Prediction of non-sentinel node status and outcome in sentinel node-positive melanoma patients

Current management of melanoma patients with nodal metastases

The management of melanoma patients with nodal metastases has undergone dramatic changes over the last decade. In the past, the standard of care for patients with a positive sentinel lymph node biopsy (SLNB) was a completion lymph node dissection (CLND), while patients with palpable macroscopic nodal disease underwent a therapeutic lymphadenectomy in cases with no evidence of systemic spread. However, studies have shown that SLN metastases present as a spectrum of disease, with certain SLN-based factors being prognostic of and correlated with outcomes. Furthermore, the results of key clinical trials demonstrate that CLND provides no survival benefit over nodal observation in positive SLN patients, while other clinical trials have shown that adjuvant immune checkpoint inhibitor therapy or targeted therapy after CLND is associated with a recurrence-free survival benefit. Given the efficacy of these systemic therapies in the adjuvant setting, these agents are now being evaluated and utilized as neoadjuvant treatments in patients with regionally-localized or resectable metastatic melanoma. Multiple options now exist to treat melanoma patients with nodal disease, and determining the best treatment course for a particular case requires an in-depth knowledge of current data and an informed discussion with the patient. This review will provide an overview of the various options for treating melanoma patients with nodal metastases and will discuss the data that supported the development of these treatment options.

Predictors of Nonsentinel Lymph Node Metastasis in Cutaneous Melanoma: A Systematic Review and Meta-Analysis

BACKGROUND

Although completion lymph node dissection (CLND) is not routinely performed for a positive sentinel lymph node (SLN) anymore, adjuvant therapy depends on the risk factors available from SLN biopsy, including the risk of nonsentinel node metastases (NSNM). A systematic review and meta-analysis was performed in an attempt to identify risk factors that could be used to predict the risk of NSNM.

MATERIALS AND METHODS

Medline, Web of Science, Embase, and Cochrane were searched for articles discussing predictive factors for NSNM. PRISMA guidelines were followed, and RevMan software was used to calculate pooled odds ratios (OR) using the Mantel-Haenszel test.

RESULTS

Fifty publications were suitable for additional analysis. The clinical and primary tumor factors that were consistently identified as risk factors for NSNMs were: age >50, T stage 3 or 4, Clark level IV/V, ulceration, microsatellitosis, lymphovascular invasion, nodular histology, and extremity versus trunk primary tumor location. SLN factors that predicted NSNMs were >1 positive SLN, SLN micrometastatic tumor burden, diameter >2 mm, extracapsular extension, nonsubcapsular location (Dewar), and Rotterdam > 1 mm or ≥ 0.1 mm.

CONCLUSIONS

The findings in this study support that many clinical and pathologic risk factors that can be assessed with SLN biopsy alone can be used to predict the risk of NSNMs. The factors identified in this review should be evaluated in clinical prediction models to predict the risk of NSNMS, a prediction that may be used to select patients for adjuvant therapy in high-risk melanoma.

Unique Genes in Tumor-Positive Sentinel Lymph Nodes Associated with Nonsentinel Lymph Node Metastases in Melanoma

BACKGROUND

Current risk assessment tools to estimate the risk of nonsentinel lymph node metastases after completion lymphadenectomy for a positive sentinel lymph node (SLN) biopsy in cutaneous melanoma are based on clinical and pathologic factors. We identified a novel genetic signature that can predict non-SLN metastases in patients with cutaneous melanoma staged with a SLN biopsy.

METHODS

RNA was collected for tumor-positive SLNs in patients staged by SLN biopsy for cutaneous melanoma. All patients with a tumor-positive SLN biopsy underwent completion lymphadenectomy. A 1:10 case:control series of positive and negative non-SLN patients was analyzed by microarray and quantitative RT-PCR. Candidate differentially expressed genes were validated in a 1:3 case:control separate cohort of positive and negative non-SLN patients.

RESULTS

The 1:10 case:control discovery set consisted of 7 positive non-SLN cases matched to 70 negative non-SLN controls. The cases and controls were similar with regards to important clinicopathologic factors, such as gender, primary tumor site, age, ulceration, and thickness. Microarray and RT-PCR identified six potential differentially expressed genes for validation. In the 40-patient separate validation set, 10 positive non-SLN patients were matched to 30 negative non-SLN controls based on gender, ulceration, age, and thickness. Five of the six genes were differentially expressed. The five gene panel identified patients at low (7.1%) and high risk (66.7%) for non-SLN metastases.

CONCLUSIONS

A novel, non-SLN gene score based on differential expressed genes in a tumor-positive SLN can identify patients at high and low risk for non-SLN metastases.

Is the non-sentinel lymph node compartment the next site for melanoma progression from the sentinel lymph node compartment in the regional nodal basin?

