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

A Retrospective Cohort Study on Patients with Lentigo Maligna Melanoma

BACKGROUND

More epidemiological data about lentigo maligna melanoma (LMM) are required to define follow-up guidelines. The study focused on recurrence, progression, and overall survival of LMM managed with primary wide local excision.

METHODS

In a 23-year retrospective study (1994 to 2016), a cohort of patients with LMM was evaluated by collecting data about the tumor location, the Breslow depth, the presence of ulceration, and patients' age and sex. Local recurrences, locoregional and distant metastases, and disease-free and overall survival were additionally assessed.

RESULTS

Overall, 150 cases (84 male, 66 female, mean age 71.3 ± 11.3 years) of single, localized, primary LMM with a mean follow-up of 6.6 ± 4.4 years were included. A total of 33 (22.2%) patients underwent sentinel lymph node biopsy (SLNB) during surgical excision. However, positive SLNB was detected in none of them. The multivariable Cox analysis indicated that age of diagnosis and male gender significantly influenced the overall survival, while a shorter disease-free survival could be correlated with a greater Breslow thickness. The metastatic potential turned out to be low, entailing 7 deaths in the context of the LMM.

CONCLUSION

Male gender, age over 70 at diagnosis, and a Breslow thickness greater than 0.75 mm were associated with a statistically significant decrease in overall disease-free survival in the current study. The results of the study confirm the favorable outcome of LMM. However, diagnosed patients should undertake regular follow-ups. The intensity of follow-up in these patients can be individualized based on the probability of recurrence/metastasis and overall survival. Furthermore, the study showed that SLNB might not be a necessary staging procedure in patients with LMM.

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 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.

Acral lentiginous melanoma of the foot misdiagnosed as a traumatic ulcer. A cautionary case

The incidence of cutaneous melanoma is rising faster than that of almost any other cancer in the United States. Acral lentiginous melanoma is a subtype of melanoma that involves the palms, soles, and nail beds. Although it is one of the rarer types of melanoma, it has a poorer prognosis than other more common subtypes. We describe a case of plantar acral melanoma in a 66-year-old woman that was initially misdiagnosed as a traumatic foot ulcer. We highlight this case to emphasize the importance of close observation and biopsy of ulcerative lesions of the foot that have atypical features or are refractory to standard treatment.

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.

Outcome of sentinel lymph node biopsy and prognostic implications of regression in thin malignant melanoma

Thin melanomas with partial or complete regression may provide clues about antitumor immunity, but their management remains controversial. We have characterized the management and clinical outcomes of regressed thin (<1 mm) T1a melanomas and hypothesized that regression increases the risk of regional metastases when compared with nonregressed thin melanomas. A prospectively collected clinical database was reviewed, and T1a melanomas with regression were identified. Histology, surgical approach, outcome, and survival were evaluated. The primary outcome measures were sentinel node positivity, subsequent lymph node metastasis, and survival. A total of 75 patients with T1a or in-situ melanomas were grouped into three subsets. Group 1: 35 underwent a sentinel node biopsy (SNBx), none of which were positive. No patients developed nodal recurrence. The 5-year survival of this group was 93%, with a median follow-up of 52 months. Group 2: 31 were followed up without SNBx; two developed regional nodal disease (6.5%), neither of whom died of subsequent distant disease. The 5-year survival was 89%, with a median follow-up of 38 months. There was no significant difference in the survival between groups 1 and 2. Group 3: nine patients presented with metastatic disease concurrent with a regressed thin melanoma. These patients had a median survival of 2.3 years and a 4-year survival estimate of 22%. Regression should not be used as an indication for SNBx in T1a melanomas; we recommend that such patients be managed with wide local excision and a long-term clinical follow-up. The poor prognosis of thin regressed primary melanoma with simultaneous metastatic disease may indicate the existence of immune escape phenotypes supporting melanoma progression.

