No indication for performing sentinel node biopsy in melanoma patients with a Breslow thickness of less than 0.9 mm

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 efficacy of 99mTc-rituximab as a tracer for sentinel lymph node biopsy in cutaneous melanoma patients

Background

The sentinel lymph node (SLN) status is a vital prognostic factor for malignant melanoma (MM) patients. There is increasing evidence that a radioactive agent, rather than its combination with blue dye, is sufficient for a SLN biopsy (SLNB). Thus, we discussed the efficacy of ^99mTc-rituximab as a tracer in MM patients.

Methods

A total of 502 consecutive patients with MM who underwent SLNB were enrolled in this study. All participants were peritumorally injected with ^99mTc-rituximab before imaging, and scanned with single-photon emission computed tomography-computed tomography (SPECT-CT) to detect the number and location of the SLN. A gamma detection probe was employed to detect radioactive SLNs in operation. Follow up was conducted to observe whether nodal or distant recurrence occurred.

Results

The SLNs were successfully imaged via SPECT-CT and harvested from all 502 participants. No drainage tube was indwelled and 32 (6.3%) participants experienced the following complications: seroma (n=26, 5.2%), wound infections or lymphangitis (n=6, 1.2%), sensory nerve injuries (n=4, 0.8%). There were 380 patients who were diagnosed as SLN-negative and 122 (24.2%) were SLN-positive. A total of 85 SLN-positive patients received complete lymph node dissection, and 28 (32.9%) had additional positive lymph nodes. During a median follow-up of 24 months, 28 participants were found to have a false negative (FN) SLN. The FN rate was 18.7%. A higher T stage was a predictive factor for FN [odds ratio (OR) 1.77; P<0.05]. There was no significant difference in the positive or FN rate between the acral and cutaneous groups.

Conclusions

The radiopharmaceutical ^99mTc-rituximab could be employed as a simple and safe tracer in acral and cutaneous melanoma SLN biopsies.

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.

Sentinel Lymphadenectomy in Cutaneous Melanoma

Aims and Background

In the last ten years validation of the sentinel lymph node (SLN) concept has led to modification of the surgical approach for patients with intermediate-risk cutaneous melanoma.

Methods and Study Design

Forty-eight patients affected by cutaneous melanoma with a Breslow thickness between 0.65 and 4 mm were enrolled in the study. Approximately 2 mCi of radiotracer and 1 mL of vital blue dye were injected in each patient around the site of the primary lesion. Lymphoscintigraphy was performed until the lymphatic basin and the respective SLN were localized. The whole surgical procedure consisted of enlargement of the surgical margins followed by localization and excision of the SLN(s) by using both radiotracer and vital dye. Whenever the SLN proved to be histologically positive for metastasis, complete regional lymphadenectomy was performed.

Results

Within 15 minutes of radiotracer administration the lymphatic basin was localized in all 48 patients by lymphoscintigraphy. Vital dye and radiotracer successfully allowed SLN localization and excision in 46 of 48 patients (97%); in one case the SLN was detected by radiotracer alone. The SLN proved to be metastatic in six (13%) of 46 evaluable patients; interestingly, in three of them the presence of metastatic cells was revealed only by immunohistochemistry. All patients with tumor-positive SLNs had primary lesions with a Breslow thickness = 2 mm.

Conclusions

Sentinel lymphadenectomy is able to identify lymph node involvement in patients with cutaneous melanoma with a Breslow thickness >1 mm, thus avoiding the risks associated with radical regional lymphadenectomy. Lymphoscintigraphy proved to be an important tool to obtain correct preoperative localization of the drainage basin, especially for melanomas located on the face and trunk.

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.

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.

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.

Outcomes in pediatric melanoma: comparing prepubertal to adolescent pediatric patients

OBJECTIVE

The aim of this study was to determine the influence of age on outcome in pediatric melanoma patients and to identify factors associated with positive lymph node status in this population.