Melanoma patients with additional positive lymph nodes in the completion lymph node dissection (CLND) following a positive sentinel lymph node (SLN) biopsy would have a poorer prognosis than patients with no additional positive lymph nodes. We hypothesize that the progression of disease from the SLN to the non-SLN compartment is orderly and is associated with the worsening of the disease status. Thus, the SLN and non-SLN compartments are biologically different in that cancer cells, in general, arrive in the SLN compartment before spreading to the non-SLN compartment. To validate this concept, we used a large cohort of melanoma patients from our prospective SLN database in an academic tertiary medical center. Adult cutaneous melanoma patients (n = 291) undergoing CLND after a positive SLN biopsy from 1994 to 2009 were analyzed. Comparison of 5-year disease-free survival and 5-year overall survival between positive (n = 66) and negative (n = 225) CLND groups was made. The 5-year disease-free survival rates were 55% (95% CI 49-62%) for patients with no additional LN on CLND versus 14% (95% CI 8-26%) in patients with positive LN on CLND (p < 0.0001, log-rank test). The median disease-free survival time was 7.4 years with negative CLND (95% CI 4.4-15+ years) and 1.2 years with positive CLND (95% CI 1.0-1.8 years). The 5-year overall survival rates were 67% (95% CI 61-74%) for negative CLND versus 38% (95% CI 28-52%) for positive CLND (p < 0.0001, log-rank test). The median overall survival time was 12.1 years for negative CLND (95% CI 9.3-15+ years) and 2.5 years for positive CLND (95% CI 2.2-5.7 years). This study shows that CLND status is a significant prognostic factor for patients with positive SLNs undergoing CLND. Also, it suggests an orderly progression of metastasis from the SLN to the non-SLN compartment. Thus, the SLN in the regional nodal basin draining the primary melanoma may serve as an important gateway for metastasis to the non-SLN compartment and beyond to the systemic sites.

Impact of Completion Lymph Node Dissection on Patients with Positive Sentinel Lymph Node Biopsy in Melanoma

BACKGROUND

Whether patients with positive SLNB should undergo complete lymph node dissection (CLND) is an important unanswered clinical question.

STUDY DESIGN

Patients diagnosed with positive SLNB at a melanoma referral center from 1991 to 2013 were studied. Outcomes of patients who underwent CLND were compared with those who did not undergo immediate CLND (observation [OBS] group).

RESULTS

There were 471 patients who had positive SLNB; 375 (79.6%) in the CLND group and 96 (20.4%) in the OBS group. The groups were similar except that the CLND group was younger and had more sentinel nodes removed. Five-year nodal recurrence-free survival was significantly better in the CLND group compared with the OBS group (93.1% vs 84.4%; p = 0.005). However, 5-year (66.4% vs 55.2%) and 10-year (59.5% vs 45.0%) distant metastasis-free survival rates were not significantly different (p = 0.061). The CLND group's melanoma-specific survival (MSS) rate was superior to that of the OBS group; 5-year MSS rates were 73.7% vs 65.5% and 10-year MSS rates were 66.8% vs 48.3% (p = 0.015). On multivariate analysis, CLND was associated with improved MSS (hazard ratio = 0.60; 95% CI, 0.40-0.89; p = 0.011) and lower nodal recurrence (hazard ratio = 0.46; 95% CI, 0.24-0.86; p = 0.016). Increased Breslow thickness, older age, ulceration, and trunk melanoma were all associated with worse outcomes. On subgroup analysis, the following factors were associated with better outcomes from CLND: male sex, nonulcerated primary, intermediate thickness, Clark level IV or lower extremity tumors.

CONCLUSIONS

Treatment of positive SLNB with CLND was associated with improved MSS and nodal recurrence rates. Follow-up beyond 5 years was needed to see a significant difference in MSS rates.

Completion Lymph Node Dissection Based on Risk of Nonsentinel Metastasis in Cutaneous Melanoma of the Head and Neck

Objective

Theoretically, completion lymph node dissection (CNLD) should have the lowest benefit in the absence of nonsentinel lymph node (NSLN) metastases. For this reason, substantial research efforts have attempted to define specific criteria that are associated with a low-enough risk of NSLN positivity so that CLND can be deferred. Our objectives were (1) to identify features associated with low risk of NSLN positivity in sentinel lymph node–positive cutaneous melanoma of the head and neck (CMHN) and (2) to analyze the effect of CLND on 5-year disease-specific survival (DSS) among subgroups stratified by risk of NSLN metastasis.

Study Design

Retrospective analysis of population-based data.

Setting

SEER database.

Subjects and Methods

Patients with sentinel lymph node–positive CMHN were categorized according to lymph node treatment following sentinel lymph node biopsy (SLNB): 210 underwent CLND and 140 deferred. Clinicopathologic characteristics and survival were compared between SLNB+CLND and SLNB-only groups. Survival analyses were stratified by age and characteristics associated with NSLN positivity.

Results

Minimal tumor thickness and nonulceration were associated with lowest risk of positive NSLN ( P < .025). In the subgroup with the lowest risk of metastasis, patients aged <60 years who underwent CLND+SLNB had markedly better DSS than those receiving SLNB only (>90% vs <25%; P < .0025). Paradoxically, in subgroups with a higher risk of NSLN metastasis, DSS was similar whether CLND was performed or not ( P > .25).

Conclusions

Selecting patients for CLND according to risk of NSLN metastasis may be a suboptimal strategy for improving DSS. We believe that CLND should not be withheld on the basis of “low risk” features in CMHN.

Update and Review on the Surgical Management of Primary Cutaneous Melanoma

The surgical management of malignant melanoma historically called for wide excision of skin and subcutaneous tissue for any given lesion, but has evolved to be rationally-based on pathological staging. Breslow and Clark independently described level and thickness as determinant in prognosis and margin of excision. The American Joint Committee of Cancer (AJCC) in 1988 combined features from each of these histologic classifications, generating a new system, which is continuously updated and improved. The National Comprehensive Cancer Network (NCCN) has also combined several large randomized prospective trials to generate current guidelines for melanoma excision as well. In this article, we reviewed: (1) Breslow and Clark classifications, AJCC and NCCN guidelines, the World Health Organization's 1988 study, and the Intergroup Melanoma Surgical Trial; (2) Experimental use of Mohs surgery for in situ melanoma; and (3) Surgical margins and utility and indications for sentinel lymph node biopsy (SLNB) and lymphadenectomy. Current guidelines for the surgical management of a primary melanoma of the skin is based on Breslow microstaging and call for cutaneous margins of resection of 0.5 cm for MIS, 1.0 cm for melanomas ≤1.0 mm thick, 1-2 cm for melanoma thickness of 1.01-2 mm, 2 cm margins for melanoma thickness of 2.01-4 mm, and 2 cm margins for melanomas >4 mm thick. Although the role of SLNB, CLND, and TLND continue to be studied, current recommendations include SLNB for Stage IB (includes T1b lesions ≤1.0 with the adverse features of ulceration or ≥1 mitoses/mm²) and Stage II melanomas. CLND is recommended when sentinel nodes contain metastatic deposits.

