.48], P < .001) increased SLN positivity.

LIMITATIONS

Limited survival data are available.

CONCLUSIONS

Younger age, a Breslow thickness >0.8 mm, the presence of dermal mitoses, ulceration, and Clark level IV to V are positive predictors of positive SLN. While the new American Joint Committee on Cancer system has removed dermal mitotic rate from staging, continued evaluation of dermal mitotic rate could be valuable for guiding surgical decision making about SLNB.

Association between tumor-infiltrating lymphocytes and sentinel lymph node positivity in thin melanoma

BACKGROUND

Sentinel lymph node biopsy in thin invasive primary cutaneous melanoma (up to 1mm thick) is a controversial subject. The presence of tumor-infiltrating lymphocytes could be a factor to be considered in the decision to perform this procedure.

OBJECTIVE

To evaluate the association between the presence of tumor-infiltrating lymphocytes and lymph node metastases caused by thin primary cutaneous melanoma.

METHODS

Cross-sectional study with 137 records of thin invasive primary cutaneous melanoma submitted to sentinel lymph node biopsy from 2003 to 2015. The clinical variables considered were age, sex and topography of the lesion. The histopathological variables assessed were: tumor-infiltrating lymphocytes, melanoma subtype, Breslow thickness, Clark levels, number of mitoses per mm2, ulceration, regression and satellitosis. Univariate analyzes and logistic regression tests were performed as well the odds ratio and statistical relevance was considered when p <0.05.

RESULTS

Among the 137 cases of thin primary cutaneous melanoma submitted to sentinel lymph node biopsy, 10 (7.3%) had metastatic involvement. Ulceration on histopathology was positively associated with the presence of metastatic lymph node, with odds ratio =12.8 (2.77-59.4 95% CI, p=0.001). The presence of moderate/marked tumor-infiltrating lymphocytes was shown to be a protective factor for the presence of metastatic lymph node, with OR=0.20 (0.05-0.72 95% CI, p=0.014). The other variables - clinical and histopathological - were not associated with the outcome.

STUDY LIMITATIONS

The relatively small number of positive sentinel lymph node biopsy may explain such an expressive association of ulceration with metastatization.

CONCLUSIONS

In patients with thin invasive primary cutaneous melanoma, few or absent tumor-infiltrating lymphocytes, as well as ulceration, represent independent risk factors for lymph node metastasis.

Vertical Growth Phase as a Prognostic Factor for Sentinel Lymph Node Positivity in Thin Melanomas: A Systematic Review and Meta-Analysis

BACKGROUND

The 2010 American Joint Committee on Cancer guidelines recommended consideration of sentinel lymph node biopsy for thin melanoma (Breslow thickness <1.0 mm) with aggressive pathologic features such as ulceration and/or high mitotic rate. The therapeutic benefit of biopsy-based treatment remains controversial. The authors conducted a meta-analysis to estimate the risk and outcomes of sentinel lymph node positivity in thin melanoma, and examined established and potential novel predictors of positivity.

METHODS

Three databases were searched by two independent reviewers for sentinel lymph node positivity in patients with thin melanoma. Study heterogeneity, publication bias, and quality were assessed. Data collected included age, sex, Breslow thickness, mitotic rate, ulceration, regression, Clark level, tumor-infiltrating lymphocytes, and vertical growth phase. Positivity was estimated using a random effects model. Association of positivity and clinicopathologic features was investigated using meta-regression.

RESULTS

Ninety-three studies were identified representing 35,276 patients with thin melanoma who underwent sentinel lymph node biopsy. Of these patients, 952 had a positive sentinel lymph node biopsy, for an event rate of 5.1 percent (95 percent CI, 4.1 to 6.3 percent). Significant associations were identified between positivity and Breslow thickness greater than 0.75 mm but less than 1.0 mm, mitotic rate, ulceration, and Clark level greater than IV. Seven studies reported on vertical growth phase, which was strongly associated with positivity (OR, 4.3; 95 percent CI, 2.5 to 7.7).

CONCLUSIONS

To date, this is the largest meta-analysis to examine predictors of sentinel lymph node biopsy positivity in patients with thin melanoma. Vertical growth phase had a strong association with biopsy positivity, providing support for its inclusion in standardized pathologic reporting.

Mitotic rate is associated with positive lymph nodes in patients with thin melanomas

BACKGROUND

The American Joint Commission on Cancer will remove mitotic rate from its staging guidelines in 2018.

