Recent advances in the care of the patient with malignant melanoma

Innate extracellular vesicles from melanoma patients suppress β-catenin in tumor cells by miRNA-34a

Upon tumor development, new extracellular vesicles appear in circulation. Our knowledge of their relative abundance, function, and overall impact on cancer development is still preliminary. Here, we demonstrate that plasma extracellular vesicles (pEVs) of non-tumor origin are persistently increased in untreated and post-excision melanoma patients, exhibiting strong suppressive effects on the proliferation of tumor cells. Plasma vesicle numbers, miRNAs, and protein levels were elevated two- to tenfold and detected many years after tumor resection. The vesicles revealed individual and clinical stage-specific miRNA profiles as well as active ADAM10. However, whereas pEV from patients preventing tumor relapse down-regulated β-catenin and blocked tumor cell proliferation in an miR-34a-dependent manner, pEV from metastatic patients lost this ability and stimulated β-catenin-mediated transcription. Cancer-induced pEV may constitute an innate immune mechanism suppressing tumor cell activity including that of residual cancer cells present after primary surgery.

Nonvisualization of Sentinel Lymph Nodes by Lymphoscintigraphy in Primary Cutaneous Melanoma: Incidence, Risk Factors, and a Review of Management Options

BACKGROUND

Lymphoscintigraphy is often performed before sentinel lymph node biopsy, especially in areas likely to have multiple or aberrant drainage patterns. This study aims to determine the incidence and characteristics of melanoma patients with negative lymphoscintigraphic findings and to review the management options and surgical recommendations.

METHODS

This is a retrospective study of patients with primary cutaneous melanoma who underwent sentinel lymph node biopsy between 2005 and 2016. Patients with nonvisualized lymph nodes on preoperative lymphoscintigraphy were compared in a 1:4 ratio with a randomly selected unmatched cohort drawn from all melanoma patients who underwent preoperative lymphoscintigraphy within the period of the study. Demographic, clinical, and outcome data were compared between these groups.

RESULTS

A negative lymphoscintigraphic scan was seen in 2.3 percent of all cases (25 of 1073). In both univariate and multivariate analyses, predictive patient- and tumor-specific factors for negative lymphoscintigraphy included older age and head and neck location. Patients with a nonvisualized sentinel lymph node had significantly worse overall survival compared with patients who had a visualized sentinel lymph node, but there was no difference in melanoma-specific survival. In 16 of the 25 cases (64 percent), at least one sentinel lymph node was found intraoperatively despite the negative lymphoscintigraphic findings.

CONCLUSIONS

Older patients with head and neck melanomas are more likely to experience nodal nonvisualization on lymphoscintigraphy. In patients who have nodal nonvisualization, the surgeon should attempt sentinel lymph node biopsy at the time of excision of the primary lesion because a sentinel lymph node can still be found in a majority of cases, and it offers prognostic information.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Sentinel Lymph Node Status is a Main Prognostic Parameter Needful for the Correct Staging of Patients with Melanoma Thicker than 4 mm: Single-Institution Experience and Literature Meta-Analysis

PURPOSE OF THE STUDY

The usefulness of sentinel lymph node biopsy in thick melanomas is debated. The aim of this study was to evaluate the possible prognostic significance of sentinel lymph node biopsy in T4 melanoma patients and to verify whether this was a homogeneous group of patients with similar poor behavior.

MATERIALS AND METHODS

A retrospective observational study was performed. Data were extracted from the Tuscan Regional Referral Center database. The outcome of sentinel lymph node-negative and sentinel lymph node-positive T4 melanomas were compared. A systematic review of published series on this issue and a meta-analysis were performed.

RESULTS

Among 125 T4 melanoma patients, 53 patients (42.4%) were sentinel lymph node-positive and 72 (57.6%) patients were sentinel lymph node-negative. The 5-year and the 10-year melanoma specific survival were 81.9% and 72.3% for sentinel lymph node-negative patients and 42.4% and 17.9% (P < 0.001) for sentinel lymph node-positive patients. A positive sentinel lymph node showed an HR of 3.08. The meta-analysis confirmed that there was a significantly greater risk of death for patients with thick melanoma and positive sentinel lymph node (RR 1.75).

CONCLUSIONS

The results of the study point out that the sentinel lymph node biopsy is required for the correct staging of patients with melanoma thicker than 4 mm and that the status of sentinel lymph node is a significant predictor of melanoma specific survival. This knowledge allows early surgical and adjuvant treatment as well as appropriate trial enrollment and tailored follow-up.

Lymphatic mapping and sentinel lymphadenectomy in primary cutaneous melanoma

The management of clinically normal regional lymph nodes in early-stage melanoma has been controversial for over 100 years. Lymphatic mapping and sentinel lymphadenectomy has been developed as a minimally invasive surgical technique to stage regional lymph nodes without the associated morbidity of complete lymph node dissection. Multiple retrospective studies have validated the accuracy of lymphatic mapping and sentinel lymphadenectomy and the importance of the sentinel lymph node as a prognostic tool for melanoma. Several multicenter, prospective, randomized trials are underway to validate the data of the Phase II studies and determine the therapeutic benefit of lymphatic mapping and sentinel lymphadenectomy.

Sentinel node biopsy for melanoma: an update after two decades of experience

When detected and treated early, melanoma has an excellent prognosis. Unfortunately, as the tumor invades deeper into tissue the risk of metastatic spread to regional lymph nodes and beyond increases and the prognosis worsens significantly. Therefore, accurately detecting any regional lymphatic metastasis would significantly aid in determining a patient's prognosis and help guide his or her treatment plan. In 1991, Don Morton and colleagues presented new paradigm in diagnosing regional lymphatic involvement of tumors termed sentinel lymph node biopsy (SLNB). By mapping the regional lymph system around a tumor and tracing the lymphatic flow, a determination of the most likely lymph node or nodes the cancer will spread to first is made. Then, a limited biopsy of the most likely nodes is performed rather than a more-invasive removal of the entire local lymphatic chain. In 20 years that have followed, a great deal of information has been gained as to its accuracy, prognostic value, appropriate candidates, and its impact on regional disease control and survival. The SLNB has been shown to accurately stage regional lymph node basins in stage I and II melanoma patients with minimal morbidity. More sensitive histologic techniques are now being applied that may allow even greater accuracy in the staging of melanoma patients. Although specific percent risk thresholds are still in question, recommendation for SLNB when melanomas are 1 mm or thicker has gained wide acceptance. SLNB may also be appropriate for patients with melanomas that are between 0.76 and 1 mm thick and have ulceration, high mitotic rates, or reach a Clark level IV. Therefore, melanomas with IB or greater staging should be considered for SLNB.

Predictors of positive sentinel lymph node in thin melanoma

BACKGROUND

The treatment of thin melanoma (Breslow thickness <1.0 mm) may include sentinel lymph node (SLN) biopsy (SLNB). The validity of SLNB for thin melanoma remains widely debated. The purpose of this study was to elucidate pathologic factors that are predictive of SLN positivity.

METHODS

A retrospective analysis of a prospective database revealed 1,199 patients diagnosed with primary cutaneous melanoma. Multiple logistic regression was used to determine an association between pathologic factors and SLN positivity.

RESULTS

Thin melanomas were identified in 469 patients (39%). Of these, 147 patients (31%) underwent SLNB. Positive SLNs were found in 16 patients (11%). Multiple logistic regression demonstrated that both ulceration (odds ratio, 5.27; P = .047) and thickness (odds ratio, 46.69; P = .022) were associated with SLN positivity.