Staging of regional lymph nodes in melanoma: a case for including nonsentinel lymph node positivity in the American Joint Committee on Cancer staging system

IMPORTANCE

Survival varies widely in patients with stage III melanoma. The existence of clinical significance for positive nonsentinel lymph node (NSLN) status would warrant consideration for incorporation into the American Joint Committee on Cancer staging system and better prediction of survival.

OBJECTIVE

To evaluate whether disease limited to sentinel lymph nodes (SLNs) represents different clinical significance than disease spread into NSLNs.

DESIGN, SETTING, AND PARTICIPANTS

The database of the John Wayne Cancer Institute at Saint John's Health Center, Santa Monica, California, was queried for all patients with SLNs positive for cutaneous melanoma who subsequently underwent completion lymph node dissection.

MAIN OUTCOMES AND MEASURES

Disease-free survival, melanoma-specific survival (MSS), and overall survival.

RESULTS

A total of 4223 patients underwent SLN biopsy from 1986 to 2012. Of these patients, 329 had a tumor-positive SLN. Of the 329, 250 patients (76.0%) had no additional positive nodes and 79 (24.0%) had a tumor-positive NSLN. Factors predictive of NSLN positivity included older age (P = .04), greater Breslow thickness (P < .001), and ulceration (P < .02). Median overall survival was 178 months for the SLN-only positive group and 42.2 months for the NSLN positive group (5-year overall survival, 72.3% and 46.4%, respectively). Median MSS was not reached for the SLN-only positive group and was 60 months for the NSLN positive group (5-year MSS, 77.8% and 49.5%, respectively). On multivariate analysis, NSLN positivity had a strong association with recurrence (hazard ratio [HR], 1.75; 95% CI, 1.23-2.50; P = .002), shorter overall survival (HR, 2.24; 95% CI, 1.48-3.40; P < .001), and shorter MSS (HR, 2.23; 95% CI, 1.46-3.07; P < .001). To further control for the effects of total positive lymph nodes, comparison was done for patients with only N2 disease (2-3 total positive lymph nodes); the results of this comparison confirmed the independent effect of NSLN status (MSS; P = .04).

CONCLUSIONS AND RELEVANCE

Nonsentinel lymph node positivity is one of the most significant prognostic factors in patients with stage III melanoma. Subclassification of melanoma by NSLN tumor status should be considered for the American Joint Committee on Cancer staging system.

Accuracy of the non-sentinel node risk score (N-SNORE) in patients with cutaneous melanoma and positive sentinel lymph nodes: a retrospective study

BACKGROUND

Sentinel node (SLN) biopsy in patients with melanoma permits identification of those at risk for further metastases in non-sentinel lymph nodes (NSLN). However, a mere 20% of SLN-positive patients have metastases in NSLN. Therefore we need criteria to predict NSLN-positivity. A new score system known as the non-sentinel risk score, (N-SNORE) based on five clinical and pathological characteristics (gender, regression in primary melanoma, proportion of SNs containing melanoma, perinodal lymphatic invasion, and SN tumor burden), was first published in 2010. In this study, the accuracy of N-SNORE was validated in melanoma patients with positive SLN.

METHODS

A total of 106 melanoma patients with positive SLN, who had undergone complete lymph node dissection (CLND) subsequently, were included in the study. The N-SNORE was calculated in all patients, and the risk was compared to the frequency of NSLN metastases. Statistical analysis of the data was performed.

RESULTS

Thirteen patients were at very low risk for NSN metastasis (score 0), 63 patients at low risk (score 1-3), 19 at intermediate risk (score 4-5), 6 at high risk (score 6-7), and 5 at very high risk (score >8). NSLN positivity rates for these 5 risk groups were 7.7%, 18.2%, 21.1%, 33.3%, and 80%, respectively. According to Fisher's exact test, the contingency coefficient was .322; the p-value was .025.

CONCLUSION

An increasing N-SNORE was clearly correlated with a higher risk of NSLN positivity. Based on the p-value and the contingency coefficient, the overall accuracy of the N-SNORE was proven on statistical calculation.

SLN melanoma micrometastasis predictivity of nodal status: a long term retrospective study

Background

Completion lymph node dissection (CLND) is the gold standard treatment for patients with a positive sentinel lymph node (SLN) biopsy. Considering the morbidity associated with CLND it is important to identify histological features of the primary tumor and/or of SLN metastasis that could help to spare from CLND a subset of patients who have a very low risk of non-SLN metastasis. The objective of this study is to identify patients with a very low risk to develop non-SLNs recurrences and to limit unnecessary CLND.

Methods

A retrospective long-term study of 80 melanoma patients with positive SLN, undergone CLND, was assessed to define the risk of additional metastasis in the regional nodal basin, on the basis of intranodal distribution of metastatic cells, using the micro-morphometric analysis (Starz classification).

