A multicentre study of naevus-associated melanoma vs. de novo melanoma, tumour thickness and body site differences

BACKGROUND

Whether melanoma in histological contiguity with a naevus [naevus-associated melanoma (NAM)] is distinctly different from melanoma arising de novo remains unclear.

OBJECTIVES

To determine whether the characteristics of de novo melanoma differ from NAM and are not due to naevus obliteration in thicker tumours.

METHODS

We conducted a multicentre retrospective study of de novo melanoma and NAM in seven referral centres in Europe, Australia and the USA between 2006 and 2015.

RESULTS

In a total of 9474 localized melanomas, de novo melanoma was associated with thicker tumours and body site differences compared with NAM. In the subset of T1 melanomas (n = 5307), similar body site differences were found in multivariate analysis by body site. When compared with NAM, de novo melanoma was more likely to affect older individuals (≥ 70 years) when located on the head/neck [odds ratio (OR) 4·65, 95% confidence interval (CI) 2·55-8·46], the trunk (OR 1·82, 95% CI 1·40-2·36) or the upper extremity (OR 1·69, 95% CI 1·14-2·50), was more likely to affect female patients when located on the lower extremities (OR 1·36, 95% CI 1·03-1·80), and was more likely to be of the nodular melanoma subtype (OR 2·23, 95% CI 1·14-4·35) when located on the trunk. De novo melanoma was less likely to have regression present compared with NAM.

CONCLUSIONS

Clinicopathological and body site differences between de novo melanoma and NAM support the divergent pathway model of development. These differences were also found in thin melanomas, suggesting that de novo melanomas are different from NAM and their differences are not due to the obliteration of naevus remnants in thicker tumours.

Histopathological features of complete pathological response predict recurrence-free survival following neoadjuvant targeted therapy for metastatic melanoma

BACKGROUND

Recent clinical trials demonstrated the safety and efficacy of neoadjuvant dabrafenib and trametinib (DT) among patients with surgically resectable clinical stage III BRAFV600E/K mutant melanoma. Although patients achieving a complete pathological response (pCR) exhibited superior recurrence-free survival (RFS) versus those who did not, 30% of pCR patients relapsed. We sought to identify whether histopathological features of the pathological response further delineated risk of relapse.

METHODS

Surgical resection specimens from DT-treated patients in two phase 2 clinical trials were reviewed. Histopathological features, including relative amounts of viable tumour, necrosis, melanosis, and fibrosis (hyalinized or immature/proliferative) were assessed for associations with patient outcomes.

RESULTS

Fifty-nine patients underwent surgical resection following neoadjuvant DT. Patients achieving pCR (49%) had longer RFS compared with patients who did not (P = 0.005). Patients whose treated tumour showed any hyalinized fibrosis had longer RFS versus those without (P = 0.014), whereas necrosis (P = 0.012) and/or immature/proliferative fibrosis (P = 0.026) correlated with shorter RFS. Multivariable analyses showed absence of pCR or presence of immature fibrosis independently predicted shorter RFS. Among pCR patients, mature/hyalinized-type fibrosis correlated with improved RFS (P = 0.035).

CONCLUSIONS

The extent and composition of the pathological response following neoadjuvant DT in BRAFV600E/K mutant melanoma correlates with RFS, including pCR patients. These findings support the need for detailed histological analysis of specimens collected after neoadjuvant therapy.

Pathological assessment of resection specimens after neoadjuvant therapy for metastatic melanoma

Background

Clinical trials have recently evaluated safety and efficacy of neoadjuvant therapy among patients with surgically resectable regional melanoma metastases. To capture informative prognostic data connected to pathological response in such trials, it is critical to standardize pathologic assessment and reporting of tumor response after this treatment.

Methods

The International Neoadjuvant Melanoma Consortium meetings in 2016 and 2017 assembled pathologists from academic centers to develop consensus guidelines for pathologic examination and reporting of surgical specimens from AJCC (8th edition) stage IIIB/C/D or oligometastatic stage IV melanoma patients treated with neoadjuvant-targeted or immune therapy. Patterns of pathologic response are provided context to inform these guidelines.

Results

Based on our collective experience and guided by efforts in well-established neoadjuvant settings like breast cancer, procedures directing handling of pre- and post-neoadjuvant therapy-treated melanoma specimens are provided to facilitate comparison of findings across different trials and centers. Definitions of pathologic response are provided together with guidelines for reporting and quantifying the extent of pathologic response. Finally, the spectrum of histopathologic responses observed following neoadjuvant-targeted and immune-checkpoint therapy is described and illustrated.

Conclusions

Standardizing pathologic evaluation of resected melanoma metastases following neoadjuvant-targeted or immune-checkpoint therapy allows more robust stratification of patient outcomes. This includes recognizing the spectrum of histopathologic response patterns to neoadjuvant therapy and a standard approach to grading pathologic responses. Such an approach will facilitate comparison of results across clinical trials and inform ongoing correlative studies into the mechanisms of response and resistance to agents applied in the neoadjuvant setting.

Gut microbiome modulates response to anti-PD-1 immunotherapy in melanoma patients

Preclinical mouse models suggest that the gut microbiome modulates tumor response to checkpoint blockade immunotherapy; however, this has not been well-characterized in human cancer patients. Here we examined the oral and gut microbiome of melanoma patients undergoing anti-programmed cell death 1 protein (PD-1) immunotherapy (n = 112). Significant differences were observed in the diversity and composition of the patient gut microbiome of responders versus nonresponders. Analysis of patient fecal microbiome samples (n = 43, 30 responders, 13 nonresponders) showed significantly higher alpha diversity (P < 0.01) and relative abundance of bacteria of the Ruminococcaceae family (P < 0.01) in responding patients. Metagenomic studies revealed functional differences in gut bacteria in responders, including enrichment of anabolic pathways. Immune profiling suggested enhanced systemic and antitumor immunity in responding patients with a favorable gut microbiome as well as in germ-free mice receiving fecal transplants from responding patients. Together, these data have important implications for the treatment of melanoma patients with immune checkpoint inhibitors.

Abstract A146: Stromal neuregulin-1 modulates the response to MEK inhibitors in WT BRAF/WT NRAS (WT/WT) melanomas

MEK-ERK1/2 signaling is elevated in the majority of melanomas. While MEK inhibitors (MEKi) are FDA-approved for mutant BRAF melanoma, and have some activity against NRAS mutant tumors, they have shown little activity in patients with melanomas that are wild type for BRAF and NRAS (WT/WT). Since the tumor microenvironment (TME) often regulates drug resistance, we tested the effects of growth factors on WT/WT melanoma growth in the presence of MEKi. Neuregulin-1 (NRG1) protected patient-derived WT/WT human melanoma cell lines from growth inhibition mediated by trametinib (MEKi). Phospho-proteomic analysis and clinical grade neutralizing antibodies implicated adaptive activation of ErbB3/ErbB2 complexes in the protective effects of NRG1. NRG1 was detected in fibroblasts and cancer-associated fibroblasts (CAF), and CAF-conditioned medium activated ErbB3/ErbB2 signaling in MEK inhibited WT/WT melanoma cells. ErbB3 and ErbB2 neutralizing antibodies blocked the protective effects of fibroblast- and CAF-derived NRG1 in vitro and cooperated with MEKi to delay xenograft growth in vivo. Together our results provide a rationale for the treatment of WT/WT melanomas with the combination of MEKi and anti-ErbB3/ErbB2 antibodies.

