Faculty Bibliography

Background: Several studies have provided evidence that solid tumors are polyclonal malignancies, an observation which may contribute to difficulties in achieving durable treatment responses. In some patients, molecularly targeted therapies may be compromised due to heterogeneity among tumor subclones. In this study we compared conventional DNA sequencing with a fluorescent-based mutant-specific PCR (MS-PCR) assay to detect the BRAF hotspot mutation V600E in a large panel of patient tumors, including paired primary and metastatic tumors from individual patients. Methods: BRAF MS-PCR and conventional sequencing were performed on DNA from 304 tumors (112 melanoma, 110 ovarian, 82 prostate) to determine the presence of the BRAFV600E hot-spot mutation. Among the melanomas were 18 matched primary and metastatic specimens, and 40 metastatic specimens from 19 patients, each of whom had 2 or more metastases. Results: DNA sequencing detected mutations in 5/110 (4.5%) ovarian tumors, 1/82 (1.2%) prostate tumors, and 36/112 (32%) melanomas. In contrast, the MS-PCR assay detected mutations in 12/110 (11%) ovarian tumors, 15/82 (18%) prostate tumors and 85/112 (76%) melanomas. The presence of contaminating normal tissue was scored for each melanoma sample, but excess normal tissue did not influence the results using either methodology. In all cases mutations detected by sequencing were also detected by MSPCR. Among 18 patients with matched primary and metastatic melanoma, 8/18 (44%) had discordant results including 2 patients with mutant primary tumors and wild-type metastases; among the 19 patients with multiple metastases 5/19 (26%) had discordant (both wild-type and mutant) tumors. Conclusions: Using a highly sensitive BRAF mutation detection method, we observed substantial evidence for heterogeneity within clinical tumor specimens. This was especially true in melanoma samples, where multiple specimens from individual patients differed with respect to the presence of the mutant BRAF allele. These results suggest that failures of molecularly targeted therapies, such as those directed against mutant BRAF, may be due in part to a lack of clonality among the tumors under treatment

PURPOSE: In certain cancers, MDM2 SNP309 has been associated with early tumor onset in women. In melanoma, incidence rates are higher in women than in men among individuals less than 40 years of age, but among those older than 50 years of age, melanoma is more frequent in men than in women. To investigate this difference, we examined the association among MDM2 SNP309, age at diagnosis, and gender among melanoma patients. EXPERIMENTAL DESIGN: Prospectively enrolled melanoma patients (N = 227) were evaluated for MDM2 SNP309 and the related polymorphism, p53 Arg72Pro. DNA was isolated from patient blood samples, and genotypes were analyzed by PCR-restriction fragment length polymorphism. Associations among MDM2 SNP309, p53 Arg72Pro, age at diagnosis, and clinicopathologic features of melanoma were analyzed. RESULTS: The median age at diagnosis was 13 years earlier among women with a SNP309 GG genotype (46 years) compared with women with TG+TT genotypes (59 years; P = 0.19). Analyses using age dichotomized at each decade indicated that women with a GG genotype had significantly higher risks of being diagnosed with melanoma at ages <50 years compared with women >or=50 years, but not when the comparison was made between women <60 and >or=60 years. At ages <50 years, women with a GG genotype had a 3.89 times greater chance of being diagnosed compared with women with TG+TT genotypes (P = 0.01). Similar observations were not seen among men. CONCLUSIONS: Our data suggest that MDM2 may play an important role in the development of melanoma in women. The MDM2 SNP309 genotype may help identify women at risk of developing melanoma at a young age