CONCLUSIONS

Patients with thin melanomas >.75 mm and/or ulceration should be considered for SLNB.

The accuracy of sentinel node mapping according to T stage in patients with gastric cancer

BACKGROUND

Sentinel lymph node (SLN) mapping has been recently introduced to the field of gastric cancer. To the best of our knowledge, no study has dealt with the accuracy of SLN mapping according to the T stage of the primary tumor. The aim of the present study was to evaluate SLN status according to the T stage of the primary tumors.

METHODS

Eighty patients with gastric cancer underwent SLN mapping with patent blue dye during gastric resection.

RESULTS

Forty-seven patients underwent distal subtotal gastrectomy; 17 patients, proximal gastrectomy; 14, total gastrectomy; and 2, gastric stump resection. SLNs were stained in 61/80 patients (76.3%). The number of stained SLNs varied from 1 to 16 (mean, 3.3). Patients undergoing proximal gastrectomy had a mean of 3 stained SLNs, whereas patients undergoing distal subtotal gastrectomy had a mean of 2.8 stained SLNs. In 55/61 patients (90.2%) with stained SLNs a positive correlation was found between the presence of metastases and stained or non-stained SLNs. Ten out of 11 patients (90.9%) with T1 tumors (mean, 3.27 SLNs per patient) and 15/17 patients with T2 tumors (88.2%; mean, 3 SLNs per patient) had stained SLNs as compared to only 33/48 (68.8%) of patients with T3 tumors (mean, 3.3 SLNs per patient). The positive predictive value of the SLN mapping was 100%, the negative predictive value was 76.9%, and sensitivity was 85.4%.

CONCLUSION

While in T1 and T2 tumors sentinel node mapping may be of assistance in the decision-making process regarding the extent of lymphadenectomy (sensitivity, 100%; negative predictive value, 90%-100%), SLN mapping in patients with T3 tumors will be misleading in a third of the patients and should not be attempted.

Ganglioside signatures of primary and nodal metastatic melanoma cell lines from the same patient

The primary cutaneous melanoma initially migrates to the regional lymph nodes (LNs). Human melanoma overexpresses gangliosides, the sialylglycosphingolipids. The ganglioside signatures may differ between primary and LN melanomas owing to the differences in the tumor microenvironments. The melanoma cells obtained from the primary and LN of the same patient might be useful to evaluate the above hypothesis. For this purpose, the cryopreserved cell lines from a primary cutaneous melanoma (IGR-39) and its nodal metastasis (IGR-37) from the same patient were used. We have also compared the ganglioside signatures of freshly obtained melanoma cells from primary, LN and organ metastases from different patients. Gangliosides were extracted, purified and identified by resorcinol and specific murine monoclonal antibodies. Comparison of the primary cell line with the nodal metastatic line obtained from the same patient distinctly showed the following features: (i) an increased production of gangliosides, (ii) O-acetylation of GM2 and GD3, (iii) an increased and altered O-acetylation of GD2 and (iv) possibly de-N-acetylation of GD3. These findings suggest that the nodal microenvironment might favor activation of O-acetyl-transferases capable of O-acetylating both alpha2, 3 and alpha2, 8 sialic acids of gangliosides. Supporting this, the primary melanoma cells obtained from different patients, showed no O-acetylation of GD3 or GD2. The cell line from groin LN showed the presence of O-acetyl (O-Ac)GD3. The cell lines from thyroid, spleen and jejunum expressed O-AcGD2. In all metastatic melanoma cell lines GD1a is more prevalent than GD3, suggesting that GD1a may be a major melanoma-ganglioside.

Sentinel lymph node biopsy in patients with thin melanomas

The aim of the present study is to report our experience with lymphatic mapping (LM) and sentinel lymph node biopsy (SLNB) in a selected group of patients with thin primary cutaneous melanomas. Fifty patients (22 females and 28 males; mean age, 57.8 years; range, 30-77 years) with a mean tumor thickness of 0.63 mm (range, 0.24-1.00 mm) underwent LM/SLNB. Twenty-eight (56%) of them had Clark level II, 20 (40%) had Clark level III, and two (4%) had Clark level IV. Tumor ulceration was present in two patients (4%) and histological regression in 35 patients (70%). Sentinel lymph node (SLN) metastases occurred in two of 50 patients (4%). The first case was a 0.88-mm thick, Clark level III, non-ulcerated superficial spreading melanoma of the trunk, without any regression. The second case was a 0.95-mm thick, Clark level IV, non-ulcerated superficial spreading melanoma of the neck, with regression. Both patients were disease-free 76 and 50 months after the SLNB procedure and followed complete lymph node dissection, respectively. The patients with negative SLN were disease-free after a median follow up of 44 months (mean, 43.2; range, 15-84 months). Published data and our experience suggest that LM/SLNB is not routinely indicated for melanomas less than 0.75 mm. Our results confirmed the accuracy of the new American Joint Committee on Cancer/International Union Against Cancer criteria, in which SLNB is required for thin melanomas less than 1.0 mm when they have ulceration or Clark level IV and V invasion.

Distinct mechanisms of loss of IFN-gamma mediated HLA class I inducibility in two melanoma cell lines

Background

The inability of cancer cells to present antigen on the cell surface via MHC class I molecules is one of the mechanisms by which tumor cells evade anti-tumor immunity. Alterations of Jak-STAT components of interferon (IFN)-mediated signaling can contribute to the mechanism of cell resistance to IFN, leading to lack of MHC class I inducibility. Hence, the identification of IFN-γ-resistant tumors may have prognostic and/or therapeutic relevance. In the present study, we investigated a mechanism of MHC class I inducibility in response to IFN-γ treatment in human melanoma cell lines.

Methods

Basal and IFN-induced expression of HLA class I antigens was analyzed by means of indirect immunofluorescence flow cytometry, Western Blot, RT-PCR, and quantitative real-time RT-PCR (TaqMan^® Gene Expression Assays). In demethylation studies cells were cultured with 5-aza-2'-deoxycytidine. Electrophoretic Mobility Shift Assay (EMSA) was used to assay whether IRF-1 promoter binding activity is induced in IFN-γ-treated cells.

Results

Altered IFN-γ mediated HLA-class I induction was observed in two melanoma cells lines (ESTDAB-004 and ESTDAB-159) out of 57 studied, while treatment of these two cell lines with IFN-α led to normal induction of HLA class I antigen expression. Examination of STAT-1 in ESTDAB-004 after IFN-γ treatment demonstrated that the STAT-1 protein was expressed but not phosphorylated. Interestingly, IFN-α treatment induced normal STAT-1 phosphorylation and HLA class I expression. In contrast, the absence of response to IFN-γ in ESTDAB-159 was found to be associated with alterations in downstream components of the IFN-γ signaling pathway.

Conclusion

We observed two distinct mechanisms of loss of IFN-γ inducibility of HLA class I antigens in two melanoma cell lines. Our findings suggest that loss of HLA class I induction in ESTDAB-004 cells results from a defect in the earliest steps of the IFN-γ signaling pathway due to absence of STAT-1 tyrosine-phosphorylation, while absence of IFN-γ-mediated HLA class I expression in ESTDAB-159 cells is due to epigenetic blocking of IFN-regulatory factor 1 (IRF-1) transactivation.

