Benefit of elective lymph node dissection in subgroups of melanoma patients. Results of a multicenter study of 3616 patients

Detection of Melanoma Cells in Peripheral Blood and Sentinel Lymph Nodes by RT-PCR Analysis: A Comparative Study with Immunohistochemistry

The presence of lymph node metastases is the best prognostic factor for predicting relapse or survival in melanoma patients. It has been demonstrated that melanoma metastases spread through the first lymph node(s) draining the tumor (sentinel lymph node, SN) to the lymphatic system and that detection of melanoma cells in peripheral blood directly correlates with prognosis in melanoma.

To identify lymph node metastases and circulating melanocytes, we developed a single-step reverse transcriptase-polymerase chain reaction assay (RT-PCR) for detection of two melanoma-specific markers: the tyrosinase gene, which encodes an enzyme associated with melanin synthesis, and melanoma antigen-related T-cells, which are present in tumor infiltrating T-lymphocytes. This method detects two tumor cells in a background of 107 lymphocytes.

Thirty patients with stage I–IV cutaneous melanoma entered the study. Blood samples were taken preoperatively, one month after excision of the primary melanoma lesion and the SN or total lymphadenectomy, and before the start of chemotherapy and every three months thereafter in metastatic patients. SNs were collected from 22 patients, bisected and analyzed by RT-PCR and routine pathological and immunohistochemical tests. The preliminary results indicate that RT-PCR for melanoma markers is a sensitive and valuable method for the detection of micrometastases and for early diagnosis and staging of melanoma.

Managing malignant melanoma

The incidence of melanoma is increasing worldwide. Melanomas represent 3 percent of all skin cancers but 65 percent of skin cancer deaths. Melanoma is now the fifth most common cancer diagnosed in the United States. Excisional biopsy should be performed for lesions suspicious for melanoma. The pathologist's report provides essential information for surgical treatment; the most important information is the Breslow depth of the lesion. In addition to wide surgical excision of the primary lesion, sentinel lymph node biopsy is the standard of care for early identification of regional metastasis. Nodal metastasis found in the sentinel lymph node biopsy should be followed with a complete lymph node dissection. Although surgery remains the primary treatment of melanoma, recent advances in chemotherapy may offer further survival benefits to patients with metastatic disease.

Sentinel lymph node biopsy for cutaneous melanoma: results of 10 years' experience in two regional training hospitals in the Netherlands

BACKGROUND AND OBJECTIVE

The Multicenter Selective Lymphadenectomy Trial (MSLT-I) demonstrated that the sentinel node (SN) status in cutaneous melanoma affects prognosis and that completion lymphadenectomy in SN-positive patients may improve survival. Our objective was to evaluate sentinel lymph node biopsy (SLNB) in two regional hospitals in the Netherlands.

METHODS

Patients with localized melanoma were planned for wide excision and SLNB. Completion lymphadenectomy was recommended for positive SN status. Data were compared with the MSLT-I.

RESULTS

A median of 2 (1-7) SNs were identified in 305 patients and complications occurred in 11%. Fifty-four patients (18%) demonstrated SN metastases and 45 underwent completion lymphadenectomy (20% additional metastases). Six patients with initially negative SN developed lymph node metastases (sensitivity 90%). Overall disease-free survival was 83% (SN-negative 91% vs. SN-positive 41%; p < 0.001) and melanoma-specific survival was 93% (SN-negative 97% vs. SN-positive 62%; p < 0.001). Multivariate regression analysis revealed the SN status to be the most significant predictor for recurrence and melanoma-related death.

CONCLUSION

Our results of SLNB are comparable to data from high-volume centers participating in MSLT-I. From a patient perspective, the false-negative SN rate of 10% and complication rate of 11% should be weighed against being informed about prognosis and having a possible therapeutic benefit from completion lymphadenectomy.

Role of selective sentinel lymph node dissection in head and neck melanoma

Selective sentinel lymph node dissection (SLND) plays an important role in the staging of the regional nodal basins for head and neck (H&N) melanoma. Preoperative lymphoscintigraphy is mandatory to identify the regional nodal basin(s) accurately for a newly diagnosed H&N primary melanoma of at least 1mm or greater. A wide local excision should be delayed if SLN mapping is indicated, to minimize watershed effect and maximize accuracy in identifying the "true" SLN because of the complex lymphatic network in the H&N region. An experienced multidisciplinary team is required for optimal identification of H&N SLNs. In general, selective SLND can replace ELND to minimize the complications of a neck dissection. Completion lymph node dissection is only indicated when the SLN is positive. A nerve stimulator should be used during selective SLND in the parotid and posterior triangle to minimize the injury to the facial and spinal accessory nerve.

Reliability of sentinel lymph-node extirpation as a diagnostic method for malignant melanoma of the head and neck region

A series of 106 patients with malignant melanoma of the head and neck and clinically negative local lymph-node status were included in a multimodal therapy programme and underwent sentinel lymph-node extirpation in 1999-2003. Out of 246 preoperatively marked lymph nodes, only 172 (70%) were identified intraoperatively and removed. In 89% of all patients at least one sentinel lymph node was removed. Histological examination revealed metastases in the sentinel lymph nodes of 17 patients. In the mean follow-up period of 47 months (range 4-76 months), regional lymph-node metastases were found in another eight patients. The non-marked lymph nodes that were often removed at the same time, in an elective cervical lymph-node dissection, did not reveal any metastasis in any of the cases where the sentinel lymph nodes were negative. The sensitivity of sentinel lymph-node extirpation was influenced by the length of the follow-up period and the detection rate, and was 68% (17/17+8), a result superior to that of any other diagnostic tool. Sentinel lymph-node extirpation is a valuable method in addition to elective lymph-node dissection.