BACKGROUND:: Despite the lack of an established survival benefit of sentinel lymph node (SLN) biopsy, this technique has been increasingly applied in the staging of thin (</=1 mm) melanoma patients, without clear evidence to support this recommendation. The authors performed a meta-analysis to estimate the risk, potential predictors, and outcome of SLN positivity in this group of patients. METHODS:: MEDLINE, EMBASE, and Cochrane databases were searched for rates of SLN positivity in patients with thin melanoma. The methodologic quality of included studies was assessed using the Methodological Index for Non-Randomized Studies criteria. Heterogeneity was assessed using the Cochran Q statistic, and publication bias was examined through funnel plot and the Begg and Mazumdar method. Overall SLN positivity in thin melanoma patients was estimated using the DerSimonial-Laird random effect method. RESULTS:: Thirty-four studies comprising 3651 patients met inclusion criteria. The pooled SLN positivity rate was 5.6%. Significant heterogeneity among studies was detected (P = .005). There was no statistical evidence of publication bias (P = .21). Eighteen studies reported select clinical and histopathologic data limited to SLN-positive patients (n = 113). Among the tumors from these patients, 6.1% were ulcerated, 31.5% demonstrated regression, and 47.5% were Clark level IV/V. Only 4 melanoma-related deaths were reported. CONCLUSIONS:: Relatively few patients with thin melanoma have a positive SLN. To the authors' knowledge, there are no clinical or histopathologic criteria that can reliably identify thin melanoma patients who might benefit from this intervention. Given the increasing diagnosis of thin melanoma, in addition to the cost and potential morbidity of this procedure, alternative strategies to identify patients at risk for lymph node disease are needed. Cancer 2009. (c) 2008 American Cancer Society

Several challenges face the development and operation of a biospecimen bank linked to clinical information, a critical component of any effective translational research program. Melanoma adds particular complexity and difficulty to such an endeavor considering the unique characteristics of this malignancy. We describe here a review of biospecimen bank and our experience in establishing a multi-disciplinary, prospective, integrated clinicopathological-biospecimen database in melanoma. The Interdisciplinary Melanoma Cooperative Group (IMCG), a prospective clinicopathological and biospecimen database, was established at the New York University (NYU) Langone Medical Center. With patients' informed consent, biospecimens from within and outside NYU, clinicopathological data, and follow-up information are collected using developed protocols. Information pertaining to biospecimens is recorded in 35 fields, and clinicopathological information is recorded in 371 fields within 5 modules in a virtual network system. Investigators conducting research utilizing the IMCG biospecimen resource are blind to clinicopathological information, and molecular data generated using biospecimens are linked independently with clinicopathological data by biostatistics investigators. This translational research enterprise acts as a valuable resource to efficiently translate laboratory discoveries to the clinic

BACKGROUND: Nodular melanoma (NM) may be biologically aggressive compared with the more common superficial spreading melanoma (SSM), with recent data suggesting underlying genetic differences between these 2 subtypes. To better define the clinical behavior of NMs, the authors compared their clinical and histopathologic features to those of SSMs at their institution, a tertiary referral center, over 3 decades. METHODS: A total of 1,684 patients diagnosed with 1,734 melanomas were prospectively enrolled. Of these, 1,143 patients (69% SSM, 11% NM, 20% other) were diagnosed between 1972 and 1982; 541 patients (54% SSM, 23% NM, 23% other) were diagnosed between 2002 and the present. Differences between the features of NM and SSM within each time period as well as changes over time were analyzed. RESULTS: The authors found that SSMs are now diagnosed as thinner lesions (P < .0001) with a low incidence of histologic ulceration (P < .0001), whereas there was no significant change in the median tumor thickness or ulceration status of NMs over time (P = .10, P = .30, respectively). The median age at diagnosis of NM, however, did significantly increase over time (51 years to 63 years, P < .01). The median duration of NMs was reported to be only 5 months compared with 9 months in SSM patients. CONCLUSIONS: The authors' data suggest that improvements have been made in the early detection of SSM but not NM. Modifications of current screening practices, including increased surveillance of high-risk patients with an emphasis on the 'E' for 'evolution' criterion of the ABCDE acronym used for early detection of melanoma, are thus warranted

