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

Sentinel lymph node assessment in melanoma: current state and future directions

Assessment of sentinel lymph node status is an important step in the evaluation of patients with melanoma for both prognosis and therapeutic management. Pathologists have an important role in this evaluation. The methodologies have varied over time, from the evaluation of dimensions of metastatic burden to determination of the location of the tumour deposits within the lymph node to precise cell counting. However, no single method of sentinel lymph node tumour burden measurement can currently be used as a sole independent predictor of prognosis. The management approach to sentinel lymph node-positive patients has also evolved over time, with a more conservative approach recently recognised for selected cases. This review gives an overview of past and current status in the field with a glimpse into future directions based on prior experiences and clinical trials.

The sentinel node invasion level (SNIL) as a prognostic parameter in melanoma

Sentinel lymph node (SN) tumor burden is becoming increasingly important and is likely to be included in future N classifications in melanoma. Our aim was to investigate the prognostic significance of melanoma infiltration of various anatomically defined lymph node substructures. This retrospective cohort study included 1250 consecutive patients with SN biopsy. The pathology protocol required description of metastatic infiltration of each of the following lymph node substructures: intracapsular lymph vessels, subcapsular and transverse sinuses, cortex, paracortex, medulla, and capsule. Within the SN with the highest tumor burden, the SN invasion level (SNIL) was defined as follows: SNIL 1 = melanoma cells confined to intracapsular lymph vessels, subcapsular or transverse sinuses; SNIL 2 = melanoma infiltrating the cortex or paracortex; SNIL 3 = melanoma infiltrating the medulla or capsule. We classified 338 SN-positive patients according to the non-metric SNIL. Using Kaplan-Meier estimates and Cox models, recurrence-free survival (RFS), melanoma-specific survival (MSS) and nodal basin recurrence rates were analyzed. The median follow-up time was 75 months. The SNIL divided the SN-positive population into three groups with significantly different RFS, MSS, and nodal basin recurrence probabilities. The MSS of patients with SNIL 1 was virtually identical to that of SN-negative patients, whereas outgrowth of the metastasis from the parenchyma into the fibrous capsule or the medulla of the lymph node indicated a very poor prognosis. Thus, the SNIL may help to better assess the benefit-risk ratio of adjuvant therapies in patients with different SN metastasis patterns.

Eight Years' Experience of Sentinel Lymph Node Biopsy in Melanoma Using Lymphoscintigraphy and Gamma Probe Detection After Radiocolloid Mapping

BACKGROUND

Isosulfan blue dye peripheral injection is used in preoperative sentinel lymph node (SLN) identification alone or, to increase sensitivity, in conjunction with radiocolloid mapping. However, isosulfan blue dye has certain drawbacks and limitations.

OBJECTIVE

This study assesses the authors' experience of SLN biopsy using only radiocolloid tracer.

MATERIALS AND METHODS

Between 2000 and 2008, 218 patients underwent SLN biopsy with radiocolloid mapping, preoperative localization by lymphoscintigraphy and intraoperative confirmation by gamma probe in primary malignant cutaneous melanoma.

RESULTS

Mean Breslow index was 2.1 mm. The SLN biopsy success rate was above 98% at all sites and 87% in head and neck locations. The 5-year overall survival rate was 90% and that of 5-year disease-free survival was 80%. False-negative rate, with a mean follow-up time of 41 months, was 5.5%.

CONCLUSION

Sentinel lymph node biopsy can be successfully performed in patients with melanoma using only radiocolloid tracer without blue dye staining. In circumstances where blue dye cannot be used such as head and neck tumors, allergic reactions and pregnancy, radiocolloid tracer mapping alone is not a loss of chance for patients with melanoma.

Micrometastatic cancer cells in lymph nodes, bone marrow, and blood: Clinical significance and biologic implications

Cancer metastasis may be regarded as a progressive process from its inception in the primary tumor microenvironment to distant sites by way of the lymphovascular system. Although this type of tumor dissemination often occurs in an orderly fashion via the sentinel lymph node (SLN), acting as a possible gateway to the regional lymph nodes, bone marrow, and peripheral blood and ultimately to distant metastatic sites, this is not a general rule as tumor cells may enter the blood and spread to distant sites, bypassing the SLN. Methods of detecting micrometastatic cancer cells in the SLN, bone marrow, and peripheral blood of patients have been established. Patients with cancer cells in their SLN, bone marrow, or peripheral blood have worse clinical outcomes than patients with no evidence of spread to these compartments. The presence of these cells also has important biologic implications for disease progression and the clinician's understanding of the process of cancer metastasis. Further characterization of these micrometastatic cancer cells at each stage and site of metastasis is needed to design novel selective therapies for a more "personalized" treatment.

