Richard Essner

Validation of the Accuracy of Intraoperative Lymphatic Mapping and Sentinel Lymphadenectomy for Early-Stage Melanoma: A Multicenter Trial

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 centers 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.

Sentinel node biopsy for early-stage melanoma - Accuracy and morbidity in MSLT-I, an international multicenter trial

Objective:The objective of this study was to evaluate, in an international multicenter phase III trial, the accuracy, use, and morbidity of intraoperative lymphatic mapping and sentinel node biopsy (LM/SNB) for staging the regional nodal basin of patients with early-stage melanoma. Summary Background Data:Since our introduction of LM/SNB in 1990, this technique has been widely adopted and has become part of the American Joint Committee on Cancer (AJCC) staging system. Eleven years ago, the authors began the international Multicenter Selective Lymphadenectomy Trial (MSLT-I) to compare 2 treatment approaches: wide excision (WE) plus LM/SNB with immediate complete lymphadenectomy (CLND) for sentinel node (SN) metastases, and WE plus postoperative observation with CLND delayed until the subsequent development of clinically evident nodal metastases. Methods:After each center achieved 85% accuracy of SN identification during a 30-case learning phase, patients with primary cutaneous melanoma (≥1 mm with Clark level ≥III, or any thickness with Clark level ≥IV) were randomly assigned in a 4:6 ratio to WE plus observation (WEO) with delayed CLND for nodal recurrence, or to WE plus LM/SNB with immediate CLND for SN metastasis. The accuracy of LM/SNB was determined by comparing the rates of SN identification and the incidence of SN metastases in the LM/SNB group versus the subsequent development of nodal metastases in the regional nodal basin of those patients with tumor-negative SNs. Early morbidity of LM/SNB was evaluated by comparing complication rates between the 2 treatment groups. Trial accrual was completed on March 31, 2002, after enrollment of 2001 patients. Results:Initial SN identification rate was 95.3% overall: 99.3% for the groin, 95.3% for the axilla, and 84.5% for the neck basins. The rate of false-negative LM/SNB during the trial phase, as measured by nodal recurrence in a tumor-negative dissected SN basin, decreased with increasing case volume at each center: 10.3% for the first 25 cases versus 5.2% after 25 cases. There were no operative mortalities. The low (10.1%) complication rate after LM/SNB increased to 37.2% with the addition of CLND; CLND also increased the severity of complications. Conclusions:LM/SNB is a safe, low-morbidity procedure for staging the regional nodal basin in early melanoma. Even after a 30-case learning phase and 25 additional LM/SNB cases, the accuracy of LM/SNB continues to increase with a centers experience. LM/SNB should become standard care for staging the regional lymph nodes of patients with primary cutaneous melanoma.

Prognostic Significance of Occult Metastases Detected by Sentinel Lymphadenectomy and Reverse Transcriptase–Polymerase Chain Reaction in Early-Stage Melanoma Patients

PURPOSE Detection of micrometastases in the regional tumor-draining lymph nodes is critical for accurate staging and prognosis in melanoma patients. We hypothesized that a multiple-mRNA marker (MM) reverse transcriptase-polymerase chain reaction (RT-PCR) assay would improve the detection of occult metastases in the sentinel node (SN), compared with hematoxylin and eosin (H&E) staining and immunohistochemistry (IHC), and that MM expression is predictive of disease relapse. PATIENTS AND METHODS Seventy-two consecutive patients with clinical early-stage melanoma underwent sentinel lymphadenectomy (SLND). Their SNs were serially sectioned and assessed for MAGE-3, MART-1, and tyrosinase mRNA expression by RT-PCR, in parallel with H&E staining and IHC, for melanoma metastases. MM expression in the SNs was correlated with H&E and IHC assay results, standard prognostic factors, and disease-free survival. RESULTS In 17 patients with H&E- and/or IHC-positive SNs, 16 (94%) expressed two or more mRNA markers. Twenty (36%) of 55 patients with histopathologically negative SNs expressed two or more mRNA markers. By multivariate analysis, patients at increased risk of metastases to the SN had thicker lesions (P =.03), were 60 years of age or younger (P <.05), and/or were MM-positive (P <.001). Patients with histopathologically melanoma-free SNs who were MM-positive, compared with those who were positive for one or fewer mRNA markers, were at increased risk of recurrence (P =.02). Patients who were MM-positive with histopathologically proven metastases in the SN were at greatest risk of disease relapse (P =. 01). CONCLUSION H&E staining and IHC underestimate the true incidence of melanoma metastases. MM expression in the SN more accurately reflects melanoma micrometastases and is also a more powerful predictor of disease relapse than are H&E staining and IHC alone.

Intraoperative lymphatic mapping and selective cervical lymphadenectomy for early-stage melanomas of the head and neck.