Citation Format: Claudia Capparelli, Timothy J. Purwin, Shea Heilman, Inna Chervoneva, Michael A. Davies, Jeffrey  E. Gershenwald, Andrew E. Aplin. Stromal neuregulin-1 modulates the response to MEK inhibitors in WT BRAF/WT NRAS (WT/WT) melanomas [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A146.

Is surviving enough? Coping and impact on activities of daily living among melanoma patients with lymphoedema

We assessed the impact of lymphoedema (defined as ≥ 10% limb volume change) on quality of life (QOL), ability to perform activities of daily living (ADLs) and coping in 277 melanoma patients. Limb volume was measured prospectively, pre-operatively and every 3-6 months for 18 months post-operatively using a perometer. Three questionnaires were administered to measure QOL, coping and impact on ADLs. Statistical analyses were conducted using longitudinal logistic regression models. At 18 months, the cumulative incidence of lymphoedema was 31% in patients with upper extremity nodal basin treatment and 40% in lower extremity nodal basin treatment patients. Patients with lower extremity lymphoedema reported lower QOL scores than those with upper extremity lymphoedema. Over 18 months, both groups with mild and moderate lymphoedema showed improvement in coping [odds ratio (OR): 6.67, 95% confidence interval (CI): 3.30-13.47] and performance of ADLs (OR: 7.46, CI: 3.38-16.47). Over the course of 18 months, men were found to have poorer coping scores than women (OR: 2.91, CI: 1.35-6.27). Lymphoedema was associated with improvement in coping over time (P = 0.08) and a higher reported interference with ADLs (OR: 2.53, CI: 1.29-4.97). Patient education about lymphoedema at the time of surgical consent may improve self-efficacy and coping ability. Effective management of lymphoedema may improve patient QOL and reduce interference with ADLs.

Multimethod imaging, staging, and spectrum of manifestations of metastatic melanoma

The incidence of melanoma has been steadily increasing. Imaging plays an important role in tumour assessment as metastatic melanoma can involve multiple organs. Computed tomography (CT) is currently the most widely used technique for tumour staging, surveillance and assessment of therapeutic response, but ultrasound, magnetic resonance imaging (MRI) and positron-emission tomography (PET)-CT also play important roles in the imaging of this tumour. In this article, we review the pathways of spread, staging according to the recently updated TNM classification, pathology, typical and atypical imaging features at common and uncommon sites, and treatment of metastatic melanoma.

[Effects of vascular endothelial growth factor D on the signaling cascade of sentinel lymphatic endothelial cells from melanoma patients undergoing sentinel lymphadenectomy]

Advances in surgical treatment, including sentinel lymphadenectomy, permit the pathologic staging of regional lymph nodes most likely to contain metastasis by identifying afferent lymphatic channels, which specifically drain the primary tumor site. Recently, a new member of the angiogenic molecule in VEGF family, VEGF-D, has been identified that induces lymphangiogenesis via high-affinity binding to VEGFR-3. VEGF-D is predominantly expressed in lymphatic endothelium. We have previously developed a novel method for the isolation of anatomically-defined lymphatic endothelial cells (LECs) from human sentinel lymphatic channel during SLN biopsy. The effect of VEGF-D on the extracellular signal-regulated kinases (Erk)-1/2 and Akt signaling pathway was examined by Western blot analysis. VEGF-D (500 ng/ml) apparently upregulated phospho-p44/phospho-p42 activity in human isolated LECs by Western blot analysis, while phospho-Akt activity was not at all changed by VEGF-D exposure without the change of total p44/p42 and Akt expression. U0126 (20 microM), the MEK1/2 inhibitor, could completely block the VEGF-D induced phospholylation of Erk1/2 signaling pathway. These data demonstrate that VEGF-D induces p44/p42 in human LECs and suggests that this signaling pathway activation may be important in LEC biology and lymphoangiogenesis, which may lead to the progression of new strategies of cancer treatment.

Epidermal hyperplasia overlying human melanoma correlates with tumour depth and angiogenesis

The aim of this study was to determine whether epidermal hyperplasia overlying cutaneous human melanoma is associated with increased tumour angiogenesis, tumour growth and the potential for metastasis. Forty-two surgical specimens of cutaneous human melanoma of different depths, each containing epidermis present in the tumour-free margin, were analysed by immunohistochemistry for the expression of the pro-angiogenic molecules basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) and the anti-angiogenic molecule interferon-beta (IFN-beta). The epidermis overlying intermediate and thick (1.0-10.0 mm), but not thin (0.5-1.0 mm), melanoma specimens was hyperplastic. Although the expression level of bFGF, VEGF and IL-8 in the epidermis directly overlying the tumour was similar to that in the distant epidermis, the expression of IFN-beta was significantly decreased in keratinocytes overlying intermediate and thick, but not thin, melanomas. The microvessel density was also increased in intermediate and thick specimens. Human melanoma cells were injected subcutaneously into nude mice. The resulting tumours were used to determine the association between overlying epidermal hyperplasia and neoplastic angiogenesis. Similar to human autochthonous melanomas, epidermal hyperplasia was found only over lesions produced by metastatic cells. Although there was no change in the expression of the pro-angiogenic molecules, the expression of IFN-beta was significantly decreased in the hyperplastic epidermis. Conditioned medium collected from cultures of the metastatic cell line induced in vitro proliferation of mouse keratinocytes, whereas conditioned medium collected from cultures of the non-metastatic cell line did not. Collectively, the data demonstrate that metastatic melanoma cells induce keratinocyte proliferation, leading to decreased expression of the negative regulator of angiogenesis, IFN-beta, and hence to increased angiogenesis.

Melanoma

The presentations at the American Society of Clinical Oncology 2001 meeting reported or updated the results of phase I, II, and III randomized trials and also reported important meta-analyses and retrospective studies impacting on the management of patients with melanoma. In the treatment of early stage melanoma, the prognostic significance of pathologic status of sentinel lymph nodes was affirmed. With respect to regional nodal involvement (American Joint Committee on Cancer [AJCC] stage III), investigators presented the interim results of the United Kingdom randomized low-dose interferon (IFN) trial, and up-to-date meta-analyses of several IFN trials including a pooled analysis of the Eastern Cooperative Oncology Group trials evaluating interferon in the adjuvant setting. In the advanced disease setting (AJCC stage IV), several studies elucidated the pros and cons of biochemotherapy in patients with metastatic melanoma, with an emphasis on seeking to improve response in the central nervous system and durability of response in general. Thought provoking was new data regarding the potential for lovastatin to act as a chemopreventive agent for melanoma. Translational studies were presented, one supporting the importance of HLA-typing in developing targeted vaccine therapy. Finally, the results of a novel experimental melanoma vaccine were presented using autologous tumor-derived heat-shock protein peptide complex-96 (HSPPC-96).

Improved staging of node-negative patients with intermediate to thick melanomas (>1 mm) with the use of lymphatic mapping and sentinel lymph node biopsy

BACKGROUND

Elective lymph node dissection (ELND) may contribute to a survival benefit in certain stratified subsets of melanoma patients. We hypothesized that lymphatic mapping and sentinel lymph node (SLN) biopsy (with complete node dissection if metastases are present) may improve both staging and survival of patients with clinically negative nodes, without subjecting all patients to the morbidity associated with complete ELND.