METHODS

A retrospective review of a prospective pediatric melanoma database, using sentinel lymph node biopsy (SLNB), from 1992 to 2006, identified 109 patients with the primary diagnosis of melanoma. Patient age was dichotomized as prepubescent (<10 years of age) and adolescent (≥10-18 years of age). Factors investigated included patient race, sex, and lymph node status and tumor thickness, Spitzoid or Non-Spitzoid histology, radial growth phase, and vascular invasion. The Fisher's exact test was used to compare patient groups. Time-to-event analysis was performed using the Kaplan-Meier method.

RESULTS

There were 25 prepubescent and 84 adolescent patients. Prepubescent patients were more often non-White, had greater tumor thickness, more spitzoid tumors and more vascular invasion. Ten-year overall survival (OS) was 89% and 10-year event-free survival (EFS) was 73%. Among 57 patients who had an SLNB, prepubertal patients had a higher percentage of sentinel lymph node positivity. The odds having a positive SLNB decreased by 13% each year with increasing age. Patients with a tumor thickness ≥2.01 mm had higher odds of having a positive lymph node compared with those patients with a tumor thickness ≤1.0.

CONCLUSIONS

This is the largest known study of prepubertal melanoma patients. Although OS and EFS did not differ by age groups, younger ages showed increased risk of lymph node metastasis and thicker tumors. This suggests that the younger pediatric patients may have a disease that differs biologically from that of the older pediatric patients.

Meta-analysis of sentinel lymph node positivity in thin melanoma (<or=1 mm)

BACKGROUND

Despite the lack of an established survival benefit of sentinel lymph node (SLN) biopsy, this technique has been increasingly applied in the staging of thin (

METHODS

MEDLINE, EMBASE, and Cochrane databases were searched for rates of SLN positivity in patients with thin melanoma. The methodologic quality of included studies was assessed using the Methodological Index for Non-Randomized Studies criteria. Heterogeneity was assessed using the Cochran Q statistic, and publication bias was examined through funnel plot and the Begg and Mazumdar method. Overall SLN positivity in thin melanoma patients was estimated using the DerSimonial-Laird random effect method.

RESULTS

Thirty-four studies comprising 3651 patients met inclusion criteria. The pooled SLN positivity rate was 5.6%. Significant heterogeneity among studies was detected (P = .005). There was no statistical evidence of publication bias (P = .21). Eighteen studies reported select clinical and histopathologic data limited to SLN-positive patients (n = 113). Among the tumors from these patients, 6.1% were ulcerated, 31.5% demonstrated regression, and 47.5% were Clark level IV/V. Only 4 melanoma-related deaths were reported.

CONCLUSIONS

Relatively few patients with thin melanoma have a positive SLN. To the authors' knowledge, there are no clinical or histopathologic criteria that can reliably identify thin melanoma patients who might benefit from this intervention. Given the increasing diagnosis of thin melanoma, in addition to the cost and potential morbidity of this procedure, alternative strategies to identify patients at risk for lymph node disease are needed.

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Key Words Collapse

MESH Headings

• Clinical Trials as Topic
• Female
• Humans
• Lymph Node Excision
• Lymphatic Metastasis
• Male
• Melanoma/secondary
• Middle Aged
• Mitosis
• Periodicals as Topic
• Sentinel Lymph Node Biopsy
• Skin Neoplasms/pathology

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Grants

• P30 CA016087 NCI NIH HHS
• 5 P30 CA 016087-27 NCI NIH HHS

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Affiliation(s)

Melanie A. Warycha Department of Dermatology, New York University School of Medicine, New York, NY
Jan Zakrzewski Department of Dermatology, New York University School of Medicine, New York, NY
Quanhong Ni Division of Biostatistics and Epidemiology, Department of Public Health, Weill Medical College of Cornell University, New York, NY
Richard L. Shapiro Department of Surgery, New York University School of Medicine, New York, NY
Russell S. Berman Department of Surgery, New York University School of Medicine, New York, NY
Anna C. Pavlick Department of Dermatology, New York University School of Medicine, New York, NY Department of Medicine, New York University School of Medicine, New York, NY
David Polsky Department of Dermatology, New York University School of Medicine, New York, NY Department of Pathology, New York University School of Medicine, New York, NY
Madhu Mazumdar Division of Biostatistics and Epidemiology, Department of Public Health, Weill Medical College of Cornell University, New York, NY
Iman Osman Department of Dermatology, New York University School of Medicine, New York, NY Department of Medicine, New York University School of Medicine, New York, NY