PURPOSE We developed intraoperative lymphatic mapping with selective lymphadenectomy (SLND) to identify micrometastatic spread of cutaneous melanoma to regional lymph nodes. This study was undertaken to assess the sensitivity and specificity of our technique in patients with clinical stage I (CS-I) melanoma of the head or neck. PATIENTS AND METHODS Seventy-two CS-I melanoma patients underwent intraoperative lymphatic mapping of primary cutaneous melanomas located on the head, neck, or upper chest/back draining to the neck. Key (sentinel) cervical lymph nodes in the regional lymphatic drainage basin were identified, selectively excised during SLND, and examined for microscopic evidence of tumor cells. If these sentinel nodes were tumor-negative, the surgery was concluded; if the sentinel nodes were tumor-positive, all nodes in the drainage basin were removed during en bloc lymphadenectomy (LND). RESULTS Intraoperative lymphatic mapping identified sentinel nodes in 90% of the regional drainage basins. Fifteen percent of these nodes were tumor-positive, indicating the need for LND. There were no false-negative sentinel nodes, and extended follow-up showed no local nodal recurrences in patients whose sentinel-node histology did not indicate the need for LND. CONCLUSION Intraoperative lymphatic mapping and SLND is a minimally invasive and highly accurate screening technique for determining which patients with CS-I head and neck melanomas have subclinical node metastases and therefore might benefit from cervical LND.

Lymphatic mapping and sentinel lymphadenectomy for early-stage melanoma: therapeutic utility and implications of nodal microanatomy and molecular staging for improving the accuracy of detection of nodal micrometastases.

Objective: Lymphatic mapping and sentinel lymphadenectomy (LM/SL) have been applied to virtually all solid neoplasms since our original description of LM/SL for melanoma. Our objectives were to determine the diagnostic and therapeutic utility of LM/SL, investigate carbon dye for mapping the microanatomy of lymphatic flow within the sentinel node (SN), and determine the prognostic accuracy of molecular assessment of the SN. Methods: Since 1985, 1599 patients with AJCC Stage I/II melanoma have been treated by LM/SL at our institution and 4590 have been treated by wide excision (WE) without nodal staging. We examined the incidence of clinical nodal recurrence after WE alone, the incidence of subclinical nodal metastases found by LM/SL, and the incidence of nodal recurrence in basins with histopathology-negative SNs. Results: In 1514 LM/SL patients with a primary of known Breslow thickness, the incidence of metastasis in nodes claimed to be sentinel was 7.3%, 19.7%, 33.2%, and 39.7% for primary lesions ≤1.0, 1.01–2.0, 2.01–4.0, and >4.0 mm, respectively. In 3652 WE-only patients, the corresponding rates of nodal recurrence were 12.0%, 32.0%, 34.4%, and 30.1%. Thus, LM/SL detected only 60% of expected nodal metastases from primary melanomas <2.01 mm. Forty of 1599 (3.1%) patients developed recurrence in basins with immunohistochemistry (IH)-negative SNs. To determine whether nonrandom intranodal distribution of tumor cells could explain missed SN metastases, we coinjected carbon particles and blue dye during LM/SL in 166 patients: 25 (16%) patients had nodal metastases, all of which were found only in nodal subsectors containing carbon particles. When paraffin-embedded SNs from a subset of 162 IH-negative patients were re-examined by quantitative multimarker reverse-transcriptase polymerase chain reaction (qRT) assay, 49 (30%) gave positive signals. These patients had a significantly higher risk of disease recurrence and death than did patients whose IH and qRT results were negative (p < 0.0001). Comparison of 287 prognostically matched pairs of patients who underwent immediate (after LM/SL) versus delayed (after observation) dissection of nodal metastases revealed 5-, 10-, and 15-year survival rates of 73%, 69%, and 69% versus 51%, 37%, and 32%, respectively (P ≤ 0.001). Conclusions: SN assessment based on intranodal compartmentalization of lymphatic flow (carbon dye mapping) should increase the accuracy of IH and, in combination with multimarker qRT assessment, will allow confident identification of most patients for whom surgery alone is curative. Our data suggest a significant therapeutic benefit for immediate dissection based on identification of a tumor-involved SN.

Prolonged Survival After Complete Resection of Disseminated Melanoma and Active Immunotherapy With a Therapeutic Cancer Vaccine

PURPOSE The curative effect of surgery in certain patients with metastatic melanoma suggests the presence of endogenous antitumor responses. Because melanoma is immunogenic, we investigated whether a therapeutic cancer vaccine called Canvaxin (CancerVax Corporation, Carlsbad, CA) could enhance antitumor immune responses and thereby prolong survival. PATIENTS AND METHODS Of 263 patients who underwent complete resection of American Joint Committee on Cancer stage IV melanoma, 150 received postoperative adjuvant vaccine therapy and 113 did not. The overall survival (OS) for the two groups was compared by Cox regression. Further survival analysis was performed by matched-pair analysis according to three prognostic variables: sex, metastatic site, and number of tumor-involved organ sites. RESULTS Five-year OS rates were 39% for vaccine and 19% for nonvaccine patients. On multivariate analysis, vaccine therapy was the most significant prognostic variable in this cohort (P =.0001). Analysis of 107 matched pairs of vaccine and nonvaccine patients revealed a significant OS advantage for vaccine therapy (P =.0009): 5-year OS was 39% for vaccine patients versus 20% for nonvaccine patients. There was a significant delayed-type hypersensitivity (DTH) response to adjuvant vaccine therapy (P =.0001), and OS was significantly correlated with DTH to vaccine (P =.0001) but not with DTH to purified protein derivative (PPD), a control antigen. CONCLUSION Prolonged survival was observed in patients who received postoperative active immunotherapy with Canvaxin therapeutic cancer vaccine. The correlation of survival with vaccine-DTH responses but not PPD-DTH indicates a treatment-specific effect. These findings suggest that adjuvant active specific immunotherapy should be considered after cytoreductive surgery for advanced melanoma.