Results

This study demonstrates that among the demographic and pathologic features of primary melanoma and of SLN only the Starz classification shows prognostic significance for non-SLN status (p<0.0001). This parameter was also significantly associated with disease-free survival rate (p<0.0013).

Conclusion

The Starz classification can help to identify, among SLN positive patients, those who can have a real benefit from CLND. From the clinical point of view this easy and reliable method could lead to a significant reduction of unnecessary CLND in association with a substantial decrease in morbidity. The study results indicate that most of S1 subgroup patients might be safely spared from completion lymphatic node dissection. Furthermore, our experience demonstrated that Starz classification of SLN is a safe predictive index for patient stratification and treatment planning.

Completion lymph node dissection after a positive sentinel node: no longer a must?

PURPOSE OF REVIEW

Sentinel node biopsy (SNB) for primary melanoma is accepted worldwide as a diagnostic procedure. When sentinel node positive, the invasive completion lymph node dissection (CLND) is usually performed. Approximately 20% of CLND patients have nonsentinel node (NSN) metastases. The therapeutic benefit is unknown. This review analyzed the necessity of CLND in sentinel node positive patients.

RECENT FINDINGS

Prognosis of sentinel node positive patients is highly heterogeneous. The Rotterdam and Dewar criteria and S-classification are important sentinel node tumor burden criteria to stratify melanoma patients for prognosis and risk of NSN metastases. Patients with less than 0.1 mm metastases seem to have similar prognosis as sentinel node negative patients, especially when located in the subcapsular area. This depends on the use of an extensive sentinel node pathology protocol identifying possibly clinically irrelevant micrometastases.

SUMMARY

Consensus on the sentinel node pathology work-up and analysis protocols are crucial for correct risk stratification and for clinical decision-making. Primary and sentinel node tumor burden parameters and patient comorbidities should be taken into consideration when offering CLND to an individual patient. In the future, prospective studies such as the MSLT-II and the EORTC 1208 (Minitub) will provide answers to whether CLND has a therapeutic benefit and to which patients might safely be spared CLND.

Is complete lymph node dissection after a positive sentinel lymph node biopsy for cutaneous melanoma always necessary? A meta-analysis

BACKGROUND

The current recommendation for patients with cutaneous melanoma and a positive sentinel lymph node (SLN) biopsy is a complete lymph node dissection (CLND). However, metastatic melanoma is not present in approximately 80% of CLND specimens. A meta-analysis was performed to identify the clinicopathological variables most predictive of non-sentinel node (NSN) metastases when the sentinel node is positive in patients with melanoma.

METHODS

A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google scholar, Science Direct, and Web of Science. The search identified 54 relevant articles reporting the frequency of NSN metastases in melanoma. Original data was abstracted from each study and used to calculate a pooled odds ratio (OR) and 95% confidence interval (95% CI).

FINDINGS

The pooled estimates that were found to be significantly associated with the high likelihood of NSN metastases were: ulceration (OR: 1.88, 95% CI: 1.53-2.31), satellitosis (OR: 3.25, 95% CI: 1.86-5.66), neurotropism (OR: 2.51, 95% CI: 1.39-4.53), >1 positive SLN (OR: 1.77, 95% CI: 1.2-2.62), Starz 3 (old) (OR: 1.83, 95% CI: 0.89-3.76), Angiolymphatic invasion (OR: 2.46, 95% CI: 1.34-4.54), extensive location (OR: 2.22, 95% CI: 1.74-2.81), macrometastases >2 mm (OR: 1.95, 95% CI: 1.61-2.35), extranodal extension (OR: 3.38, 95% CI: 1.79-6.40) and capsular involvement (OR: 3.16, 95% CI: 1.37-7.27). There were 3 characteristics not associated with NSN metastases: subcapsular location (OR: 0.51, 95% CI: 0.38-0.67), Rotterdam Criteria <0.1 mm (OR: 0.29, 95% CI: 0.17-0.50) and Starz I (new) (OR: 0.44, 95% CI: 0.22-0.91). Other variables including gender, Breslow thickness 2-4 mm and extremity as primary site were found to be equivocal.

INTERPRETATION

This meta-analysis provides evidence that patients with low SLN tumor burden could probably be spared the morbidity associated with CLND. We identified 9 factors predictive of non-SLN metastases that should be recorded and evaluated routinely in SLN databases. However, further studies are needed to confirm the standard criteria for not performing CLND.

Diversity of stage III melanoma in the era of sentinel lymph node biopsy

BACKGROUND

Sentinel lymph node (SLN) biopsy for melanoma often detects minimal nodal tumor burden. Although all node-positive patients are considered stage III, there is controversy regarding the necessity of adjuvant therapy for all patients with tumor-positive SLN.

METHODS

Post hoc analysis was performed of a prospective multi-institutional study of patients with melanoma ≥ 1.0 mm Breslow thickness. All patients underwent SLN biopsy; completion lymphadenectomy was performed for patients with SLN metastasis. Kaplan-Meier analysis of disease-free survival (DFS) and overall survival (OS) was performed. Univariate and multivariate Cox regression analyses were performed. Classification and regression tree (CART) analysis also was performed.

RESULTS

A total of 509 patients with tumor-positive SLN were evaluated. Independent risk factors for worse OS included thickness, age, gender, presence of ulceration, and tumor-positive non-SLN (nodal metastasis found on completion lymphadenectomy). As the number of tumor-positive SLN and the total number of tumor-positive nodes (SLN and non-SLN) increased, DFS and OS worsened on Kaplan-Meier analysis. On CART analysis, the 5-year OS rates ranged from 84.9% (women with thickness < 2.1 mm, age < 59 years, no ulceration, and tumor-negative non-SLN) to 14.3% (men with thickness ≥ 2.1 mm, age ≥ 59 years, ulceration present, and tumor-positive non-SLN). Six distinct subgroups were identified with 5-year OS in excess of 70%.