METHODS

We reviewed the data for all 14,914 N0 patients of the AJCC Melanoma Staging Database to determine the effect of SLN biopsy and ELND on staging and survival.

RESULTS

Retrospective analysis revealed that there was an apparent statistically significant survival advantage to SLN biopsy in patients with melanomas > 1 mm (n = 9024; 68.5% and 26.2% reduction in mortality compared with patients staged to be N0 by clinical exam and ELND, respectively; P < .0001). Five-year survivals were 90.5%, 77.7%, and 69.8%, respectfully, for patients staged by SLN biopsy (n = 2552), ELND (n = 2014), and clinical examination alone (n = 5192). The survival advantage of SLN biopsy was statistically significant for each T-stage category (T2, T3, and T4) and ulceration status. There was no advantage to SLN biopsy in patients with melanomas <1 mm (n = 5890).

CONCLUSIONS

SLN biopsy provides more accurate staging and may contribute to a survival benefit in populations of patients with melanoma.

Patterns of regional and distant metastasis in patients with conjunctival melanoma: experience at a cancer center over four decades

OBJECTIVE

The regional lymph nodes generally are believed to be the most common first site of metastasis for conjunctival malignant melanoma, but the pattern of nodal metastasis in this disease has not been well established. The goal of this study was to determine the frequency, location, and timing of regional lymph node metastasis in patients with conjunctival melanoma treated at one cancer center over four decades.

DESIGN

Retrospective case series.

PARTICIPANTS

Twenty-seven patients.

METHODS

The clinical records of 27 patients with conjunctival malignant melanoma were reviewed retrospectively.

MAIN OUTCOME MEASURES

The rates of local conjunctival recurrence, regional nodal metastasis, and distant metastasis were analyzed along with overall survival. The follow-up time ranged from 2.5 to 17 years (median, 6 years).

RESULTS

Eleven patients (41%) experienced clinical regional lymph node metastasis 1.5 to 6.0 years (mean, 3.2 years) after the initial diagnosis. The involved lymphatics were the preauricular (parotid) nodes in 8 patients (73%), the submandibular nodes in 1 patient (9%), and the deeper cervical nodes in 2 patients (18%). In seven patients (26%), distant metastasis developed without evidence of prior or concurrent regional nodal disease. Patients in whom distant metastasis developed without clinical evidence of regional nodal involvement were more likely to have had local conjunctival recurrence (P = 0.03) and a higher number of local recurrences (P = 0.05) compared with patients with regional lymph nodes as the site of first metastasis. The 5- and 10-year overall survival rates were 74% and 41%, respectively.

CONCLUSIONS

Regional lymph node metastasis occurred in a higher percentage of patients with conjunctival malignant melanoma than has been reported previously. Preauricular lymph nodes were most commonly involved. Distant metastasis without prior or concurrent lymph node involvement was not a rare event.

Sentinel lymph node biopsy for conjunctival melanoma

OBJECTIVE

To investigate the feasibility and safety of preoperative lymphoscintigraphy and sentinel lymph node (SLN) biopsy for conjunctival melanoma.

METHODS

A 49-year-old man with a biopsy-proven malignant melanoma of the conjunctiva (caruncle) underwent preoperative lymphoscintigraphy and SLN biopsy using a technique in which both isosulfan blue dye and technetium Tc 99 m sulfur colloid were injected in the subconjunctival space around the primary lesion. The conjunctival melanoma was excised just before identification and removal of the SLNs. The SLNs were excised along with concomitant dissection of their associated lymph node basins. The SLNs were evaluated histologically using serial sectioning and immunohistochemical staining with antisera against the S-100 protein and the melanoma antigen HMB-45.

RESULTS

Three SLNs were identified in the left submandibular and the left upper and middle jugular lymph node basins during the preoperative lymphoscintigraphy. The same three SLNs were successfully identified in the operating room. The SLNs were histologically negative, and the immunohistochemical staining against S-100 and HMB-45 was also negative. We did not observe any immediate adverse effects on the globe or the periocular structures from lymphatic mapping and SLN biopsy. By 24 hours after injection of blue dye, only a faint trace of blue was visible on the ocular surface.

CONCLUSIONS

Preoperative lymphoscintigraphy and SLN biopsy can be performed safely in patients with conjunctival melanoma. A larger study is planned to determine the sensitivity of this technique for the detection of occult regional nodal disease in patients with conjunctival melanoma.

Final version of the American Joint Committee on Cancer staging system for cutaneous melanoma

PURPOSE

To revise the staging system for cutaneous melanoma under the auspices of the American Joint Committee on Cancer (AJCC).

MATERIALS AND METHODS

The prognostic factors analysis described in the companion publication (this issue), as well as evidence from the published literature, was used to assemble the tumor-node-metastasis criteria and stage grouping for the melanoma staging system.

RESULTS

Major changes include (1) melanoma thickness and ulceration but not level of invasion to be used in the T category (except for T1 melanomas); (2) the number of metastatic lymph nodes rather than their gross dimensions and the delineation of clinically occult (ie, microscopic) versus clinically apparent (ie, macroscopic) nodal metastases to be used in the N category; (3) the site of distant metastases and the presence of elevated serum lactic dehydrogenase to be used in the M category; (4) an upstaging of all patients with stage I, II, and III disease when a primary melanoma is ulcerated; (5) a merging of satellite metastases around a primary melanoma and in-transit metastases into a single staging entity that is grouped into stage III disease; and (6) a new convention for defining clinical and pathologic staging so as to take into account the staging information gained from intraoperative lymphatic mapping and sentinel node biopsy.

CONCLUSION

This revision will become official with publication of the sixth edition of the AJCC Cancer Staging Manual in the year 2002.

Prognostic factors analysis of 17,600 melanoma patients: validation of the American Joint Committee on Cancer melanoma staging system

PURPOSE

The American Joint Committee on Cancer (AJCC) recently proposed major revisions of the tumor-node-metastases (TNM) categories and stage groupings for cutaneous melanoma. Thirteen cancer centers and cancer cooperative groups contributed staging and survival data from a total of 30,450 melanoma patients from their databases in order to validate this staging proposal.

PATIENTS AND METHODS

There were 17,600 melanoma patients with complete clinical, pathologic, and follow-up information. Factors predicting melanoma-specific survival rates were analyzed using the Cox proportional hazards regression model. Follow-up survival data for 5 years or longer were available for 73% of the patients.

RESULTS

This analysis demonstrated that (1) in the T category, tumor thickness and ulceration were the most powerful predictors of survival, and the level of invasion had a significant impact only within the subgroup of thin (< or = 1 mm) melanomas; (2) in the N category, the following three independent factors were identified: the number of metastatic nodes, whether nodal metastases were clinically occult or clinically apparent, and the presence or absence of primary tumor ulceration; and (3) in the M category, nonvisceral metastases was associated with a better survival compared with visceral metastases. A marked diversity in the natural history of pathologic stage III melanoma was demonstrated by five-fold differences in 5-year survival rates for defined subgroups. This analysis also demonstrated that large and complex data sets could be used effectively to examine prognosis and survival outcome in melanoma patients.