Regional Nodal Metastatic Disease Is the Strongest Predictor of Survival in Patients with Thin Vertical Growth Phase Melanomas: A Case for SLN Staging Biopsy in These Patients

BACKGROUND

The benefit of sentinel lymph node (SLN) biopsy for patients with thin (< or =1.0 mm) melanomas, even for prognostic value, is controversial. This may partly result from the relatively small number and short follow-up of SLN-positive patients in this group. Previously, we have shown that clinical regional nodal metastatic disease (RNMD) serves as a good surrogate for SLN positivity. Here, we use RNMD as a validated surrogate for SLN positivity and examine its prognostic value in a large pre-SLN group of patients with thin vertical growth phase (VGP) lesions who would today commonly be offered SLN biopsy in our practice.

METHODS

Between 1972 and 1991, 472 patients with thin VGP melanomas with at least 10 years' follow-up were eligible for the study. Kaplan-Meier survival curves were computed for patients with and without RNMD. A multivariate Cox model and classification tree analysis were used to evaluate clinical and histopathologic predictors of survival.

RESULTS

Sixty-seven patients (14.2%) developed recurrence, 53.7% of whom developed RNMD. Forty-five patients (9.5%) experienced melanoma-related deaths (MRD). The most statistically significant predictor of MRD was RNMD (hazard ratio [HR] 13.5, P < .0001). Thickness (HR 10.5, P = .004), axial location (HR 4.6, P = .001), and age >60 years (HR 2.7, P = .005) additionally were independently associated with an increased risk of MRD. RNMD patients demonstrated a 44.4% 10-year disease-specific mortality.

CONCLUSIONS

RNMD was the most statistically significant factor associated with MRD in patients with thin VGP lesions. This supports the prognostic use of SLN biopsy in this group, recognizing that additional factors, including thickness, axial location, and older age were independently associated with a worse survival outcome.

The role of sentinel lymph node biopsy in the management of melanoma

During the last 2 decades, the development and wide acceptance of SLN biopsy have affected the management of melanoma profoundly. This technique represents a considerable improvement in the ability to evaluate the tumor status of the regional lymph node basin, which is the most important predictor of survival in patients who have melanoma. Histopathologic and molecular assessment of the SLN has enhanced the detection of clinically occult nodal metastases, thereby distinguishing patients who might benefit from immediate lymphadenectomy from those for whom this procedure is unlikely to be helpful. This technique also identifies patients who would be candidates for clinical trials of adjuvant therapy. Centers can offer SLN biopsy without routine CLND once they reach a level of proficiency that usually corresponds to a learning phase of 55 cases. The role of molecular technology in the identification and analysis of the SLN remains to be established. Although molecular evidence of SLN metastasis has been identified in patients who have early-stage melanoma, its clinical relevance cannot be determined until marker selection is improved. The markers presently under study lack sensitivity and specificity. The role of molecular biomarkers can be validated only through large, multicenter, randomized. controlled trials such as the MSLT-II, a trial that will determine the benefit of multimarker RT-PCR assay in SLN specimens. SLN offers a promising future in staging lymph nodes and will improve the management of patients who have melanoma. Although SLN biopsy has become widely accepted as a minimally invasive technique of staging regional lymph nodes, its use in patients who have melanoma continues to be challenged. The future of SLN biopsy holds promise if prospective multicenter trials confirm a survival benefit for SLN biopsy as compared with watch-and-wait observation.

Histological features of melanoma sentinel lymph node metastases associated with status of the completion lymphadenectomy and rate of subsequent relapse

BACKGROUND

The current recommendation for patients with cutaneous melanoma and a positive sentinel lymph node (SLN) biopsy is a completion lymph node dissection (CLND). This study sought to define a population of SLN-positive patients, based on their histological pattern of SLN metastases, who may not require CLND.

METHODS

All patients with SLN-positive cutaneous melanoma who underwent CLND between March 1999 and December 2004 at a single academic institution were enrolled. Metastatic deposits in the SLN were categorized by their histological zone of involvement (subcapsular, parenchymal and/or sinusoidal). Logistic regression was used to examine the effect of SLN zone, size of nodal metastases, and other histological factors on CLND positivity. Kaplan-Meier and Cox models were used to study disease recurrence.

RESULTS

A total of 127 patients were included, and 15.8% had positive non-sentinel nodes. In adjusted analyses, the size of the largest tumor deposit in the SLN was the only factor associated with CLND status. No patients with a tumor deposit <or=0.20 mm had a positive CLND. Although a specific zone of tumor involvement was not predictive of CLND status, involvement of all three zones was independently associated with increased recurrence. Size of the largest tumor deposit was also associated with recurrence, with no recurrences in patients with nodal deposits <or=0.20 mm.

CONCLUSION

Histologic features of tumor metastases in positive SLN may be useful in defining a population of patients who may be spared CLND and a group at high risk of recurrence.

Can Melan-A Replace S-100 and HMB-45 in the Evaluation of Sentinel Lymph Nodes From Patients With Malignant Melanoma?

The sentinel lymph node (SLN) biopsy has become an increasingly important procedure used in the primary staging of malignant melanoma. However, micrometastases in a lymph node can be easily missed on routine H&E-stained sections. Therefore, S-100 and HMB-45 IHC stains are standardly performed on grossly negative SLNs for detection of metastatic melanoma. Each of these IHC markers, however, is not ideal. The authors investigated whether the newer IHC marker Melan-A would improve the detection of metastatic melanoma in SLN biopsies. Forty lymph nodes previously diagnosed with metastatic melanoma were retrospectively evaluated for S-100, HMB-45, and Melan-A expression. In addition, 42 SLN biopsies for metastatic melanoma detection were prospectively collected and evaluated for S-100, HMB-45, and Melan-A expression. All lymph nodes with metastatic melanoma from the retrospective study demonstrated S-100 reactivity. Five of the lymph nodes with metastatic melanoma from the retrospective study failed to express either HMB-45 or Melan-A, all of which displayed a desmoplastic morphology. One of the metastases positive for S-100 and HMB-45 failed to show reactivity with Melan-A (3%). The prospective study found 10 lymph nodes from 42 cases to be positive for metastatic melanoma, which were positive for S-100 (100%). Nine of the involved lymph nodes were positive for HMB-45(90%), and nine were positive for Melan-A (90%). Melan-A, although very specific, cannot replace the use of S-100 and HMB-45 for the detection of metastatic melanoma in SLNs. It can, however, substitute for HMB-45 with equally good results.

Clinical patterns of metastasis

In human solid cancer, lymph node status is the most important indicator for clinical outcome. Recent developments in the sentinel lymph node concept and technology have resulted in a more precise way of examining micrometastasis in the sentinel lymph node and the role of lymphovascular system in the facilitation of cancer metastasis. Different patterns of metastasis are described with respect to different types of solid cancer. Expect perhaps for papillary carcinoma and sarcoma, the overwhelming evidence is that solid cancer progresses in an orderly progression from the primary site to the regional lymph node or the sentinel lymph node in the majority of cases with subsequent dissemination to the systemic sites. The basic mechanisms of cancer metastasis through the lymphovascular system form the basis of rational therapy against cancer. Beyond the clinical patterns of metastasis, it is imperative to understand the biology of metastasis and to characterize patterns of metastasis perhaps due to heterogeneous clones based on their molecular signatures.

Prognostic significance of molecular staging study of sentinel lymph nodes by reverse transcriptase-polymerase chain reaction for tyrosinase in melanoma patients

BACKGROUND

We performed this study to evaluate the clinical effect of microscopic and submicroscopic metastases in sentinel lymph nodes (SLNs) from patients with early-stage melanoma.