Comparison of sentinel lymph node micrometastatic tumor burden measurements in melanoma

BACKGROUND

Multiple methods have been proposed to classify the micrometastatic tumor burden in sentinel lymph nodes (SLN) for melanoma. The purpose of this study was to determine the classification scheme that best predicts nonsentinel node (NSN) metastasis, disease-free survival (DFS), and overall survival (OS).

STUDY DESIGN

A single reviewer reanalyzed tumor-positive SLN from a multicenter, prospective clinical trial of patients with melanoma ≥ 1.0 mm Breslow thickness who underwent SLN biopsy. The following micrometastatic disease burden measurements were recorded: Starz classification, Dewar classification (microanatomic location), maximum diameter of the largest focus of metastasis, maximum tumor area, and sum of all diameters. Univariate and multivariate models and Kaplan-Meier analysis were used to evaluate each classification system.

RESULTS

We reviewed 204 tumor-positive SLNs from 157 patients. On univariate analysis, all criteria except Starz classification were statistically significant risk factors for NSN metastasis. On multivariate analysis, including Breslow thickness, ulceration, age, sex, and NSN status, maximum diameter (using a cut-off of 3 mm) was the only classification system that was an independent risk factor predicting DFS (hazard ratio 2.31, p = 0.0181) and OS (hazard ratio 3.53, p = 0.0005). By Kaplan-Meier analysis, DFS and OS were significantly different among groups using maximum diameter cut-offs of 1 and 3 mm.

CONCLUSIONS

Maximum tumor diameter outperformed other measurements of metastatic tumor burden, including microanatomic tumor location (Dewar classification), Starz classification, maximum tumor area, and sum of all diameters for prediction of survival. Maximum tumor diameter is a simple method of assessing micrometastatic tumor burden that should be reported routinely.

The prognostic significance of sentinel node tumour burden in melanoma patients: an international, multicenter study of 1539 sentinel node-positive melanoma patients

INTRODUCTION

Sentinel node (SN) biopsy (SNB) and completion lymph node dissection (CLND) when SN-positive have become standard of care in most cancer centres for melanoma. Various SN tumour burden parameters are assessed to determine the heterogeneity of SN-positivity. The aim of the present study was to validate the prognostic significance of various SN tumour burden micromorphometric features and classification schemes in a large cohort of SN-positive melanoma patients.

METHODS

In 1539 SN-positive patients treated between 1993 and 2008 at 11 melanoma treatment centres in Europe and Australia, indices of SN tumour burden (intranodal location, tumour penetrative depth (TPD) and maximum size of SN tumour deposits) were evaluated.

RESULTS

Non-subcapsular location, increasing TPD and increasing maximum size were all predictive factors for non-SN (NSN) status and were independently associated with poorer melanoma-specific survival (MSS). Patients with subcapsular micrometastases <0.1mm in maximum dimension had the lowest frequency of NSN metastasis (5.5%). Despite differences in SN biopsy protocols and clinicopathologic features of the patient cohorts (between centres), most SN parameters remained predictive in individual centre populations. Maximum SN tumour size>1mm was the most reliable and consistent parameter independently associated with higher non-SN-positivity, poorer disease-free survival (DFS) and poorer MSS.

CONCLUSIONS

In this large retrospective, multicenter cohort study, several parameters of SN tumour burden including intranodal location, TPD and maximum size provided prognostic information, but their prognostic significance varied considerably between the different centres. This could be due to sample size limitations or to differences in SN detection, removal and examination techniques.

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.

Progression of cutaneous melanoma: implications for treatment

The survival rates of melanoma, like any type of cancer, become worse with advancing stage. Spectrum theory is most consistent with the progression of melanoma from the primary site to the in-transit locations, regional or sentinel lymph nodes and beyond to the distant sites. Therefore, early diagnosis and surgical treatment before its spread is the most effective treatment. Recently, new approaches have revolutionized the diagnosis and treatment of melanoma. Genomic profiling and sequencing will form the basis for molecular taxonomy for more accurate subgrouping of melanoma patients in the future. New insights of molecular mechanisms of metastasis are summarized in this review article. Sentinel lymph node biopsy has become a standard of care for staging primary melanoma without the need for a more morbid complete regional lymph node dissection. With recent developments in molecular biology and genomics, novel molecular targeted therapy is being developed through clinical trials.

Prognosis in patients with sentinel node-positive melanoma without immediate completion lymph node dissection

Background

The therapeutic value of immediate completion lymph node dissection (CLND) for sentinel node (SN)-positive melanoma is unknown. The aim of this study was to evaluate the impact of immediate CLND on the outcome of patients with SN-positive melanoma.

