Screening costs associated with donor selection for fecal microbiota transplantation for treatment of PD-1 refractory melanoma patients.

The gut microbiome acts as a tumor-extrinsic regulator of responses to immune-checkpoint inhibitors (ICIs) targeting PD-1 and CTLA-4 receptors. Primary resistance to anti-PD-1 ICI can be reversed via responder-derived fecal microbiota transplant (FMT) in patients with refractory melanoma. Efforts to create stool banks for FMT have proved difficult. Therefore, we aimed to establish a novel donor-screening program to generate responder-derived FMT for use in PD-1 refractory melanoma. Candidate PD-1 responder donors and PD-1 refractory recipients were recruited via clinic-based encounters at the University of Pittsburgh Medical Center hospitals. Eligible donors and recipients underwent physician assessment and screening of serum, stool and nasopharynx for transmissible agents, which included SARS-CoV-2 modification. The cost of donor and recipient screening was calculated. Initially, 29 donors were screened with 14 eligible donors identified after exclusion; of the 14 donors, eight were utilized in clinical trials. The overall efficiency of screening was 48%. Seroprevalence rates for cytomegalovirus, Epstein-Barr virus, HSV-2, HHV-6, HTLV-1, HTLV-2, and syphilis were similar to published statistics from healthy blood donors in the USA. Donor stool studies indicated a 3.6% incidence of E. histolytica and norovirus, 3.7% incidence of giardia and 7.1% incidence of C. difficile. A single donor tested positive for SARS-CoV-2 in stool only. The cost for finding a single eligible donor was $2260.24 (pre-COVID) and $2,460.24 (post-COVID). The observed screening efficiency suggests that a well-resourced screening program can generate sufficient responder-derived donor material for clinical trial purposes. Eliminating testing for low-prevalence organisms may improve cost-effectiveness.

Intestinal microbiota signatures of clinical response and immune-related adverse events in melanoma patients treated with anti-PD-1.

Ample evidence indicates that the gut microbiome is a tumor-extrinsic factor associated with antitumor response to anti-programmed cell death protein-1 (PD-1) therapy, but inconsistencies exist between published microbial signatures associated with clinical outcomes. To resolve this, we evaluated a new melanoma cohort, along with four published datasets. Time-to-event analysis showed that baseline microbiota composition was optimally associated with clinical outcome at approximately 1 year after initiation of treatment. Meta-analysis and other bioinformatic analyses of the combined data show that bacteria associated with favorable response are confined within the Actinobacteria phylum and the Lachnospiraceae/Ruminococcaceae families of Firmicutes. Conversely, Gram-negative bacteria were associated with an inflammatory host intestinal gene signature, increased blood neutrophil-to-lymphocyte ratio, and unfavorable outcome. Two microbial signatures, enriched for Lachnospiraceae spp. and Streptococcaceae spp., were associated with favorable and unfavorable clinical response, respectively, and with distinct immune-related adverse effects. Despite between-cohort heterogeneity, optimized all-minus-one supervised learning algorithms trained on batch-corrected microbiome data consistently predicted outcomes to programmed cell death protein-1 therapy in all cohorts. Gut microbial communities (microbiotypes) with nonuniform geographical distribution were associated with favorable and unfavorable outcomes, contributing to discrepancies between cohorts. Our findings shed new light on the complex interaction between the gut microbiome and response to cancer immunotherapy, providing a roadmap for future studies.

Dendritic cell vaccines targeting tumor blood vessel antigens in combination with dasatinib induce therapeutic immune responses in patients with checkpoint-refractory advanced melanoma.