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Imaging in cutaneous melanoma

Cutaneous melanoma (CM) is a common malignancy and imaging, particularly lymphoscintigraphy (LS), positron-emission tomography with 2-fluoro-2-deoxyglucose (FDG-PET), ultrasound, radiography computed tomography (CT) and magnetic resonance imaging have important roles in staging and restaging, surgical guidance, surveillance and assessment of recurrent disease. This review aims to summarize the available data regarding these and other imaging modalities in CM and provide the basis for subsequent formulation of guidelines regarding the use of imaging in CM. PubMed and Medline searches were performed and reference lists from publications were also searched. The published data were reviewed and tabulated. There is level I evidence supporting the use of LS and sentinel lymph node biopsy in nodal staging for CM. There is level III evidence demonstrating the superiority of ultrasound to palpation in the assessment of lymph nodes in CM. There is level IV evidence supporting FDG-PET in American Joint Committee on Cancer stage III/IV and recurrent CM and that FDG-PET/CT may be superior to FDG-PET. Level IV evidence also supports the use of CT in the same group of patients and the role of CT appears to be complementary to FDG-PET. Various imaging modalities, especially LS/sentinel lymph node biopsy and FDG-PET/CT, add incremental information in the management of CM and the various modalities have complementary roles depending on the clinical situation.

The prognostic importance of sentinel lymph node biopsy in thin melanoma

BACKGROUND

Sentinel lymph node biopsy (SLNB) is prognostically useful in patients with cutaneous melanoma with Breslow thickness > 1 mm. The objective of this study was to determine whether sentinel node histology has similar prognostic importance in patients with thin melanomas (< or = 1 mm).

METHODS

This was a retrospective study of patients who underwent SLNB for clinically localized melanoma at Indiana University Medical Center between 1994 and 2003. SLNB results and traditional melanoma prognostic indicators were studied in univariate log-rank tests.

RESULTS

One hundred eighty-four patients with melanomas < or = 1 mm thick underwent SLNB. SLNB was tumor positive in 12 patients (6.5%). Univariate analysis of SLNB results revealed that Breslow thickness, Clark level of invasion, and mitotic index were associated with SLNB status. Tumor positivity was observed at different rates in tumor thickness subsets: < .75 mm, 2.3%; and .75 to 1.0 mm, 10.2% (P = .0372). Disease-free survival and overall survival were significantly associated with SLNB results in melanomas < or = 1 mm (log-rank test: P < .0001 and P = .0125, respectively) at a median follow-up of 26.3 months.

CONCLUSIONS

SLNB histology in melanomas < or = 1.0 mm deep is a significant predictor of outcome. SLNB should be considered for selected patients with melanomas .75 to 1.0 mm.

Sentinel lymph node status in melanoma: a valuable prognostic factor?

BACKGROUND

Sentinel lymph node (SLN) biopsy is advocated as the standard of care for patients with primary melanoma. It is a procedure with few side-effects and provides valuable staging information about the regional lymphatics.

OBJECTIVES

To investigate the prognostic value of SLN biopsy and to compare it with that of other known risk factors in primary melanoma.

METHODS

One hundred and forty-nine patients with primary melanomas (tumour thickness >1.0 mm) underwent SLN biopsy between May 1998 and April 2004 at our department. This report summarizes the follow-up data of this cohort until October 2004.