Tumour–induced immune modulation of sentinel lymph nodes

Sentinel lymph nodes (SLNs), being the first nodes to receive lymph from a primary tumour and the preferential site of initial tumour metastases, are intensively exposed to the bioactive products of tumour cells and other associated cells. This makes them ideal for studies of the factors that determine selective tissue susceptibility to metastases. We postulate that tumour-induced immune modulation of SLNs facilitates lymph-node metastases by inhibiting the generation of tumour-specific cytotoxic T cells that are active against tumour cells of primary and metastatic melanomas. Immune modulation of the lymph nodes can be reversed by granulocyte/macrophage colony-stimulating factor (GM-CSF), a finding that has implications for the future therapy of lymph-node metastases.

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 (∼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.

Factors Predictive of Tumor-Positive Nonsentinel Lymph Nodes After Tumor-Positive Sentinel Lymph Node Dissection for Melanoma

PURPOSE Approximately 20% of sentinel node (SN) positive melanoma patients have additional non-SN (NSN) metastasis. The rationale for this study was to identify the factors associated with additional nodal disease, as a method to determine which patients may most benefit from completion lymph node dissection (CLND). PATIENTS AND METHODS During 1990 to 2002, 1,599 patients have undergone SN biopsy at our institute. 19.5% underwent CLND for tumor-positive SN. One hundred ninety-one of these patients had clinicopathologic information available for review. Univariate analyses used chi2 test, Wilcoxson rank sum test, and chi2 test for trend. Multivariate analyses used logistic regression and Wald test. RESULTS Forty-six (24%) patients had tumor-positive NSN. Univariate analyses showed that primary thickness (Breslow and Clark), primary site, SN tumor size, and number of tumor-positive SNs were significantly associated with tumor-positive NSN. Multivariate analysis (167 patients), confirmed that Breslow and SN tumor size were independently predictive. Sex, histology, ulceration, mitotic index, and SN basin location were not predictive. Risk stratification by the number of prognostic factors present (Breslow > or = 3 mm and SN tumor size > or = 2 mm) showed that probability of finding tumor-positive NSN was 12.3% in the low-risk group (0 factors), 30.9% in the intermediate-risk group (1 factor), and 41.9% in the high-risk group (2 factors). CONCLUSION Thicker primary and larger SN tumor size are factors that correlate best with tumor-positive NSN. Although none of these factors are absolutely predictive of residual nodal disease, these factors must be strongly considered if the SN contains metastasis, as they provide enhanced risk assessment for NSN tumor-positivity.

Role of Sentinel Lymphadenectomy in Thin Invasive Cutaneous Melanomas

PURPOSE Regional lymph node status is the strongest prognostic determinant in early-stage melanoma. Lymphatic mapping and sentinel lymphadenectomy (LM/SL) is standard to stage regional nodes because it is accurate and minimally morbid, yet its role for thin (<or= 1.5 mm) primary melanomas is unknown. PATIENTS AND METHODS Our melanoma database of more than 10,000 patients was reviewed for patients with melanomas <or= 1.50 mm thick who underwent LM/SL. All had lymphoscintigrams and LM/SL via dye alone or with radiopharmaceutical. Patients with tumor-positive sentinel nodes (SNs) underwent completion dissections. RESULTS Five hundred twelve patients underwent LM/SL. Most were men (57%), and median age was 49 years. Most primary melanomas were on the torso (44%). Twenty-five patients (4.9%) had tumor-positive SNs. The thinnest lesion with a nodal metastasis was 0.35 mm. The SN-negative and SN-positive cohorts were equivalent by sex, but SN+ patients tended to be younger (P =.053), with significantly more SN metastases in those younger than 44 years (P =.005). No consistent pathology among SN-positive primary melanomas was found. Among those with 1.01- to 1.05-mm primaries, 7.1% were SN-positive. Among 272 patients with lesions <or= 1.00 mm, 2.9% had positive SNs and 1.7% with lesions <or= 0.75 mm had SN metastases. All 13 deaths were in SN-negative patients. Median follow-up durations in SN-positive and SN-negative patients were 25 and 45 months, respectively. CONCLUSION The high nodal positivity rate associated with primary melanomas 1.01 to 1.50 mm thick suggests that LM/SL is indicated in this group. Younger age may be correlated with nodal metastases in patients with lesions <or= 1.00 mm. Lesions <or= 0.75 mm have minimal metastatic potential, and therefore LM/SL is rarely indicated.