OBJECTIVE

Using a large nationally representative cohort, we examined the association between mitotic rate and lymph node positivity among thin melanomas.

METHODS

A total of 149,273 thin melanomas in the National Cancer Database were examined for their association of high-risk features of mitotic rate, ulceration, and Breslow depth with lymph node status.

RESULTS

Among 17,204 patients with thin melanomas with data on Breslow depth, ulceration, and mitotic rate who underwent a lymph node biopsy, there was a strong linear relationship between odds of having a positive lymph node and mitotic rate (R² = 0.96, P < .0001, β = 3.31). The odds of having a positive node increased by 19% with each 1-point increase in mitotic rate (odds ratio, 1.19; 95% confidence interval, 1.17-1.21). Cases with negative nodes had a mean mitotic rate of 1.54 plus or minus 2.07 mitoses/mm² compared with 3.30 plus or minus 3.54 mitoses/mm² for those with positive nodes (P < .0001).

LIMITATIONS

The data collected do not allow for survival analyses.

CONCLUSIONS

Mitotic rate was strongly associated with the odds of having a positive lymph node and should continue to be reported on pathology reports.

Assessing Tumor-Infiltrating Lymphocytes in Solid Tumors: A Practical Review for Pathologists and Proposal for a Standardized Method from the International Immuno-Oncology Biomarkers Working Group: Part 2: TILs in Melanoma, Gastrointestinal Tract Carcinomas, Non-Small Cell Lung Carcinoma and Mesothelioma, Endometrial and Ovarian Carcinomas, Squamous Cell Carcinoma of the Head and Neck, Genitourinary Carcinomas, and Primary Brain Tumors

Assessment of the immune response to tumors is growing in importance as the prognostic implications of this response are increasingly recognized, and as immunotherapies are evaluated and implemented in different tumor types. However, many different approaches can be used to assess and describe the immune response, which limits efforts at implementation as a routine clinical biomarker. In part 1 of this review, we have proposed a standardized methodology to assess tumor-infiltrating lymphocytes (TILs) in solid tumors, based on the International Immuno-Oncology Biomarkers Working Group guidelines for invasive breast carcinoma. In part 2 of this review, we discuss the available evidence for the prognostic and predictive value of TILs in common solid tumors, including carcinomas of the lung, gastrointestinal tract, genitourinary system, gynecologic system, and head and neck, as well as primary brain tumors, mesothelioma and melanoma. The particularities and different emphases in TIL assessment in different tumor types are discussed. The standardized methodology we propose can be adapted to different tumor types and may be used as a standard against which other approaches can be compared. Standardization of TIL assessment will help clinicians, researchers and pathologists to conclusively evaluate the utility of this simple biomarker in the current era of immunotherapy.

The natural history of thin melanoma and the utility of sentinel lymph node biopsy

BACKGROUND AND OBJECTIVES

Current literature may overestimate the risk of nodal metastasis from thin melanoma due to reporting of data only from lesions treated with SLNB. Our objective was to define the natural history of thin melanoma, assessing the likelihood of nodal disease, in order to guide selection for SLNB.

METHODS

Retrospective review. The primary outcome was the rate of nodal disease. Clinicopathologic factors were evaluated to find associations with nodal disease.

RESULTS

Five hundred and twelve lesions, follow up available for 488 (median: 48 months). Lesions treated with WLE/SLNB compared to WLE alone were more likely to have high-risk features. The rate of nodal disease was higher in the WLE/SLNB group (24 positive SLNB, five false-negative SLNB with nodal recurrence: 10.2%) compared to WLE alone (four nodal recurrences: 2.0%). Univariate analysis showed age ≤45, Breslow depth ≥0.85 mm, mitotic rate >1 mm² , and ulceration were associated with nodal disease. Multivariate analysis confirmed the association of age ≤45 and ulceration.

CONCLUSIONS

SLNB for melanoma 0.75-0.99 mm should be considered in patients age ≤45, Breslow depth ≥0.85 mm, mitotic rate >1 mm² , and/or with ulceration. Thin melanoma <0.85 mm without high-risk features may be treated with WLE alone.

Identification of high-risk cutaneous melanoma tumors is improved when combining the online American Joint Committee on Cancer Individualized Melanoma Patient Outcome Prediction Tool with a 31-gene expression profile-based classification

BACKGROUND

A significant proportion of patients with American Joint Committee on Cancer (AJCC)-defined early-stage cutaneous melanoma have disease recurrence and die. A 31-gene expression profile (GEP) that accurately assesses metastatic risk associated with primary cutaneous melanomas has been described.