RESULTS

SLN biopsies of 49 of 149 patients (33%) revealed micrometastatic disease. Of all clinical and histological criteria, only the clinical type of primary melanoma (11 of 19 patients with acrolentiginous melanomas) and the Clark level were predictive for SLN positivity. Progression was observed in 22 patients (15%). It was significantly associated with ulceration of the primary tumour, tumour thickness, clinical type and localization of the primary tumour, female sex and older age. In contrast, SLN positivity was not significantly associated with a higher risk of progression (eight of 49 SLN-positive vs. 14 of 100 SLN-negative patients; P = 0.807). Twelve of 149 patients (8%) died because of melanoma in the follow-up period. Significant criteria for death were ulceration of the tumour, clinical type and localization of the primary tumour, but not SLN positivity.

CONCLUSIONS

A high percentage of positive SLNs was observed in the patients with melanoma in our study (33%). The fractions of patients both with progressive disease and with tumour-related death were not significantly higher in patients with positive SLN than in those with negative SLN. We therefore conclude that the SLN status is not a reliable prognostic factor for progression of melanoma.

Results of Sentinel Lymph Node Biopsy in Patients With Thin Melanoma

BACKGROUND

Sentinel lymph node (SLN) biopsy has been shown to be a highly accurate method of staging nodal basins in melanoma patients. Although this technique is widely accepted in patients with intermediate-thickness tumors, it is unclear what the indications are for thin (< or = 1 mm) melanoma.

METHODS

From May 1991 to October 2004, 223 patients with thin melanoma underwent SLN biopsy at Memorial Sloan-Kettering Cancer Center. Most patients with thin melanoma were selected for the procedure because of high-risk clinicopathologic features.

RESULTS

Nodal metastases were found in eight patients (3.6%) who underwent SLN biopsy. All positive SLNs were found in patients with > or = .75 mm-thick and Clark level IV melanoma (8 of 114; 7%). Age, sex, tumor location, thickness, Clark level, ulceration, regression, tumor-infiltrating lymphocytes, mitotic rate, and number of mapped nodal basins were not predictive of positive SLNs (chi(2); P = not significant). With a median follow-up of 25 months, there have been no recurrences or deaths in patients with melanoma < .75 mm. Six patients have had regional and/or systemic recurrences (2.7%), only one of whom had a positive SLN. Three patients have died of melanoma; all had negative SLNs.

CONCLUSIONS

Nodal metastasis in thin melanoma is uncommon, especially in patients with < .75 mm and Clark level II or III melanoma. In our experience, no single clinicopathologic factor was predictive of nodal metastases. The prognostic implications of positive SLNs in thin melanoma remain undefined.

American Joint Committee on Cancer Clinical Stage as a Selection Criterion for Sentinel Lymph Node Biopsy in Thin Melanoma

BACKGROUND

A significant proportion of newly diagnosed melanomas are thin lesions (< or = 1.00 mm). Because tumor thickness correlates with the risk for nodal metastases, sentinel lymph node (SLN) biopsy in this subset is controversial. Incorporating other prognostic factors (Clark level and ulceration), we evaluated the 6th edition American Joint Committee on Cancer (AJCC) clinical stage as a simple and widely applicable guideline for offering SLN biopsy for thin melanoma.

METHODS

This study was a review of a prospective melanoma SLN database from 1993 to 2003 with emphasis on SLN positivity rates based on the 6th edition AJCC primary tumor thickness intervals and clinical stage.

RESULTS

Three hundred five patients underwent SLN biopsy, with an overall positivity rate of 17.7%. By the 6th edition AJCC, lesions < or = 1.00 mm had an SLN positivity rate of 6.6%. By 6th edition clinical stage, SLN positivity rates were 4.9% for stage IA and 10.4% for stage IB. By using stage IA as the criterion for not offering SLN biopsy, this procedure would have been avoided in 46% (39 of 85) of < or = 1.00-mm melanoma patients with a negative SLN.

CONCLUSIONS

Sixth edition AJCC clinical stage IB as a selection criterion for performing SLN biopsy in thin melanoma identifies most patients with a positive SLN while also avoiding a negative SLN biopsy in many patients. Until additional widely accepted and validated selection criteria are available, SLN biopsy for clinical stage IB, but not stage IA, thin melanomas is a reasonable approach.

