Sentinel lymph node biopsy in patients with thin primary cutaneous melanoma

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.

Absence of Tumor-Infiltrating Lymphocyte Is a Reproducible Predictive Factor for Sentinel Lymph Node Metastasis: A Multicenter Database Study by the Brazilian Melanoma Group

Aims

The aim of this study is to confirm the function of tumor-infiltrating lymphocytes (TILs) in sentinel lymph node (SLN) metastasis.

Materials and Methods

This retrospective study included 633 patients with invasive melanoma who underwent sentinel lymph node biopsy in 7 referral centers certified by the Brazilian Melanoma Group. Independent risk factors of sentinel node metastasis (SNL) were identified by multiple logistic regression.

Results

SLN metastasis was detected in 101 of 633 cases (16.1%) and in 93 of 428 patients (21.7%) when melanomas ≤ 1mm were excluded. By multiple logistic regression, the absence of TILs was as an independent risk factor of SLN metastasis (OR = 1.8; 95%CI: 1.1–3.0), in addition to Breslow index (greater than 2.00 mm), lymph vascular invasion, and presence of mitosis.

Conclusion

SLNB can identify patients who might benefit from immunotherapy, and the determination of predictors of SLNB positivity can help select the proper population for this type of therapy. The absence of TILs is a reproducible parameter that can predict SLNB positivity in melanoma patients, since this study was made with several centers with different dermatopathologists.

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.

Current staging and prognostic factors in melanoma

The current American Joint Commission for Cancer staging system for melanoma includes thickness, ulceration, and mitotic index as primary tumor factors for patients with stage I and II disease. Number and size of nodal metastases, presence of satellitosis and in-transit disease, and tumor ulceration status categorize patients with stage III disease. Presence and location of distant metastatic disease and increased lactate dehydrogenase level stratify prognosis in patients with stage IV disease. Factors predictive of sentinel lymph node positivity are also studied, particularly in patients with T1 melanomas, but are not always congruent with those predictive of survival.

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.

Identification of Patients with Intermediate Thickness Melanoma at Low Risk for Sentinel Lymph Node Positivity

INTRODUCTION

Sentinel lymph node (SLN) biopsy is recommended for all patients with intermediate-thickness melanomas. We sought to identify such patients at low risk of SLN positivity.

METHODS

All patients with intermediate-thickness melanomas (1.01-4 mm) undergoing SLN biopsy at a single institution from 1995-2011 were included in this retrospective cohort study. Univariate and multivariate logistic regression determined factors associated with a low risk of SLN positivity. Classification and regression tree (CART) analysis was used to stratify groups based on risk of positivity.

RESULTS

Of the 952 study patients, 157 (16.5 %) had a positive SLN. In the multivariate analysis, thickness <1.5 mm (odds ratio [OR] 0.29), age ≥60 (OR 0.69), present tumor-infiltrating lymphocytes (OR 0.60), absent lymphovascular invasion (OR 0.46), and absent satellitosis (OR 0.44) were significantly associated with a low risk of SLN positivity. CART analysis identified thickness of 1.5 mm as the primary cut point for risk of SLN metastasis. Patients with a thickness of <1.5 mm represented 36 % of the total cohort and had a SLN positivity rate of 6.6 % (95 % confidence interval 3.8-9.4 %). In patients with melanomas <1.5 mm in thickness, the presence of additional low risk factors identified 257 patients (75 % of patients with <1.5 mm melanomas) in which the rate of SLN positivity was <5 %.

CONCLUSIONS

Despite a SLN positivity rate of 16.5 % overall, substantial heterogeneity of risk exists among patients with intermediate-thickness melanoma. Most patients with melanoma between 1.01 and 1.5 mm have a risk of SLN positivity similar to that in patients with thin melanomas.

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.