BACKGROUND: A first-in-human, randomized pilot phase II clinical trial combining vaccines targeting overexpressed, non-mutated tumor blood vessel antigens (TBVA) and tyrosine kinase inhibitor dasatinib was conducted in human leukocyte antigen (HLA)-A2+ patients with advanced melanoma. METHODS: Patient monocyte-derived type-1-polarized dendritic cells were loaded with HLA-A2-presented peptides derived from TBVA (DLK1, EphA2, HBB, NRP1, RGS5, TEM1) and injected intradermally as a vaccine into the upper extremities every other week. Patients were randomized into one of two treatment arms receiving oral dasatinib (70 mg two times per day) beginning in week 5 (Arm A) or in week 1 (Arm B). Trial endpoints included T cell response to vaccine peptides (interferon-γ enzyme-linked immunosorbent spot), objective clinical response (Response Evaluation Criteria in Solid Tumors V.1.1) and exploratory tumor, blood and serum profiling of immune-associated genes/proteins. RESULTS: Sixteen patients with advanced-stage cutaneous (n=10), mucosal (n=1) or uveal (n=5) melanoma were accrued, 15 of whom had previously progressed on programmed cell death protein 1 (PD-1) blockade. Of 13 evaluable patients, 6 patients developed specific peripheral blood T cell responses against ≥3 vaccine-associated peptides, with further evidence of epitope spreading. All six patients with specific CD8+ T cell response to vaccine-targeted antigens exhibited evidence of T cell receptor (TCR) convergence in association with preferred clinical outcomes (four partial response and two stabilization of disease (SD)). Seven patients failed to respond to vaccination (one SD and six progressive disease). Patients in Arm B (immediate dasatinib) outperformed those in Arm A (delayed dasatinib) for immune response rate (IRR; 66.7% vs 28.6%), objective response rate (ORR) (66.7% vs 0%), overall survival (median 15.45 vs 3.47 months; p=0.0086) and progression-free survival (median 7.87 vs 1.97 months; p=0.063). IRR (80% vs 25%) and ORR (60% vs 12.5%) was greater for females versus male patients. Tumors in patients exhibiting response to treatment displayed (1) evidence of innate and adaptive immune-mediated inflammation and TCR convergence at baseline, (2) on-treatment transcriptional changes associated with reduced hypoxia/acidosis/glycolysis, and (3) increased inflammatory immune cell infiltration and tertiary lymphoid structure neogenesis. CONCLUSIONS: Combined vaccination against TBVA plus dasatinib was safe and resulted in coordinating immunologic and/or objective clinical responses in 6/13 (46%) evaluable patients with melanoma, particularly those initiating treatment with both agents. TRIAL REGISTRATION NUMBER: NCT01876212.

Neoadjuvant Pembrolizumab and High-Dose IFNα-2b in Resectable Regionally Advanced Melanoma.

PURPOSE: Neoadjuvant immunotherapy may improve the clinical outcome of regionally advanced operable melanoma and allows for rapid clinical and pathologic assessment of response. We examined neoadjuvant pembrolizumab and high-dose IFNα-2b (HDI) therapy in patients with resectable advanced melanoma. PATIENTS AND METHODS: Patients with resectable stage III/IV melanoma were treated with concurrent pembrolizumab 200 mg i.v. every 3 weeks and HDI 20 MU/m2/day i.v., 5 days per week for 4 weeks, then 10 MU/m2/day subcutaneously 3 days per week for 2 weeks. Definitive surgery followed, as did adjuvant combination immunotherapy, completing a year of treatment. Primary endpoint was safety of the combination. Secondary endpoints included overall response rate (ORR), pathologic complete response (pCR), recurrence-free survival (RFS), and overall survival (OS). Blood samples for correlative studies were collected throughout. Tumor tissue was assessed by IHC and flow cytometry at baseline and at surgery. RESULTS: A total of 31 patients were enrolled, and 30 were evaluable. At data cutoff (October 2, 2019), median follow-up for OS was 37.87 months (range, 33.2-43.47). Median OS and RFS were not reached. Radiographic ORR was 73.3% [95% confidence interval (CI): 55.5-85.8], with a 43% (95% CI: 27.3-60.1) pCR rate. None of the patients with a pCR have had a recurrence. HDI and pembrolizumab were discontinued in 73% and 43% of patients, respectively. Correlative analyses suggested that intratumoral PD-1/PD-L1 interaction and HLA-DR expression are associated with pCR (P = 0.002 and P = 0.008, respectively). CONCLUSIONS: Neoadjuvant concurrent HDI and pembrolizumab demonstrated promising clinical activity despite high rates of treatment discontinuation. pCR is a prognostic indicator.See related commentary by Menzies et al., p. 4133.

Fecal microbiota transplant overcomes resistance to anti-PD-1 therapy in melanoma patients.

Anti-programmed cell death protein 1 (PD-1) therapy provides long-term clinical benefits to patients with advanced melanoma. The composition of the gut microbiota correlates with anti-PD-1 efficacy in preclinical models and cancer patients. To investigate whether resistance to anti-PD-1 can be overcome by changing the gut microbiota, this clinical trial evaluated the safety and efficacy of responder-derived fecal microbiota transplantation (FMT) together with anti-PD-1 in patients with PD-1-refractory melanoma. This combination was well tolerated, provided clinical benefit in 6 of 15 patients, and induced rapid and durable microbiota perturbation. Responders exhibited increased abundance of taxa that were previously shown to be associated with response to anti-PD-1, increased CD8+ T cell activation, and decreased frequency of interleukin-8-expressing myeloid cells. Responders had distinct proteomic and metabolomic signatures, and transkingdom network analyses confirmed that the gut microbiome regulated these changes. Collectively, our findings show that FMT and anti-PD-1 changed the gut microbiome and reprogrammed the tumor microenvironment to overcome resistance to anti-PD-1 in a subset of PD-1 advanced melanoma.