Sentinel node metastasectomy in thin ≤1-mm melanoma

BACKGROUND AND AIMS

Sentinel lymph node biopsy (SLNB) has been widely accepted as a precise tool to stage melanoma. In thin T1 melanomas (<or=1 mm), the indication of SLNB is controversial since the risk of nodal metastasis is low. The aim of this study was to assess if SLNB detects occult nodal metastases among patients with thin melanomas.

PATIENTS AND METHODS

SLNB was performed prospectively in 135 patients with invasive melanoma in any depth category, including 56 T1 melanomas.

RESULTS

Nodal metastases were detected in 18% by SLNB, and there were three sentinel-positive thin melanomas, constituting 5% of the T1 cases. Histopathologically, there were no factors of the primary tumors that would have predicted these metastases.

CONCLUSION

SLNB is a precise method to detect clinically silent nodal metastases in thin invasive melanoma. Certain histopathologic features of a thin primary lesion may correlate with the predictive probability of the sentinel node status. We were unable to identify these predictors, but the conclusions from this study are limited by the small sample size. Advanced melanoma is a lethal disease, and accurate staging is essential also in the T1 group. For stage III patients with occult nodal metastases, metastasectomy is a better option for cure than observation.

Melanoma

The surgical management of melanoma continues to evolve. A large body of information serves as a foundation for the oncologic principles, surgical excisions, and reconstructive methodologies that are currently in use. This article serves as a guide for the physician considering surgical management of the melanoma patient.

Indications for lymphatic mapping and sentinel lymphadenectomy in patients with thin melanoma (Breslow thickness < or =1.0 mm)

BACKGROUND

Patients with thin (Breslow thickness < or =1.0 mm) melanoma have a good prognosis (5-year survival >90%). Consequently, the added benefit of lymphatic mapping and sentinel lymphadenectomy (LM/SL) in these patients is controversial. We hypothesize that LM/SL with a focused examination of the sentinel node (SN) will detect a significant number of SN metastases in patients with thin melanoma and that certain clinical or histopathologic factors may serve as predictors of SN tumor involvement.

METHODS

Over 6 years, 349 patients with melanoma underwent LM/SL and were prospectively entered into an institutional review board (IRB)-approved database. LM/SL was performed with a combined radiotracer and blue dye technique. SNs were serially sectioned, and each section was examined by a dermatopathologist at multiple levels with hematoxylin and eosin as well as immunohistochemical stains.

RESULTS

One hundred forty-six patients (42%) had a melanoma with Breslow thickness < or =1.0 mm; six (4%) of these 146 patients had a tumor-involved SN. On multivariate analysis, none of the clinical or histopathologic factors examined were significantly associated with SN tumor involvement in patients with thin melanoma. Completion lymphadenectomy was performed on all patients with a tumor-involved SN. None of the patients had non-SN tumor involvement.

CONCLUSIONS

The incidence of SN tumor involvement in patients with thin melanoma is considerable. Although we were unable to identify predictors of SN tumor involvement in patients with thin melanoma, efforts to identify predictors of SN tumor involvement should continue. Until better predictors are identified, we continue to advocate offering LM/SL to patients with thin melanomas who demonstrate clinical or histopathologic characteristics that have historically been associated with an increased risk of recurrence and mortality.

Sentinel node biopsy procedures with an analysis of recurrence patterns and prognosis in melanoma patients: technical advantages using computer-assisted gamma probe with adjustable collimation