CONCLUSIONS

Stage III melanoma in the era of SLN is associated with a very wide range of prognosis. CART analysis of prognostic factors allows discrimination of low-risk subgroups for which adjuvant therapy may not be warranted.

Evidence for a better nodal staging system for melanoma: the clinical relevance of metastatic disease confined to the sentinel lymph nodes

BACKGROUND

The hypothesis tested in this study was whether patients with stage III metastatic melanoma confined to their sentinel lymph nodes (SLNs) had a more favorable prognosis than patients who had SLN and non-SLN (NSLN) metastases.

METHODS

Patients were identified who were clinically negative in their regional basins but with lymphatic mapping were found to have positive SLNs (331 patients). All patients subsequently underwent a complete lymph node dissection of the lymphatic basin involved, and the total number of metastatic SLNs and NSLNs were documented.

RESULTS

As the regional metastatic disease involves NSLNs, disease-free survival (DFS) and overall survival (OS) decreases. For patients with a total of 2 nodes positive, those with disease confined to the SLNs had a significant better prognosis (DFS and OS: P < .00001) than those in whom 1 SLN and 1 non-SLN was involved. This difference was apparent for those patients with N2 and N3 disease (2 or more nodes positive in their regional basin). A multivariate regression analysis that included Breslow thickness, ulceration, number of positive nodes, and NSLN positivity showed that NSLN positivity (P = .0019) was the most powerful predictor of DFS and OS.

CONCLUSIONS

When metastatic melanoma overwhelms the SLN and involves NSLNs, the biologic behavior changes to portend a worse survival, regardless of the total node count positive. These data make the argument that the current N staging system should be changed to incorporate SLN vs NSLN involvement.

Analysis of predictive factors for the outcome of complete lymph node dissection in melanoma patients with metastatic sentinel lymph nodes

BACKGROUND

Sentinel lymph node biopsy (SLNB) is a widely accepted procedure to accurately stage patients with melanoma. However, there is no consensus concerning the practical consequences of a positive SLN, since a survival benefit of a complete lymph node dissection (CLND) has not yet been demonstrated.

OBJECTIVE

We wondered whether we could identify a subgroup of patients with metastatic involvement of the SLN who could be excluded from the recommendation to undergo CLND.

METHODS

At the Department of Dermatology at the University of Munich, a total of 213 patients with metastatic SLNs (24.9%) were identified among 854 patients who had undergone SLNB between 1996 and 2007. All SLN-positive patients had been advised to have CLND. Survival analyses were performed by using the Kaplan-Meier approach.

RESULTS

A total of 176 (82.6%) of 213 SLN-positive patients underwent CLND. In this group, 26 patients (14.8%) showed metastatic disease in non-sentinel lymph nodes (NSLN). The 5-year overall survival (OS) was 26.1% in NSLN-positive patients and 74% in NSLN-negative patients. SLN-positive patients who refused CLND had a better prognosis than patients with CLND. Breslow tumor thickness was significantly associated with positive CLND status with higher median values in CLND-positive than CLND-negative patients (3.03 vs 2.22 mm).

LIMITATIONS

The subgroup of patients with metastatic disease in CLND may have been too small to reach statistical significance for other tumor- or patient-related parameters. Mitotic indices of the primary melanomas had not been determined in this retrospective study; thus a possible correlation with lymph node status could not be tested.

CONCLUSION

Among SLN-positive patients, the presence of metastatic NSLN is a highly significant poor prognostic factor. Tumor thickness is a significant prognostic parameter for positive CLND status and might be considered in the decision to perform CLND in case of metastatic SLN.

Prognosis in patients with sentinel node-positive melanoma is accurately defined by the combined Rotterdam tumor load and Dewar topography criteria

PURPOSE

Prognosis in patients with sentinel node (SN)-positive melanoma correlates with several characteristics of the metastases in the SN such as size and site. These factors reflect biologic behavior and may separate out patients who may or may not need additional locoregional and/or systemic therapy.

PATIENTS AND METHODS

Between 1993 and 2008, 1,080 patients (509 women and 571 men) were diagnosed with tumor burden in the SN in nine European Organisation for Research and Treatment of Cancer (EORTC) melanoma group centers. In total, 1,009 patients (93%) underwent completion lymph node dissection (CLND). Median Breslow thickness was 3.00 mm. The median follow-up time was 37 months. Tumor load and tumor site were reclassified in all nodes by the Rotterdam criteria for size and in 88% by the Dewar criteria for topography.

RESULTS

Patients with submicrometastases (< 0.1 mm in diameter) were shown to have an estimated 5-year overall survival rate of 91% and a low nonsentinel node (NSN) positivity rate of 9%. This is comparable to the rate in SN-negative patients. The strongest predictive parameter for NSN positivity and prognostic parameter for survival was the Rotterdam-Dewar Combined (RDC) criteria. Patients with submicrometastases that were present in the subcapsular area only, had an NSN positivity rate of 2% and an estimated 5- and 10-year melanoma-specific survival (MSS) of 95%.

CONCLUSION

Patients with metastases < 0.1 mm, especially when present in the subcapsular area only, may be overtreated by a routine CLND and have an MSS that is indistinguishable from that of SN-negative patients. Thus the RDC criteria provide a rational basis for decision making in the absence of conclusions provided by randomized controlled trials.