Mise au point sur la prise en charge chirurgicale du mélanome malin cutané. Revue de la littérature

Nowadays managing a cutaneous malignant melanoma can concern different kind of physicians: dermatologists, general or plastic surgeons The primary surgical procedure is a major step of the treatment. Biopsy must be total to properly determine the thickness of the tumor in case of malignancy. Wide local excision of the scar is often necessary to decrease the local and general recurrence rates. Wide local excision must be performed conforming to its own surgical rules. Managing tumor located on the face or limb extremities is a matter of plastic surgery. Sentinel node biopsy has succeeded to elective lymph node dissection. This procedure allows research of lymphatic spreading of the disease. Practice of sentinel node biopsy must be achieved in a protocolar way. Topography of the lesion can modified achievement and results of this procedure. Prognosis benefit of sentinel biopsy is now clear. Elective lymph node dissection is only performed in case of invaded sentinel node or clinically invaded lymph nodes. Local or locoregional recurrences mainly respond to surgical treatment using wide excision. However, alternative solutions are being evaluated (isolated limb perfusion).

Sentinel-Node-Biopsie

Sentinel node biopsy (SNB) is increasingly being used as a minimally invasive staging procedure in patients with malignant melanoma. For decades elective lymph node dissection (ELND) was performed in many centers on patients at risk for lymph node metastasis but without clinically detectable lymph node involvement. Today, selective lymph node dissection (SLND) is offered only to patients with histologically proven metastasis in a SN (10-29%). A positive SN is one of the most important prognostic parameters. Ten years after the introduction of the technique, the role of SNB in the treatment of cutaneous melanoma still remains controversial. Issues include the usefulness of highly sensitive evaluation of SN using molecular biology or cytology techniques, as well as the therapeutic impact of the SNB per se and the associated combined surgical or medical adjuvant therapies.

Sentinel lymph node biopsy progress in surgical treatment of cancer

BACKGROUND

Forty-three years after the first description of the sentinel lymph node technique in malignant tumours of the parotid by Gould, sentinel lymph node biopsy (SNLB) has become a precious tool in the treatment of solid tumours.

METHODS

In the following review we give a synopsis of the fundamentals of the sentinel lymph node concept and then proceed to an overview of recent advances of SNLB in gastrointestinal cancers.

RESULTS

In some tumour entities, SNLB has been shown to reflect reliably the lymph node status of the tumour-draining lymph node basin. In melanoma and breast cancer, it became a widely accepted element of the routine surgical management of these malignant diseases. In gastrointestinal tumours, the technique is currently under intense investigation. First reports on its application in other solid tumours, such as non-small cell lung cancer, thyroid carcinoma, oropharyngeal carcinoma, vulvar carcinoma, and Merckel cell carcinoma of the skin, were published more recently.

CONCLUSION

SNLB has become an important component of diagnosis and treatment of solid tumours. A growing number of publications on SNLB in gastrointestinal cancer documents the interest of many investigators in the application of this technique in this tumour entity. As long as imaging techniques like 18FDG PET or other molecular imaging techniques are limited by their spatial resolution, SNLB remains the technique of choice for lympho-nodal staging.

Sentinel lymph node biopsy

The introduction of sentinel lymph node biopsy (SLNB) has been an important development in the management of malignant melanoma. Lymph nodes have long been known to play a key role in melanoma metastasis. The importance of nodal staging accounted for the previous surgical practice of elective lymph node dissection (ELND) even with its controversial impact on final outcomes and associated morbidity. Although this morbidity has been reduced with the ability to identify the SLN, numerous questions have subsequently surfaced with respect to this procedure's utility and therapeutic efficacy. This chapter will focus on the indications for SLNB, as well as the current controversies surrounding this procedure.

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

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

Sentinel Lymph Node Biopsy Has No Benefit for Patients with Primary Cutaneous Melanoma Metastatic to a Lymph Node: An Assertion Based on Comprehensive, Critical Analysis

The thesis is set forth in this treatise that there is no place in the routine practice of medicine for the procedure for melanoma known conventionally and universally as sentinel node biopsy. Our assertion is based on assessment of the extensive body of literature devoted to the subject of treatment of melanoma before any metastasis has manifested itself clinically and of that dedicated to therapy for overt metastatic melanoma by a variety of modalities, chief among those addressed here being elective lymph node dissection and sentinel lymph node biopsy. In this era of sentinel lymph node biopsy, elective lymph node dissection has been modified to include only patients with metastasis of melanoma to lymph nodes, a procedure now termed "selective complete lymph node dissection." Among adjuvant medical therapies, the most popular today is interferon alpha-2B. Critical, incisive scrutiny of the literature leads to the conclusion, incontrovertibly, that elective lymph node dissection has no benefit for a patient and that all modifications of it also are devoid of value. The reason, logically, for the lack of utility of elective lymph node dissection becomes apparent by virtue of the route taken by cells of melanoma as they metastasize; those cells proceed in the same fashion as does lymph, bacteria, foreign material (including vital dyes and radioactive tracers), and other kinds of cells, to wit, by passing rapidly through nodes, including the sentinel one, and even bypassing entirely the nodes. In reality, cells of metastatic melanoma are not held up in nodes for any significant period of time, contrary to what is asserted repeatedly, but without any basis in fact, by many students of the subject. Moreover, not a single adjuvant medical therapy available currently is effective against metastatic melanoma and, therefore, none of them should be invoked to justify performance of sentinel node biopsy. Even if the sentinel node is found to house cells of melanoma, which, as a rule, conveys a grim message regarding the future, the finding in an individual patient is meaningless; a particular patient may live in harmony with metastases of melanoma for more than 30 years and even die of an unrelated malady. In short, no surgeon, pathologist, or oncologist is a seer, diviner, or prophet when it comes to predicting accurately the outcome for a patient with metastasis of melanoma; the end could come in weeks, months, or decades. If, however, a sentinel node is found to contain nary a cell of metastatic melanoma, it, too, means nothing for an individual patient because the existence of metastases widely is not excluded by that finding. In short, sentinel node biopsy cannot be considered the standard of care in the daily practice of medicine; it is woefully substandard because it is without benefit. There is no justification, whatsoever, for the procedure, scientifically or practically, and for that reason it should be abandoned, without delay, now.