OBJECTIVE

We sought to compare accuracy of the GEP in combination with risk determined using the web-based AJCC Individualized Melanoma Patient Outcome Prediction Tool.

METHODS

GEP results from 205 stage I/II cutaneous melanomas with sufficient clinical data for prognostication using the AJCC tool were classified as low (class 1) or high (class 2) risk. Two 5-year overall survival cutoffs (AJCC 79% and 68%), reflecting survival for patients with stage IIA or IIB disease, respectively, were assigned for binary AJCC risk.

RESULTS

Cox univariate analysis revealed significant risk classification of distant metastasis-free and overall survival (hazard ratio range 3.2-9.4, P < .001) for both tools. In all, 43 (21%) cases had discordant GEP and AJCC classification (using 79% cutoff). Eleven of 13 (85%) deaths in that group were predicted as high risk by GEP but low risk by AJCC.

LIMITATIONS

Specimens reflect tertiary care center referrals; more effective therapies have been approved for clinical use after accrual.

CONCLUSIONS

The GEP provides valuable prognostic information and improves identification of high-risk melanomas when used together with the AJCC online prediction tool.

Breslow density is a novel prognostic feature in cutaneous malignant melanoma

AIMS

In 1970, Breslow described his eponymously named thickness measurement. No-one has sought to enhance the Breslow thickness (BT). The aim of this study was to demonstrate a proof of concept that the density of melanoma cells at the position where the BT is measured is a morphological prognostic biomarker, which we name the Breslow density (BD). The hypothesis was that the BD has prognostic value for overall survival (OS) and is independent of the BT.

METHODS AND RESULTS

We analysed 100 cutaneous melanomas, and followed REMARK guidelines. The BD was the estimated percentage dermal area occupied by melanoma cells in a specified location. The BT and BD had a strong correlation (P = 2.1 × 10-11 ) but, despite this, they were independent prognostic factors for OS in Cox regression [BD hazard ratio (HR) 1.03, P = 0.001849; and BT HR 1.09, P = 0.000146]. This was corroborated by an independent effect on melanoma-specific survival. We assessed whether the BT and BD could be combined into a Breslow score. A prognostic index based on Cox regression coefficients was used, and this showed a marginal improvement in predicted 5-year survival as compared with the BT alone (area under the curve of 94.8% versus 96.7%).

CONCLUSIONS

We show a proof of concept that the BD represents a novel morphological prognostic biomarker that is independent of the BT, and that there is potential to combine these into a Breslow score. Larger studies are needed to validate the BD, but the simplicity of this biomarker makes it a strong candidate for translation to clinical practice.

Thin Melanoma with Nodal Involvement: Analysis of Demographic, Pathologic, and Treatment Factors with Regard to Prognosis

BACKGROUND

Although only a small proportion of thin melanomas result in lymph node metastasis, the abundance of these lesions results in a relatively large absolute number of patients with a diagnosis of nodal metastases, determined by either sentinel lymph node (SLN) biopsy or clinical nodal recurrence (CNR).

METHODS

Independent cohorts with thin melanoma and either SLN metastasis or CNR were identified at two melanoma referral centers. At both centers, SLN metastasis patients were included. At center 1, the CNR cohort included patients with initial negative clinical nodal evaluation followed by CNR. At center 2, the CNR cohort was restricted to those presenting in the era before the use of SLN biopsy. Uni- and multivariable analyses of melanoma-specific survival (MSS) were performed.

RESULTS

At center 1, 427 CNR patients were compared with 91 SLN+ patients. The 5- and 10-year survival rates in the SLN group were respectively 88 and 84 % compared with 72 and 49 % in the CNR group (p < 0.0001). The multivariate analysis showed age older than 50 years (hazard ratio [HR] 1.5; 95 % confidence interval [CI] 1.2-1.9), present ulceration (HR 1.9; 95 % CI 1.2-2.9), unknown ulceration (HR 1.6; 95 % CI 1.3-2.1), truncal site (HR 1.6; 95 % CI 1.2-2.2), and CNR (HR 3.3; 95 % CI 1.8-6.0) to be associated significantly with decreased MSS (p < 0.01 for each). The center 2 cohort demonstrated remarkably similar findings, with a 5-year MSS of 88 % in the SLN (n = 29) group and 76 % in the CNR group (n = 39, p = 0.09).

