Multicenter Selective Lymphadenectomy Trial-I confirms the central role of sentinel node biopsy in contemporary melanoma management: response to 'No survival benefit for patients with melanoma undergoing sentinel lymph node biopsy: critical appraisal of the Multicenter Selective Lymphadenectomy Trial-I final report'.

Sentinel lymph node (SLN) biopsy has become a standard procedure for many patients with melanoma and is recommended in numerous national and professional melanoma guidelines. The Multicenter Selective Lymphadenectomy Trial (MSLT-1) confirms earlier large database studies and prospective clinical trials in demonstrating the independent and unequalled prognostic value of the SLN. It also demonstrates the ability of biopsy-directed management to provide effective regional disease control with the least possible morbidity. These benefits are not in question and provide ample justification for the procedure, even without evidence of a survival benefit. However, MSLT-1 also provides strong evidence of a substantial reduction in the risk of melanoma death for patients with intermediate thickness melanomas who harbour occult nodal metastases at the time of presentation. Denying appropriately selected patients with melanoma the opportunity to undergo SLN biopsy is no longer reasonable or acceptable.

Golf science research at the beginning of the twenty-first century.

At the beginning of the twenty-first century, there are 30,000 golf courses and 55 million people who play golf worldwide. In the USA alone, the value of golf club memberships sold in the 1990s was US dollar 3.2 billion. Underpinning this significant human activity is a wide variety of people researching and applying science to sustain and develop the game. The 11 golf science disciplines recognized by the World Scientific Congress of Golf have reported 311 papers at four world congresses since 1990. Additionally, scientific papers have been published in discipline-specific peer-reviewed journals, research has been sponsored by the two governing bodies of golf, the Royal and Ancient Golf Club of St. Andrews and the United States Golf Association, and confidential research is undertaken by commercial companies, especially equipment manufacturers. This paper reviews much of this human endeavour and points the way forward for future research into golf.

Current practice and future directions in pathology and laboratory evaluation of the sentinel node.

We developed the techniques of lymphatic mapping and sentinel node (SN) biopsy to improve the management of patients with high-risk (thick and deep) primary melanoma. The SN is the first lymph node on the direct lymphatic drainage path from the primary tumor. This node is uniquely immune-modulated by the primary tumor and is the node most likely to contain the earliest stages of metastases. Accurate assessment of the SN requires careful evaluation of multiple sections removed from the areas of the node most likely to contain tumor. These sections are stained with hematoxylin and eosin and by immunohistochemistry with antibodies directed to tumor-associated markers (S-100, HMB-45, and Melan-A/MART-1) in the case of melanoma and to cytokeratins for breast cancer. Studies are in progress to determine whether molecular biology techniques will detect additional nodes that contain truly occult tumor deposits.

The morphology, immunophenotype and distribution of paracortical dendritic leucocytes in lymph nodes regional to cutaneous melanoma.

Our aim was to identify and delineate alterations in the distribution and immunophenotype of the lymphocytes and paracortical dendritic leucocytes (interdigitating dendritic cells; IDCs) in lymph nodes regional to tumours. Using immunocytochemistry and computer-assisted image analysis we examined 65 lymph nodes excised from 47 patients with malignant melanoma. Twenty-nine patients had American Joint Committee on Cancer (AJCC) stage II melanoma (no tumour spread beyond the primary site) and 18 had AJCC stage III disease (metastases in the regional nodes). There were significant differences in the frequency, morphology, immunophenotype and anatomical distribution of the IDCs and in the complexity of their dendritic processes in different areas within individual lymph nodes. We conclude that morphological and phenotypical variations in IDCs correlate with differing levels of antigen presentation. Downregulation of antigen presentation in lymph nodes regional to tumours is most probably mediated by tumour products. Differences in IDC distribution and characteristics in lymph nodes from different anatomical sites must be considered in interpreting studies of nodal morphology and function.

Sentinel lymph nodes show profound downregulation of antigen-presenting cells of the paracortex: implications for tumor biology and treatment.