Detection of multiple melanoma-associated markers in melanoma cell lines by RT in situ PCR

New surgical oncology techniques, such as lymphatic mapping and sentinel node biopsy, require precise identification of the presence of even very small numbers of tumor cells. The gold standard for such analysis remains microscopic assessment of tissue sections, stained conventionally or by immunohistochemistry for appropriate tumor markers. This approach is limited by sampling constraints and requires a high degree of expertise from the microscopist. Recent studies have demonstrated a subgroup of patients whose sentinel nodes are negative on microscopy, but whose nodes yield an enhanced signal for melanoma markers when evaluated by RT-PCR. These enhanced signals reflect a mixture of signal sources, including small numbers of melanoma cells and cells other than melanoma cells that express the relevant markers(s). Because the preparative techniques for RT-PCR destroy the structural integrity of the tissues and disrupt individual cells, the exact cellular source of enhanced signal from a tissue cannot be demonstrated by conventional RT-PCR. RT in situ PCR, in which the RT-PCR technique is applied on a tissue section, does identify the cells that are the source of signal. We have attempted to optimize this interesting approach and have applied it to the detection of relevant melanoma markers in tissue culture lines.

Clinical outcome of stage I/II melanoma patients after selective sentinel lymph node dissection: long-term follow-up results

PURPOSE

Although sentinel lymph node (SLN) status is part of the new American Joint Committee on Cancer staging system, there is no final proof that the SLN procedure in melanoma patients influences outcome of disease. This study investigated the accuracy of the SLN procedure and clinical outcome in melanoma patients after at least 60 months of follow-up.

PATIENTS AND METHODS

Between 1993 and 1996, 209 patients with stage I/II cutaneous melanoma underwent selective SLN dissection by the triple technique. If the SLN contained metastatic disease, a completion lymphadenectomy was performed. Survival analyses were performed using the Kaplan-Meier approach. Factors associated with survival were analyzed using the Cox proportional hazards regression model.

RESULTS

The success rate was 99.5%. Median follow-up was 72 months. Forty patients (19%) had a positive SLN. The false-negative rate was 9%. Five-year overall survival was 87% for the entire group and 92% and 67% for SLN-negative and SLN-positive patients (P <.0001), respectively. All patients with a positive SLN and a Breslow thickness < or = 1.00 mm survived, and SLN-positive patients with a Breslow thickness less than 2.00 mm tend to have a better prognosis compared with SLN-negative patients with a Breslow thickness greater than 2.00 mm. SLN status (P =.002), Breslow thickness (P =.002), and lymphatic invasion (P =.0009) were all found to be independent prognostic factors for overall survival.

CONCLUSION

With a success rate of 99.5% and a false-negative rate of 9% after long-term follow-up, the triple-technique SLN procedure is a reliable and accurate method. Survival data seem promising, although a therapeutic effect is still questionable. As shown in this study, not all SLN-positive patients have a poor prognosis.

Patterns of recurrence in patients with melanoma and histologically negative but RT-PCR-positive sentinel lymph nodes

BACKGROUND

We studied the patterns of recurrence of patients with only reverse transcriptase-polymerase chain reaction (RT-PCR) evidence of regional nodal spread to see whether or not proposed treatment interventions are likely to be effective.

STUDY DESIGN

One hundred seventy-five patients who underwent selective lymphadenectomy for clinical stage I and II melanomas were included in this analysis. We preserved a portion of each sentinel lymph node (SLN) in liquid nitrogen in the operating room and performed RT-PCR on the specimens to detect the melanoma/melanocyte-specific marker tyrosinase. We then compared the pattern of recurrence (regional dermal metastases, regional nodal recurrence, or distant metastatic spread) of the patients with histologically positive SLNs to that of patients who had histologically negative SLNs.

RESULTS

The mean followup time of the 175 patients was 33.83 months (SD = 15.94, median = 34.17, maximum = 62.95, minimum = 6.21). Thirty-four patients had at least one histologically positive SLN, and 17 of these patients had a recurrence (50%). Of the 141 patients that had histologically negative SLNs, 73 had SLNs that were also negative for tyrosinase by RT-PCR, and none of these patients had a recurrence. Of the 68 patients that had histologically negative but RT-PCR-positive SLNs, 14 had a recurrence (20.6%).

CONCLUSIONS

Because the pattern of recurrence of patients with only RT-PCR evidence of melanoma in SLNs was identical to that in patients who had histologically evident melanoma in the SLN and underwent subsequent completion lymphadenectomy, we conclude that completion lymphadenectomy might be ineffective in decreasing the recurrence rate of patients with only RT-PCR evidence of melanoma in SLNs.

Pattern and incidence of first site recurrences following sentinel node procedure in melanoma patients

Studies of large series of melanoma patients indicated that the average incidence of developing a recurrence during follow-up was 40%. The most frequent first sites of these recurrences were the regional lymph nodes. We hypothesized that the sentinel node (SN) procedure may change the pattern of recurrence by reducing the number of first recurrences in the regional lymph node basin during follow-up to a negligible number, and that locoregional cutaneous and distance metastases are the major future sites of recurrence. We further studied the influence of SN status together with different influential factors on prognosis. An SN procedure with a triple technique was performed in 250 consecutive patients with proven AJCC stages I and II cutaneous melanoma. The median follow-up was 38 months. So far, 44 patients (18%) have developed a recurrence of the disease. The distribution of localization of the first metastases was as follows: 23 patients (52%) with a locoregional cutaneous recurrence; 4 (9%) with recurrence in the regional lymph node basin; 2 (5%) with recurrence in an interval node; and 15 (34%) with distant recurrence. The relative risk of developing recurrence for SN-positive patients is 4.2; for Breslow thickness of 1.51 to 4.00 mm it is 5.5, and thicker than 4.0 mm it is 6.2; for lymphatic invasion 7.6; and for ulceration 3.8. We conclude that the SN procedure changes the pattern of recurrences during follow-up by reducing the number of first recurrences within the regional lymph node basin to a negligible number. High Breslow thickness, lymphatic invasion, and ulceration of the primary melanoma are strong risk factors for recurrence.