CONCLUSION

The results of this evidence-based methodology were incorporated into the AJCC melanoma staging as described in the companion publication.

Dominant-negative transcription factor AP-2 augments SB-2 melanoma tumor growth in vivo

We have previously demonstrated that the transition of melanoma to the metastatic phenotype is associated with a loss of expression of the transcription factor AP-2. To further investigate the role of AP-2 in the progression of human melanoma, we attempted to inactivate AP-2 in primary cutaneous SB-2 melanoma cells by using a dominant-negative AP-2, or AP-2B, gene. AP-2B is an alternatively spliced AP-2 variant capable of inhibiting AP-2 trans-activator function. Stable transfection of primary cutaneous melanoma SB-2 cells with the dominant-negative AP-2B gene was confirmed by RT--PCR and Northern blot analyses. Electromobility shift assay using nuclear extracts from these cell lines demonstrated decreased functional binding of AP-2B-transfected cells to the AP-2 consensus binding sequence compared with neo-transfected controls. In addition, CAT activity driven by a construct containing the AP-2 consensus binding sequence was downregulated in the AP-2B transfected cells, indicating AP-2 activity was quenched in the transfected cells. Orthotopic (subcutaneous) injection of the dominant-negative (AP-2B)-transfected cell lines into nude mice increased their tumorigenicity compared to control neo-transfected cells. The AP-2B-transfected cells displayed an increase in MMP-2 expression (by Northern blot) and MMP-2 activity (by zymography), which resulted in an increase in invasiveness through Matrigel-coated filters. The AP-2B-transfected tumors also displayed an increase in MMP-2 expression, microvessel density, and angiogenesis in vivo. These results demonstrate that inactivation of AP-2 contributes to the progression of melanoma, at least partially via deregulation of the MMP-2 gene.

Sentinel lymph node biopsy for melanoma: controversy despite widespread agreement

Although sentinel lymph node (SLN) biopsy for melanoma has been adopted throughout the United States and abroad as a standard method of determining the pathologic status of the regional lymph nodes, some controversy still exists regarding the validity and utility of this procedure. SLN biopsy is a minimally invasive procedure, performed on an outpatient basis at the time of wide local excision of the melanoma, with little morbidity. Numerous studies have documented the accuracy of this procedure for identifying nodal metastases. There are four major reasons to perform SLN biopsy. First, SLN biopsy improves the accuracy of staging and provides valuable prognostic information for patients and physicians to guide subsequent treatment decisions. Second, SLN biopsy facilitates early therapeutic lymph node dissection for those patients with nodal metastases. Third, SLN biopsy identifies patients who are candidates for adjuvant therapy with interferon alfa-2b. Fourth, SLN biopsy identifies homogeneous patient populations for entry onto clinical trials of novel adjuvant therapy agents. Overall, the benefit of accurate nodal staging obtained by SLN biopsy far outweighs the risks and has important implications for patient management.

Sentinel lymph node biopsy for melanoma: how many radioactive nodes should be removed?

BACKGROUND

Sentinel lymph node (SLN) biopsy has become a standard method of staging patients with cutaneous melanoma. Sentinel lymph node biopsy usually is performed by intradermal injection of a vital blue dye (isosulfan blue) plus radioactive colloid (technetium sulfur colloid) around the site of the tumor. Intraoperative gamma probe detection has been shown to improve the rate of SLN identification compared to the use of blue dye alone. However, multiple sentinel nodes often are detected using the gamma probe. It is not clear whether these additional lymph nodes represent true sentinel nodes, or second-echelon lymph nodes that have received radiocolloid particles that have passed through the true sentinel node. This analysis was performed to determine the frequency with which these less radioactive lymph nodes contain metastatic disease when the most radioactive, or "hottest," node does not.

MATERIALS AND METHODS

In the Sunbelt Melanoma Trial, 1184 patients with cutaneous melanoma of Breslow thickness 1.0 mm or more had sentinel lymph nodes identified. Sentinel lymph node biopsy was performed by injection of technetium sulfur colloid plus isosulfan blue dye in 99% of cases. Intraoperative determination of the degree of radioactivity of sentinel nodes (ex vivo) was measured, as well as the degree of blue dye staining.

RESULTS

Sentinel nodes were identified in 1373 nodal basins in 1184 patients. A total of 288 of 1184 patients (24.3%) were found to have sentinel node metastases detected by histology or immunohistochemistry. Nodal metastases were detected in 306 nodal basins in these 288 patients. There were 175 nodal basins from 170 patients in which at least one positive sentinel node was found and more than one sentinel node was harvested. Blue dye staining was found in 86.3% of the histologically positive sentinel nodes and 66.4% of the negative sentinel nodes. In 40 of 306 positive nodal basins (13.1%), the most radioactive sentinel node was negative for tumor when another, less radioactive, sentinel node was positive for tumor. In 20 of 40 cases (50%), the less radioactive positive sentinel node contained 50% or less of the radioactive count of the hottest lymph node. The cervical lymph node basin was associated with an increased likelihood of finding a positive sentinel node other than the hottest node.

CONCLUSIONS

If only the most radioactive sentinel node in each basin had been removed, 13.1% of the nodal basins with positive sentinel nodes would have been missed. It is recommended that all blue lymph nodes and all nodes that measure 10% or higher of the ex vivo radioactive count of the hottest sentinel node should be harvested for optimal detection of nodal metastases.

Significance of plasma cytokine levels in melanoma patients with histologically negative sentinel lymph nodes

INTRODUCTION

Although sentinel lymph node (SLN) status is the most powerful predictor of prognosis in patients with clinically localized melanoma, a proportion of melanoma patients with histologically negative SLNs will still recur. It is hypothesized that tumor response may be altered or mediated by specific cytokines. We therefore investigated whether levels of IL-4, IL-6, IL-10, TNF-alpha, or IFN-gamma would predict disease recurrence in melanoma patients with histologically negative SLNs.

METHODS

This prospective cohort study involved 218 patients with clinically localized melanoma who underwent a histologically negative SLN biopsy. Preoperative plasma cytokine levels were determined by enzyme-linked immunosorbent assay on these patients, as well as on 90 healthy controls. Kaplan-Meier life tables were constructed, and Cox proportional hazards analyses were performed to assess predictors of disease-free survival (DFS).

RESULTS

At a median follow-up of 43 months, 33 of 218 patients (15%) had suffered disease recurrence. Melanoma patients had significant elevations of IL-4, IL-6, and IL-10 compared to healthy controls; levels of IFN-gamma were less elevated in melanoma patients compared to controls. Despite this, melanoma patients with detectable IFN-gamma levels were at significantly higher risk for recurrence compared to patients with undetectable levels (5-year DFS 70% vs. 86%, P = .03). On multivariate analysis including standard melanoma prognostic factors, only tumor thickness (P = .004) and the presence of detectable IFN-gamma levels (P = .05) were significant independent prognostic factors for disease-free survival.

CONCLUSIONS

Among melanoma patients with clinically localized disease who have undergone a histologically negative SLN biopsy, presence of a detectable plasma level of IFN-gamma is an independent predictor of disease recurrence. Elevated levels of IFN-gamma may identify a group of early-stage melanoma patients who are more likely to have recurrence of disease and who may benefit from adjuvant therapies, including immunotherapies.