Phase Ib/II Study of Pembrolizumab and Pegylated-Interferon Alfa-2b in Advanced Melanoma.

PURPOSE: Objective responses are reported in 34% to 37% of patients with programmed death-1 (PD-1)-naïve advanced melanoma treated with PD-1 inhibitors. Pre-existing CD8+ T-cell infiltrate and interferon (IFN) gene signature correlate with response to PD-1 blockade. Here, we report a phase Ib/II study of pembrolizumab/pegylated (PEG)-IFN combination in PD-1-naïve advanced melanoma. PATIENTS AND METHODS: PEG-IFN (1, 2, and 3 µg/kg per week) was dose escalated using a modified toxicity probability interval design in three cohorts of four patients each, whereas pembrolizumab was dosed at 2 mg/kg every 3 weeks in the phase Ib portion. Thirty-one patients were enrolled in the phase II portion. Primary objectives were safety and incidence of dose-limiting toxicities. Secondary objectives included objective response rate, progression-free survival (PFS), and overall survival. RESULTS: Forty-three patients with stage IV melanoma were enrolled in the phase Ib and II portions of the study and included in the analysis. At the data cutoff date (December 31, 2017), median follow-up duration was 25 months (range, 1 to 38 months). All 43 patients experienced at least one adverse event; grade 3/4 treatment-related adverse events occurred in 21 of 43 patients (48.8%). Objective responses were seen at all three dose levels among 43 evaluable patients. The objective response rate was 60.5%, with 46.5% of patients exhibiting ongoing response. Median PFS was 11.0 months in all patients and unreached in responders, whereas median overall survival remained unreached in all patients. The 2-year PFS rate was 46%. CONCLUSION: Pembrolizumab/PEG-IFN demonstrated an acceptable toxicity profile with promising evidence of clinical efficacy in PD-1-naïve metastatic melanoma. These results support the rationale to further investigate this pembrolizumab/PEG-IFN combination in this disease.

Evaluation of Biodistribution of Sulforaphane after Administration of Oral Broccoli Sprout Extract in Melanoma Patients with Multiple Atypical Nevi.

Broccoli sprout extract containing sulforaphane (BSE-SFN) has been shown to inhibit ultraviolet radiation-induced damage and tumor progression in skin. This study evaluated the toxicity and potential effects of oral BSE-SFN at three dosages. Seventeen patients who each had at least 2 atypical nevi and a prior history of melanoma were randomly allocated to 50, 100, or 200 µmol oral BSE-SFN daily for 28 days. Atypical nevi were photographed on days 1 and 28, and plasma and nevus samples were taken on days 1, 2, and 28. Endpoints assessed were safety, plasma and skin sulforaphane levels, gross and histologic changes, IHC for phospho-STAT3(Y705), Ki-67, Bcl-2, HMOX1, and TUNEL, plasma cytokine levels, and tissue proteomics. All 17 patients completed 28 days with no dose-limiting toxicities. Plasma sulforaphane levels pooled for days 1, 2, and 28 showed median postadministration increases of 120 ng/mL for 50 µmol, 206 ng/mL for 100 µmol, and 655 ng/mL for 200 µmol. Median skin sulforaphane levels on day 28 were 0.0, 3.1, and 34.1 ng/g for 50, 100, and 200 µmol, respectively. Plasma levels of proinflammatory cytokines decreased from day 1 to 28. The tumor suppressor decorin was increased from day 1 to 28. Oral BSE-SFN is well tolerated at daily doses up to 200 µmol and achieves dose-dependent levels in plasma and skin. A larger efficacy evaluation of 200 µmol daily for longer intervals is now reasonable to better characterize clinical and biological effects of BSE-SFN as chemoprevention for melanoma. Cancer Prev Res; 11(7); 429-38. ©2018 AACR.

Do the effects of adolescent employment differ by employment intensity and neighborhood context?

Research on the effects of adolescent employment on primarily middle-class youth suggests that intense employment, working more than 15 or 20 hours during the school year, is associated with increased participation in risky behavior. Despite these findings, scholars who focus on the development of youth living in low-income urban areas often hypothesize that adolescent employment will have beneficial effects on this population. There is some evidence that adolescent employment is associated with increased educational achievement and adult employment for low-income urban youth. The impact of adolescent employment on future engagement in risky behavior across levels of neighborhood deprivation and employment intensity was investigated on a sample of 1,057 adolescents from the Project on Human Development in Chicago Neighborhoods, a longitudinal study of neighborhood effects on development. After controlling for individual characteristics, intense employment during adolescence did predict increased use of cigarettes and alcohol and having a greater number of sexual partners 2 years after employment was measured. There were no significant interactions between neighborhood SES and adolescent employment status on involvement in risky behavior. These findings suggest that intense adolescent employment is associated with detrimental developmental outcomes for youth regardless neighborhood context.