The role of sentinel lymph node biopsy for melanoma

Regional lymph nodes are a common site of melanoma metastases, and the presence or absence of melanoma in regional lymph nodes is the single most important prognostic factor for predicting survival. Furthermore, identification of metastatic melanoma in lymph nodes and excision of these nodes may enhance survival in a subgroup of patients whose melanoma has metastasized only to their regional lymph nodes and not to distant sites. Sentinel lymph node (SLN) biopsy was developed as a low morbidity technique to stage the lymphatic basin without the potential morbidity of lymphedema and nerve injury. The presence or absence of metastatic melanoma in the SLN accurately predicts the presence or absence of metastatic melanoma in that lymph node basin. When performed by experienced centers, the false-negative rate of SLN biopsy is very low. As such, the nodal basin that contains a negative SLN will usually be free of microscopic disease. Since occult micrometastatic disease affects only 12% to 15% of patients with melanoma, selective SLN dissection allows up to 85% of patients with melanoma to be spared a formal lymph node dissection, thus avoiding the complications usually associated with that procedure. While standard pathologic evaluation of lymph nodes may miss metastatic melanoma cells, more sensitive techniques are developing which may identify micrometastases more accurately. The clinical significance of these micrometastases remains unknown and is the subject of active investigations.

Lymph-node metastases in patients with melanoma: what is the optimum management?

Lymph-node metastasis is an indicator of poor prognosis for patients with melanoma. The management of regional nodes is controversial, with continuing debate about whether surgery or radiotherapy of positive lymph nodes improves long-term survival or whether nodal involvement is merely a marker of aggressive disease. However, there is general agreement that systemic chemotherapy is rarely an effective form of management. This review therefore considers surgical and radiotherapeutic aspects of lymph-node management in patients with melanoma. We discuss regional control and survival after lymph-node surgery in retrospective series, randomised trials of elective lymph-node dissection, the role of 'sentinel' lymph-node biopsy, radiobiology and radiotherapy fractionation issues in melanoma treatment, retrospective studies of adjuvant nodal radiotherapy, and finally, randomised trials of adjuvant radiotherapy after lymph-node dissection.

NY-ESO-1 and CTp11 expression may correlate with stage of progression in melanoma

BACKGROUND

As tumor cells spread beyond their primary site they undergo changes in their gene expression that may be detectable and useful for microstaging. The cancer/testis (CT) antigens are a family of proteins that include MAGE 1-3, NY-ESO-1, SSX 1-5, and others that are potential markers for microstaging melanoma. CT antigens are produced by many tumor types but few normal tissues other than testis. One CT antigen, CTp11, was shown to be expressed by metastasizing melanoma cell lines but not by nonmetastasizing variants. We tested this finding by studying the expression of CTp11 and NY-ESO-1 by melanoma samples from different stages of progression.

MATERIALS AND METHODS

We collected 20 primary, 22 locoregional, and 10 distant metastatic melanoma samples. We extracted total RNA, and reverse transcription yielded cDNA, which was PCR-amplified using primers to detect beta-actin, tyrosinase, MART-1, NY-ESO-1, and CTp11. The PCR products were separated on ethidium bromide-stained agarose gels and visualized by UV transillumination.

RESULTS

All samples were positive for beta-actin and MART-1 and all but two were positive for tyrosinase, confirming RNA integrity and the presence of melanoma. Twenty-seven samples were positive for NY-ESO-1, CTp11, or both. CTp11 tended to be expressed by primary melanomas and NY-ESO-1 by metastatic samples (P < 0.02).

CONCLUSIONS

There is a statistically significant difference in the distribution of the expression of CTp11 and NY-ESO-1 in melanoma from different stages of progression. NY-ESO-1 may be a marker of more advanced disease and CTp11 of less advanced disease.

Early Recurrence After Lymphatic Mapping and Sentinel Node Biopsy in Patients With Primary Extremity Melanoma: A Comparison With Elective Lymph Node Dissection

INTRODUCTION

Although sentinel node biopsy with completion lymphadenectomy in node-positive patients (SLND) has been widely adopted in the management of patients with early stage melanoma, reports detailing the outcome of patients after SLND are limited. To address this issue, we analyzed our experience with SLND and provided a comparison to patients treated with elective lymph node dissection (ELND).

METHODS

All patients who underwent SLND (1991-1998) and ELND (1974-1994) were identified from single institution melanoma databases.

RESULTS

A total of 152 and 329 patients with early-stage melanoma of the extremity underwent SLND and ELND, respectively. Nodal metastases were present in 44 of 329 ELND patients (13%) and in 31 of 152 SLND patients (20%). Early relapse-free and disease-specific survivals were similar for the entire population, although in patients at higher risk for recurrence (age >50 years, thickness >3.0 mm), there was an increased rate of relapse in the SLND group (P = .04). Among all sites of early recurrences, locoregional sites were more common in patients undergoing SLND (72%) compared with ELND (39%, P < .01). SLN-negative patients with nodal recurrence had evidence of metastases on retrospective enhanced pathologic analysis in four of seven cases.

CONCLUSIONS

Although overall relapse-free and disease-specific survivals are similar, there is a higher rate of relapse in a subset of SLND node-negative patients who are at high risk for nodal metastases. ELND and SLNB should not be thought of as equivalent approaches until studies with longer follow-up are available.

Adjuvant therapy of malignant melanoma and the role of sentinel node mapping

BACKGROUND

Controversy still exists about standard management of a primary melanoma. Over the last decades randomized phase III trials have addressed questions about the width of margin in relation to the Breslow thickness of the primary lesion, the role of prophylactic isolated limb perfusion, and the role of elective lymph node dissection. Overall these trials have demonstrated that less extensive surgery is as good as more extensive surgery. Wide excision margins, prophylactic isolated limb perfusions, or the elective lymph node dissection did not improve overall survival significantly in any of the phase III trials conducted.

ADJUVANT THERAPY IN HIGH RISK MELANOMA

No standard systemic adjuvant therapy with confirmed impact on overall survival has been identified thus far for clinically node negative stage I-II (TxN0M0) patients after excision of the primary, nor for clinically node positive stage III (TxN1-2M0) patients after lymph node dissection for metastatic regional node involvement. Poor Staging in the Past. One of the main problems associated with the trials assessing systemic adjuvant treatments in management of high risk primary melanoma is the fact that in general patients were poorly staged. About 25%-30% of patients with primaries thicker than 1.5 mm have micro-metastatic disease in the regional lymph nodes and beyond. This population was usually submerged by the other 70%-75% of the patients with excellent prognosis, obscuring the potential benefit of the adjuvant surgical procedure (ELND) or a systemic adjuvant treatment.