The purpose of this study was to investigate whether a computer-assisted gamma probe with adjustable collimation could aid in the detection of sentinel nodes (SNs) and to analyse the patterns of recurrence and prognosis in SN-positive and SN-negative cases. We analysed 385 SN biopsies. The SN identification rate was 87.2% using preoperative lymphoscintigraphy and blue dye, 93.9% using preoperative lymphoscintigraphy, blue dye and different probes, and 100% using preoperative lymphoscintigraphy, blue dye and a computer-assisted probe with adjustable collimation. The computer-assisted probe was particularly advantageous in cases where the melanoma was located very close to the SN and in cases of deep-seated nodes or nodes with low uptake, due to the possibility of changing the collimation during the procedure. The SN-positive rate according to the thickness of the primary melanoma was 1.7% for melanomas < or = 1 mm in thickness and 27.5% for melanomas > or = 1 mm. In 4.9% of cases we identified nodes outside the regional nodal basin. In one case we found a micrometastasis in a blue and hot interval node of the lateral abdominal wall. Analysing the node counts registered by the computer-assisted probe, we verified that the blue-positive node for tumour metastases was not the most radioactive node in the field in six out of 52 positive cases (11.5%). Distant metastases were present in 2.0% of SN-negative patients, and in 24% of SN-positive patients (P < 0.001). Highly statistically significant differences were found between SN-negative and SN-positive patients in both the 3 year disease-free survival (86.3% versus 49.2%) and the 3 year disease-specific survival (92.3% versus 77.1%) (P < 0.001).

Five years of sentinel node biopsy for melanoma: the St George's Melanoma Unit experience

Sentinel node biopsy has become an integral part of the management of malignant melanoma. Here, the authors describe the technique that is used at the St George's Hospital Melanoma Unit. Results obtained over the past 5 years on a cohort of patients are presented. Three hundred and forty seven patients were entered in the study. Population demographics were analysed for both the primary melanoma and for sentinel node positive status. Histological features of the primary, particularly regression were noted and, in addition to metastatic disease, the presence of capsular naevus cells within the node also recorded. Complications associated with the procedure have been presented along with the specificity and sensitivity of the technique. The relative influence of both Breslow thickness and sentinel node positivity were analysed statistically and Kaplan-Meier survival curves produced for the cohort as a whole. This confirmed the accuracy of sentinel node biopsy and its role as a prognostic indicator.

Thin melanomas: predictive lethal characteristics from a 30-year clinical experience

OBJECTIVE

To guide treatment and clinical follow-up by defining the natural history of thin melanomas and identifying negative prognostic characteristics that may delineate high-risk patients.

SUMMARY BACKGROUND DATA

In following > 10,000 patients with cutaneous melanoma over the past 30 years, our institution has observed nodal or metastatic disease in approximately 15% of patients with a thin (<1 mm) primary lesion.

METHODS

A database query of patients with cutaneous melanoma returned 1158 patients with primary lesion < or = 1 mm thick and who received their initial treatment at a single institution. Median follow-up was 11 years (range, 1 to 34 years). Patient and melanoma characteristics as well as outcomes were recorded and statistically analyzed.

RESULTS

6.6% of patients had nodal or distant disease at presentation. Over time, an additional 9.4% developed metastases, including nodal and distal recurrences. Overall incidence of advanced disease was 15.3%. Univariate analysis identified male gender (P = 0.01), advanced age (>45 years; P = 0.05), and Breslow thickness (>0.75 mm; P = 0.008) as significant negative prognostic characteristics. Of patients with these 3 high-risk characteristics, 19.7% developed advanced disease (likelihood ratio 6.3; P = 0.007 versus nonhigh-risk patients). This group had more than twice the incidence of nodal recurrences. Patients with recurrence had significantly decreased 10-year survival (82% versus 45%; P < 0.0001). Surprisingly, neither ulceration nor Clark level predicted advanced disease.

CONCLUSIONS

Thin melanomas are potentially lethal lesions. Long-term follow-up identified a high-risk population of older males with tumors between 0.75 mm and 1.0 mm whose risk of recurrent disease approaches 20%. Traditionally accepted negative prognostic factors such as ulceration and discordant Clark levels are not predictive for metastasis in this population. Given the poor prognosis associated with recurrent disease, we recommend close clinical evaluation and follow-up to maximize accurate staging and therapeutic options.