Classification and staging of melanoma

Although a standardized and uniformly accepted cancer staging system is an essential and fundamental requirement to enable meaningful comparisons across patient populations, the sometimes capricious biologic behavior of melanoma makes developing such a staging system particularly difficult. Since the earliest well-documented attempts at classifying patients with cutaneous melanoma were described more than 50 years ago, the identification of increasingly powerful prognostic factors has led to sequential modifications of the cutaneous melanoma staging system. The current AJCC staging system is based on relatively well-established prognostic factors; however, several recent reports have identified additional prognostic factors not included in the current system, and other studies support the re-evaluation of some of the currently employed staging criteria. Some of the more controversial areas include the relevance of level of invasion versus tumor thickness, optimal cutoffs for tumor thickness, importance of ulceration, the grouping of satellites with in-transit metastases, the inclusion of microsatellites and local recurrences as a separate staging criterion, the replacement of size of nodal mass with number of positive nodes, the importance of nodal metastases in more than one nodal basin, and the prognostic significance of distant metastases. Future modifications of the staging system are anticipated to better incorporate these observations. Stage-specific staging recommendations for the patient with melanoma provide the clinician with a framework to most efficiently assess extent of disease in an era of cost-conscious clinical practice. In the asymptomatic patient with primary melanoma (stage I or II), we recommend a chest roentgenogram and evaluation of alkaline phosphatase and LDH levels; extensive radiologic evaluations are not indicated, because the rate of detection in this population is extremely low. Additional staging information should also be obtained by the technique of lymphatic mapping and sentinel lymphadenectomy. For patients with local-regional disease (stage III, satellites, and local recurrence), a selective approach to imaging studies is warranted. For this patient population, we recommend complete blood count, liver function tests including alkaline phosphatase and LDH, a chest roentgenogram, and a CT scan of the abdomen. Although the yield of these tests, particularly CT of the abdomen, in detecting distant metastases in asymptomatic patients is low, they may identify false-positive abnormalities and provide an important baseline for future studies in this high-risk population. For patients with disease below the waist or in the head and neck region, we recommend CT of the pelvis and CT of the neck, respectively. Additional studies should be done only if clinically indicated. Finally, patients with known systemic disease (stage IV) should be more comprehensively evaluated, because the likelihood of detecting asymptomatic metastases is higher. Accordingly, in addition to the work-up outlined previously for stage III patients, we also perform a CT scan of the chest and MR imaging of the brain; other studies (e.g., bone scan, gastrointestinal series) are performed on the basis of symptoms.

How many lymph nodes are enough during sentinel lymphadenectomy for primary melanoma?

BACKGROUND

Sentinel lymph node (SLN) biopsy has been shown to reliably identify nodal metastases and the subsequent need for further surgical and adjuvant therapy in patients with cutaneous melanoma. Although SLN identification rates have improved with the addition of radioactive colloid to the blue dye technique, it remains unclear how many lymph nodes should be removed to accurately determine the histologic status of the nodal basin. The objective of this study was to determine the optimal extent of SLN biopsy in these patients.

METHODS

The records of 633 consecutive patients with melanoma (765 nodal basins) whose primary treatment included SLN biopsy with the use of a combination of blue dye and technetium Tc 99 labeled sulfur colloid were reviewed. SLN biopsy consisted of the removal of all of the blue-stained nodes and all nodes with radiotracer uptake activity of at least twice background.

RESULTS

SLN biopsy was successful in 765 of 772 basins (99%). A mean of 1.9 SLNs (median, 2 SLNs) per basin were excised. At least 3 SLNs were removed in 176 basins (23%). The overall histologic status of a basin was always established by the first or second SLN harvested (ie, in no patient was the third or subsequent SLN positive when 1 of the first 2 was not). Of the 124 basins containing lymphatic metastases, the SLN that contained the maximal radiotracer uptake (hottest) and/or stained blue was pathologically positive in 118 basins (95%). In only 6 of the 124 positive basins (5%) was the sole evidence of occult nodal metastases identified in an SLN that was neither blue-stained nor the hottest. All but 1 of these SLNs had counts that were at least 66% of the hottest node in the basin.

CONCLUSIONS

With a combined modality approach to SLN biopsy, removal of more than 2 SLNs did not provide information that upstaged any patient with primary melanoma. Removal of additional nonblue SLN(s) that contained radioactive counts of at least twice background but lower than two thirds of the SLNs with maximal radiotracer uptake affected patient management in less than 0.2% of all cases. These findings may be helpful in minimizing the extent of surgery and perhaps in reducing the costs and resource use associated with operating room time and pathologic examination.

Clinical classification and staging

The identification of increasingly powerful prognostic factors has led to sequential modifications of the cutaneous melanoma staging system. Changes in the staging system are anticipated as more refined prognostic factors are identified. This article provides an overview of the system, including a brief history and an introduction to recent advances in staging of patients with primary melanoma (i.e., sentinel lymphadenectomy). Practical recommendations for a stage-specific workup for the patient, which are especially important given the need for quality care in an increasingly cost-conscious environment, are provided.

Significance of multiple nodal basin drainage in truncal melanoma patients undergoing sentinel lymph node biopsy

BACKGROUND

Although previous studies have demonstrated that truncal site is associated with an adverse prognosis, explanations for such risk are lacking. In addition, the number of nodal basins as well as the number of lymph nodes containing regional metastases are important prognostic factors in these patients. Because the lymphatic drainage pattern of truncal melanoma often includes more than one basin, we designed a study to evaluate (1) whether patients with multiple nodal basin drainage (MNBD) were at an increased risk of lymph node metastases identified by sentinel lymph node (SLN) biopsy, and (2) whether the histological status of an individual basin reliably predicted the status of the other draining basins in patients with MNBD.

METHODS

The records of 295 consecutive truncal melanoma patients who were managed primarily with intraoperative lymphatic mapping and SLN biopsy, between 1991 and 1997, were reviewed. All patients underwent preoperative lymphoscintigraphy, which established the number and location of draining nodal basins. Univariate and multivariate analyses of relevant clinicopathological factors were performed to assess which factors may predict the presence of a pathologically positive SLN.

RESULTS

At least one SLN was identified in 281 patients. MNBD was present in 86 (31%) patients, and a pathologically positive SLN was found in 56 (20%) patients. By multivariate analysis, the presence of MNBD (relative risk = 1.9; P = .03), tumor thickness (P = .007), and tumor ulceration (relative risk = 2.4; P = .01) were significant independent risk factors for the presence of at least one pathologically positive SLN. SLN pathology in one basin did not predict the histology of other basins in 19 (22%) of 86 patients with MNBD.

CONCLUSIONS

MNBD is independently associated with an increased risk of nodal metastases in truncal melanoma patients. Because the histological status of an individual basin did not reliably predict the status of the other draining basins in patients with MNBD, it is important to adequately identify and completely assess all nodal basins at risk, as defined by lymphoscintigraphy, in truncal melanoma patients.

Regional nodal basin control is not compromised by previous sentinel lymph node biopsy in patients with melanoma

BACKGROUND

Regional nodal basin control is an important goal of lymphadenectomy in the management of melanoma patients with nodal disease. The purpose of this study was to determine if previous sentinel lymph node (SLN) biopsy compromises the ultimate regional nodal control achieved by subsequent therapeutic lymph node dissection in melanoma patients with microscopic lymph node metastases.