SENTINEL LYMPH NODE MAPPING

Sentinel lymph node (SLN) mapping is resolving many of the inadequacies of the past and has completely changed the management of primary melanoma. As a small procedure with low morbidity it identifies that part of the population which has microscopic involvement of regional lymph nodes with greater precision than an elective lymph node dissection. SLN-mapping allows for a detailed histopathologic evaluation involving multiple sections, H&E staining in combination with IHC (immunohistochemical staining) of the node with the highest chance of containing metastatic foci. Moreover in the near future it is most likely that RT-PCR on negative nodes will complete the diagnostic workup as a promising last step in the procedure to determine whether tumor cells are present in the sentinel node. Sentinel lymph node status has been shown recently to be by far the strongest independent prognostic factor of melanoma stage I-II patients. SLN-status is a much stronger prognostic factor than tumor thickness, which looses its prognostic relevance in SLN-positive patients.

CONSEQUENCES FOR DEVELOPMENT AND/OR ALLOCATION OF ADJUVANT THERAPY

Thus we now have a procedure by which the melanoma stage I-II population can be dissected in a group at truly high risk for recurrence and a group with truly low risk of recurrence. The high risk group with a greater than 75% chance for systemic disease can then be selected for trial participation of various systemic adjuvant therapy regimens that may be allowed to be toxic, considering the very high risk for relapse in these patients. The node negative group of patients can be selected for participation in trials evaluating systemic adjuvant treatment of low toxicity considering the low chance for distant metastatic disease.

Sentinel lymph node biopsy in the management of patients with primary cutaneous melanoma: review of a large single-institutional experience with an emphasis on recurrence

OBJECTIVE

To analyze the authors' experience with sentinel lymph node biopsy (SLNB) and the subsequent incidence and pattern of recurrence in patients with positive and negative nodes.

SUMMARY BACKGROUND DATA

Lymphatic mapping with SLNB has become widely accepted in the management of patients with melanoma who are at risk for occult regional lymph node metastases. Because this procedure is relatively new, the pattern of recurrence after SLNB is not yet clear.

METHODS

All patients with primary cutaneous melanoma who underwent SLNB from 1991 through 1998 were identified from a prospective single-institution melanoma database.

RESULTS

Three hundred fifty-seven consecutive patients with localized primary cutaneous melanoma who underwent SLNB were identified. The sentinel node was identified in 332 patients (93%) and was positive in 56 (17%). Fourteen percent of patients had developed a recurrence at a median follow-up of 24 months. The median time to recurrence was 13 months. The 3-year relapse-free survival rates for patients with positive and negative nodes were 56% and 75%, respectively. SLN status was the most important predictor of disease recurrence. The site of first recurrence in patients with negative and positive nodes was more commonly locoregional than distant. Reexamination of the SLN in 11 patients with negative nodes with initial nodal and in-transit recurrence showed evidence of metastases in 7 (64%).

CONCLUSIONS

Patients with positive sentinel nodes have a significantly increased risk for recurrence. The early pattern of first recurrence for patients with negative and positive results is characterized by a preponderance of locoregional sites, similar to that reported in previous series of elective lymph node dissection. These data underscore the need for careful pathologic analysis of the SLN as well as a careful, directed locoregional physical examination in the follow-up of these patients.

Biological behaviour and clinical implications of micrometastases

BACKGROUND

The most important prognostic determinant in cancer is the identification of disseminated tumour burden (metastases). Micrometastases are microscopic (smaller than 2 mm) deposits of malignant cells that are segregated spatially from the primary tumour and depend on neovascular formation (angiogenesis) to propagate.

METHODS

The electronic literature (1966 to present) on micrometastases and their implications in malignant melanoma and epithelial cancers was reviewed.

RESULTS

Immunohistochemical techniques combined with serial sectioning offer the best accuracy for detection of nodal micrometastases. Molecular techniques should be reserved for blood samples or bone marrow aspirates. Detection of micrometastases in regional lymph nodes and/or bone marrow confers a poor prognosis in epithelial cancers. The concept of sentinel node biopsy combined with serial sectioning and dedicated screening for micrometastases may improve staging procedures. Strategies against angiogenesis may provide novel therapies to induce and maintain micrometastatic dormancy.

CONCLUSION

The concept of micrometastases has resulted in a paradigm shift in the staging of epithelial tumours and our overall understanding of malignant processes.

Judging the therapeutic value of lymph node dissections for melanoma

BACKGROUND

The management of the regional lymph nodes remains controversial for early-stage melanoma and for those patients with lymph node metastases; American Joint Committee on Cancer stage III. This study examines the importance of quality of the surgical resection measured by the extent of lymph node dissection (quartile of the total number of lymph nodes removed) to determine if this factor is an important prognostic factor for survival.

STUDY DESIGN

We reviewed our computer-assisted database of more than 8,700 melanoma patients prospectively collected from 1971 through the present to identify patients who underwent lymph node dissection for stage III melanoma. We included only patients who had their nodal dissections performed at our institute. Patients who underwent sentinel lymph node dissection were excluded. These patients were then analyzed as a group and by individual lymphatic basins: cervical, axillary, and inguinal basins. Univariate and multivariate analyses were used to examine the model that included tumor burden, thickness of the primary melanoma, gender, age, clinical status of the lymph nodes (palpable versus not palpable), and the primary site. The survival and recurrence rates were analyzed using the Cox proportional hazards model.

RESULTS

Five hundred forty-eight patients underwent regional lymph node dissections. Of these patients, 214 underwent axillary dissections, 181 inguinal dissections, and 153 cervical dissections. The extent of the nodal dissections was based on the quartile of nodes excised, ranging from 1 to 98 (mean +/- SD = 25.8 +/- 15.8). Patients were stratified by tumor burden and quartile of number of lymph nodes removed. The overall 5-year survival of patients with four or more lymph nodes having tumor and the highest quartile of lymph nodes removed was 44% and was 23% for the lowest quartile of total lymph nodes excised (p = 0.05). By univariate analysis, tumor burden (p = 0.0001), quartile of total lymph nodes removed (p = 0.043), and primary site (p = 0.047) were statistically significant for predicting overall survival. Gender, clinical status of the nodes, primary tumor thickness, age, and dissected basin were not significant (p > 0.05). By multivariate analysis only the tumor burden (p = 0.0001) and quartile of lymph nodes resected (p = 0.044) were statistically significant.