METHODS

Patients with confirmed cutaneous melanoma (American Joint Committee on Cancer stages I and II) underwent standard lymphoscintigraphy and SLN biopsy. Serial sections were divided between routine histopathology with hematoxylin and eosin plus immunohistochemistry for HMB-45 and molecular analysis by nested reverse transcriptase-polymerase chain reaction (RT-PCR) assay for tyrosinase (using beta-actin as a control).

RESULTS

Of 180 patients analyzed (318 SLNs), 38 (21%) patients had positive SLN(s) by routine hematoxylin and eosin and immunohistochemistry (microscopic disease; group 1), and 142 (79%) had negative histological results. Analysis by RT-PCR detected tyrosinase in at least 1 SLN from 124 (69%) patients. Among patients with histologically negative SLN(s), tyrosinase was detected in 86 (48%) patients (submicroscopic disease; group 2), whereas 40 (22%) patients had negative results by both histology and RT-PCR (group 3). Sixteen (9%) patients had histologically negative SLNs and ambiguous RT-PCR results (group 4). Among 138 patients in the analysis of recurrence (mean follow-up, 45 months), only 18 patients had a recurrence: 11 (31%) of 35 in group 1, 5 (10%) of 51 in group 2, and 2 (5%) of 37 in group 3. No recurrences were seen in group 4. Only group 1 had a significantly shorter disease-free survival and overall survival compared with the other groups.

CONCLUSIONS

After a long follow-up period, molecular upstaging by tyrosinase RT-PCR failed to detect a subgroup of patients with an increased probability of recurrence.

Hybrid SPECT-CT: an additional technique for sentinel node detection of patients with invasive bladder cancer

OBJECTIVES

To explore the feasibility of performing lymphoscintigraphy combined with computed tomography (CT) for preoperative detection of sentinel lymph nodes in patients with invasive bladder cancer.

MATERIALS

Six consecutive patients scheduled for radical cystectomy underwent lymphoscintigraphy after transurethral injection of Albures-technetium 99m in the detrusor muscle peritumourally both with planar imaging and with single-photon emission computed tomography/CT (SPECT/CT). CT for anatomic fusion was performed directly after the SPECT/CT and both investigations were combined to a fused image. Radical cystectomy started with extended lymphadenectomy and intraoperative detection of sentinel nodes with both Geiger probe and dye marker. The conventional planar lymphoscintigraphies and the fused SPECT/CT were compared with each other and with the outcome of intraoperative sentinel node detection and final histopathologic analyses.

RESULTS

The method allowed anatomically detailed preoperative visualisation of 21 sentinel nodes in five of the six patients, whereas planar pictures only visualised two sentinel nodes in two of six patients. Two patients had lymph node metastases and in the other four the nodes were negative. The combined method visualised all metastatic sentinel nodes, whereas planar lymphoscintigraphy detected only one of six node metastases.

CONCLUSIONS

The combination of lymphoscintigraphy with CT enhanced preoperative anatomic localisation of sentinel nodes in bladder cancer and aided in the identification of sentinel nodes during surgery. The yield of detected sentinel nodes, both metastatic and nonmetastatic, was markedly increased using the combined method compared to conventional planar lymphoscintigraphy.

Predictors of regional nodal disease in patients with thin melanomas

BACKGROUND

Most melanoma patients present with thin (<or=1.0 mm) lesions. Indications for sentinel lymph node (SLN) biopsy are not well defined for this group. Previously, we reported an association between mitotic rate (MR) and SLN positivity in these patients. The study was limited by a relatively small sample size and low statistical power. In this study, we evaluated a large population of patients with thin melanoma from the pre-SLN era to identify predictors of regional nodal disease (RND) that may serve as a surrogate for SLN positivity.

METHODS

Eight hundred eighty-two patients evaluated between 1972 and 1991 were included in the study. Univariate and multivariate regression analyses were performed by using clinical and histological data to identify factors associated with RND. A multivariate logistic regression model was developed and applied to the previously reported group of patients with thin melanomas who underwent SLN biopsy between 1996 and 2004 for validation.

RESULTS

Thirty-eight patients (4.3%) had evidence of RND. In the multivariate analysis, a MR>0, vertical growth phase (VGP), male sex, and ulceration were statistically significant predictors of RND. Patients at the highest risk according to a classification tree analysis (VGP and MR>0) had an RND rate of 11.9%. The regression model developed predicted well the SLN status in the validation sample.

CONCLUSIONS

Investigation of a large pre-SLN population identified MR>0, ulceration, VGP, and male sex as independently predictive of RND in patients with thin melanomas. These factors may help to identify subgroups of these patients that have clinically significant risks of SLN positivity.

Should all melanoma patients undergo sentinel lymph node biopsy?

PURPOSE OF REVIEW

It is now well established that sentinel lymph node biopsy is a powerful test to predict prognosis for melanoma patients. Controversy exists, however, regarding the appropriate selection of patients for sentinel lymph node biopsy, especially among patients with thin melanomas (< 1 mm Breslow thickness), thick melanomas (> 4 mm Breslow thickness), or locally recurrent melanoma.

RECENT FINDINGS

The majority of the studies in the past 2 years regarding sentinel lymph node biopsy have been concerned with identifying factors that can better predict regional nodal metastasis and survival. Other studies have proposed a better risk stratification model, which includes these factors, to best select those patients at increased risk of nodal positivity.

SUMMARY

Although much research has been done to select appropriate patients for sentinel lymph node biopsy based on multiple prognostic factors, further studies are necessary to completely define the indications for this procedure in patients with thin, thick and locally recurrent melanomas.

Vital dye is enough for inguinal sentinel lymph node biopsy in melanoma patients

PURPOSE

The importance of gamma probe detection (GPD) combined with vital dye for sentinel node (SN) biopsy is well accepted. We evaluated the efficacy of patent blue dye (PBD) in identifying inguinal SN.

METHODS

Ninety-four cutaneous melanoma patients with inferior extremity lesions were submitted to SNB according to a established protocol. Patients were randomized in two groups: Blue group, where SN was identified by PPD and Probe group, where SN was identified by GPD. The median age was 44.2 years and median Breslow thickness was 2.1 mm. Preoperative lymphoscintigraphy, lymphatic mapping with PBD and intra-operative GPD was performed on all patients. Histological examination of SN consisted of hematoxylin-eosin and immunohistochemical staining. If micrometastases were present complete lymphadenectomy was performed. The SN was considered as identified by PBD if it was blue and identified by GPD if it demonstrated at least ten times greater radioactivity than background.

RESULTS

It was explored 94 inguinal lymphatic basins, 145 SN were excised (70 guided primarily by blue dye and 75 guided primarily by probe). All SN identified by preoperative lymphoscintigraphy were excised. In the Blue group PPD identified all SN and all of them were hot. In the Probe group all SN were identified by probe and were blue. The coincidence of PPD and GPD was 100%.

CONCLUSION

Patent blue dye is enough to identify superficial inguinal SN in cutaneous melanoma.

Biology of desmoplastic melanoma: a case-control comparison with other melanomas

PURPOSE

Previous studies have established that patients with desmoplastic melanoma (DM) have thicker primary tumors. Consequently, comparisons with other forms of melanoma have been strongly biased by differences in Breslow stage. This is the first case-matched control study comparing DM with other forms of melanoma.

PATIENTS AND METHODS

From a database of 3,202 melanoma patients treated at one institution, 89 patients with DM and 178 case-matched control patients (2:1) were identified by matching for tumor thickness, age, sex, and year of diagnosis. Clinical, pathologic, and outcome information was obtained from chart review.