METHODS

A surgical melanoma database and hospital records were reviewed for 602 patients with primary cutaneous melanoma who underwent successful lymphatic mapping and SLN biopsy between 1991 and 1997.

RESULTS

A total of 105 (17%) of 602 patients had histologically positive SLNs and were offered therapeutic lymphadenectomy; 101 (96%) underwent this procedure. Thirty-six patients (36%) developed recurrent melanoma at one or more sites. The median follow-up period was 30 months. Recurrence in the previously dissected nodal basin was observed in 10 patients (10%); none had recurrence at only that site. Nodal basin disease appeared after local/in-transit (n = 6) or distant (n = 1) failure in seven patients and, as a component of the first site of failure, simultaneously with local/in-transit (n = 2) or distant (n = 1) recurrence in three patients.

CONCLUSIONS

Nodal basin failure after lymphadenectomy in patients who underwent previous biopsy of a histologically positive SLN is primarily a function of aggressive locoregional disease rather than of contamination from previous surgery. Because regional nodal control was comparable with that in other series, we conclude that SLN biopsy with selective lymphadenectomy does not compromise regional nodal basin control.

A new American Joint Committee on Cancer staging system for cutaneous melanoma

The Melanoma Staging Committee of the AJCC has proposed major revisions of the melanoma TNM and stage grouping criteria. The committee members represent most of the major cooperative groups and cancer centers worldwide with a special interest in melanoma; the committee also collectively has had clinical experience with over 40,000 patients. The new staging system better reflects independent prognostic factors that are used in clinical trials and in reporting the outcomes of various melanoma treatment modalities. Major revisions include 1) melanoma thickness and ulceration, but not level of invasion, to be used in the T classification; 2) the number of metastatic lymph nodes, rather than their gross dimensions, the delineation of microscopic versus macroscopic lymph node metastases, and presence of ulceration of the primary melanoma to be used in the N classification; 3) the site of distant metastases and the presence of elevated serum LDH, to be used in the M classification; 4) an upstaging of all patients with Stage I,II, and III disease when a primary melanoma is ulcerated; 5) a merging of satellite metastases around a primary melanoma and in-transit metastases into a single staging entity that is grouped into Stage III disease; and 6) a new convention for defining clinical and pathologic staging so as to take into account the new staging information gained from intraoperative lymphatic mapping and sentinel lymph node biopsy. The AJC Melanoma Staging Committee invites comments and suggestions regarding this proposed staging system before a final recommendation is made.

Role for lymphatic mapping and sentinel lymph node biopsy in patients with thick (> or = 4 mm) primary melanoma

BACKGROUND

Historically, patients with thick (> or =4 mm) primary melanoma have not been considered candidates for elective lymph node dissection, because their risk for occult distant disease is significant. Sentinel lymph node (SLN) biopsy offers an alternative approach to assess disease in the regional nodal basin, but no studies have specifically addressed the role for this technique in patients with thick melanoma. Although adjuvant therapy benefits patients who develop nodal metastases, data that supports its routine use in all patients with thick melanoma is both limited and controversial. This study was performed to determine whether pathological status of the SLN is an important risk factor in this heterogeneous group and, thus, provides a rationale for SLN biopsy.

METHODS

The records of 131 patients with primary cutaneous melanoma whose primary tumors were at least 4 mm thick and who underwent lymphatic mapping and SLN biopsy were reviewed. Several known prognostic factors, i.e., tumor thickness, ulceration, Clark level, location, sex, as well as SLN pathological status were analyzed with respect to disease-free and overall survival.

RESULTS

Lymphatic mapping and SLN biopsy was successful in 126 (96%) of 131 patients who underwent the procedure. In 49 patients (39%), the SLN biopsy was positive by conventional histology, although it was negative in 77 patients (61%). The median follow-up was 3 years. Although presence of ulceration and SLN status were independent prognostic factors with respect to disease-free and overall survival, SLN status was the most powerful predictor of overall survival by univariate and multivariate analyses.

CONCLUSIONS

Lymphatic mapping and SLN biopsy is a highly accurate method of staging lymph node basins at risk for regional metastases in patients with thick melanoma and identifies those patients who may benefit from earlier lymphadenectomy as well as patients with a more favorable prognosis. Pathological status of the SLN in these patients with clinically negative nodes is the most important prognostic factor for survival and is essential to establish stratification criteria for future adjuvant trials in this high-risk group.

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.

Synchronous elective contralateral mastectomy and immediate bilateral breast reconstruction in women with early-stage breast cancer

BACKGROUND

The role of elective contralateral mastectomy (ECM) in women with early-stage breast cancer who elect or require an ipsilateral mastectomy and desire immediate bilateral breast reconstruction (IBR) is an intellectual and emotional dilemma for both patient and physician. In an attempt to clarify the rationale for this approach, we reviewed our experience with ECM and IBR and evaluated operative morbidity, the incidence of occult contralateral breast cancer, and patterns of recurrence.

PATIENTS AND METHODS

We retrospectively reviewed the records of 155 patients with primary unilateral breast cancer (stage 0, I, or II) and negative findings on physical and mammographic examinations of the contralateral breast who underwent ipsilateral mastectomy and simultaneous ECM with IBR between 1987 and 1995.

RESULTS

The median age of the patients was 46 years (range, 25 to 69 years). Clinical stage at diagnosis was stage 0, I, and II in 19.4%, 54.2%, and 26.4% of patients, respectively. Factors likely to influence the use of ECM were family history of breast cancer in first-degree relatives (30%), any family history of breast cancer (56%), difficulty anticipated in contralateral breast surveillance (48%), associated lobular carcinoma in situ (23%), multicentric primary tumor (28%), significant reconstructive issues (14%), and failure of mammographic identification of the primary tumor (16%). Skin-sparing mastectomies were performed in 81% of patients. Overall, 70% of patients underwent reconstruction using autogenous tissue transfer. Reoperations for suspected anastomotic thrombosis were performed in seven patients. Two patients experienced significant partial or complete flap loss. Histopathologic findings in the ECM specimen were as follows: benign, 80% of patients; atypical ductal hyperplasia, 12% of patients; lobular carcinoma in situ, 6.5% of patients; ductal carcinoma in situ, 2.7% of patients; and invasive carcinoma, 1.3% of patients. Eighteen patients (12%) had evidence of locoregional or distant recurrences, with a median follow-up of 3 years. In one patient (0.6%), invasive ductal carcinoma developed on the side of the elective mastectomy.

CONCLUSIONS

The use of ECM and IBR cannot be justified if the only oncologic criterion considered is the incidence of occult synchronous contralateral disease. However, in a highly selected population of young patients with a difficult clinical or mammographic examination and an increased lifetime risk of developing a second primary tumor, ECM and IBR is a safe approach.

Improved sentinel lymph node localization in patients with primary melanoma with the use of radiolabeled colloid

BACKGROUND

The purpose of this study was to determine whether the sentinel lymph node (SLN) localization technique, which uses blue dye and 99mTc-labeled sulfur colloid, provides advantages over blue dye alone in the management of patients with stages I and II cutaneous melanoma.