CONCLUSION

Patients with nodal metastases from thin melanomas have a substantial risk of melanoma death. This risk is lower among patients whose disease is discovered by SLN biopsy rather than CNR.

Sentinel Lymph Node Biopsy in Thin Cutaneous Melanoma: A Systematic Review and Meta-Analysis

BACKGROUND

Most patients with melanoma have a thin (≤1.00 mm) lesion. There is uncertainty as to which patients with thin melanoma should undergo sentinel lymph node (SN) biopsy. We sought to quantify the proportion of SN metastases in patients with thin melanoma and to determine the pooled effect of high-risk features of the primary lesion on SN positivity.

METHODS

Published literature between 1980 and 2015 was searched and critically appraised. Primary outcome was the proportion of SN metastases in patients with thin cutaneous melanoma. Secondary outcomes included the effect of high-risk pathological features of the primary lesion on the proportion of SN metastases. Summary measures were estimated by Mantel-Haenszel method using random effects meta-analyses.

RESULTS

Sixty studies (10,928 patients) met the criteria for inclusion. Pooled SN positivity was 4.5 % [95 % confidence interval (CI) 3.8-5.2 %]. Predictors of a positive SN were: thickness ≥0.75 mm [adjusted odds ratio (AOR) 1.90 (95 % CI 1.08-3.34); with a likelihood of SN metastases of 8.8 % (95 % CI 6.4-11.2 %)]; Clark level IV/V [AOR 2.24 (95 % CI 1.23-4.08); with a likelihood of 7.3 % (95 % CI 6.2-8.4 %)]; ≥1 mitoses/mm² [AOR 6.64 (95 % CI 2.77-15.88); pooled likelihood 8.8 % (95 % CI 6.2-11.4 %)]; and the presence of microsatellites [unadjusted OR 6.94 (95 % CI 2.13-22.60); likelihood 26.6 % (95 % CI 4.3-48.9 %)].

CONCLUSIONS

The pooled proportion of SN metastases in thin melanoma is 4.5 %. Thickness ≥0.75 mm, Clark level IV/V, mitoses, and microsatellites significantly increased the odds of SN positivity and should prompt strong consideration of SN biopsy.

Molecular techniques for predicting behaviour in melanocytic neoplasms

Molecular tools are rapidly emerging as novel tools for clinicians caring for cancer patients. Roles for these assays in melanocytic neoplasms include diagnosis for histologically ambiguous tumors, prognosis for conventional melanoma, and theragnosis for advanced disease. The introduction of these molecular strategies is timely, as different therapeutic options are rapidly developing to treat melanoma. With the development of new and effective therapeutic options, it is more critical than ever to improve the discrimination between patients with aggressive disease and those with more indolent tumours. In this review, we will evaluate the traditional staging of melanoma and what are the likely greatest opportunities for improvement with molecular strategies. We will explore a number of molecular assays that are now commercially available for the assessment of melanocytic neoplasms, which include techniques such as fluorescence in situ hybridisation, comparative genomic hybridisation, mRNA expression profiling and next generation sequencing, and discuss the optimal utilisation of each of these assays.

Surgical Management of Melanoma

The surgical management of melanoma has undergone considerable changes over the past several decades, as new strategies and treatments have become available. Surgeons play a pivotal role in all aspects of melanoma care: diagnostic, curative, and palliative. There is a high potential for cure in patients with early-stage melanoma and the selection of an appropriate operation is very important for this reason. Staging the nodal basin has become widespread since the adoption of sentinel lymph node biopsy (SLNB) for the management of melanoma. This operation provides the best prognostic information that is currently available for patients with melanoma. The surgeon plays a central role in the palliation of symptoms resulting from nodal disease and metastases, as melanoma has a propensity to spread to almost any site in the body.

How staging of thin melanoma is changed after the introduction of TNM 7th edition: a population-based analysis

INTRODUCTION

In 2009, the American Joint Committee on Cancer (AJCC) incorporated the tumor mitotic rate in the melanoma pathological TNM staging system. To investigate the effect of this change on the pT1 substaging of primary cutaneous melanomas, we reclassified the cases collected by a cancer registry according to the 6th and the 7th editions of AJCC melanoma staging.

METHODS

Patients with pathological T1 melanoma diagnosed in the period 2000-2008 were selected from Tuscan Cancer Registry. The histological reports were reviewed and pT1 melanomas classified according to both the 6th and the 7th editions of the AJCC staging system. The shift of melanomas between pT1 substages was analyzed.