Methods

Patients with SN metastases treated between 1993 and 2008 at ten cancer centres from the European Organization for Research and Treatment of Cancer Melanoma Group were included in this retrospective study. Maximum tumour size, intranodal location and penetrative depth of SN metastases were measured. Outcome in those who had CLND was compared with that in patients who did not undergo completion lymphadenectomy.

Results

Of 1174 patients with SN-positive melanoma, 1113 (94·8 per cent) underwent CLND and 61 (5·2 per cent) did not. Median follow-up for the two groups was 34 and 48 months respectively. In univariable survival analysis, CLND did not significantly influence disease-specific survival (hazard ratio (HR) 0·89, 95 per cent confidence interval 0·58 to 1·37; P = 0·600). However, patients who did not undergo CLND had more favourable prognostic factors. Matched-pair analysis, with matching for age, Breslow thickness, tumour ulceration and SN tumour burden, showed that CLND had no influence on survival (HR 0·86, 0·46 to 1·61; P = 0·640). After adjusting for prognostic factors in multivariable survival analyses, no difference in survival was found.

Conclusion

In these two cohorts of patients with SN-positive melanoma and prognostic heterogeneity, outcome was not influenced by CLND.

Lymphatic drainage patterns from melanomas on the shoulder or upper trunk to cervical lymph nodes and implications for the extent of neck dissection

Purpose

To determine the incidence and pattern of cervical lymphatic drainage in patients with melanomas located on the upper limb or trunk, and to evaluate our current neck dissection protocol for those patients with a N+ neck.

Methods

Of 1192 melanoma patients who underwent sentinel node biopsy, 631 were selected with a primary tumor on the upper limb or trunk. All lymphoscintigrams, SPECT/CT images and operative reports were reviewed to determine the exact locations of sentinel nodes visualized preoperatively and dissected during operation.

Results

Thirty-nine (6.2 %) of 631 patients with a melanoma on the upper limb or trunk showing cervical lymph node drainage were identified. In 34 (87 %) of 39 patients, sentinel nodes were excised from level IV or Vb, and in 30 of those 39 patients simultaneous from the axilla. In the remaining five patients (13 %), sentinel nodes were collected from level IIb, level III or the suboccipital region. All collected sentinel nodes were located in the intended dissection area for N+ patients. Thirteen patients (33 %) had a total of 22 tumor-positive sentinel nodes in either the axilla (n = 10), level IV (n = 2), Vb (n = 9) or suboccipital (n = 1).

Conclusions

Only a minority of the patients with upper limb or trunk melanomas demonstrated lymphatic drainage to cervical lymph node basins, with preferential drainage to levels IV and Vb. Our current dissection protocol of levels II–V, with or without extension to the suboccipital region, in those patients with involved cervical sentinel nodes seems sufficient.

Sentinel lymph nodes containing very small (<0.1 mm) deposits of metastatic melanoma cannot be safely regarded as tumor-negative

BACKGROUND

Some authors have suggested that patients with very small (<0.1 mm) deposits of metastatic melanoma in sentinel lymph nodes (SLNs) should be considered SLN-negative, whereas others have reported that such patients can have adverse long-term outcomes. The aims of the present study were to determine whether extensive sectioning of SLNs resulted in more accurate categorization of histologic features of tumor deposits and to assess prognostic associations of histologic parameters obtained using more intensive sectioning protocols.

METHODS

From patients with a single primary cutaneous melanoma who underwent SLN biopsy between 1991 and 2008, those in which the maximum size of the largest tumor deposit (MaxSize) in SLNs was <0.1 mm in the original sections were identified. Five batches of additional sections were cut from the SLN tissue blocks at intervals of 250 μm. The 1st batch was cut from the blocks without any trimming; these sections were therefore immediately adjacent to the original sections. Each batch included 5 sequential sections, the 1st and 5th stained with hematoxylin-eosin, and the 2nd, 3rd, and 4th stained immunohistochemically with S-100, HMB-45, and Melan-A, respectively. In each batch of sections, the following histologic features of tumor deposit(s) in the SLNs were evaluated: MaxSize; tumor penetrative depth (TPD) (defined as the maximum depth of tumor deposit(s) from the inner margin of the lymph node capsule), and intranodal location (classified as subcapsular if the tumor deposit(s) were confined to the subcapsular zone or parenchymal if there was any involvement of the nodal parenchyma beyond the subcapsular zone). The measured histologic parameters were compared in each batch of sections. The association of histologic parameters with overall survival was assessed for the parameters measured in each batch of sections.