METHODS

The records of 626 consecutive patients with melanoma who underwent lymphatic mapping and SLN biopsy between 1991 and 1997 at the M.D. Anderson Cancer Center were reviewed. Lymphatic mapping was performed with isosulfan blue dye alone (n = 252) or in combination with 99mTc-labeled sulfur colloid accompanied by a hand-held gamma probe (n = 374). SLNs were defined as those that stained blue or demonstrated increased focal radiotracer uptake.

RESULTS

SLN identification rates improved from 87% (dye alone) to 99% (dye and colloid) (P < .0001) with the combined technique in all anatomic sites examined. The mean number of SLNs harvested from each basin was significantly greater in the patients mapped with dye and colloid (1.74 vs 1.31; P < .0001). Occult metastatic disease was identified in 17.5% of all patients and did not significantly differ between groups. In 92% of patients who had at least one positive SLN and were mapped with both agents, lymphatic metastases were identified in the SLN that contained the greatest radiotracer uptake.

CONCLUSIONS

SLN identification is enhanced by the addition of radiolabeled sulfur colloid and intraoperative use of the hand-held gamma probe and may identify SLNs missed by the blue dye alone. These data support the combined use of radiolabeled sulfur colloid and blue dye in lymphatic mapping procedures to improve the nodal staging of stages I and II melanoma.

Classification and staging of melanoma

Although a standardized and uniformly accepted cancer staging system is an essential and fundamental requirement to enable meaningful comparisons across patient populations, the sometimes capricious biologic behavior of melanoma makes developing such a staging system particularly difficult. Since the earliest well-documented attempts at classifying patients with cutaneous melanoma were described more than 50 years ago, the identification of increasingly powerful prognostic factors has led to sequential modifications of the cutaneous melanoma staging system. The current AJCC staging system is based on relatively well-established prognostic factors; however, several recent reports have identified additional prognostic factors not included in the current system, and other studies support the re-evaluation of some of the currently employed staging criteria. Some of the more controversial areas include the relevance of level of invasion versus tumor thickness, optimal cutoffs for tumor thickness, importance of ulceration, the grouping of satellites with in-transit metastases, the inclusion of microsatellites and local recurrences as a separate staging criterion, the replacement of size of nodal mass with number of positive nodes, the importance of nodal metastases in more than one nodal basin, and the prognostic significance of distant metastases. Therefore, future modifications of the staging system are anticipated to better incorporate these observations. Stage-specific staging recommendations for the patient with melanoma provide the clinician with a framework to most efficiently assess extent of disease in an era of cost-conscious clinical practice. In the asymptomatic patient with primary melanoma (stage I or II), we recommend a chest roentgenogram and evaluation of alkaline phosphatase and LDH levels; extensive radiologic evaluations are not indicated, because the rate of detection in this population is extremely low. Additional staging information should also be obtained by the technique of lymphatic mapping and sentinel lymphadenectomy. For patients with local-regional disease (stage III, satellites, and local recurrence), a selective approach to imaging studies is warranted. For this patient population, we recommend complete blood count, liver function tests including alkaline phosphatase and LDH, a chest roentgenogram, and a CT scan of the abdomen. Although the yield of these tests, particularly CT of the abdomen, in detecting distant metastases in asymptomatic patients is low, they may identify false-positive abnormalities and provide an important baseline for future studies in this high-risk population. For patients with disease below the waist or in the head and neck region, we recommend CT of the pelvis and CT of the neck, respectively. Additional studies should be done only if clinically indicated. Finally, patients with known systemic disease (stage IV) should be more comprehensively evaluated, because the likelihood of detecting asymptomatic metastases is higher. Accordingly, in addition to the work-up outlined previously for stage III patients, we also perform a CT scan of the chest and MR imaging of the brain; other studies (e.g., bone scan, gastrointestinal series) are performed on the basis of symptoms.

Loss of AP-2 results in up-regulation of MCAM/MUC18 and an increase in tumor growth and metastasis of human melanoma cells

MCAM/MUC18 is a cell-surface glycoprotein of 113 kDa, originally identified as a melanoma antigen, whose expression is associated with tumor progression and the development of metastatic potential. We have previously shown that enforced expression of MCAM/MUC18 in primary cutaneous melanoma led to increased tumor growth and metastatic potential in nude mice. The mechanism for up-regulation of MCAM/MUC18 during melanoma progression is unknown. Here we show that up-regulation of MCAM/MUC18 expression in highly metastatic cells correlates with loss of expression of the transcription factor AP-2. The MCAM/MUC18 promoter contains four binding sites for AP-2, and electrophoretic mobility shift assay gels demonstrated that the AP-2 protein bound directly to the MCAM/MUC18 promoter. Transfection of AP-2 into highly metastatic A375SM melanoma cells (AP-2-negative and MCAM/MUC18-positive) inhibited MCAM/MUC18 promoter-driven chloramphenicol acetyltransferase reporter gene in a dose-dependent manner. MCAM/MUC18 mRNA and protein expression were down-regulated in AP-2-transfected but not in control cells. In addition, re-expression of AP-2 in A375SM cells inhibited their tumorigenicity and metastatic potential in nude mice. These results indicate that the expression of MCAM/MUC18 is regulated by AP-2 and that enforced AP-2 expression suppresses tumorigenicity and metastatic potential of human melanoma cells, possibly by down-regulating MCAM/MUC18 gene expression. Since AP-2 also regulates other genes that are involved in the progression of human melanoma such as c-KIT, E-cadherin, MMP-2, and p21(WAF-1), we propose that loss of AP-2 is a crucial event in the development of malignant melanoma.

Surgical margins and prognostic factors in patients with thick (>4mm) primary melanoma

BACKGROUND

Randomized trials have demonstrated the efficacy of 1- and 2-cm excision margins for thin and intermediate-thickness melanomas, respectively. The optimal margin of excision for thick melanomas is still unknown, however. We evaluated whether the margins used for intermediate-thickness melanomas can be applied safely to thicker lesions.

METHODS

The charts of 278 patients with thick primary melanomas treated between 1985 and 1996 were retrospectively reviewed. Patients with distant metastases at presentation or with follow-up less than 6 months were excluded. Median follow-up was 27 months. Known melanoma prognostic factors and excision margins were evaluated for their impact on local recurrence (LR), disease-free survival (DFS), and overall survival (OS).

RESULTS

Median tumor thickness was 6.0 mm, and 57% were ulcerated. At presentation, 201 patients (72%) were node negative and 77 (28%) were node positive (palpable or occult). The 5-year OS and DFS rates were 55% and 30%, respectively. The LR rate for all patients was 12%. Although nodal status, thickness, and ulceration were significantly associated with OS by multivariate analysis, neither LR nor excisional margin (<2 cm vs. >2 cm) significantly affected DFS or OS in these patients.

CONCLUSIONS

Because margins of excision greater than 2 cm do not improve LR, DFS, or OS compared to a margin of 2 cm or less, a 2-cm margin of excision is adequate for patients with thick melanoma. Because nodal status is a significant prognostic factor in these patients, staging by sentinel node biopsy should be considered in patients with thick melanomas and clinically negative nodal basins to allow proper entry and stratification in adjuvant therapy trials.