CONCLUSIONS

The extent of lymph node dissection for melanoma when analyzed by quartiles is an independent factor in overall survival. This factor appears to be more important with increasing tumor burden in the lymphatic basin. The extent of lymph node dissection should be considered as a prognostic factor in the design of clinical trials that involve stage III melanoma.

Lymphatic mapping and sentinel lymphadenectomy after wide local excision of primary melanoma

BACKGROUND

Lymphatic mapping and sentinel lymphadenectomy (LM/SL) are generally avoided in patients who have already undergone wide local excision (WLE) of a primary melanoma, because of concern that disruption of the cutaneous lymphatics might alter lymphatic flow to the sentinel node. We reviewed carefully chosen patients who had undergone LM/SL after WLE to identify circumstances that might make this approach otherwise safe and clinically accurate.

STUDY DESIGN

From our melanoma database of 8,300 patients, of whom 1,015 had undergone LM/SL, we retrospectively identified 47 patients who had previously undergone WLE. Patient and tumor characteristics were collected and compared with followup data from clinic files.

RESULTS

Median WLE surgical margins before LM/SL were 2.0 cm and most patients had extremity lesions. Eleven of the 47 patients (23%) had tumor-involved sentinel nodes, and 8 of these patients (73%) had a solitary nodal metastasis. With a median followup period of 36 months, 3 sentinel node-negative patients developed nodal recurrences. Two of these patients had positive sentinel nodes on pathology re-review and were not considered failures of the lymphatic mapping surgical procedure. The third patient developed in-transit metastases and delayed nodal recurrence. An additional patient, who had a primary tumor on the trunk, developed a nodal recurrence in the basin opposite that identified by lymphoscintigraphy. The overall error rate of the technique was 4 in 36 (11%). This included 2 pathology misdiagnoses (5.6%), 1 nodal recurrence associated with in-transit regional metastases (2.8%), and 1 lymphatic mapping error (2.8%).

CONCLUSIONS

LM/SL can be cautiously performed in patients who have undergone previous WLE if the primary resection margin was no greater than 2.0 cm and the primary was not in a region of ambiguous drainage. Lymphatic mapping may be inaccurate when melanomas have been resected with large margins, especially if the wound was closed with rotation flaps, and when melanomas are on the head and neck or trunk regions.

Multi-institutional melanoma lymphatic mapping experience: the prognostic value of sentinel lymph node status in 612 stage I or II melanoma patients

PURPOSE

To compare the effect of pathologic sentinel lymph node (SLN) status with that of other known prognostic factors on recurrence and survival in patients with stage I or II cutaneous melanoma.

PATIENTS AND METHODS

We reviewed the records of 612 patients with primary cutaneous melanoma who underwent lymphatic mapping and SLN biopsy between January 1991 and May 1995 to determine the effects of tumor thickness, ulceration, Clark level, location, sex, and SLN pathologic status on disease-free and disease-specific survival.

RESULTS

In the 580 patients in whom lymphatic mapping and SLN biopsy were successful, the SLN was positive by conventional histology in 85 patients (15%) but negative in 495 patients (85%). SLN status was the most significant prognostic factor with respect to disease-free and disease-specific survival by univariate and multiple covariate analyses. Although tumor thickness and ulceration influenced survival in SLN-negative patients, they provided no additional prognostic information in SLN-positive patients.

CONCLUSION

Lymphatic mapping and SLN biopsy is highly accurate in staging nodal basins at risk for regional metastases in primary melanoma patients and identifies those who may benefit from earlier lymphadenectomy. Furthermore, pathologic status of the SLN in these patients with clinically negative nodes is the most important prognostic factor for recurrence. The information from SLN biopsy is particularly helpful in establishing stratification criteria for future adjuvant trials.

Therapeutic trends in cutaneous melanoma

Many advances in the management of melanoma have occurred in the last few years. These make this an exciting time for clinicians and allows them to offer glimmers of hope for patients with this disease. This article looks at the therapeutic aspects of the treatment of cutaneous melanoma.

Lymph node micrometastases of cutaneous melanoma: increased sensitivity of molecular diagnosis in comparison to immunohistochemistry

The presence of regional lymph node metastases is one of the most significant prognostic factors for predicting survival in patients with clinical stage I or II cutaneous melanoma. For accurate staging of the primary tumor a sensitive technique is required to detect occult nodal micrometastases. This prospective diagnostic study was designed to evaluate the incidence of nodal micrometastases using nested reverse transcription-polymerase chain reaction (RT-PCR) for tyrosinase in comparison to immunohistochemical examination. Furthermore, the incidence of melanoma micrometastases detected by RT-PCR was analysed in correlation to major prognostic factors. A total of 466 regional lymph nodes from 79 patients with primary cutaneous melanoma (tumor thickness > 0.75 mm) were investigated. In 49 lymph nodes from 31 patients immunohistochemistry demonstrated melanoma metastases. Using tyrosinase RT-PCR, nodal micrometastases were detected in 136 lymph nodes from 52 patients including all lymph nodes positive by immunohistochemical examination. Out of the 417 lymph nodes negative by immunohistochemistry, 87 nodes (21%) were identified to express tyrosinase by the RT-PCR technique. Among the 48 patients negative by immunohistochemical assessment, 21 (44%) had nodal micrometastases (n = 40) using RT-PCR. All 68 lymph nodes from 46 non-melanoma patients serving as negative controls for tyrosinase RT-PCR were negative. The detection of melanocytic nodal micrometastases by tyrosinase RT-PCR is a highly specific method with a sensitivity significantly higher than that achieved by immunohistochemistry (p < 0.0001). Patients with nodal micrometastases identified exclusively by RT-PCR had significantly higher tumor thickness as compared to patients with negative results by RT-PCR (p < 0.01).