RESULTS

Controls were matched successfully to patients for tumor thickness, age, sex, and year of diagnosis. Presentation with American Joint Committee on Cancer stage III or IV disease is less common in patients with DM compared to case-matched control patients (5% v 21%; P < .001). Re-excisions to obtain clear surgical margins are required more often in patients with DM compared to case-matched control patients (21% v 6%; P < .001). Risk of positive sentinel nodes is lower in patients with DM compared to case-matched control patients (8% v 34%; P = .013). Despite these differences, survival rates of patients with DM are the same as case-matched control patients.

CONCLUSION

Use of case-matched control patients matched for tumor thickness avoids biases introduced by the advanced Breslow stage of DMs. DMs are more locally aggressive than thickness-matched controls, and positive sentinel nodes are limited to patients with thick primary tumors. Importantly, patients with DM have survival rates similar to patients with other melanomas of similar thickness.

Selective sentinel lymphadenectomy for malignant melanoma, Merkel cell carcinoma, and squamous cell carcinoma

To date, selective sentinel lymphadenectomy (SSL) should be considered a standard approach for staging patients with primary invasive melanoma greater than or equal to 1 mm. It is imperative that the multidisciplinary team master the techniques of preoperative lymphoscintigraphy, intraoperative lymphatic mapping, and postoperative pathologic evaluation of the sentinel lymph nodes (SLNs). An SLN is defined as a blue, "hot" and any subsequent lymph node greater than 10% of the ex vivo count of the hottest lymph node. Any enlarged or indurated lymph node in the nodal basin should be excised. Frozen sections are not recommended. For extremity melanoma, delayed SSL may be performed. Preoperative lymphoscintigraphy for extremity melanoma may be done the night before so that the surgery can be scheduled as the first case of the following day. Every surgeon who uses blue dye should be aware of the potential adverse reaction to isosulfan blue and treatment for such a potential fatal reaction. A complete lymph node dissection is done if the SLN is found to be positive. Elective lymph node dissection (ELND) should not be done if an SSL can be performed as a staging procedure. SSL has further been applied to stage the nodal basin for Merkel cell carcinoma and high-risk squamous cell carcinoma. It is important for investigators involved with the SSL to follow the clinical outcome of these patients, so that the role of SSL can be further defined.

Evaluation of extensive initial staging procedure in intermediate/high-risk melanoma patients

INTRODUCTION

Early diagnosis and treatment of metastases have been shown to improve overall survival of melanoma patients. The purpose of this study was to evaluate the impact of extensive initial staging, including positron emission tomography (PET) scan on the management of melanoma patients.

PATIENTS AND METHODS

Forty-three patients with intermediate/poor prognosis primary melanoma benefited from complementary excision and sentinel lymph node biopsy (SLB) after clinical and paraclinical staging (computed tomography, nuclear magnetic resonance and whole body fluorodeoxyglucose PET scan).

RESULTS

No systemic metastases were demonstrated, while the SLB procedure emphasized the presence of regional lymph node metastases in 10 patients as suggested by the PET scan in four patients (sensitivity of the PET scan 40%). These 10 patients with early diagnosed lymph node involvement benefited from early surgery and were included in adjuvant treatment protocols. A secondary primary cancer was fortuitously diagnosed and treated early in two patients.

CONCLUSIONS

The development of new adjuvant therapies and therapeutic procedures (specific and non-specific immunotherapy, gamma-knife radiosurgery, etc.) now raises the relevance of extensive staging in intermediate/poor prognosis melanoma patients. We confirm in our series that PET scan is not useful to detect micrometastasis and cannot replace SLB in initial regional staging. However, we show in our study that 12 of 43 patients were treated early or were included early in treatment protocols thanks to the extensive staging procedure. Nevertheless, it seems important to evaluate through larger prospective trials the real impact of these early diagnoses and new treatments on overall survival before defining new diagnostic and therapeutic guidelines.

Malignant melanoma in a black child: predisposing precursors and management

Malignant melanoma (MM) remains a pediatric rarity world-wide, but perhaps more so in black Africans. To the best of our knowledge, the current report of MM in a two-and-a-half-year-old Nigerian who had a pre-existing congenital giant hairy nevus is probably the first (in an accessible literature) in a black African child. Primary neoplastic transformation and metastatic spread were suggested by the appearance of multiple swellings over the "garment" precursor nevus at the posterior trunk, multiple ipsilateral axillary nodal enlargement, and fresh occipital swellings postadmission. Smaller-sized hyperpigmented lesions with irregular, nonlobulated, and frequently hairy surfaces were also discernible over the upper and lower extremities, but the face, anterior trunk, and mucosal surfaces were relatively spared. A diagnosis of MM was confirmed by the subsequent histopathologic findings from the fine-needle aspirate and biopsy specimens. Chemotherapy was initiated but was truncated shortly after by parent-pressured discharge. Despite the rarity of MM in a tropical African setting where management options are few, the current case underscores the need for a high clinical index of diagnostic suspicion, an early pursuit of investigative confirmation, and prophylactic excision in children with the predisposing skin lesions, like congenital giant hairy nevus. An expounded discourse of the possible precursors and management options of MM is provided. We emphasize the need for institutional cost subsidy for anticancer care in tropical children.

Sentinel lymph node mapping and selective lymphadenectomy: the standard of care for melanoma

Selective sentinel lymphadenectomy (SSL) should be considered a standard of care approach for staging patients with primary invasive melanoma 1 mm or greater. It is essential that multidisciplinary teams should master the techniques of preoperative lymphoscintigraphy, intraoperative lymphatic mapping, and pathologic evaluation of the sentinel lymph nodes (SLNs). An SLN may be blue, hot, or any lymph node (LN) greater than 10% of the in-vivo count of the hottest LN. An enlarged or indurated LN should be removed because it may contain metastatic cancer cells that block blue dye or radiotracer entry. Frozen sections are not recommended. Surgeons who use isosulfan blue dye should be cognizant of treatment for a potentially fatal reaction. Prophylactic LN dissection should not be performed if a SSL can be performed as a staging procedure. A complete LN dissection is performed if the SLN is positive. It is important to follow the clinical outcome of patients undergoing SSL, thus its role can be further defined.

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

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

Paradigm of metastasis for melanoma and breast cancer based on the sentinel lymph node experience

Lymph node status is the most reliable prognostic indicator for patients with melanoma and breast cancer. Because it is the first node draining the primary cancer, the sentinel lymph node (SLN) is most likely to harbor metastatic cancer cells. The Breslow thickness of the primary melanoma and the size of primary breast cancer are highly correlated with SLN metastasis. If the SLN is negative, its negative predictive value for the remaining nodal basin exceeds 95%; thus, survival rates for melanoma and breast cancer increase when the SLN is negative. The rate of SLN identification is more than 95%, and the false-negative rate is about 5%. SLN data from melanoma and breast cancer are so convincing that they have been incorporated into the new American Joint Committee on Cancer classification of these cancers. The therapeutic value of additional lymph node dissection after a positive SLN for melanoma or breast cancer is still controversial. In melanoma, a 3-year follow-up may confirm better survival when the SLN is negative. However, about 25% of histologically negative SLNs may be upstaged by molecular techniques, and patients whose SLNs are positive by polymerase chain reaction (PCR) assay may develop recurrence. In most cases, melanoma and breast cancer follow an orderly progression of metastasis to the SLN; however, a small subgroup may develop systemic dissemination without SLN involvement. Current SLN experience has confirmed that the earlier the cancer, the less its potential for metastasis. Since treatments for metastatic cancer are still limited, early detection and resection are imperative. Better understanding of the molecular and genetic mechanisms of metastasis will be critical to select high-risk patients for adjuvant therapy.