Patterns of recurrence following a negative sentinel lymph node biopsy in 243 patients with stage I or II melanoma

PURPOSE

To determine the patterns of recurrence and causes of regional nodal basin failure in stage I or II melanoma patients who had a histologically negative sentinel lymph node (SLN) and whose regional nodal basins were not dissected following lymphatic mapping and SLN biopsy.

PATIENTS AND METHODS

The records of 344 patients with primary cutaneous melanoma who underwent lymphatic mapping and SLN biopsy between 1991 and 1995 at The University of Texas M.D. Anderson Cancer Center were reviewed. Of 322 patients who underwent successful lymphatic mapping procedures, 270 had histologically negative SLNs; mapped nodal basins were observed without further surgical intervention in 243 of these 270 patients. Recurrence patterns were analyzed from this cohort and a histologic reevaluation of all previously identified SLNs on which a biopsy had been taken was performed in patients who developed recurrent disease.

RESULTS

Of 243 patients with a histologically negative SLN, 27 (11%) developed local, in-transit, regional nodal, and/or distant metastases after a median follow-up time of 35 months. Ten patients (4.1%) developed a nodal recurrence in the previously mapped basin, either solely or as a component of the first site of recurrence. Detailed analysis of the SLNs in these 10 patients demonstrated evidence of occult metastases in 80% by serial sectioning or immunohistochemical staining.

CONCLUSION

Regional nodal failures in melanoma patients following a negative SLN biopsy are infrequent and to date have most commonly occurred because conventional histologic evaluation was unable to identify occult metastatic disease. These data provide further evidence that lymphatic mapping and SLN biopsy accurately reflect the status of the regional nodal basin. Specialized pathologic techniques are necessary to reduce further the already low false-negative rates and to improve disease staging.

Expression of interleukin-8 by human melanoma cells up-regulates MMP-2 activity and increases tumor growth and metastasis

Expression of interleukin-8 (IL-8) by human melanoma cells correlates with their metastatic potential. Moreover, UV-B irradiation of primary cutaneous melanoma cells induces IL-8 mRNA and protein production and increases both tumor growth and metastasis in nude mice. Although IL-8 has been shown to be an angiogenic factor, the biological consequences of increased IL-8 production by melanoma cells and the role of IL-8 in the metastatic process remains unclear. The purpose of this study was to determine the role of IL-8 in tumor growth and metastasis of human melanoma cells. Nonmetastatic SB-2 melanoma cells with negligible levels of IL-8 were transfected with IL-8 cDNA and subsequently analyzed for changes in their tumorigenic and metastatic potential. Enforced expression of IL-8 rendered the melanoma cells highly tumorigenic and increased their metastatic potential as compared with parental and control transfected cells. The IL-8-transfected cells displayed up-regulation in M(r) 72,000 collagenase type IV (MMP-2) mRNA and collagenase activity and increased invasiveness through Matrigel-coated filters. Moreover, when the MMP-2 promoter was linked upstream of the chloramphenicol acetyltransferase (CAT) reporter gene, CAT activity was up-regulated in IL-8 but not in control transfected cells, suggesting that IL-8 is involved in MMP-2 gene transcription. Activation of type IV collagenase by IL-8 can enhance the invasion of host stroma by the tumor cells and increase angiogenesis and, hence, metastasis.

Tolerance to endotoxin prevents mortality in infected thermal injury: association with attenuated cytokine responses

Endotoxin, a lipopolysaccharide (LPS), is a bacterial cell wall product instrumental in producing deleterious host responses to infection. This LPS appears to act, in part, by triggering release of endogenous mediators such as cytokines. Repeated exposures to endotoxin produce attenuated responses to this molecule. To examine the mechanisms and biologic consequences of this tolerance to LPS, Wistar rats were subjected to a 14-day course of LPS administration. Tolerance to LPS with regard to anorexia, weight loss, and acute-phase responses was noted. Attenuation of these physiologic responses was accompanied by abrogation of circulating cytokine appearance in response to endotoxin, suggesting that tolerance to LPS is in part due to a decreased production of cytokines. Tolerance to LPS also diminished the response to a subsequent infected thermal injury, as measured by food intake, body weight, fibrinogen levels, and mortality. Thus, clinical conditions involving repeated exposure to LPS may modify the host's responses to subsequent injury. The attenuated responses to injury accompanying the decreased production of cytokines further implicate cytokines in the pathogenesis of injury and disease.

Interleukin 1 receptor blockade attenuates the host inflammatory response

Cytokines, including interleukin 1 (IL-1), tumor necrosis factor alpha, and interleukin 6, are often produced in response to tissue injury and contribute to several host responses such as weight loss, anorexia, and acute-phase protein synthesis. However, the role of IL-1 in specific tissue responses is unclear. To test our hypothesis that specific in vivo blockade of IL-1's action might inhibit the catabolic host changes associated with inflammation, mice were passively immunized with a monoclonal antibody directed against the murine IL-1 receptor prior to initiation of a turpentine-induced sterile abscess. This antibody prevents IL-1-mediated proliferation of murine thymocytes in vitro by inhibiting IL-1 alpha and IL-1 beta by way of competition for a common receptor. Weight loss following turpentine challenge was prevented by daily injections of anti-IL-1 receptor monoclonal IgG. Body composition analysis confirmed that lean tissue and fat were preserved by passive immunization. Furthermore, pretreatment with an anti-IL-1 receptor monoclonal antibody significantly attenuated the plasma amyloid P and interleukin 6 responses but did not affect the decline in plasma albumin or the increase in circulating corticosterone. Passive immunization of similar mice with polyclonal antisera against another cytokine, tumor necrosis factor alpha, failed to prevent either the weight loss or hepatic acute-phase protein changes observed in this inflammatory model. These findings suggest that IL-1 orchestrates weight loss and body compositional changes during inflammation and contributes to the induction of interleukin 6 and acute-phase protein synthesis.

Monoclonal antibodies to avian lipoprotein lipase. Purification of the enzyme by immunoaffinity chromatography

Three monoclonal antibodies to avian lipoprotein lipase have been isolated by fusing spleen cells from immunized BALB/c mice with myeloma P3X-63 Ag 8. The antibodies were detected by their ability to bind immobilized lipoprotein lipase in enzyme-linked immunosorbent assay (ELISA) and by immunoprecipitation of purified enzyme in the presence of second (rabbit anti-mouse) antibodies. Two of these antibodies, CAL1-7 and CAL1-11, inhibited catalytic activity, whereas with CAL1-2 interaction with lipoprotein lipase could be demonstrated only in ELISA and in Western blot assays following denaturation of the enzyme with sodium dodecyl sulfate. An immunoadsorbent column was prepared by coupling immunopurified CAL1-11 to Sepharose-4B. When acetone powder extracts of adipose tissue were applied on the column, 70% of the catalytic activity bound to the matrix. Effective elution was achieved with 1.8 M NaCl, 40% glycerol, 5% acetone, 20 mM Chaps (3[(3-cholamidopropyl)dimethylammonio]propanesulfonate), 0.5 mM EDTA, 1 mM phosphate (pH 6.5). After concentration of the active fractions on a heparin-Sepharose 4B column, the purified enzyme was obtained with an overall recovery of 25%. Sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrates that the preparation is homogeneous with a major band at Mr 60900. Thus, avian adipose lipoprotein lipase has been purified by a one-step immunoaffinity followed by a concentrating step on heparin-Sepharose 4B.