The sentinel lymph node (SN) is the first node on the direct lymphatic drainage pathway from a tumor. Melanoma-associated SNs are the most likely site of early metastases and their immune functions are strikingly down-modulated. We evaluated histologic and cytologic characteristics of 21 SNs and 21 nonsentinel nodes (NSNs) from melanoma patients who had clinically localized (AJCC Stage I--II) primary cutaneous melanoma. SNs showed highly significant reductions in total paracortical area and in the area of the paracortical subsector occupied by dendritic cells. The frequency of paracortical interdigitating dendritic cells (IDCs) was dramatically reduced in SNs, and most IDCs (approximately 99%) lacked the complex dendrites associated with active antigen presentation. The release of immunosuppressive factors from the primary melanoma may induce a localized and specific paralysis in the SN, which prevents the recognition of otherwise immunogenic melanoma antigens by IDCs. This immune paralysis may facilitate the implantation and growth of melanoma cells in the SN. Cytokine therapy may be able to reverse this immune paralysis. These findings have an important practical application in the histopathologic confirmation that a node is truly sentinel. They also offer an hypothesis to explain the failure of the immune surveillance mechanisms to identify and respond to a small primary melanoma that expresses immunogenic tumor antigens.

The role of practising pathologists in the generation of novel and original observations.

This editorial comments on an important study by a group of practising pathologists and clinicians, which is published in the current issue of this Journal. The authors of the study used standard immunohistochemical techniques to study the expression of melanoma-associated antigens during the evolution of melanomas from primary to metastases. Expression of the epitopes remained relatively steady during melanoma evolution. This has important implications for specific immunotherapy protocols and provides guidance to diagnostic pathologists in regard to the antibody combinations that may be used to confirm melanocytic histogenesis. The findings from this study reinforce the important role which working pathologists play in the generation of critical findings in bioscience. Pathologists in training should be exposed to the philosophy and techniques of scientific investigation and afforded protected time to gain experience in these activities.

Is the node of Cloquet the sentinel node for the iliac/obturator node group?

PURPOSE: Some surgeons question the survival advantage of ilioinguinal lymphadenectomy for metastatic melanoma because they believe that deep nodal involvement signifies a poor prognosis that is unchanged by surgery. However, several series, including our own, have reported 5-year survival rates reaching 30%. New adjuvant therapies may further improve survival after ilioinguinal lymphadenectomy, but this applies only to nodal basins with metastatic disease. We hypothesized that the node of Cloquet accurately reflects the pathologic status of the iliac/obturator nodes, allowing deep pelvic lymphadenectomy to be selectively performed. PATIENTS AND METHODS: Between 1972 and 1998, 691 patients with primary cutaneous melanoma underwent both elective and therapeutic complete (superficial and deep) ilioinguinal lymphadenectomy. Of the 204 (30%) patients with tumor-positive inguinal and/or iliac/obturator nodes, 68 had a node of Cloquet identified during pathologic review of the lymphadenectomy specimen. Chart and computer database review of these 68 patients was undertaken to determine the association between the tumor status of Cloquet's node and that of deep pelvic nodes. Immunohistochemical analysis was performed on eight of 11 negative Cloquet's nodes in patients with positive iliac/obturator nodes. Paraffin blocks of the other three negative nodes of Cloquet were unavailable for immunohistochemistry, and they were excluded from analysis. RESULTS: Tumor-positive deep nodes were identified in the lymphadenectomy specimen from 20 of 30 (67%) patients with a positive Cloquet's node and from eight of 35 (23%) patients with a negative Cloquet's node (P = 0.0019). Re-examination of these eight tumor-negative Cloquet's nodes using immunostaining with S-100 and HMB45 identified tumor in 3 nodes, increasing the sensitivity of Cloquet's node for predicting deep nodal metastases from 71% to 82%. The 6.8 odds ratio of positive iliac/obturator nodes given a positive node of Cloquet increased to 12.4 after immunohistochemical analysis. The positive and negative predictive values were also enhanced from 67% to 70% and 77% to 84%, respectively. DISCUSSION: The tumor status of the node of Cloquet significantly reflects the tumor status of the iliac/obturator nodes, particularly when Cloquet's node is examined by immunohistochemical analysis. The node of Cloquet assumes the role of the sentinel node in patients whose superficial inguinal lymph nodes drain through Cloquet's node to the iliac/obturator nodes.

Penetration of human metastatic melanoma cells through an authentic dermal-epidermal junction is associated with dissolution of native collagen types IV and VII.