The new staging system for cutaneous melanoma in the era of lymphatic mapping

In 2002, the American Joint Committee on Cancer (AJCC) revised the staging system for cutaneous melanoma on the basis of a survival analysis of important melanoma prognostic factors. Features of the revised system include new strata for primary tumor thickness, incorporation of primary tumor ulceration as an important staging criterion in both the tumor (T) and node (N) classifications, revision of the N classification to reflect the prognostic significance of regional nodal tumor burden, and new categories for distant metastatic disease. These changes reflect evolving insight into melanoma arising from the results of numerous clinical investigations and database analyses. One of the most important recent changes in melanoma care is the establishment of lymphatic mapping and sentinel lymph node (SLN) biopsy as a highly accurate and minimally morbid technique for pathologic regional nodal staging. In this article, the salient features of the revised melanoma staging system are examined, with specific attention paid to its use in this era of lymphatic mapping and SLN biopsy.

Vulvar melanoma: a report of 20 cases and review of the literature

BACKGROUND

Vulvar melanoma is the second most common vulvar malignancy and represents a significant women's health issue.

OBJECTIVE

To report experience with 21 cases of vulvar melanoma in 20 patients and to review the literature about the condition.

METHODS

Parameters retrospectively reviewed included age at diagnosis, family history of melanoma, location on the vulva, atypical nevi, Breslow depth, ulceration status, histologic pattern, presenting signs and symptoms, and the results of sentinel lymph node biopsy. Molecular characterization of the melanocortin type 1 receptor was performed in 1 patient.

RESULTS

A family history of cutaneous melanoma was present in 15% of cases. The mean Breslow depth was 2.8 mm (range, 0.0-11.0 mm). Ten patients successfully underwent sentinel lymph node biopsy, results of which were positive in 2 (20%). Reported for the first time is that one patient had a germline mutation in the melanocortin type 1 receptor.

CONCLUSION

Vulvar and cutaneous melanoma behave similarly despite their unique pathogeneses. Sentinel lymph node biopsy can be performed successfully for vulvar melanoma.

Radioguided sentinel lymph node biopsy in patients with malignant cutaneous melanoma: the nuclear medicine contribution

As for other solid tumors, malignant cutaneous melanoma drains in a logical way through the lymphatic system, from the first to subsequent levels. Therefore, the first lymph node encountered (the sentinel node) will most likely be the first to be affected by metastasis, and a negative sentinel node makes it highly unlikely that other nodes in the same lymphatic basin are affected. Sentinel lymph node biopsy distinguishes patients without nodal metastases, who can avoid nodal basin dissection with its associated risk of lymphedema, and those with metastatic involvement who might benefit from additional therapy. This procedure represents a significant advantage as a minimally invasive procedure, considering that only an average 20% of melanoma patients with Breslow thickness between 1.5 and 4 mm harbour metastasis in their sentinel node(s) and are therefore candidates to elective lymph node dissection procedures. The cells that originate cutaneous melanomas are located between dermis and epidermis, a zone that drains to the inner lymphatic network in the reticular dermis, in turn to larger collecting lymphatics in subcutis. Therefore, the optimal modality of interstitial administration of radiocolloids for lymphoscintigraphy and subsequent radioguided sentinel lymph node biopsy is through intradermal/subdermal injection. (99m)Tc-labeled colloids in various size ranges are equally adequate for radioguided sentinel lymph node biopsy in patients with cutaneous melanoma, depending on local experience and availability. For melanomas located in the midline area of the head, neck, and trunk, particular consideration should be given to ambiguous lymphatic drainage, which frequently requires interstitial administration virtually all around the tumor or surgical scar from prior excision of the melanoma. Lymphoscintigraphy is an essential part of radioguided sentinel lymph node biopsy because images are used to direct the surgeon to the sites of the node(s). The sentinel lymph node should have a significantly higher count than that of background (at least 10:1 intraoperatively). After removal of the sentinel node, the surgical bed must be reexamined to ensure that all radioactive sites are identified and removed for analysis. The success rate of radioguidance in localizing the sentinel lymph node in melanoma patients is about 98% in institutions where a high number of procedures are performed, approaching 99% when combined with the vital blue dye technique. The procedure is becoming the standard of care for patients with cutaneous melanoma because of its high prognostic value that has led to include the procedure in the most recent version of the TNM staging system.

Melanoma patient staging: histopathological versus molecular evaluation of the sentinel node

Lymphatic mapping and sentinel lymphadenectomy provide a minimally invasive means of directly determining the status of the regional lymph nodes in all patients who have a primary melanoma >1 mm thick but no clinical evidence of nodal involvement. Since the histological status of the sentinel node (SN) has been shown to be the most important prognostic factor in primary melanoma patients, the World Health Organization has recently recommended that sentinel lymphadenectomy should become the new standard of care for primary melanoma patients. This paper reviews the literature with regards to developments in and the current status of SN evaluation. Developments in the histopathological versus molecular detection of melanoma nodal metastases are reviewed, with specific emphasis on the strengths, limitations and clinical significance of these techniques. Molecular evaluation of the SN offers several advantages over standard histopathological analysis. These include an improved sensitivity, the cost-effective use of multiple markers for the improvement of detection rate and prognosis, as well as being less labour-intensive and costly. Moreover, molecular analysis has the potential to allow estimation of tumour burden. We review the potential causes of technical false-negative and false-positive reverse transcription-polymerase chain reaction (RT-PCR) results and how these could be eliminated by a systematic approach consisting of (i) careful and systematic assay design, which would include efficient tissue homogenization, choice of reagents and molecular markers, primer design and the use of one-stage versus two-stage PCR; (ii) careful optimization of the RT-PCR parameters (in particular the PCR cycle number) through the use of appropriate control tissues; and (iii) aiming for high assay reproducibility and lastly by applying the necessary positive and negative controls with each batch of samples. We also review the significant improvement in patient prognosis and management that has been made possible by the development of sentinel lymphadenectomy and histopathological evaluation of the SN, and compare the clinical (predictive) value of histopathological analysis with that of RT-PCR. Although RT-PCR is able to detect additional, clinically significant SN metastases that are missed by routine histopathology, its current limitation is that it overestimates the number of patients who have clinically significant melanoma metastases. Therefore, we suggest and discuss appropriate steps that need to be taken in order to minimize these false-positives and make this molecular tool more acceptable for routine clinical use.

Sentinel lymph node biopsy in patients with Stage I/II melanoma: Clinical experience and literature review

BACKGROUND

The sentinel lymph node (sN) represents one of the most powerful predictors of the outcome of patients with Stages I and II cutaneous melanoma, and may be relevant for the therapeutic planning of early-stage melanoma patients. Since adopting the technique of lymphatic mapping with vital blue dye (Patent Blue-V) in July 1993, we have periodically up-dated the methodology and revised our results in order to define the contribution of radio-guided surgery (RGS) to the detection of the sN as well as the role of intraoperative frozen section examination of the sN.

MATERIALS AND METHODS

Between July 1993 and December 1997, 180 patients with clinically node-negative primary cutaneous melanoma (Stages I-II) underwent sN biopsy followed by "selective lymph node dissection" (SLND) whenever sN metastasis was detected. Presently, complete data are available in 165 patients who were divided into two consecutive subsets of 39 and 126 patients, based on the technique for the identification of the sN: Patent Blue-V only or Patent Blue-V associated to RGS. Moreover, in this second subset of patients intraoperative frozen section findings were compared with definitive pathologic examination.