RESULTS

Among the 242 pT1 melanomas collected in the study period and with mitotic index available, there were 202 (83 % of all pT1) and 175 (72 %) pT1a, according to the 6th and the 7th editions of the AJCC melanoma staging, respectively. When the 7th edition was used, 20 % of all pT1a melanomas shifted to pT1b, and 32 % of all pT1b melanomas shifted to pT1a. A poor level agreement between the two TNM staging systems, measured by the Cohen's kappa coefficient, was found (K = 0.37).

CONCLUSIONS

The addition of mitotic activity to the pathological staging resulted in an increase in pT1b proportion and in a change in the classification of some cases. This modification could influence the clinical approach, with a different use of the sentinel lymph node biopsy, and underlines the role of mitosis evaluation in the management of thin melanoma patients.

A retrospective, multicenter analysis of the predictive value of mitotic rate for sentinel lymph node (SLN) positivity in thin melanomas

BACKGROUND

There is a paucity of studies to substantiate whether the presence of a single mitosis justifies sentinel lymph node (SLN) biopsy (SLNB) in thin melanomas.

OBJECTIVE

We sought to determine if mitotic rate is associated with SLNB outcome when taking into account other prognostic factors.

METHODS

All cases of melanoma that underwent SLNB in the province of Alberta, Canada, between 2007 and 2013 were reviewed through a provincial tumor database.

RESULTS

A total of 1072 patients fulfilled inclusion criteria. When analyzing all melanomas regardless of thickness, mitotic rate was a good predictor of SLN status. When stratified by Breslow thickness, only intermediate melanomas (1.01-2.0 mm) demonstrated a significant relationship between mitotic rate and positive SLN status (P = .010). For melanomas 1 mm or smaller, mitotic rate was not associated with SLN status. A statistically significant interaction was identified between Breslow thickness and mitotic rate such that for decreasing Breslow depth, the effect of mitotic rate on SLNB status diminished (P = .028).

LIMITATIONS

The study was retrospective in nature. There is underlying variability in mitotic rate reporting methods over time, and between different dermatopathologists.

CONCLUSIONS

Mitotic rate does not have unequivocal utility in predicting SLNB status in thin melanomas. There is a significant interaction between mitotic rate and Breslow depth, such that the predictive value of mitotic rate on SLN positivity may be dependent on Breslow thickness.

[Update on surgical treatment of primary and metastatic cutaneous melanoma]

Melanoma is a common cutaneous tumour. It is of great importance due to its increasing incidence and aggressive behaviour, with metastasis to lymph nodes and internal organs. When suspecting melanoma, excisional biopsy should be performed to obtain complete histological information in order to determine the adverse factors such as ulceration, mitosis rate, and Breslow depth, which influence preoperative staging and provide data for sentinel lymph biopsy decision making. The indicated management for melanoma is wide local excision, observing recommended and well-established excision margins, depending on Breslow depth and anatomical location of the tumour. Therapeutic lymphadenectomy is recommended for patients with clinically or radiologically positive lymph nodes. This article reviews surgical treatment of melanoma, adverse histological factors, sentinel lymph node biopsy, and radical lymphadenectomy. Details are presented on special situations in which management of melanoma is different due to the anatomical location (plantar, subungual, lentigo maligna), or pregnancy.

Tumor Cell Adhesion As a Risk Factor for Sentinel Lymph Node Metastasis in Primary Cutaneous Melanoma

PURPOSE

Less than 20% of patients with melanoma who undergo sentinel lymph node (SLN) biopsy based on American Society of Clinical Oncology/Society of Surgical Oncology recommendations are SLN positive. We present a multi-institutional study to discover new molecular risk factors associated with SLN positivity in thin and intermediate-thickness melanoma.

PATIENTS AND METHODS

Gene clusters with functional roles in melanoma metastasis were discovered by next-generation sequencing and validated by quantitative polymerase chain reaction using a discovery set of 73 benign nevi, 76 primary cutaneous melanoma, and 11 in-transit melanoma metastases. We then used polymerase chain reaction to quantify gene expression in a model development cohort of 360 consecutive thin and intermediate-thickness melanomas and a validation cohort of 146 melanomas. Outcome of interest was SLN biopsy metastasis within 90 days of melanoma diagnosis. Logic and logistic regression analyses were used to develop a model for the likelihood of SLN metastasis from molecular, clinical, and histologic variables.