Reassessing the role of lymphatic mapping and sentinel lymphadenectomy in the management of cutaneous malignant melanoma

Lymphatic mapping and sentinel lymphadenectomy was developed as a minimally invasive technique to provide regional lymph node staging information for patients at high risk for metastatic melanoma, but without clinically palpable disease. Only patients who demonstrate micrometastases undergo complete regional lymphadenectomy, sparing approximately 80% of patients the expense and morbidity of an elective lymph node dissection. This technique has been widely accepted as the preferred method to determine the pathologic status of the regional lymph nodes and the staging information gained is incorporated into the latest version of the American Joint Committee on Cancer staging system for cutaneous melanoma. Still, there is much controversy as to the use of this technique as a staging procedure and its overall therapeutic benefit in the treatment of patients with melanoma. Currently ongoing clinical trials will determine if lymphatic mapping and sentinel lymphadenectomy directly influences overall survival for patients with malignant melanoma. We review the latest technical aspects of this procedure and discuss the controversies surrounding its use.

The risk of regional lymph node metastases in patients with melanoma less than 1.0 mm thick: recommendations for sentinel lymph node biopsy

BACKGROUND

Lymphatic mapping and sentinel lymph node biopsy can upstage patients with intermediate thickness (1.0 to 4.0 mm) melanoma. Currently, there are no strict guidelines for sentinel lymph node biopsy in patients with melanoma <1.0 mm thick.

STUDY DESIGN

A retrospective review of our patient database (598 patients treated at two institutions in Baltimore, MD, between January 1970 and June 2002) was performed to identify patients with primary cutaneous melanoma <1.0 mm thick who developed recurrent disease. This cohort of patients with > or =5 years of followup from the date of diagnosis was compared with patients with primary melanoma of similar thickness and similar followup intervals without recurrent disease.

RESULTS

A total of 114 patients with primary cutaneous melanoma <1.0 mm thick were identified, 17 of whom developed disease recurrence. In 13 patients, the site of first recurrence was the regional lymph nodes and in 4 patients disease recurred with distant metastases. The median time to lymph node recurrence was 55 months (range 2 to 112) months. Patients with regional lymph node recurrences had a significant (p = 0.02) difference in median primary tumor thickness of 0.80 mm versus 0.45 mm in patients without recurrent disease; there was no association of Clark level of invasion to recurrence (p = 0.42). In all, 35% of patients (7 of 20) presenting with melanoma 0.80 to 0.99 mm thick developed lymph node recurrence a median of 41 months (range 8 to 112 months) after surgical treatment.

CONCLUSIONS

Sentinel lymph node biopsy can be justified for patients with melanoma > or =0.8 mm thick provided that the technique would detect metastatic disease years before it becomes clinically evident.

Role of sentinel lymph node biopsy in patients with thin (<1 mm) primary melanoma

BACKGROUND

Thin melanomas have become increasingly prevalent, and lesions < or =1 mm in thickness are frequently diagnosed. They are considered highly curable when treated solely with wide local excision, with reported 5-year disease-free survivals of 95% to 98%. However, thin Clark level III and IV melanomas may have increased potentials for metastasizing and late recurrences because of dermal lymphatics located at the interface of the papillary and reticular dermis. We have addressed this controversial area by reviewing the outcomes of patients with invasive thin melanomas.

METHODS

We performed 266 sentinel lymph node biopsy procedures, using both radioisotope and blue dye, over a 5-year period. Sixty-five of the 266 invasive melanomas were thin and were treated by wide local excision and sentinel lymph node biopsy.

RESULTS

Two (3%) of the 65 thin melanomas were found to have a positive sentinel lymph node. In melanomas thinner than.75 mm, no positive sentinel lymph node was found. Therefore, only 3% of patients may benefit from tumor upstaging by sentinel lymph node biopsy.

CONCLUSIONS

The occurrence of regional lymph node metastases in thin melanomas is rather low. Our data suggest that sentinel lymph node biopsy may not justified in patients with melanoma <.75 mm thick.

Sentinel lymph node biopsy for the T1 (thin) melanoma: is it necessary?