Livedo reticularis.

Livedo reticularis (LR) is a net-like, violaceous, hyperpigmented pattern on the skin that reflects an underlying change in cutaneous blood flow. The causes of LR are many and most commonly include connective tissue diseases, vasculitis, hypercoagulability, and embolic events. We describe a 49-year-old man who presented with painful LR and ulcers on the lower extremities as a manifestation of chronic natural killer cell leukemia (CNKL). There have been only a few cases previously reported in the literature. We report an additional case of a patient with both LR and CNKL and suggest a possible mechanism that explains this association.

Syringocystadenoma.

We present a case of a 35-year-old woman with a yellow, verrucous, and itchy plaque on her scalp. Within this plaque, there was an erythematous, bleeding papule. Histopathologic findings were compatible with a diagnosis of syringocystadenoma papilliferum within a nevus sebaceous. We present a brief review of the natural history of nevus sebaceus, its pathogenesis, and management.

Successful treatment of facial telangiectasias using a micropulse 1,064-nm neodymium-doped yttrium aluminum garnet laser.

OBJECTIVES: To evaluate the safety and efficacy of a microsecond 1,064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser for the treatment of facial telangiectasias. METHODS: Subjects ages 35-70 with Fitzpatrick skin types I to III and facial telangiectasias underwent two treatments with a micropulse (0.65 ms) 1,064-nm Nd:YAG laser. Treatments were spaced 30 days apart, with a final evaluation 60 days after the second treatment. Evaluation included digital photography and an assessment of the degree of improvement on a scale from 1 to 5 by the subject and a nontreating investigator. RESULTS: Twenty subjects (18 women, two men) with Fitzpatrick skin type II and III completed the study. The nontreating investigator rated the objective clinical response as total clearance (100% clear) in 10% (n = 2) of subjects, significant clearance (≥50% clear) in 75% (n = 15), and some clearance (0-49% clear) in 15% (n = 3). None of the subjects was rated as having no clearance or worsening. In terms of subjective clearance reported by subjects, 80% (n = 16) reported significant clearance, with the remainder reporting some clearance. No adverse events were reported. CONCLUSION: The micropulse 1,064-nm Nd:YAG successfully treated facial telangiectasias with a high degree of patient satisfaction, minimal discomfort, and no adverse events.

Safety and efficacy of intradermal injection of botulinum toxin for the treatment of oily skin.

OBJECTIVE: To evaluate the safety and efficacy of intradermal injection of abobotulinumtoxinA for the treatment of oily skin. METHODS AND MATERIALS: Twenty-five patients with oily skin were treated in the forehead region with intradermal injections of botulinum toxin. Baseline and post-treatment sebum production was measured using a sebometer. Photographs were taken. Patients were also asked to rate their satisfaction with the treatment in terms of improvement in their oily skin. RESULTS: Treatment with botulinum toxin resulted in significantly lower sebum production at 1 week and 1, 2, and 3 months after injection (p < .001, t-test). Twenty-one patients (91%) reported that they were satisfied (50-75% improvement) with intradermal botulinum toxin as a treatment for oily skin. [Correction added after online publication 7-Jan-2013: the number of satisfied patients has been updated] CONCLUSION: Intradermal injection of botulinum toxin significantly reduced sebum production in the forehead region, with a high degree of patient satisfaction. Intradermal botulinum toxin may be an effective treatment to reduce sebum production in patients with oily skin. Larger, randomized, blinded, placebo-controlled studies are warranted.

Esthetic rejuvenation of the temple.

Loss of volume in the temples is an early sign of aging that is often overlooked by both the physician and the patient. Augmentation of the temple using soft tissue fillers improves the contours of the upper face with the secondary effect of lengthening and lifting the lateral brow. After replacement of volume, treatment of the overlying skin with skin-tightening devices or laser resurfacing help to complete a comprehensive rejuvenation of the temple and upper one-third of the face.

Necrobiotic xanthogranuloma.