RESULTS

There were 20 eligible patients (15 females, 5 males, median age 60 years). After a median follow-up duration of 40 months, 4 patients had died from melanoma and 2 patients of unknown causes. Completion lymph node dissection (CLND) was performed in 13 cases (65%) and was negative in all cases. Relative to the measured values on the original sections, all 3 parameters were upstaged in subsequent batches of sections, but no further upstaging of MaxSize, TPD, or location was seen beyond batch 3, batch 4, and batch 2, respectively. Increasing MaxSize was associated with significantly poorer overall survival in batches 1, 2, and 3. Parenchymal involvement was significantly associated with poorer survival in batches 2-5. TPD was not significantly associated with overall survival.

CONCLUSIONS

The results of this study indicate that very small (<0.1 mm) deposits of melanoma in SLNs may be associated with adverse clinical outcomes and that this is due, at least in part, to the underestimation of SLN tumor burden in the initial sections. Our evidence does not support clinical decision-making on the assumption that patients with very small melanoma deposits in SLNs have the same outcome as those who are SLN-negative.

The impact of primary melanoma thickness and microscopic tumor burden in sentinel lymph nodes on melanoma patient survival

BACKGROUND

The primary objectives of this work are to (1) quantitate tumor burden in sentinel lymph nodes (SLNs), and (2) assess the independent contributions of SLN tumor burden and primary melanoma thickness (PMT) with respect to progression-free survival (PFS) and overall survival (OS).

METHODS

Sixty-three patients (41 male and 22 female) with one or more positive SLNs were available for review in this study, with median follow-up of 6.8 years. PMT was measured and SLN metastases were assessed for size, as maximum metastasis size (MMS) in mm, by hematoxylin and eosin (H&E) and immunohistochemistry (S100 and HMB45). PFS and OS were calculated from time of SLN resection until melanoma recurrence or death. Univariate and multivariate analyses and trend test were performed.

RESULTS

Kaplan-Meier estimates of PFS and OS differed significantly by MMS (log-rank P = 0.031 for PFS and P = 0.016 for OS) and PMT (log-rank P = 0.036 for PFS and P < 0.001 for OS). After adjusting for age and gender, the hazard ratio (HR) associated with MMS was 1.09 per mm increase (P = 0.05) for PFS, and 6.30 (P = 0.014) and 5.41 (P = 0.048) for OS in patients, respectively, with MMS of 0.6-5.5 mm and MMS ≥5.5 mm compared with those with MMS <0.6 mm. When patients were stratified by their tumor characteristics of PMT, the risk for disease progression and worse OS was substantially higher for the group with PMT ≥ 4.5 mm (HR = 13.10 and P = 0.022 for PFS; HR = 17.26 and P < 0.001 for OS) relative to the baseline group with PMT <1.6 mm. All patients had completion lymph node dissection (CLND) except for four patients. Patients with positive CLND (14, 22.2%) showed significant worse PFS (P = 0.002) and OS (P = 0.0003) than the negative CLND group (45, 71.4%).

CONCLUSIONS

PMT and MMS were independently prognostic of PFS and OS in melanoma patients. Patients with negative CLND had significantly better PFS and OS than those with positive CLND.

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.

Age as a key factor influencing metastasizing patterns and disease-specific survival after sentinel lymph node biopsy for cutaneous melanoma

In our study, we investigated the impact of the constitutional factor age on the clinical courses of melanoma patients with sentinel lymph node (SLN) biopsy. Descriptive statistics, Kaplan-Meier estimates, logistic regression analysis and the Cox proportional hazards model were used to study a population of 2,268 consecutive patients from three German melanoma centers. Younger age was significantly related to less advanced primary tumors. Nevertheless, patients younger than 40 years of age had a twofold risk of being SLN-positive (p < 0.000001). Of the young patients with primary melanomas with a thickness of 0.76 mm to 1.0 mm, 19.7% were SLN-positive. Using multivariate analysis, younger age, increasing Breslow thickness, ulceration and male sex were significantly related to a higher probability of SLN-metastasis. During follow-up, older patients displayed a significantly increased risk of in-transit recurrences (p = 0.000002) and lymph node recurrences (p = 0.0004). With respect to melanoma specific overall survival the patient's age was highly significant in the multivariate analysis. The unfavorable effect of being older was significant in the subgroups with positive and negative SLNs. Age remained also significant for the survival after the onset of distant metastases (p = 0.002). In conclusion, the patient's age is a strong and independent predictor of melanoma-specific survival in patients with localized melanomas, in patients with positive SLNs and after the onset of distant metastases. Younger patients have a better prognosis despite their higher probability of SLN metastasis. Older patients are less frequently SLN-positive but have a higher risk of loco-regional recurrence.