The prevalence of occult metastases in nonsentinel lymph nodes after step-serial sectioning and immunohistochemistry in cN0 oral squamous cell carcinoma

OBJECTIVES

To examine the prevalence of isolated tumor cells (ITC) and micrometastases (MM) in nonsentinel lymph nodes (NSN) using additional step-serial sectioning and immunohistochemistry (IHC) as for sentinel lymph nodes (SN).

STUDY DESIGN

Prospective, consecutive, and clinically controlled trial.

METHODS

Fifty-one patients with oral cavity squamous cell carcinoma (OSCC) T1-T2 and clinically N0 neck underwent surgical treatment including sentinel-node biopsy (SNB) assisted selective neck dissection (SND). The location of the SN was determined using dynamic and planar lymphoscintigraphy and SPECT-CT. The harvested NSN from the neck dissections underwent the same histopathologic examinations as the SN using step-serial sectioning (SSS) at 150-micron intervals. Two sections from each level were stained with hematoxylin-eosin (H&E) and cytokeratin antibodies (AE1/AE3) and examined for tumor deposits. Results were compared with the previous routine examination of the NSN.

RESULTS

A total of 403 NSN were examined with a median of 8 per patient. A total of 1/51 patients (2%) had involvement of an additional NSN not found on routine examination. This was the only lymph node with involvement not detected previously. However, this patient had metastases in SN and in another NSN detected on routine examination. The overall incidence of occult metastasis (SN + NSN) was 21.6% (11/51) as previously reported.

CONCLUSIONS

The incidence of occult metastases in NSN after additional SSS and IHC was 2%. The risk of NSN involvement would seem to be extremely low in patients with early OSCC and negative SN. This study further validates SNB as an accurate staging tool for cN0 early OSCC.

The prognostic significance of nonsentinel lymph node metastasis in melanoma

BACKGROUND

We hypothesized that metastasis beyond the sentinel lymph nodes (SLN) to the nonsentinel nodes (NSN) is an important predictor of survival.

MATERIALS AND METHODS

Analysis was performed of a prospective multi-institutional study that included patients with melanoma ≥ 1.0 mm in Breslow thickness. All patients underwent SLN biopsy; completion lymphadenectomy was performed for all SLN metastases. Disease-free survival (DFS) and overall survival (OS) were computed by Kaplan-Meier analysis; univariate and multivariate analyses were performed to identify factors associated with differences in survival among groups.

RESULTS

A total of 2335 patients were analyzed over a median follow-up of 68 months. We compared 3 groups: SLN negative (n = 1988), SLN-only positive (n = 296), and both SLN and NSN positive (n = 51). The 5-year DFS rates were 85.5, 64.8, and 42.6% for groups 1, 2, and 3, respectively (P < 0.001). The 5-year OS rates were 85.5, 64.9, and 49.4%, respectively (P < 0.001). On univariate analysis, predictors of decreased OS included: SLN metastasis, NSN metastasis, increased total number of positive LN, increased ratio of positive LN to total LN, increased age, male gender, increased Breslow thickness, presence of ulceration, Clark level ≥ IV, and axial primary site (in all cases, P < 0.01). When the total number of positive LN and NSN status were evaluated using multivariate analysis, NSN status remained statistically significant (P < 0.01), while the total number of positive LN and LN ratio did not.

CONCLUSIONS

NSN melanoma metastasis is an independent prognostic factor for DFS and OS, which is distinct from the number of positive lymph nodes or the lymph node ratio.

Importance of tumor load in the sentinel node in melanoma: clinical dilemmas

There are two hypotheses to explain melanoma dissemination: first, simultaneous lymphatic and hematogeneous spread, with regional lymph nodes as indicators of metastatic disease; and second, orderly progression, with regional lymph nodes as governors of metastatic disease. The sentinel node (SN) has been defined as the first draining lymph node from a tumor and is harvested with the use of the triple technique and is processed by an extensive pathology protocol. The SN status is a strong prognostic factor for survival (83-94% for SN negative, 56-75% SN-positive patients). False-negative rates are considerable (9-21%). Preliminary results of the MSLT-1 trial did not demonstrate a survival benefit for the SN procedure, although a subgroup analysis indicates a possible benefit. A mathematical model has demonstrated 24% prognostic false positivity. SN tumor burden represents a heterogeneous patient population and is classified most frequently with the Starz, Dewar or Rotterdam Criteria. A completion lymph-node dissection might not be indicated in all SN-positive patients. Patients classified with metastases <0.1 mm by the Rotterdam Criteria have excellent survival rates. Ultrasound-guided fine-needle aspiration cytology is emerging as a staging tool for high-risk patients, but more research is necessary before this can change clinical practice.

Ratio of marked and excised sentinel lymph nodes and scintigraphic appearance time in melanoma patients with negative sentinel lymph node

AIM

Metastases can occur in up to 15% of all melanoma patients with negative sentinel lymph node examination (SN -). We retrospectively investigated the number of preoperatively marked sentinel lymph nodes (SNs) with lymphoscintigraphy and effectively surgically removed SNs in SN--patients with cutaneous melanoma >or=0.5 mm. Ratio of these parameters was calculated and impact of this ratio as well as impact of scintigraphic appearance time (SAT) on disease progression was studied.

MATERIALS AND METHODS

Data on 122 SN--patients--70 women (58%), mean age 56.5 years--were analyzed. Mean follow-up time was 58 months.