The events occurring during the penetration of melanoma cells through the dermal-epidermal junction, which is the first crucial step in the process of metastasis, are poorly understood, partly because no suitable tissue models exist. In the in vitro model reported here, two melanoma clones (T1C3, which generates lung metastases in experimental animals, and IC8, which does not) derived from a single parental cell line were co-seeded with normal allogenic keratinocytes onto acellular human de-epidermized dermis with preserved intact basement membrane and cultured for up to 1 month at an air-liquid interface. Histological, immunohistochemical and ultrastructural studies showed that melanoma cells from the metastatic clone (T1C3), but not from the non-metastatic clone (IC8), penetrated the dermal-epidermal junction to invade the dermis after 3 weeks of culture. Local invasion was associated with the dissolution of the native epidermal basement membrane collagens type IV and VII. Confocal laser scanning microscopy analysis demonstrated that numerous T1C3 cells were able to colonize the interstitial dermis and to rapidly penetrate empty dermal cavities. Our model represents a significant technical advance over others currently available since: (i) the organized three-dimensional architecture of the native dermal-epidermal junction is preserved; (ii) the active invasion process coincides with the dissolution of native components of the epidermal basement membrane, i.e. collagen types IV and VII; and (iii) the ability of melanoma cells to cross the dermal-epidermal junction correlates with their metastatic potential. This model provides a valuable tool for the study of the time-course of the cellular and molecular events that occur during the earliest steps of invasion in cutaneous melanoma. It also offers new opportunities to study the possible role of the keratinocyte environment in melanoma invasion.

Principles of sentinel lymph node identification: background and clinical implications.

The management of clinically negative regional lymph nodes in early-stage melanoma has been controversial for many years. While some advocate wide excision of the primary with elective node dissection (ELND), others recommend excision of the primary alone and therapeutic node dissection (TLND) for recurrences in the nodal basin. ELND is based on the concept that metastases occur by passage of the tumor from the primary to the regional nodes and distant sites, in which case early dissection of regional nodes will disrupt metastatic progression and prevent the spread of disease. Advocates of the "wait and watch" approach suggest that regional node metastases are markers for disease progression and that distant disease can occur without node metastases. Four randomized prospective studies comparing ELND and TLND have not demonstrated overall survival advantage for ELND, but suggest that patients with early regional metastases may benefit from ELND. As an alternative, Morton et al., from UCLA and the John Wayne Cancer Institute, devised intraoperative lymphatic mapping and sentinel lymphadenectomy (LM/SL). These minimally invasive operative procedures allow identification of the first and key (sentinel) lymph node (SN). The technique accurately maps the lymphatics by lymphoscintigraphy, and vital blue dye leads the surgeon to the SN. The pathologist then concentrates on seeking metastases in the nodes most likely to contain metastases. Patients with tumor-positive SN undergo completion lymph node dissection (CLND), while those without SN metastases avoid the complications and costs associated with this procedure. Morton et al., in a report on their initial experience of LM/SL, performed CLND in all cases regardless of SN tumor status and demonstrated the precise staging capacity of the procedure. Since this initial report, numerous studies have validated the accuracy and low morbidity of the procedure. Each center must master a learning phase. The procedure is dependent on the close cooperation of nuclear medicine physicians, surgeons, and pathologists. While LM/SL is now almost standard practice in the US, the results of clinical trials are awaited to determine whether LM/SL can replace ELND and TLND in the management of early-stage melanoma.

Individualized prognosis for melanoma patients.