Role of elective lymph node dissection in melanoma

In the last several years, much debate has centered on the management of the regional lymph nodes in malignant melanoma. The regional lymph nodes are the most common site of melanoma metastases and surgical excision of these involved nodes is the most effective treatment for either cure or local disease control. The issue still in question is the approach to the clinically negative regional lymph node basin. Retrospective studies have yielded conflicting results regarding the value of routine elective lymph node dissection (ELND) when nodes are clinically negative. Four prospective randomized clinical trials have been completed which have indicated that routine ELND is not worthwhile for the majority of melanoma patients. However, ELND may be associated with improved outcome in certain subgroups of patients: those <60 years age with 1 to 2 mm thick melanomas with or without ulceration. In addition, lymphatic mapping with sentinel lymph node biopsy has become increasingly available and has allowed clinicians an alternative to ELND. In the absence of sentinel lymph node biopsy, the role for ELND in these subgroups of patients is one of the remaining unresolved issues.

Malignant melanoma of the head and neck: effect of treatment on survival

This study compared outcomes for intermediate-thickness (1.5 to 3.99 mm) head and neck melanomas treated with or without elective lymph node dissection (ELND). The records of all head and neck melanomas treated at Virginia Mason Medical Center from 1974 through 1995 were reviewed and analyzed for outcome by stage and elective or therapeutic lymph node dissection. One hundred seventy-four patients with head and neck melanomas were treated in the study period, of which only 25% had intermediate-thickness lesions. Of 38 clinically node-negative patients with intermediate-thickness lesions followed more than 3 years, 10 underwent ELND, yielding two positive dissections (20%). The rate of distant metastases and the mortality rate were 44% and 35% lower in patients undergoing ELND compared with stage II patients who did not undergo ELND, but the difference did not achieve statistical significance (P = 0.12 and 0.21, respectively). The role of ELND in head and neck melanoma is uncertain. This retrospective study is limited by the small number of intermediate-thickness lesions, yet there appears to be a survival advantage to ELND in head and neck melanoma, even in negative dissections. Conventional histologic stains miss micrometastases detected by immunohistological and polymerase chain techniques. Removal of such micrometastases may explain the improved outcome. A multicenter prospective trial in head and neck melanomas, incorporating the latest techniques of sentinel node biopsy and immunohistological staining of node specimens, is needed to clarify definitive therapy for this increasingly common diagnosis.

Lymphatic Mapping for Melanoma: Long-term Results of Regional Nodal Sampling With Radioguided Surgery

BACKGROUND: Lymphatic mapping and sentinel lymph node (SLN) biopsy are new techniques used in the surgical treatment of patients with malignant melanoma. These procedures have the potential to change the surgical treatment of the disease to provide a more rational approach to adjuvant therapy. METHODS: A prospective database of melanoma patients undergoing lymphatic mapping and SLN biopsy was reviewed to identify prognostic factors for overall and disease-free survival in this patient population. RESULTS: Five-year overall and disease-free survival was 92.3% and 79.0%, with a median follow-up of 17 months. The number of histologically positive SLNs was the most powerful predictor of overall and disease-free survival. Patients with no histologically positive SLNs had a five-year overall and disease-free survival of 97.9% and 93.3%, respectively. Tumor ulceration and Clark level greater than or equal to III were the significant prognostic factors for survival. CONCLUSIONS: The use of lymphatic mapping and SLN biopsy effectively stages patients with primary cutaneous melanoma. Additionally, the presence of histologically positive SLNs is the most powerful indicator of overall and disease-free survival for these patients.

Initial assessment of positron emission tomography for detection of nonpalpable regional lymphatic metastases in melanoma

BACKGROUND

The purpose of this pilot study is to determine the feasibility of positron emission tomography with fluorodeoxyglucose (FDG-PET) for detection of nonpalpable regional lymph node metastases in patients with melanoma.

METHODS

Adult patients with histologically proven cutaneous melanoma planned to undergo surgical lymphadenectomy for treatment of nonpalpable subclinical or residual metastatic melanoma in regional lymph node basin(s) participated. Each patient underwent attenuation-corrected PET imaging of the regional lymph node basin(s) with F18 fluorodeoxyglucose (FDG) followed by complete surgical lymphadenectomy. FDG-PET scans were interpreted prospectively by an experienced nuclear medicine physician. FDG-PET scan interpretations and histologic results were then correlated.

RESULTS

Eleven patients underwent 12 FDG-PET scans followed by 12 operations to clear 14 regional lymph node basins. FDG-PET correctly predicted the presence of metastatic melanoma in seven of seven surgical specimens. FDG-PET scans correctly predicted the absence of disease in seven of seven histologically negative node basins. Sensitivity was 1.0; specificity was 1.0.

CONCLUSIONS

This study suggests that increased fluorodeoxyglucose uptake in palpably unremarkable regional lymph node basins in patients with melanoma is highly suggestive of metastatic disease.

Localizing the sentinel node in cutaneous melanoma: gamma probe detection versus blue dye

BACKGROUND

Sentinel node (SN) biopsy can be used to select patients with melanoma for therapeutic lymphadenectomy. We investigated the value of two methods to locate the SN: patent blue dye (PBD) and gamma probe detection of 99mTc-nanocolloid.

METHODS

One hundred ten patients with cutaneous melanoma were studied. Lymphoscintigraphy with 99mTc-nanocolloid was performed to determine the position of the SN. Before operation, PBD was injected at the same site as the radiopharmaceutical. When a blue node was identified intraoperatively, its radioactivity level was measured with the probe. In the absence of blue coloration, the probe was used to trace the SN.

RESULTS

Scintigrams visualized a total of 219 SNs in 141 basins. Eight SNs were not explored. One SN was not found. The remaining 210 and 27 additional intraoperatively identified SNs were excised. From the total of 237 removed SNs, 200 (84%) were found using PBD only. All 37 nodes that were not found with the PBD were localized with the probe so that the probe combined with PBD identified 99.5% of all SNs. In 23 patients the SN contained tumor. In three patients the SN was false-negative for metastasis.

CONCLUSION

The gamma probe together with PBD can identify more SNs (99.5%) than lymphatic mapping with PBD alone (84%).

Malignant melanoma of the vulva. Report of 89 patients

BACKGROUND

Rates of melanoma have increased worldwide over the last few decades. Currently, this rate of increase is greater for melanoma than for any other cancer in the U.S. Approximately 3% of all melanomas diagnosed in women are located within the genital tract, predominantly affecting the vulva. Overall, melanomas of the vulva account for 2-10% of all malignancies of the female external genitalia. Due to the rarity of this disease, treatment recommendations do not exist.