BACKGROUND: Different Insulin-like Growth Factor Binding Proteins (IGFBPs) have been investigated as potential biomarkers in several types of tumors. In this study, we examined both IGFBP-3 and -4 levels in tissues and sera of melanoma patients representing different stages of melanoma progression. METHODS: The study cohort consisted of 132 melanoma patients (primary, n = 72; metastatic, n = 60; 64 Male, 68 Female; Median Age = 56) prospectively enrolled in the New York University School of Medicine Interdisciplinary Melanoma Cooperative Group (NYU IMCG) between August 2002 and December 2006. We assessed tumor-expression and circulating sera levels of IGFBP-3 and -4 using immunohistochemistry and ELISA assays. Correlations with clinicopathologic parameters were examined using Wilcoxon rank-sum tests and Spearman-rank correlation coefficients. RESULTS: Median IGFBP-4 tumor expression was significantly greater in primary versus metastatic patients (70% versus 10%, p = 0.01) A trend for greater median IGFBP-3 sera concentration was observed in metastatic versus primary patients (4.9 microg/ml vs. 3.4 microg/ml, respectively, p = 0.09). However, sera levels fell within a normal range for IGFBP-3. Neither IGFBP-3 nor -4 correlated with survival in this subset of patients. CONCLUSION: Decreased IGFBP-4 tumor expression might be a step in the progression from primary to metastatic melanoma. Our data lend support to a recently-described novel tumor suppressor role of secreting IGFBPs in melanoma. However, data do not support the clinical utility of measuring levels of IGFBP-3 and -4 in sera of melanoma patients

PURPOSE: Extracellular matrix remodeling during tumor growth plays an important role in angiogenesis. Our preclinical data suggest that a newly identified cryptic epitope (HU177) within collagen type IV regulates endothelial and melanoma cell adhesion in vitro and angiogenesis in vivo. In this study, we investigated the clinical relevance of HUI77 shedding in melanoma patient sera. EXPERIMENTAL DESIGN: Serum samples from 291 melanoma patients prospectively enrolled at the New York University Medical Center and 106 control subjects were analyzed for HU177 epitope concentration by a newly developed sandwich ELISA assay. HU177 serum levels were then correlated with clinical and pathologic parameters. RESULTS: Mean HU177 epitope concentration was 5.8 ng/mL (range, 0-139.8 ng/mL). A significant correlation was observed between HU177 concentration and nodular melanoma histologic subtype [nodular, 10.3 +/- 1.6 ng/mL (mean +/- SE); superficial spreading melanoma, 4.5 +/- 1.1 ng/mL; all others, 6.1 +/- 2.1 ng/mL; P = 0.01 by ANOVA test]. Increased HU177 shedding also correlated with tumor thickness (< or =1.00 mm, 3.8 +/- 1.1 ng/mL; 1.01-3.99 mm, 8.7 +/- 1.3 ng/mL; > or =4.00 mm, 10.3 +/- 2.4 ng/mL; P = 0.003 by ANOVA). After multivariate analysis controlling for thickness, the correlation between higher HU177 concentration and nodular subtype remained significant (P = 0.03). The mean HU177 epitope concentration in control subjects was 2.4 ng/mL. CONCLUSIONS: We report that primary melanoma can induce detectable changes in systemic levels of cryptic epitope shedding. Our data also support that nodular melanoma might be biologically distinct compared with superficial spreading type melanoma. As targeted interventions against cryptic collagen epitopes are currently undergoing phase I clinical trial testing, these findings indicate that patients with nodular melanoma may be more susceptible to such targeted therapies

T cell-mediated immunity to microbes and to cancer can be enhanced by the activation of dendritic cells (DCs) via TLRs. In this study, we evaluated the safety and feasibility of topical imiquimod, a TLR7 agonist, in a series of vaccinations against the cancer/testis Ag NY-ESO-1 in patients with malignant melanoma. Recombinant, full-length NY-ESO-1 protein was administered intradermally into imiquimod preconditioned sites followed by additional topical applications of imiquimod. The regimen was very well tolerated with only mild and transient local reactions and constitutional symptoms. Secondarily, we examined the systemic immune response induced by the imiquimod/NY-ESO-1 combination, and show that it elicited both humoral and cellular responses in a significant fraction of patients. Skin biopsies were assessed for imiquimod's in situ immunomodulatory effects. Compared with untreated skin, topical imiquimod induced dermal mononuclear cell infiltrates in all patients composed primarily of T cells, monocytes, macrophages, myeloid DCs, NK cells, and, to a lesser extent, plasmacytoid DCs. DC activation was evident. This study demonstrates the feasibility and excellent safety profile of a topically applied TLR7 agonist used as a vaccine adjuvant in cancer patients. Imiquimod's adjuvant effects require further evaluation and likely need optimization of parameters such as formulation, dose, and timing relative to Ag exposure for maximal immunogenicity