The clinical course of malignant melanoma is notoriously variable. Current approaches to prognostication allow assignment to risk categories but do not permit accurate assessment of prognosis on an individual patient basis. We analyzed a melanoma histology database that comprises 1,042 sequential melanoma patients evaluated by A.J.C. at UCLA between 1980 and 1990 for 30 separate variables according to a standard protocol. After censoring for absent data, a univariate Cox model analysis was performed that showed 20 individual variables that were significantly linked to clinical outcome. A step-up multivariate analysis was then performed. The combined analysis shows 5 variables: gender, site of primary, age relative to 60 years, Breslow thickness, and presence and width of ulceration to be linked to survival. Probability of survival is calculated using a 2-step approach. The survival-linked variables are multiplied to give an individualized risk score. This is converted into probability of survival by the formula .987 (risk score) for 3-year survival, .975 (risk score) for 5-year survival, and .960 (risk score) for 10-year survival. Thus, a 55-year-old woman with a 1.8-mm nonulcerated melanoma on the leg would have a risk score of (1 x 1 x 1 x 2 x 1) = 2 and a predicted probability of survival at 5 years of .9752 (95%) and at 10 years of .9602 (92%). We used similar techniques to develop individualized risk scores for likelihood of recurrence. The significant variables in this case are anatomic site of the primary melanoma, melanoma subtype, Breslow thickness, and presence and width of ulceration. The formulae for likelihood of recurrence at different periods after initial surgical removal of the primary melanoma are at 3 years, .979(risk score); at 5 years, .971(risk score); and at 10 years, .957(risk score). This relatively simple approach to prognostication uses readily available demographic information and is likely to be more accurate than single-factor analysis.

The pathologist's role in sentinel lymph node evaluation.

Patients with high-risk (thick, deeply invasive) primary melanoma were, in the past, managed by wide local excision and elective node dissection or wide local excision alone, with subsequent lymphadenectomy if the regional nodes developed clinically detectable metastases. We recently developed a more logical approach called selective lymph node dissection. To be effective, this requires close collaboration of surgeons, pathologists, and nuclear medicine physicians. The draining lymph node basin is identified preoperatively by lymphoscintigraphy. During surgery, a marker dye (isosulfan blue) and radioactive technetium labeled albumin are injected intradermally around the primary melanoma and the afferent lymphatics are followed up to the first lymph nodes of the ipsilateral regional nodal basin. The surgeon excises the blue-colored and maximally radioactive sentinel nodes and the pathologist critically evaluates these for the presence of a metastatic tumor. If the sentinel nodes are tumor free, no further nodal dissection is undertaken; if a tumor is present, a complete dissection of the nodal basin is performed. We have examined 1,119 sentinel lymph nodes from 669 patients treated by selective lymph node dissection. We identified melanoma cells in sentinel nodes from 126 patients (17.8%). A single node contained tumors in 67% of patients, 2 nodes were positive in 25%, and the remaining 12% of patients had three tumor-containing nodes. Melanoma cells were dispersed singly or in variably sized groups, usually in the peripheral nodal sinus. In around 40% of patients, immunohistochemistry is required to identify minute numbers of tumor cells. With experience, pathologists identify tumors in hematoxylin and eosin (H&E) preparations in an increasing proportion of lymph nodes. Tumor cells are more frequent in the sentinel nodes of patients with primary tumors of deeper Clark level and greater Breslow thickness. Tumor cells must be discriminated from capsular nevus cells, interdigitating dendritic leukocytes, macrophages, and intranodal neural tissues.

Melanoma metastases through the lymphatic system.

Pathologists can expect to receive sentinel nodes from patients with cancers other than melanoma, such as breast, vulvar, thyroid, and colon cancers. Many of the recommendations in this article can be extrapolated to cancers other than melanoma, but there are some peculiarities that relate to each type of tumor. The pathologist should carefully review the published literature before attempting to evaluate sentinel nodes from patients with an unfamiliar form of cancer.

The shifting patterns of metastatic melanoma.

Management of cutaneous melanoma becomes more difficult as tumor cells metastasize to sites that are remote from the primary tumor. There is a hierarchy of risk associated with cancer spread by different routes and to different organs. Differences in clinical outcome indicate critical variations in pathobiology at different stages in disease evolution. Prevention of the evolution of melanoma is critical, especially beyond the stage of nodal involvement.

Validation of the accuracy of intraoperative lymphatic mapping and sentinel lymphadenectomy for early-stage melanoma: a multicenter trial. Multicenter Selective Lymphadenectomy Trial Group.