RESULTS

As regards the first subset of 39 patients (17 males and 22 females; mean age 51.3 years), the sN was identified in 35 patients (89.7%); 8 patients (22.8%) were found to have metastatic melanoma cells in their sN, and they all underwent SLND of the affected basin. As regards the second set of 126 patients (54 males and 72 females; mean age 53.5 years), the sN was detected in every case by means of the combined technique (Patent Blue-V and RGS): in 4 of 126 patients (3.2%), the sN was detected by means of RGS only whereas in no patient was the sN detected by Patent Blue-V only. Frozen section examination was performed in 123 of 126 patients who had sN detection by Patent Blue-V and RGS, and the intraoperative examination had a sensitivity of 66.6% (22 of 33), specificity of 100% (90 of 90), negative predictive value of 89.1% (90 of 101), and accuracy of 91% (112 of 123). The benefit of frozen section examination in avoiding a two-stage procedure was 17.9% (22 of 123 patients). In patients with thicker lesions (pT(3)-pT(4)), the sensitivity and the benefit of intraoperative examination were 76% (19 of 25) and 32% (19 of 59 patients), respectively.

CONCLUSIONS

Sentinel node lymphadenectomy can be better accomplished when both procedures (lymphatic mapping with Patent Blue-V and RGS) are used because the two methods look quite complementary. In fact, the use of the radiocolloid mapping allows to detect a hot spot in the regional basin prior to making the skin incision in order to perform a minimal invasive access, and it may also more accurately differentiate the true sN from a secondary echelon node (non-sN). The use of frozen section examination should be restricted to patients with pT(3)-pT(4) primary melanoma, due to the higher sensitivity and benefit in terms of avoiding a two-stage operative procedure.

Candidate???s Thesis: The Application of Sentinel Node Radiolocalization to Solid Tumors of the Head and Neck: A 10-Year Experience

OBJECTIVES/HYPOTHESIS

The goals of the research study were to develop an easily mastered, accurate, minimally invasive technique of sentinel node radiolocalization with biopsy (SNRLB) in the feline model; to compare it with blue-dye mapping techniques; and to test the applicability of sentinel node radiolocalization biopsy in three head and neck tumor types: N0 malignant melanoma, N0 Merkel cell carcinoma, and N0 squamous cell carcinoma.

STUDY DESIGN

Prospective consecutive series studies were performed in the feline model and in three head and neck tumor types: N0 malignant melanoma (43 patients), N0 Merkel cell carcinoma (8 patients), and N0 squamous cell carcinoma (20 patients).

METHODS

The technique of sentinel node radiolocalization with biopsy was analyzed in eight felines and compared with blue-dye mapping. Patterns of sentinel node gamma emissions were recorded. Localization success rates were determined for blue dye and sentinel node with radiolocalization biopsy. In the human studies, all patients had sentinel node radiolocalization biopsy performed in a similar manner. On the morning of surgery, each patient had sentinel node radiolocalization biopsy of the sentinel lymph node performed using an intradermal or peritumoral injection of technetium Tc 99m sulfur colloid. Sentinel nodes were localized on the skin surface using a handheld gamma detector. Gamma count measurements were obtained for the following: 1) the "hot" spot/node in vivo before incision, 2) the hot spot/node in vivo during dissection, 3) the hot spot/node ex vivo, 4) the lymphatic bed after hot spot/node removal, and 5) the background in the operating room. The first draining lymph node(s) was identified, and biopsy of the node was performed. The radioactive sentinel lymph node(s) was submitted separately for routine histopathological evaluation. Preoperative lymphoscintigrams were performed in patients with melanoma and patients with Merkel cell carcinoma. In patients with head and neck squamous cell carcinoma, the relationship between the sentinel node and the remaining lymphatic basin was studied and all patients received complete neck dissections. The accuracy of sentinel node radiolocalization with biopsy, the micrometastatic rate, the false-negative rate, and long-term recurrence rates were reported for each of the head and neck tumor types. In the melanoma study, the success of sentinel node localization was compared for sentinel node radiolocalization biopsy, blue-dye mapping, and lymphoscintigraphy. In the Merkel cell carcinoma study, localization rates were evaluated for sentinel node radiolocalization biopsy and lymphoscintigraphy. In the head and neck squamous cell carcinoma study, the localization rate of sentinel node radiolocalization biopsy and the predictive value of the sentinel node relative to the remaining lymphatic bed were determined. All results were analyzed statistically.

RESULTS

Across the different head and neck tumor types studied, sentinel node radiolocalization biopsy had a success rate approaching 95%. Sentinel node radiolocalization biopsy was more successful than blue-dye mapping or lymphoscintigraphy at identifying the sentinel node, although all three techniques were complementary. There was no instance of a sentinel node-negative patient developing regional lymphatic recurrence. In the head and neck squamous cell carcinoma study, there was no instance in which the sentinel node was negative and the remaining lymphadenectomy specimen was positive.

CONCLUSION

In head and neck tumors that spread via the lymphatics, it appears that sentinel node radiolocalization biopsy can be performed with a high success rate. This technique has a low false-negative rate and can be performed through a small incision. In head and neck squamous cell carcinoma, the histological appearance of the sentinel node does appear to reflect the regional nodal status of the patient.

Vulvar Melanoma: Review of Diagnosis, Staging, and Therapy

OBJECTIVES

To update, assimilate, and bridge the contemporary literature on vulvar and cutaneous melanoma regarding diagnosis, staging, and therapy to provide a useful clinical reference for managing and counseling for affected patients.

MATERIALS AND METHODS

A computerized search for reports in the literature up to June 2003 was carried out using PubMed and MEDLINE databases. Multidisciplinary involvement was used in evaluating the available data and formulating conclusions.

RESULTS

More than 300 reports were reviewed. Diagnosis, staging, and therapy aspects of vulvar melanoma are summarized.

CONCLUSIONS

Vulvar melanoma represents a subtype of cutaneous melanoma, with similar prognostic and staging factors. The most recent American Joint Committee on Cancer staging system for cutaneous melanoma is applicable to vulvar melanoma. Sentinel lymph node biopsy is reliable for staging the regional lymph node basin for vulvar melanoma. Standardized documentation of clinical and histopathologic parameters is needed to standardize grouping of cases for future comparison studies.

Detection of micrometastases in sentinel lymph nodes from melanoma patients

The technique of sentinel lymph node (SLN) dissection is a reliable predictor of metastatic disease in the lymphatic basin draining the primary melanoma. Reverse transcription-polymerase chain reaction (RT-PCR) is emerging as a highly sensitive technique to detect micrometastases in SLNs, but its specificity has been questioned. A prospective SLN study in melanoma patients was undertaken to compare in detail immunopathological versus molecular detection methods. Sentinel lymphadenectomy was performed on 57 patients, with a total of 71 SLNs analysed. SLNs were cut in slices, which were alternatively subjected to parallel multimarker analysis by microscopy (haematoxylin and eosin and immunohistochemistry for HMB-45, S100, tyrosinase and Melan-A/MART-1) and RT-PCR (for tyrosinase and Melan-A/MART-1). Metastases were detected by both methods in 23% of the SLNs (28% of the patients). The combined use of Melan-A/MART-1 and tyrosinase amplification increased the sensitivity of PCR detection of microscopically proven micrometastases. Of the 55 immunopathologically negative SLNs, 25 were found to be positive on RT-PCR. Notably, eight of these SLNs contained naevi, all of which were positive for tyrosinase and/or Melan-A/MART-1, as detected at both mRNA and protein level. The remaining 41% of the SLNs were negative on both immunohistochemistry and RT-PCR. Analysis of a series of adjacent non-SLNs by RT-PCR confirmed the concept of orderly progression of metastasis. Clinical follow-up showed disease recurrence in 12% of the RT-PCR-positive immunopathology-negative SLNs, indicating that even an extensive immunohistochemical analysis may underestimate the presence of micrometastases. However, molecular analyses, albeit more sensitive, need to be further improved in order to attain acceptable specificity before they can be applied diagnostically.