Non-Sentinel Node Risk Score (N-SNORE): a scoring system for accurately stratifying risk of non-sentinel node positivity in patients with cutaneous melanoma with positive sentinel lymph nodes

PURPOSE

Sentinel node (SN) biopsy allows identification of patients with melanoma at risk of further metastatic disease in regional non-sentinel nodes (NSN). We investigated clinicopathologic factors that predict NSN positivity in an attempt to identify patients who may be safely spared completion lymph node dissection (CLND).

PATIENTS AND METHODS

Clinicopathologic factors previously shown to be predictive of NSN positivity were analyzed in 409 patients with SN-positive disease (309 of whom underwent CLND) managed at a single melanoma center. A weighted score Non-Sentinel Node Risk Score [N-SNORE] incorporating predictive factors was derived, and the efficacy of N-SNORE at stratifying risk of NSN involvement was studied.

RESULTS

Factors independently predictive of NSN positivity included primary tumor regression, proportion of harvested SNs involved by melanoma (%PosSN), sex (trend), and SN tumor burden indices (maximum size of largest deposit [MaxSize], % cross-sectional area of SN occupied by tumor, tumor penetrative depth, intranodal location of tumor) and perinodal lymphatic invasion (PLI). Of SN tumor burden criteria, MaxSize was the strongest predictor. N-SNORE was the sum of scores for five parameters: sex (female = 0, male = 1), regression (absent = 0, present = 2), %PosSN (absent = 0, present = 2), MaxSize (≤ 0.5 mm = 0, 0.51 to 2.00 mm = 1, 2.01 to 10.00 mm = 2, > 10.00 mm = 3), and PLI (absent = 0, present = 3). N-SNOREs of 0, 1 to 3, 4 to 5, 6 to 7, and ≥ 8 were associated with very low (0%), low (5% to 10%), intermediate (15% to 20%), high (40% to 50%), and very high (70% to 80%) risks of NSN involvement.

CONCLUSION

A weighted score (N-SNORE) based on clinicopathologic characteristics accurately stratifies risk of NSN involvement in patients with melanoma. If validated in future studies, N-SNORE will better predict prognosis, aid in management decisions, and stratify patient groups for entry into clinical trials.

Influence of sentinel lymph node tumor burden on survival in melanoma

BACKGROUND

Completion lymph node dissection (CLND) is the standard procedure for patients with positive sentinel lymph nodes (SLN). With extensive pathological workup, increased numbers of small metastatic deposits are detected in SLN. This study evaluated the prognostic significance of SLN metastatic deposits < or = 0.2 mm in patients treated in a referral cancer center in Brazil.

METHODS

Patients with stage I/II melanoma, consecutively submitted to a SLN procedure by the same surgeon from 2000 to 2006, were evaluated. All positive SLN and randomly selected negative cases were reviewed by two pathologists. Different prognostic factors and SLN tumor burden were recorded. Additional positive non-SLN after CLND, and disease outcome were evaluated.

RESULTS

Of 381 patients who underwent SLN biopsy, 103 (27%) were positive. The mean/median Breslow tumor thickness in the overall group was 3.4/2.0 mm and in the SLN positive patients was 5.72/4.0 mm. Among these patients, 48 (47%) had metastatic deposits >2 mm (macrometastasis), 49 (47%) had metastatic deposits < or =2 mm but >0.2 mm (micrometastasis), and 6 (6%) had metastatic deposits < or =0.2 mm (submicrometastasis). Additional positive non-SLN were detected in 29% of patients with macrometastasis, in 25% of patients with micrometastasis, and in 0% of patients with submicrometastases. At median follow-up of 35 months, the estimated 3-year overall survival was 92% for negative SLN, 64% for micrometastases, 53% for macrometastases, and 100% for submicrometastases (P < 0.001).

CONCLUSION

In the present study, patients with SLN metastatic deposits < or =0.2 mm had no additional positive non-SLNs, and no recurrences or deaths were recorded, suggesting that their prognosis is equivalent to that of patients with negative SLN.

Significance of sentinel lymph node biopsy in malignant melanoma: overview of international data

The notion of sentinel lymph node (SLN) mapping and its use during surgery for staging cancer was initially reported in 1992, in a study involving patients with malignant melanoma. To date SLN biopsy (SLNB) has emerged as a rational approach for staging regional lymph nodes in patients with clinically node-negative melanoma (stage I and II disease). The significance of SLNB as a staging and prognostic tool in melanoma is widely accepted. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of the SLN remains very controversial. Whether SLNB improves survival in melanoma patients remains an open question.