RESULTS

ITGB3, LAMB1, PLAT, and TP53 expression were associated with SLN metastasis. The predictive ability of a model that included these molecular variables in combination with clinicopathologic variables (patient age, Breslow depth, and tumor ulceration) was significantly greater than a model that only considered clinicopathologic variables and also performed well in the validation cohort (area under the curve, 0.93; 95% CI, 0.87 to 0.97; false-positive and false-negative rates of 22% and 0%, respectively, using a 10% cutoff for predicted SLN metastasis risk).

CONCLUSION

The addition of cell adhesion-linked gene expression variables to clinicopathologic variables improves the identification of patients with SLN metastases within 90 days of melanoma diagnosis.

Comparative effectiveness in melanoma

The worldwide incidence of melanoma continues to rise. It is a leading cause of cancer death and the second leading cause of loss of productive years of life. Although the diagnosis of melanoma is straightforward, there remain many controversies regarding treatment and surveillance. This chapter addresses important questions in melanoma treatment such as sentinel lymph node biopsy, what to do with a positive sentinel lymph node, margins of resection for melanoma, radiation for primary, nodal and metastatic melanoma, and routine use imaging. Through this chapter, the evidence for these controversial subjects and the barriers to resolution will be elucidated.

Follow-up in patients with low-risk cutaneous melanoma: is it worth it?

Follow-up examinations in melanoma aim to detect recurrences or secondary melanomas in an early phase of development. Follow-up guidelines that have been developed in many European countries, the USA and Australia show varying recommendations and are controversial, especially in patients with melanomas of 1.0 mm tumor thickness or less. This group contains 50-70% of all melanoma patients and the majority is unlikely to develop recurrences. On the other hand, within this entity, subgroups at higher risk for recurrences can be defined who require a more intense follow-up. This article discusses recommendations for the frequency, duration and costs of follow-up in low-risk melanoma patients. Patient preferences are addressed and a risk-adapted follow-up scheme is proposed.

A review of sentinel lymph node biopsy for thin melanoma

INTRODUCTION

Although there is a lack of established survival benefit of sentinel lymph node biopsy (SLNB), this technique has been increasingly applied in the staging of patients with thin (≤1.00 mm) melanoma (T1Nx), without clear supportive evidence.

METHODS

We review the guidelines and available literature on the indications and rationale for performing SLNB in thin melanoma.

RESULTS

As a consequence of the paucity of evidence of SLNB in thin melanoma, there is considerable variability in the guidelines. It is difficult to define clinicopathologic factors that reliably predict the presence of nodal metastasis. SLNB does not yet inform management in thin melanoma to improve survival outcome.

CONCLUSION

Based on available evidence, high risk patients with melanomas between 0.75 and 1.00 mm may be appropriate candidates to be considered for SLN biopsy after discussing the likelihood of finding evidence of nodal progression, the risks of sentinel node biopsy, and the lack of proven survival benefit from any form of surgical nodal staging.

Prediction of survival in patients with thin melanoma: results from a multi-institution study

PURPOSE

Cutaneous melanoma incidence is increasing. Most new cases are thin (≤ 1 mm) with favorable prognoses, but survival is nonetheless variable. Our aim was to investigate new prognostic factors and construct a nomogram for predicting survival in individual patients.

PATIENTS AND METHODS

Data from 2,243 patients with thin melanoma were retrieved from prospectively maintained databases at six centers. Kaplan-Meier survival and crude cumulative incidences of recurrence were estimated, and competing risks were taken into account. Multivariable Cox regression was used to investigate survival predictors.

RESULTS

Median follow-up was 124 months (interquartile range, 106 to 157 months); 12-year overall survival was 85.3% (95% CI, 83.4% to 87.2%). Median times to local, regional, and distant recurrence were 79, 78, and 107 months, respectively. Relapse was significantly related to age, Breslow thickness, mitotic rate (MR), ulceration, lymphovascular invasion (LVI), and regression; incidence was lower and subgroup differences were less marked for distant metastasis than for regional relapse. The worst prognosis categories were age older than 60 years, Breslow thickness more than 0.75 mm, MR ≥ 1, presence of ulceration, presence of LVI, and regression ≥ 50%. Breslow thickness more than 0.75 mm, MR ≥ 1, presence of ulceration, and LVI (all P = .001) were significantly associated with sentinel node positivity. Age, MR, ulceration, LVI, regression, and sentinel node status were independent predictors of survival and were used to construct a nomogram to predict 12-year overall survival. The nomogram was well calibrated and had good discriminative ability (adjusted Harrell C statistic, 0.88).