Prevalence of additional positive lymph nodes in complete lymphadenectomy specimens after positive sentinel lymphadenectomy findings for early-stage melanoma of the head and neck

In this study, the prevalence of additional positive lymph nodes in subsequent complete lymphadenectomy specimens for patients with early-stage melanoma of the head and neck, after positive sentinel lymphadenectomy results, was retrospectively analyzed. In the past 5 years at the authors' institution, 23 consecutive patients with clinical stage I or stage II melanoma of the head and neck underwent complete lymphadenectomies after positive sentinel lymph node biopsies and wide local excisions of the primary lesions. Sentinel lymph nodes were identified with intraoperative lymphatic mapping techniques (radiolymphoscintigraphy and vital blue dye injection) and were examined with routine histological methods and immunohistochemical staining for S-100. All lymph nodes harvested in complete lymphadenectomies were examined with routine histological techniques. Twenty-one patients (91.3 percent) demonstrated no additional positive lymph nodes in subsequent complete lymphadenectomy specimens; two patients (8.7 percent) each demonstrated one additional positive lymph node in the complete lymphadenectomy specimens. Both patients had ulcerated primary lesions more than 5 mm in depth. No patient developed a regional nodal recurrence during a mean follow-up period of 23.7 months (range, 2 to 56 months). The low prevalence of additional positive lymph nodes in complete lymphadenectomy specimens suggests that when microscopic metastases exist in the regional nodal basin, most of the time they are confined to the sentinel lymph nodes of patients with early-stage melanoma of the head and neck. Nevertheless, the question of whether subsequent complete lymphadenectomy is still necessary for this subgroup of patients warrants further study.

Complications associated with sentinel lymph node biopsy for melanoma

BACKGROUND

Sentinel lymph node (SLN) biopsy has become widely accepted as a method of staging the regional lymph nodes for patients with melanoma. Although it is often stated that SLN biopsy is a minimally invasive procedure associated with few complications, a paucity of data exists to specifically determine the morbidity associated with this procedure. This analysis was performed to evaluate the morbidity associated with SLN biopsy compared with completion lymph node dissection (CLND).

METHODS

Patients were enrolled in the Sunbelt Melanoma Trial, a prospective multi-institutional study of SLN biopsy for melanoma. Patients underwent SLN biopsy and were prospectively followed up for the development of complications associated with this technique. Patients who had evidence of nodal metastasis in the SLN underwent CLND. Complications associated with SLN biopsy alone were compared with those associated with SLN biopsy plus CLND.

RESULTS

A total of 2120 patients were evaluated, with a median follow-up of 16 months. Overall, 96 (4.6%) of 2120 patients developed major or minor complications associated with SLN biopsy, whereas 103 (23.2%) of 444 patients experienced complications associated with SLN biopsy plus CLND. There were no deaths associated with either procedure.

CONCLUSIONS

SLN biopsy alone is associated with significantly less morbidity compared with SLN biopsy plus CLND.

Superficial femoral lymph node dissection after positive sentinel lymphadenectomy for early-stage melanoma of the lower extremity

The purpose of this study was to evaluate retrospectively the value of a subsequent superficial femoral lymph node dissection for patients with early melanoma of the lower extremity after a positive sentinel lymphadenectomy. During a 6-year period at the H. Lee Moffitt Cancer Center & Research Institute, 16 consecutive patients with clinical stage I or stage II melanoma of the lower extremity underwent subsequent superficial femoral lymph node dissections after positive sentinel lymphadenectomies and wide local excisions of the primary lesions. Fifteen patients (94%) were found to have no additional positive lymph nodes from their superficial femoral lymph node dissection specimens. In contrast, only 1 patient (6%) with a thick primary lesion (7.5 mm) was found to have one additional positive lymph node on a subsequent superficial femoral lymph node dissection. No patients developed any regional nodal recurrences during a mean follow-up of 31.1 months (range, 3-80 months). This preliminary report suggests that the majority of the time the sentinel lymph node may be the only site of regional microscopic nodal disease and that a subsequent superficial femoral lymph node dissection may not be necessary in patients with early melanoma of the lower extremity after a positive sentinel lymphadenectomy. However, whether the sentinel lymphadenectomy can be used solely as a regional surgical treatment for this subgroup of patients still warrants further evaluation.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Future perspectives on malignant melanoma

Emphasis for the treatment of melanoma should be shifted more to prevention and early diagnosis, because early melanoma may potentially be cured in most cases. Clinical trials are important to establish more effective adjuvant modalities against melanoma. Multifaceted aspects of micrometastasis, including differentiation of different clones with respect to the primary tumor, acquisition of adhesion molecules, and host interaction with the microscopic tumor, will shed new light on the biology and mechanism of early metastasis. New molecular and genetic tools may be used to dissect the mechanisms of lymphatic and hematogenous routes of metastasis. If such mechanisms can be understood, potential therapeutic maneuvers can be developed to prevent the process of micrometastasis.

Surgical treatment of malignant melanoma

The surgical management of melanoma has evolved over the last 100 years. when early concepts of lymphatic permeation of the tumors and metastases led surgeons to perform radical operative procedures. Wide excision of primary melanoma is now performed with 1- to 2-cm radial margins, significantly reducing the need for complex plastic closures, skin grafts. and hospital admissions. Although elective lymph node dissection remains controversial as a therapeutic procedure, the development of SL has improved the staging of the regional lymph nodes and diminished the morbidity of lymph node dissection. The role of SL for routine care of melanoma patients remains unknown. Metastasectomy, which is the surgical resection of distant metastases with tumor-free surgical margins, has not been popular for AJCC stage IV patients with multiple metastases, because surgery is considered a local therapy and therefore of little value for management of disseminated disease. Nevertheless, the many reports of long-term survival after resection of distant melanoma metastases to diverse soft tissue and organ sites clearly indicate that this form of cytoreductive surgery can be extremely successful in carefully selected patients. Unlike chemotherapy, complete surgical metastasectomy can rapidly render a patient disease-free with only a short period of postoperative morbidity. Most patients fully recover from the surgical procedure within 6 weeks, returning to most or all activities. The ability to select patients for surgery is based on the development of more sophisticated imaging techniques, which allow better preoperative differentiation of patients with single versus multiple metastases and improve the surgeon's ability to identify and resect multiple metastatic sites. The overall data suggest that patients whose metastases can be completely resected will experience improved overall survival and occasional long-term cure regardless of the metastatic organ site and number of metastases. We believe that increased understanding of the biology of the primary and metastases, dramatic improvement in the accuracy of staging metastatic disease, and better techniques of surgical resection provide the best chance for long-term palliation or cure of melanoma. Cytoreductive surgery should be considered a form of immunotherapy. The long-term clinical benefit of this therapy depends on the patient's immune response to, the surgical reduction in tumor burden: an immune response that controls subclinical micrometastases should optimize postoperative survival.