Head and neck melanoma

Nearly 20% of malignant melanoma in the human body occurs in the head and neck. Most studies divide the sites of origin of malignant melanoma in the head and neck into the following areas: the face, the scalp and neck, the external ear, and the eyelid or medial or lateral canthal area. Sixty-five percent of malignant melanomas occur in the facial region. Given that the face represents only 3.5% of total body surface area, the face is overrepresented when compared with other sites in the head and neck. Among the sites of origin in the head and neck, melanoma of the scalp and neck carries the highest mortality, with 10-year survival being only 60%. Melanomas of the ear, face, and eyelid have 10-year survival rates of 70%, 80%, and 90%, respectively.

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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Surgery and sentinel lymph node biopsy

In patients with melanoma, surgery is pivotal not only for the primary tumor but also for regional and often distant metastases. The minimally invasive technique of sentinel node (SN) biopsy has become standard for detection of occult regional node metastasis in patients with intermediate-thickness primary melanoma; in these patients it has a central role in determining prognosis and a significant impact on survival when biopsy results are positive. Its role in thin melanoma remains under evaluation. The regional tumor-draining SN also is a useful model for studies of melanoma-induced immunosuppression. Although completion lymphadenectomy remains the standard of care for patients with SN metastasis, results of ongoing phase III trials will indicate whether SN biopsy without further lymph node surgery is adequate therapy for certain patients with minimal regional node disease.

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.

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 lymph node biopsy in thin melanoma patients

BACKGROUND

We sought to determine the incidence of positive sentinel lymph nodes in thin melanoma (<or=1.0 mm) patients and if subgroups could be identified with a higher risk of occult nodal disease.

METHODS

Patients with <or=1.0 mm lesions treated between 1997 and 2003 were reviewed. Sentinel nodes underwent microscopic analysis including step sectioning and immunohistochemical examination. Some nodes underwent reverse transcriptase-polymerase chain reaction (RT-PCR) evaluation for melanoma markers.

RESULTS

Sixty-four of 107 thin melanoma patients underwent sentinel node biopsy (SNB). Mapped patients were more likely to have Clark >or= III and thicker lesions (mean 0.77 mm vs. 0.47 mm), but were not different in regards to age, sex, or lesion location. Eight percent and 58% of sentinel nodes were positive by routine histology and RT-PCR, respectively. Among mapped patients, younger age was the only significant prognostic factor for node positivity. With a median follow-up of 18 months among all patients, one regional recurrence (at 2 years) has been identified.

CONCLUSIONS

Given the low morbidity of sentinel lymph node biopsy, this procedure should be discussed with selected thin melanoma patients to detect microscopic disease, however PCR positivity by our methods is too commonly seen to be clinically significant in thin melanoma patients and requires additional study.

[Sentinel lymph node biopsy in malignant melanoma--an update]

Ten years after the introduction of the sentinel lymph node biopsy technique in the management of malignant melanoma, it is time to take stock. The complex method has proved itself sufficiently sensitive, although a certain percentage of false-negative histological results have to be taken into account. Presently, it is still a point at issue whether sentinel lymph node biopsy should be regarded as the standard of care in high-risk patients. Three prospective multicentre trials have failed to demonstrate a survival benefit resulting from elective lymph node dissection. In contrast, a retrospective multicentre study has recently shown that patients with node metastases diagnosed by the sentinel procedure benefit from early excision of their nodal disease in terms of overall survival, as compared to patients with delayed dissection of palpable nodes. Studies worldwide have established the pathologic status of the sentinel lymph node biopsy as the most important prognostic factor for recurrence and survival after the excision of primary melanoma. As with any invasive staging procedure, sentinel lymph node biopsy should have demonstrated therapeutic consequences. Unfortunately, an unequivocally acknowledged adjuvant therapy is lacking. Moreover, the impact of complete lymph node dissection after positive sentinel biopsy on survival or local disease control has not yet been clarified.

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.

Plastic Surgery

The range of casualties treated by the Defence Medical Services in the recent Gulf conflict has reaffirmed the important role of plastic surgery within the military. This review seeks to highlight some areas of recent innovation and improvement within the realms of plastic surgery generally, of which some, such as the introduction of Flammacerium and the availability of skin substitutes, have direct military relevance.