CONCLUSION

Our findings suggest including LVI and regression as new prognostic factors in the melanoma staging system. The nomogram appears useful for risk stratification in clinical management and for recruiting patients to clinical trials.

The role of sentinel lymph node biopsy for thin cutaneous melanomas of the head and neck

From 18% to 35% of cutaneous melanomas are located in the head and neck, and nearly 70% are thin (Breslow thickness ≤ 1 mm). Sentinel lymph node biopsy (SLNB) has an established role in staging of intermediate-thickness melanomas, however its use in thin melanomas remains controversial. In this article, we review the literature regarding risk factors for occult nodal metastasis in thin cutaneous melanoma of the head and neck (CMHN). Based on the current literature, we recommend SLNB for all lesions with Breslow thickness ≥ 0.75 mm, particularly when accompanied by adverse features including mitotic rate ≥ 1 per mm(2), ulceration, and extensive regression. SLNB should also be strongly considered in younger patients (e.g. < 40 years old), especially in the presence of additional adverse features. All patients who do not proceed with sentinel lymph node biopsy must be carefully followed to monitor for regional relapse.

Sentinel lymph node biopsy in melanoma: controversies and current guidelines

ABSTRACT: 

Melanoma is a global health problem and the incidence of this disease is rising. While localized melanoma has an excellent prognosis, regional and distant disease is associated with much poorer outcomes. Optimal treatment for clinically localized melanoma requires surgical control of the primary site and accurate staging of the regional nodal basin with sentinel lymph node biopsy (SLNB). While further data are required to determine if SLNB is associated with a survival advantage, currently available data supports the use of SLNB for staging of appropriate patients and the procedure may offer benefits beyond staging. This article reviews current data that shapes guidelines regarding patient selection for SLNB in melanoma and highlights areas where performing this procedure remains controversial.

Tumor-infiltrating lymphocytes and their significance in melanoma prognosis

The role of the tumor-infiltrating lymphocyte (TIL) and its relationship to prognosis has been most extensively studied in malignant melanoma. The purpose of this chapter is to discuss in depth the immunobiology and molecular aspects of lymphocyte function in general and particularly TIL function in the context of antimelanoma immunity. Emphasis is placed upon the role of these inflammatory mediators in the enhancement and impairment of progression of this often fatal human cancer. In addition, the analysis of TILs in melanoma and their direct relationship to prognosis as well as their effect on the positivity of the sentinel lymph node will be discussed. Furthermore, details of lymph node responses to metastatic melanomas and their prognostic significance will be clarified. Finally, the importance of TILs for the evaluation of therapeutic response and how TIL immunobiology could critically inform the design of novel melanoma immunotherapeutic protocols will be elucidated.

Managing malignant melanoma

The incidence of melanoma is increasing worldwide. Melanomas represent 3 percent of all skin cancers but 65 percent of skin cancer deaths. Melanoma is now the fifth most common cancer diagnosed in the United States. Excisional biopsy should be performed for lesions suspicious for melanoma. The pathologist's report provides essential information for surgical treatment; the most important information is the Breslow depth of the lesion. In addition to wide surgical excision of the primary lesion, sentinel lymph node biopsy is the standard of care for early identification of regional metastasis. Nodal metastasis found in the sentinel lymph node biopsy should be followed with a complete lymph node dissection. Although surgery remains the primary treatment of melanoma, recent advances in chemotherapy may offer further survival benefits to patients with metastatic disease.

Clinicopathologic predictors of sentinel lymph node metastasis in thin melanoma

PURPOSE

Indications for sentinel lymph node biopsy (SLNB) for thin melanoma are continually evolving. We present a large multi-institutional study to determine factors predictive of sentinel lymph node (SLN) metastasis in thin melanoma.

PATIENTS AND METHODS

Retrospective review of the Sentinel Lymph Node Working Group database from 1994 to 2012 identified 1,250 patients who had an SLNB and thin melanomas (≤ 1 mm). Clinicopathologic characteristics were correlated with SLN status and outcome.