Skin cancer of the hand: current concepts

Skin cancer accounts for most hand cancers. Prompt recognition of lesions with malignant potential can lead to early treatment and decreased disease burden. Understanding the appropriate diagnostic algorithm for a given lesion facilitates accurate staging, which guides therapy. A multidisciplinary approach that includes hand surgeons, dermatologists, oncologists, and radiation oncologists is often necessary to manage advanced disease. For most invasive tumors, the primary treatment modality remains surgical excision; however, several effective nonsurgical treatments exist for management of unresectable or low-grade cancers.

Cutaneous malignancy of the head and neck

Most skin cancers of the head and neck are nonmelanoma skin cancers (NMSCs). Basal cell carcinoma and squamous cell carcinoma are the most frequent types of NMSCs. Treatment options including wide local excision, Mohs surgery, sentinel lymph node biopsy, and cervical lymphadenectomy and adjuvant radiation when warranted offer a high cure rate, while balancing excellent functional and cosmetic outcomes. Evaluation by a multidisciplinary team is highly recommended with advanced and aggressive lesions. Avoidance of sunburns and acute sun damage, sunscreen protection, and early identification and evaluation of suspicious lesions remain the first line of defense against skin cancers.

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.

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.

Acral lentiginous melanoma: who benefits from sentinel lymph node biopsy?

BACKGROUND

There are significant clinicopathological, genetic, and biological differences between acral lentiginous melanoma (ALM) and other types of melanoma.

OBJECTIVE

We sought to investigate the use of sentinel lymph node (SLN) biopsy for patients with ALM.

METHODS

This was a retrospective review of 116 patients with primary ALM. Melanoma-specific and disease-free survival were estimated using the Kaplan-Meier method, together with multivariate analyses using the Cox proportional hazards regression model.

RESULTS

All patients were Japanese (48 male and 68 female). Metastases in SLN were noted in 13 of 84 patients who underwent SLN biopsy. No patients with thin ALM (≤1 mm) and only 2 patients with nonulcerated ALM had tumor-positive SLN. Patients with positive SLN had significantly shorter melanoma-specific survival (5-year survival rate, 37.5% vs 84.3%; P < .0001) and disease-free survival (5-year survival, 37.5% vs 77.9%; P = .0024). Among patients with thick (>1 mm) ALM, the influence of SLN positivity on melanoma-specific survival was increased (5-year survival, 22.7% vs 80.8%; P = .0005).

LIMITATIONS

This was a retrospective study and had a small sample size.

CONCLUSIONS

SLN biopsy should be considered for patients with thick or ulcerated ALM. For patients with thin or nonulcerated ones, it may be of limited importance.

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.

Perioral lesions and dermatoses

The purpose of this article is to review the common neoplasms, infections, and inflammatory dermatoses that may present around or near the mouth. Dental professionals are well positioned to evaluate perioral skin conditions, further contributing to patients' general health. This article includes a review of seborrheic keratosis, warts, actinic keratoses, actinic cheilitis, and squamous cell carcinoma, among several other perioral cutaneous lesions.

Sentinel node biopsy improves prognostic stratification in patients with thin (pT1) melanomas and an additional risk factor

BACKGROUND

Sentinel lymph node (SLN) biopsy (SLNB) for pT1 melanomas is not generally recognized as a clinical standard. We studied the value of SLNB for pT1 melanoma patients having at least one additional risk factor.

PATIENTS

Among 931 patients with SLNB, 210 had pT1 melanomas. All of the latter showed at least one of the following risk factors: ulceration (4 %) Clark level IV (44 %), nodular growth pattern (11 %), mitoses (59 %), regression (38 %) or age ≤ 40 years (27 %).

RESULTS

In this selected pT1 population, we observed a surprisingly high SLN positivity rate of 18 %. The melanoma-specific overall survival significantly depended on SLN status. Compared with Clark IV, a lower invasion level (Clark II/III) was associated with a higher proportion of positive SLNs (25 vs. 10 %; p < 0.01). There was a trend towards a higher SLN positivity rate in younger patients (p = 0.06). Breslow, ulceration, mitoses, nodular growth pattern, and sex did not reach significance. Regression was significantly more frequently found in very thin melanomas (≤ 0.75 mm) and tended to be significant in this subgroup (p = 0.075).