METHODS

This retrospective study was designed to evaluate the significance of clinical and pathologic features for survival among 89 patients examined for malignant melanoma at 5 hospitals in Germany from 1978 to 1991. A complete workup based on age, initial symptoms, tumor localization, presence of ulceration, postoperative stage, surgical procedure, and survival, was performed.

RESULTS

The overall 5-year survival rate of 36.7% confirms the poor prognosis of this disease. Definitive treatment concepts require a standardized treatment of patients with malignant melanoma of the vulva; however, because of the rarity of vulvar melanomas, prospective studies are difficult to perform.

CONCLUSIONS

Parameters such as age, Breslow's thickness of invasion, Clark's level of invasion, lymph node involvement, anatomic site, and postoperative stage are prognostic factors for survival. Surgery should be performed in accordance with the accepted standards for cutaneous melanoma.

Surgical management of stage I and II melanoma patients: approach to the regional lymph node basin

The role for elective lymph node dissection in the management of clinically localized (Stage I and II) melanoma patients represents a long-standing controversy. Contemporary randomized elective lymph node dissection trials have been completed with recently presented results demonstrating some survival benefit for surgical therapy of micrometastases in specific subsets of patients. Lymphatic mapping and sentinel node biopsy offers a rational alternative to elective lymph node dissection for all high risk Stage I and II melanoma patients. Recent advances in lymphatic mapping techniques have resulted in improved identification of the sentinel node. Combined with advances in histologic evaluations of lymph nodes, accurate and minimally invasive mechanisms for assessing lymph node status are now available. This latter goal is critical in light of recently published data demonstrating improved survival with the use of high dose interferon alpha administered in the adjuvant setting for patients with nodal metastases.

Favorable prognostic factors in recurrent and metastatic melanoma

Survival among patients with recurrent and metastatic melanoma varies widely. Several clinical and pathologic variables correlate with improved survival. Awareness of these favorable prognostic characteristics should assist in patient counseling and help identify those who may benefit from more aggressive therapeutic intervention.

Cytogenetics of 158 patients with regional or disseminated melanoma. Subset analysis of near-diploid and simple karyotypes

We report on the cytogenetic analyses of 158 cases of metastatic malignant melanoma, comprised of 63 cases with regional disease (RD) and 95 cases with distant (metastatic) disease (DD). Clonal structural abnormalities were identified in 126 (80%) cases and were significantly increased ( < 0.01 after adjusting for multiple comparisons) on chromosomes (in order of frequency of involvement) 1, 6, 7, 11, 9, and 3. Clustering of breakpoints occurred at 1p36, 1p22-q21, 6p11-q21, 9p, 11q23-qter, 13p (especially for cases with DD), and 19q13. The most common clonal numerical abnormalities, in a subset of 49 near-diploid cases were -10, -22, -9, +7, -19, and -Y. Analysis of chromosome segment gains and losses (CSRP) showed frequent loss of chromosomes 6 and 10, followed by equal rates of involvement of chromosomes 1, 7, and 9. Whole or segmental losses of chromosome 9 (especially 9p) correlate well with recent molecular genetic studies identifying putative suppressor genes, and are also likely important genetic abnormalities. However, based on the frequency of abnormalities in this large series of metastatic melanomas, it is likely that structural abnormalities of 1 and 6, and 10 are important in the pathogenesis of sporadic advanced melanoma.

Malignant melanoma. Primary surgical management (excision and node dissection) based on pathology and staging

The diagnosis of malignant melanoma is based on clinical grounds and a properly performed biopsy, preferably excision, so that the type of melanoma and the thickness can be assessed by methods described by Clark and Breslow. These facilitate clinical and pathologic staging. Excisions with conservative margins for thin lesions (less than 1.0 mm in thickness) and more extensive margins for thicker lesions are appropriate. The issue of elective lymph node dissection is controversial. Most authors agree it is not indicated for lesions less than 1.0 mm thick and may offer little advantage for lesions greater than 4.0 mm thick. Several retrospective studies show a survival advantage in patients with "intermediate" thickness melanomas who may have occult nodal metastases. However, there are prospective randomized clinical trials supporting the concept that positive lymph nodes are a manifestations of systemic disease, and survival is equivalent in patients who have subsequent therapeutic lymph node dissections. A procedure using intraoperative lymphatic mapping and selective lymphadenectomy may identify those patients who are likely to benefit from lymphadenectomy.

Role of elective lymph node dissection in stage I malignant melanoma: evaluation by matched pair analysis

The role of elective lymph node dissection (ELND) in clinical stage I malignant melanoma continues to be controversial. We present a matched pair analysis of 375 patients treated in the Department of Dermatology in Kassel between 1979 and 1991 by wide local excision (WLE) plus ELND. Multivariate analysis revealed tumor thickness, level of invasion, age, sex, and localization as independent prognostic factors, and 375 patients treated by WLE alone were matched as controls to the patients treated by ELND and WLE. There was no significant benefit from WLE plus ELND compared to WLE alone in the total group as shown by the 5-year survival rates (87.3% versus 86.4%) and 10-year survival rates (80.1% versus 77.82%). Increased survival rates were noted for tumor thicknesses 1.51-4.0 mm for the WLE plus ELND group, as shown by the 10-year survival rates of 73.1% versus 60.3%. However, these data were not significant (p = 0.14). Disease-free survival rates were significantly higher in the group treated by additional ELND for all tumor thicknesses (p < 0.05) and even more in intermediate tumor thicknesses of 1.51-4.0 mm (p < 0.001). A significant benefit of elective lymph node dissection was detected for malignant melanoma of the trunk (all tumor thicknesses), as shown by the 5-year survival rates of 92.0% versus 79.7% and 10-year survival rates of 80.4% versus 45.16% (p < 0.05). Malignant melanoma of the extremities revealed no significant differences in survival rates. We conclude that there is a certain benefit from ELND in clinical stage I malignant melanoma for tumor thicknesses of 1.51-4.00 mm. Especially in malignant melanoma of the trunk, WLE plus ELND was more beneficious than WLE alone.