RESULTS

SLN metastases were detected in 65 (5.2%) of 1,250 patients. On univariable analysis, rates of Breslow thickness ≥ 0.75 mm, Clark level ≥ IV, ulceration, and absence of regression differed significantly between positive and negative SLN groups (all P < .05). These four variables and mitotic rate were used in multivariable analysis, which demonstrated that Breslow thickness ≥ 0.75 mm (P = .03), Clark level ≥ IV (P = .05), and ulceration (P = .01) significantly predicted SLN metastasis with 6.3%, 7.0%, and 11.6% of the patients with these respective characteristics having SLN disease. Melanomas < 0.75 mm had positive SLN rates of < 5% regardless of Clark level and ulceration status. Median follow-up was 2.6 years. Melanoma-specific survival was significantly worse for patients with positive versus negative SLNs (P = .001).

CONCLUSION

Breslow thickness ≥ 0.75 mm, Clark level ≥ IV, and ulceration significantly predict SLN disease in thin melanoma. Most SLN metastases (86.2%) occur in melanomas ≥ 0.75 mm, with 6.3% of these patients having SLN disease, whereas in melanomas < 0.75 mm, SLN metastasis rates are < 5%. By using a 5% metastasis risk threshold, SLNB is indicated for melanomas ≥ 0.75 mm, but further study is needed to define indications for SLNB in melanomas < 0.75 mm.

Clark level risk stratifies patients with mitogenic thin melanomas for sentinel lymph node biopsy

BACKGROUND

The role for sentinel lymph node biopsy (SLNB) in patients with thin melanoma (≤1 mm) remains controversial. We examined a large cohort of patients with thin melanoma to better define predictors of SLN positivity.

METHODS

From 1995 to 2011, 781 patients with thin primary melanoma and evaluable clinicopathologic data underwent SLNB at our institution. Predictors of SLN positivity were determined using univariate and multivariate regression analyses, and patients were risk-stratified using a classification and regression tree (CART) analysis.

RESULTS

In the study cohort (n = 781), 29 patients (3.7%) had nodal metastases. In the univariate analysis, mitotic rate [odds ratio (OR) = 8.11, p = 0.005], Clark level (OR 4.04, p = 0.003), and thickness (OR 3.33, p = 0.011) were significantly associated with SLN positivity. In the multivariate analysis, MR (OR 7.01) and level IV-V (OR 3.45) remained significant predictors of SLN positivity. CART analysis initially stratified lesions by mitotic rate; nonmitogenic lesions (n = 273) had a 0.7% SLN positivity rate versus 5.6% in mitogenic lesions (n = 425). Mitogenic lesions were further stratified by Clark level; patients with level II-III had a 2.9% SLN positivity rate (n = 205) versus 8.2% with level IV-V (n = 220). With median follow-up of 6.3 years, five SLN-negative patients developed nodal recurrence and four SLN-positive patients died of disease.

CONCLUSIONS

SLN positivity is low in patients with thin melanoma (3.7%) and exceedingly so in nonmitogenic lesions (0.7%). Appreciable rates of SLN positivity can be identified in patients with mitogenic lesions, particularly with concurrent level IV-V regardless of thickness. These factors may guide appropriate selection of patients with thin melanoma for SLNB.

Sentinel node biopsy in thin and thick melanoma

BACKGROUND

Although sentinel node biopsy (SNB) has become standard of care in patients with melanoma, its use in patients with thin or thick melanomas remains a matter of debate.

METHODS

This was a retrospective analysis of patients with thin (≤1 mm) or thick (≥4 mm) melanomas who underwent SNB at two Italian centers between 1998 and 2011. The associations of clinicopathologic features with sentinel lymph node positive status and overall survival (OS) were analyzed.

RESULTS

In 492 patients with thin melanoma, sentinel node was positive for metastatic melanoma in 24 (4.9 %) patients. No sentinel node positivity was detected in patients with primary tumor thickness <0.3 mm. Mitotic rate was the only factor significantly associated with sentinel node positivity (p = 0.0001). Five-year OS was 81 % for patients with positive sentinel node and 93 % for negative sentinel node (p = 0.001). In 298 patients with thick melanoma, 39 % of patients had positive sentinel lymph nodes (median Breslow thickness 5 mm). In patients with positive sentinel node, 93 % had mitotic rate >1/mm(2). Five-year OS was 49 % for patients with positive sentinel lymph nodes and 56 % for patients with negative sentinel nodes (p = 0.005).

CONCLUSIONS

The rate of sentinel node positivity in patients with thin melanoma was 4.9 %. The only clinicopathologic factor related to node positivity was mitotic rate. Given its prognostic importance, SNB should be considered in such patients. SNB should also be the standard method for melanoma ≥4 mm, not only for staging, but also for guiding therapeutic decisions.