RESULTS

Mean tumour thickness of all patients was 2.3 mm. In 51 patients (42%) the number of SNs marked in lymphoscintigraphy was higher than excised in surgery, in 47 patients (38%) the same number as marked was excised and in 24 patients (20%) a lower number was marked than excised. Metastases occurred in 17 patients (14%) after a mean time of 24.8 months. Mean tumour thickness (5.4 mm) was significantly higher in these patients than in the other patients (p = 0.000). Ratio of marked and excised SNs had no influence on disease progression; the only parameter influencing outcome was tumour thickness (p = 0.000). Short SAT was significantly associated with higher tumour thickness (p = 0.004).

CONCLUSION

Our study indicates that, in routine clinical practice, it suffices to harvest the first SN, as the ratio of marked and excised SNs has no impact on disease progression.

Sentinel node positive melanoma patients: prediction and prognostic significance of nonsentinel node metastases and development of a survival tree model

BACKGROUND

Completion lymph node dissection (CLND) following positive sentinel node biopsy (SNB) for melanoma detects additional nonsentinel node (NSN) metastases in approximately 20% of cases. This study aimed to establish whether NSN status can be predicted, to determine its effect on survival, and to develop survival tree models for the sentinel node (SN) positive population.

MATERIALS AND METHODS

Sydney Melanoma Unit (SMU) patients with at least 1 positive SN, meeting inclusion criteria and treated between October 1992 and June 2005, were identified from the Unit database. Survival characteristics, potential predictors of survival, and NSN status were assessed using the Kaplan-Meier method, Cox regression model, and logistic regression analyses, respectively. Classification tree analysis was performed to identify groups with distinctly different survival characteristics.

RESULTS

A total of 323 SN-positive melanoma patients met the inclusion criteria. On multivariate analysis, age, gender, primary tumor thickness, mitotic rate, number of positive NSNs, or total number of positive nodes were statistically significant predictors of survival. NSN metastasis, found at CLND in 19% of patients, was only predicted to a statistically significant degree by ulceration. Multivariate analyses demonstrated that survival was more closely related to number of positive NSNs than total number of positive nodes. Classification tree analysis revealed 4 prognostically distinct survival groups.

CONCLUSIONS

Patients with NSN metastases could not be reliably identified prior to CLND. Prognosis following CLND was more closely related to number of positive NSNs than total number of positive nodes. Classification tree analysis defined distinctly different survival groups more accurately than use of single-factor analysis.

Sentinel lymph node biopsy and melanoma: 2010 update Part II

This article will discuss the evidence for and against the therapeutic efficacy of early removal of potentially affected lymph nodes, morbidity associated with sentinel lymph node biopsy and completion lymphadenectomy, current guidelines regarding patient selection for sentinel lymph node biopsy, and the remaining questions that ongoing clinical trials are attempting to answer. The Sunbelt Melanoma Trial and the Multicenter Selective Lymphadenectomy Trials I and II will be discussed in detail.

LEARNING OBJECTIVES

At the completion of this learning activity, participants should be able to discuss the data regarding early surgical removal of lymph nodes and its effect on the overall survival of melanoma patients, be able to discuss the potential benefits and morbidity associated with complete lymph node dissection, and to summarize the ongoing trials aimed at addressing the question of therapeutic value of early surgical treatment of regional lymph nodes that may contain micrometastases.

Interobserver reproducibility of histologic parameters of melanoma deposits in sentinel lymph nodes: implications for management of patients with melanoma

BACKGROUND

: Histologic parameters of melanoma deposits in sentinel lymph nodes (SLNs) have been shown to be predictive of clinical outcome and the presence or absence of tumor in non-SLNs, but assessment of these parameters is prone to interobserver variation.

METHODS

: Histologic sections of 44 SLNs containing metastatic melanoma were examined by 7 pathologists. Parameters assessed included cross-sectional area of tumor deposits, cross-sectional area of SLNs, percentage of SLN area involved by tumor calculated from the 2 previous parameters, estimated percentage of SLN area involved by tumor, tumor penetrative depth, location of tumor within the SLN, and presence of extracapsular spread. Levels of interobserver agreement were measured by using intraclass correlation coefficients (ICC).

RESULTS

: There was good to excellent interobserver agreement on measurement of quantitative parameters: maximal size of largest tumor deposits, calculated area of 3 largest tumor deposits, percentage of the area of SLN involved by tumor, and tumor penetrative depth (ICC, 0.88, 0.73, 0.68, and 0.83, respectively). There was moderate agreement on the evaluation of subcapsular versus nonsubcapsular location of tumor deposits (ICC = 0.50). Agreement on assessment of extracapsular spread was fair (ICC = 0.39).

CONCLUSIONS

: Assessment of some of the quantitative parameters was highly reproducible between pathologists. However, evaluation of the location of tumor deposits within SLNs and assessment of extracapsular spread was less reproducible. Clearer definitions and training can be expected to improve the reproducibility of assessment. These results have important implications for reliability and reproducibility of these parameters in staging, prediction of outcome, and clinical management of melanoma patients. Cancer 2009. (c) 2009 American Cancer Society.

Prognostic significance of a positive nonsentinel lymph node in cutaneous melanoma

PURPOSE

Sentinel lymph node (SLN) biopsy provides important prognostic information for patients with cutaneous melanoma. There may be additional prognostic significance to melanoma spreading from the SLN to nonsentinel lymph nodes (NSLN). We examined the implications of a positive NSLN for overall and distant disease-free survival.

METHODS

Using a prospectively maintained, Institutional Review Board-approved melanoma database we studied patients who had a cutaneous melanoma, a positive SLN, and a completion lymph node dissection (CLND). Survival was determined using a combination of hospital records and the Social Security Death Index (SSDI). Univariate and multivariate Cox regression analysis was performed to further characterize predictors of overall and distant disease-free survival. Kaplan-Meier analysis was used to generate survival curves.