OBJECTIVE: To evaluate the multicenter application of intraoperative lymphatic mapping, sentinel lymphadenectomy, and selective complete lymph node dissection (LM/SL/SCLND) for the management of early-stage melanoma. SUMMARY BACKGROUND DATA: The multidisciplinary technique of LM/SL/SCLND has been widely adopted, but not validated in a multicenter trial. The authors began the international Multicenter Selective Lymphadenectomy Trial (MSLT) 5 years ago to evaluate the survival of patients with early-stage primary melanoma after wide excision alone versus wide excision plus LM/SL/SCLND. This study examined the accuracy of LM/SL/SCLND in the MSLT, using the experience of the organizing center (John Wayne Cancer Institute [JWCI]) as a standard for comparison. METHODS: Before entering patients into the randomization phase, each center in the MSLT was required to finish a 30-case learning phase with complete nuclear medicine, pathology, and surgical review. Selection of MSLT patients in the LM/SL/SCLND treatment arm was based on complete pathologic and surgical data. The comparison group of JWCI patients was selected using these criteria: primary cutaneous melanoma having a thickness > or =1 mm with a Clark level > or =III, or a thickness <1 mm with a Clark level > or =IV (MSLT criterion); LM/SL performed between June 1, 1985, and December 30, 1998; and patient not entered in the MSLT. The accuracy of LM/SL/SCLND was determined by comparing the rates of sentinel node (SN) identification and the incidence of SN metastases in the MSLT and JWCI groups. RESULTS: There were 551 patients in the MSLT group and 584 patients in the JWCI group. In both groups, LM performed with blue dye plus a radiocolloid was more successful (99.1 %) than LM performed with blue dye alone (95.2%) (p = 0.014). After a center had completed the 30-case learning phase, the success of SN identification in the MSLT group was independent of the center's case volume or experience in the MSLT. CONCLUSIONS: Lymphatic mapping and sentinel lymphadenectomy can be successfully learned and applied in a standardized fashion with high accuracy by centers worldwide. Successful SN identification rates of 97% can be achieved, and the incidence of nodal metastases approaches that of the organizing center. A multidisciplinary approach (surgery, nuclear medicine, and pathology) and a learning phase of > or =30 consecutive cases per center are sufficient for mastery of LM/SL in cutaneous melanoma. Lymphatic mapping performed using blue dye plus radiocolloid is superior to LM using blue dye alone.

Cytoplasmic accumulation of peanut agglutinin-binding glycoconjugates in the cells of primary melanoma correlates with clinical outcome.

In an experimental model, human melanoma cell lines enriched for cells that express the glycoconjugate B-D galactose N-acetyl-D-galactosamine, which reacts with the peanut agglutinin lectin (PNA), are associated with an increase in the frequency of metastases. We previously showed that this glycoconjugate is expressed on the cells of some primary melanomas in humans and that such cells are found selectively in melanomas with a high risk for developing metastases and causing death. Using fixed archival tissues from 99 primary melanomas and lectin histochemistry, we found 65 tumors that contained melanoma cells that were PNA-positive. PNA-reactive cells were not identified in normal melanocytes or in the nevocytes of 24 nevi. PNA-reactive material accumulates adjacent to the nucleus in the area of the Golgi apparatus, initially as a tiny dot, but later in quantities sufficient to displace and indent the nucleus, producing a signet ring cell-like appearance. Tumor cells containing PNA-reactive material were associated with more evolved, deeper, and thicker tumors. Two melanomas up to Clark level II were PNA positive (20%), compared with 60% of level III, 76% of level IV, and 100% of level V. Five of 13 tumors less than 0.76 mm thick (39%) were positive, compared with 50% of tumors 0.76 to 1.49 mm thick, 64% of tumors 1.5 to 2.99 mm thick, and 85% of tumors 3 mm thick or thicker. PNA-reactivity was negatively correlated with disease-free survival (PNA-negative, 49.2+/-23 months; PNA-positive grade 1, 41.6+/-26 months and PNA-positive grade 2, 24.4+/-23 months), survival rate 5 years after initial treatment (PNA-negative, 84.8%; PNA-positive grade 1, 63.8%; and PNA-positive grade 2, 31.3%) and disease-free survival at 5 years after initial treatment (PNA-negative, 69.7%; PNA-positive grade 1, 53.2%; and PNA-positive grade 2, 25%).

Recommendations for the reporting of tissues removed as part of the surgical treatment of cutaneous melanoma. The Association of Directors of Anatomic and Surgical Pathology.

The Association of Directors of Anatomic and Surgical Pathology has developed recommendations for the surgical pathology report for common malignant tumors. The recommendations for cutaneous melanoma are reported.