The use of sentinel lymph node biopsy for the T1 melanoma is controversial. Recent reports have demonstrated that certain T1 melanomas are at increased risk for early regional metastases and late recurrence when compared with all thin melanomas. The purpose of this study was to review the authors' experience with wide excision and sentinel lymph node biopsy for certain patients with T1 melanoma. A retrospective analysis of 34 patients with T1 melanoma was completed over a 3-year period. Indications for sentinel lymph node biopsy included a Breslow thickness of less than or equal to 1 mm a Clark level of III or IV tumor ulceration, or tumor regression. Twenty-four patients met these criteria (13 men and 11 women). Mean age was 47.6 years (range, 23-88 years). Mean tumor thickness for all patients was 0.69 mm (range, 0.3-1.0 mm), 0.61 mm for the Clark level III patients (N = 15), and 0.72 mm for the Clark level IV patients (N = 9). Tumor ulceration was present in 1 patient and histological regression was present in 2 patients. Regional lymph node metastases were confirmed histologically in 2 of 24 patients (8.3%) in whom the thickness of the melanoma was 0.9 mm and 1 mm. Both patients have died of metastatic melanoma. No recurrence has been demonstrated in the remaining 22 patients at the 2 to 5-year follow-up. Current indications for sentinel lymph node biopsy for patients with T1 melanoma include tumors associated with Clark level IV or V invasion, ulceration, regression, a positive deep margin on initial biopsy, or previous melanoma. Acral lentiginous melanoma associated with at least a Clark level III invasion warrant sentinel lymph node biopsy. Superficial spreading or nodular melanoma larger than 0.9 mm should include sentinel lymph node biopsy regardless of other associated histological factors.

Sentinel lymph node biopsy for patients with cutaneous desmoplastic melanoma

BACKGROUND

Although desmoplastic melanoma (DM) often presents at a locally advanced stage, nodal metastases are rare. We describe our experience with lymphatic mapping and sentinel lymph node biopsy (SLNB) in patients with DM to characterize the biological behavior of these tumors.

METHODS

Twenty-seven patients with cutaneous DM underwent wide excision and attempted SLNB between 1996 and 2001. All pathology was reviewed by a single dermatopathologist (KB). Clinical and histological features were recorded.

RESULTS

There were 20 male and 7 female patients. The median age was 64 years (range, 35-83 years). The head and neck was the most commonly involved anatomical region (n = 14). The median Breslow thickness was 2.2 mm. Twenty-four patients underwent successful SLNB. No patient had a positive sentinel node. At a median follow-up of 27 months, five patients recurred (four systemic and one local); all five had undergone successful SLNB. Two of these patients died of disease, two are alive with disease, and one remains alive and disease free. No patient experienced failure in a regional nodal basin.

CONCLUSIONS

DM is a biologically distinct form of melanoma, with a very low incidence of regional lymph node metastases, either at presentation or in long-term follow-up. This biology should be considered when designing rational treatment strategies for these patients.

How morphometric analysis of metastatic load predicts the (un)usefulness of PET scanning: the case of lymph node staging in melanoma

BACKGROUND

In primary cutaneous melanoma, the sentinel node (SN) biopsy is an accurate method for the staging of the lymph nodes. Positron emission tomography (PET) has been suggested as a useful alternative. However, the sensitivity of PET may be too low to detect SN metastases, which are often small.

AIM

To predict the value of PET for initial lymph node staging in melanoma based on morphometric analysis of SN metastatic load, without exposing patients to PET.

MATERIALS AND METHODS

In 59 SN positive patients with melanoma, the sizes of tumour deposits in the SNs and subsequent dissection specimens were measured by morphometry and correlated with the detection limits of current and future PET scanners.

RESULTS

The median tumour volume within the basin was 0.15 mm(3) (range, 0.0001-118.86). Seventy per cent of these deposits were smaller than 1 mm(3). State of the art PET scanners that have a resolution of about 5 mm would detect only 15-49% of positive basins. Logistic regression analysis revealed no pretest indicators identifying patients expected to have a positive PET. However, the SN tumour load was a significant and single predictor of the presence of PET detectable residual tumour.

CONCLUSION

Morphometric analysis of metastatic load predicts that PET scanning is unable to detect most metastatic deposits in sentinel lymph nodes of patients with melanoma because the metastases are often small. Therefore, the SN biopsy remains the preferred method for initial regional staging.