RESULTS

A total of 429 patients with positive SLN biopsies were identified, with at least one positive NSLN identified in 71 (17%). Median follow-up time was 36.8 months. Presence of a positive NSLN was significantly associated with poor outcome, although long-term survival was possible. Presence of ulceration, high mitotic rate, angiolymphatic invasion, total number of positive nodes, and volume of disease>1% in the SLN were significant predictors of survival on univariate analysis, but lost significance on multivariate. Multivariate Cox analysis revealed several predictors of overall survival: increasing age [hazard ratio (HR) 1.04, P<0.01], Breslow depth (HR 1.76, P<0.01), presence of extracapsular extension in the SLN (HR 2.39, P<0.01), and positive NSLN (HR 1.92, P<0.01).

CONCLUSION

Among node-positive melanoma patients, presence of a positive NSLN is a highly significant poor prognostic sign, even after considering the total number of positive nodes and volume of disease in the SLN. CLND after a positive SLN provides this important prognostic information.

Comparison of three micromorphometric pathology classifications of melanoma metastases in the sentinel node

OBJECTIVE

The purposes of this study were to determine which classification best predicts additional lymph node disease and survival, and to suggest a threshold below which a completion dissection may be omitted.

SUMMARY BACKGROUND DATA

Three micromorphometric parameters of melanoma sentinel node metastases were compared: invasion depth from the capsule (Starz-classification), maximum diameter (Rotterdam-criteria), and location within the node (Dewar-classification).

METHODS

The pathology slides of 116 patients with tumor-positive sentinel nodes were reviewed. The follow-up data were obtained from the prospectively kept database. The median follow-up duration was 53 months.

RESULTS

Metastases with an invasion depth under 0.3 mm or diameter less than 0.1 mm were not associated with additional involved nodes. Four percent of the patients with metastases with an invasion depth of 0.3 to 1.0 mm had other involved nodes and 3% of the patients with metastases with a diameter of 0.1 to 1.0 mm. Other nodes were involved in 3% of subcapsular metastases, 9% of both subcapsular and parenchymal metastases, and 33% in case of multifocal or extensive disease. The smallest tumor invasion depth and diameter associated with additional involved nodes was 0.4 mm. Only 5-year overall survival in the 3 successive invasion depth categories were statistically significant: 92%, 83%, and 68%. Five-year overall survival was 81% in patients with one involved sentinel node and 60% if there were more.

CONCLUSIONS

Invasion depth and diameter of the metastasis correlate best with the presence of additional nodal disease. Invasion depth best predicts overall survival. It seems justified to refrain from completion dissection in patients with a sentinel node tumor invasion depth up to 0.4 mm.

Positive nonsentinel node status predicts mortality in patients with cutaneous melanoma

While sentinel lymph node biopsy (SLN) is a highly accurate and well-tolerated procedure for patients with cutaneous melanoma, the role of the completion lymph node dissection (CLND) for patients with positive SLN biopsy remains unknown. This study aimed to look at the prognostic value of a positive nonsentinel lymph node (NSLN). A prospectively maintained database identified 222 patients with cutaneous melanoma and a positive SLN biopsy, without evidence of distant disease. All of these patients underwent CLND, and 37 patients (17%) had positive NSLN. With median follow-up of 33 months, patients with negative NSLN had median survival of 104 months, while patients with positive NSLN had median survival of 36 months (p < 0.001). There were no survivors in the patients with positive NSLN beyond 6 years. When patients with an equal number of positive nodes were analyzed, the presence of a positive NSLN was still associated with worse melanoma-specific survival (66 months for NSLN- versus 34 months for NSLN+, p = 0.04). While increasing age, tumor thickness, and male sex were associated with an increased risk of death on multivariate analysis, a positive NSLN was the most important predictor of survival (hazard ratio 2.5). We conclude that positive NSLN is an independent predictor of disease-specific survival in patients with cutaneous melanoma.

The influence of sentinel lymph node tumour burden on additional lymph node involvement and disease-free survival in cutaneous melanoma--a retrospective analysis of 392 cases

Twenty per cent of sentinel lymph node (SLN)-positive melanoma patients have positive non-SLN lymph nodes in completion lymph node dissection (CLND). We investigated SLN tumour load, non-sentinel positivity and disease-free survival (DFS) to assess whether certain patients could be spared CLND. Sentinel lymph node biopsy was performed on 392 patients between 1999 and 2005. Median observation period was 38.8 months. Sentinel lymph node tumour load did not predict non-SLN positivity: 30.8% of patients with SLN macrometastases (> or =2 mm) and 16.4% with micrometastases (< or =2 mm) had non-SLN positivity (P=0.09). Tumour recurrences after positive SLNs were more than twice as frequent for SLN macrometastases (51.3%) than for micrometastases (24.6%) (P=0.005). For patients with SLN micrometastases, the DFS analysis was worse (P=0.003) when comparing those with positive non-SLNs (60% recurrences) to those without (17.6% recurrences). This difference did not translate into significant differences in DFS: patients with SLN micrometastasis, either with (P=0.022) or without additional positive non-SLNs (P<0.0001), fared worse than patients with tumour-free SLNs. The 2-mm cutoff for SLN tumour load accurately predicts differences in DFS. Non-SLN positivity in CLND, however, cannot be predicted. Therefore, contrary to other studies, no recommendations concerning discontinuation of CLND based on SLN tumour load can be deduced.