CONCLUSIONS

SLNB improves prognostic stratification in patients with thin melanomas having an additional risk factor. Clark level IV most likely does not belong to these risk factors. The impact of regression deserves further consideration. Our data suggest that SLNB should be offered to patients with thin melanomas, if ulceration, nodular growth pattern, mitoses, or regression are present, or if the patient is younger than 40 years of age.

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.

Impact of the 2009 (7th edition) AJCC melanoma staging system in the classification of thin cutaneous melanomas

CONTEXT

The 7th (2009) edition of the AJCC melanoma staging system incorporates tumor (Breslow) thickness, MR, and ulceration in stratifying T1 primary melanomas. Compared to the prior 6th (2001) edition, MR has replaced CL for thin melanomas.

OBJECTIVE

We sought to identify and report differences of the classification of thin melanomas as well as outcome of SLNB in patients according to the 6th and 7th editions at our institution.

RESULTS

106 patients were identified with thin melanomas verified by wide excision. 31 of 106 thin melanomas were reclassified according to the 7th edition of the AJCC. Of those 31, 15 CL II/III patients (6th edition T1a) were reclassified as T1b based on the presence of mitoses while 16 CL IV patients (6th edition T1b) were categorized as T1a based on the absence of mitoses. 26/31 reclassified patients underwent SLNB, and all were negative. Patients with thin melanoma and a +SLNB (N = 3) were all classified as T1b according to both staging systems.

CONCLUSIONS

In our experience, 29% of thin melanomas were reclassified according to the 7th edition with similar proportions of patients re-distributed as T1a (14%) and T1b (15%). Cases with +SLN corresponded with T1b lesions in both 6th and 7th editions.

Outcomes and prognostic factors in superficial spreading melanoma

BACKGROUND

Prognostic factors and risk factors for positive sentinel lymph node (SLN) biopsy results are important to identify in superficial spreading melanoma (SSM).

METHODS

A single-center database and a prospective clinical trial database were reviewed for all patients with diagnoses of SSM. Logistic regression, Kaplan-Meier survival analysis, and univariate and multivariate Cox models were used.

RESULTS

A total of 1,643 patients with SSM were identified. Independent risk factors for positive SLN biopsy results were Breslow thickness (BT) ≥2.0 mm, age <60 years, and presence of ulceration. BT ≥2.0 mm, ulceration, lymphovascular invasion, and positive SLN and positive non-SLN biopsy results were independent risk factors for worse disease-free survival. Independent overall survival risk factors included BT ≥2.0 mm, age ≥60 years, ulceration, nonextremity tumor location, lymphovascular invasion, and positive SLN biopsy results.

CONCLUSIONS

BT, ulceration, lymphovascular invasion, and SLN and non-SLN status are important risk factors for SSM.

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.

An opportunity to ensure high-quality melanoma care through the use of a preoperative treatment algorithm

BACKGROUND

Studies have demonstrated variable adherence to published melanoma treatment guidelines. Payers have used algorithms to preapprove certain tests and treatments. Our objective was to develop a preoperative treatment assessment algorithm to ensure patients with melanoma receive recommended care.

METHODS

A treatment algorithm was developed using existing guidelines. Records of patients presenting with melanoma between September 2010 and May 2012 were reviewed. Surgical care was classified as having been adherent or nonadherent with the guideline-based algorithm. The algorithm was incorporated into a Web site for preoperative treatment verification.

RESULTS

A treatment algorithm was developed on the basis of three critical pieces of preoperative data: Breslow thickness, presence of adverse primary tumor prognostic factors, and regional lymph node metastases. Treatment options included wide local excision (WLE), sentinel lymph node biopsy (SLNB), and completion/formal lymph node dissection. Of 328 patients evaluated, 316 (96%) were treated according to the guideline-based algorithm. Causes of variation from predicted treatment included patient preference, severe comorbidities, difficult tumor location, and uncertain depth. All departures (n = 12) were in clinically node-negative patients: six patients did not undergo SLNB as indicated, and six underwent SLNB that was not concordant with the algorithm. An algorithm-embedded Web site was designed for preoperative verification of planned procedures.

CONCLUSIONS

As a proof of principle, an algorithm was developed to preoperatively verify that proposed melanoma treatments are concordant with established guidelines. These three pieces of information could be required during precertification, and nonconcordant treatment plans could prompt a peer-to-peer discussion. After additional pilot testing, the algorithm could offer a novel approach for quality improvement and provide a preoperative, prospective safeguard to ensure high-quality care for melanoma patients.

Evidence-based clinical practice guidelines on the use of sentinel lymph node biopsy in melanoma

Sentinel lymph node biopsy (SLNB) was introduced in 1992 to allow histopathologic evaluation of the "sentinel" node, that is, the first node along the lymphatic drainage pathway from the primary melanoma. This procedure has less risk of complications than a complete lymphadenectomy, and if the sentinel node is uninvolved by tumor the likelihood a complete lymphadenectomy would find metastatic disease in that nodal basin is very low. SLNB is now widely used worldwide in the staging of melanoma as well as breast and Merkel cell carcinomas. SLNB provides safe, reliable staging for patients with clinically node-negative melanomas 1 mm or greater in thickness, with an acceptably low rate of failure in the sentinel node-negative basin. Evidence-based guidelines jointly produced by ASCO and the Society of Surgical Oncology (SSO) recommend SLNB for patients with intermediate-thickness melanomas and also state that SLNB may be recommended for patients with thick melanomas. Major remaining areas of uncertainty include the indications for SLNB in patients with thin melanomas, pediatric patients, and patients with atypical melanocytic neoplasms; the optimal radiotracers and dyes for lymphatic mapping; and the necessity of complete lymphadenectomy in all sentinel node-positive patients.

Sentinel node biopsy is indicated for thin melanomas ≥0.76 mm

BACKGROUND

A consensus for which patients with thin melanomas (≤1 mm) should undergo sentinel lymph node biopsy (SLNB) is not established. We describe a large single institution experience with SLNB for thin melanomas to determine factors predictive of nodal metastases.

METHODS

Retrospective review from 2005 to 2010 identified 271 patients with thin melanomas who underwent SLNB, along with 13 additional patients not treated with SLNB who developed a nodal recurrence as first site of recurrence. Clinicopathologic characteristics were correlated with nodal status and outcome.

RESULTS

Median age was 55 years, and 53% of patients were male. Median Breslow thickness was 0.85 mm. Overall, a positive sentinel lymph node (SLN) was found in 22 (8.1%) of 271 cases; 8.4% of melanomas ≥0.76 mm were SLN positive with 5% of T1a melanomas ≥0.76 mm and 13% of T1b melanomas ≥0.76 mm having SLN metastases. Only two of 33 highly selected patients with melanomas <0.76 mm (both T1b) had a positive SLN. Logistic regression analysis demonstrated that mitotic rate ≥1/mm(2) significantly correlated with nodal disease (p < 0.05) and ulceration correlated with SLN metastases (p < 0.05). Median follow-up was 2.1 years. Overall survival did not differ between positive and negative SLN patients (p = 0.53) but was worse for patients presenting with a nodal recurrence (p < 0.01).

CONCLUSIONS

SLN metastases were seen in 8.4% of thin melanomas ≥0.76 mm, including 5% of T1a melanomas ≥0.76 mm. We believe these rates are sufficient to justify consideration of SLNB in these patients, while the indications for SLNB in melanomas <0.76 mm remain to be defined.

Surgical treatment of malignant melanoma: practical guidelines

Melanoma is currently the fifth and sixth most common solid malignancy diagnosed in men and women, respectively. Although accounting for only 4% of cases of all cutaneous malignancies, melanoma accounts for more than 75% of all deaths from skin cancer. This article discusses epidemiology and risk factors, proper biopsy technique, advanced histologic evaluation of biopsy material, assessment of tumor thickness and staging, preoperative metastatic evaluation, excision margin, treatment of regional lymph nodes, treatment of recurrence, and some special clinical situations.