Necrobiotic xanthogranuloma (NXG) is a rare, chronic, progressive, non-Langerhans histiocytosis that is strongly associated with hematologic malignant conditions. Only about 100 cases have been reported in the literature since it was first described in 1980. It is important for dermatologists to recognize NXG and initiate a prompt hematologic evaluation. IgG kappa is the most frequently discovered monoclonal gammopathy (65%), followed by IgG lambda (35%), and, much less commonly, IgA. Although no modality has been shown to be consistently effective, therapeutic options include glucocorticoids (topical, intralesional, and/or systemic), alkylating agents (chlorambucil and cyclophosphamide). interferon alpha, antimetabolites, antibiotics, thalidomide, and plasmaphersis.

Impact of race on survival in patients with clinically nonmetastatic prostate cancer who deferred primary treatment.

BACKGROUND: Prostate cancer (PCa) racial disparity studies typically focus on survival differences after curative treatment. The authors of this report hypothesized that comparing mortality rates between African American (AA) and Caucasian American (CA) patients who deferred primary treatment for clinically nonmetastatic PCa may provide a better assessment of the impact of race on the natural course of PCa. METHODS: The pathology database of the New York Veterans Administration Medical Center (VAMC), an equal access-of-care facility, was searched for patients with biopsy-proven PCa. Inclusion criteria included 1) no evidence of metastatic disease or death within 3 years after diagnosis, 2) no primary treatment, and 3) a minimum of 5 years of follow-up for survivors. RESULTS: In total, 518 patients met inclusion criteria between 1990 and 2005. AA patients were younger (P = .02) and had higher median prostate-specific antigen (PSA) levels (P = .001) at the time of diagnosis compared with CA patients. In a multivariate model, higher Gleason score and PSA level were associated with increased mortality (P = .001 and P = .03, respectively), but race was not a predictor of death from PCa. CONCLUSIONS: The current data suggested that race did not have a major impact on survival in patients with PCa who deferred primary treatment for clinically nonmetastatic disease.

Cheilitis granulomatosa.

Melkersson-Rosenthal Syndrome (MRS) is a rare syndrome that is characterized by a triad of facial paralysis, chronic edema of the lip, and a fissured tongue. Most commonly, one element of the triad precedes the development of the other symptoms. We present a case of cheilitis granulomatosa (CG) as a manifestation of incomplete MRS. As the etiology remains unknown, treatment of CG is challenging. Intralesional glucocorticoids remain the first-line treatment, but recurrences are common. We discuss alternative treatment strategies that include combination therapy with other anti-inflammatory agents and biologics, such as infliximab.

Clinical relevance of detection of lymphovascular invasion in primary melanoma using endothelial markers D2-40 and CD34.

Immunohistochemistry (IHC) using endothelial markers may facilitate the detection of lymphovascular invasion (LVI) in primary melanoma; however, the clinical implications of enhanced detection are unknown. We evaluated whether the use of lymphatic endothelial marker D2-40 and panvascular marker CD34 increases LVI positivity relative to routine histology alone and then evaluated the prognostic relevance of LVI detected using these markers in terms of disease-free (DFS) and overall survival (OS). A total of 246 primary melanomas were assessed for LVI using D2-40, CD34, and routine histology. Associations between LVI positivity and clinicopathologic variables, DFS, and OS were compared using univariate and multivariate analyses. The use of endothelial markers increased the rate of LVI positivity (18% using D2-40 and/or CD34 vs. 3% by routine histology, P<0.0001). On univariate analysis, IHC-detected LVI was significantly associated with more adverse clinicopathologic variables (thickness, ulceration, mitoses, and nodular subtype) compared with LVI detected by routine histology (thickness and ulceration only). In a multivariate model controlling for stage, LVI detected using IHC markers remained a significant marker of both reduced DFS [hazard ratio (HR), 2.01; 95% confidence interval (CI): 1.27-3.18; P=0.003] and OS (HR, 2.08; 95% CI: 1.25-3.46; P=0.005). Results show that D2-40 and CD34 increase the detection of LVI in primary melanoma and that cases missed by routine histology have prognostic relevance.

A high proliferative index of recurrent melanoma is associated with worse survival.

OBJECTIVE: Previous melanoma studies evaluating prognostic factors of survival at recurrence have focused on primary tumor characteristics and clinical variables at first recurrence. We examined the prognostic relevance of recurrent tumor proliferation. METHODS: 114 melanoma patients with available recurrent tissues who were prospectively enrolled at New York University Medical Center were studied. Standard of care prognostic variables (e.g. stage at initial diagnosis and lactate dehydrogenase level) and recurrent tissue expression of proliferative marker Ki-67 were evaluated for their association with overall survival. RESULTS: High Ki-67 expression was observed in 57 (50%) of the 114 recurrent melanomas. On univariate analysis, the median overall survival of patients whose recurrent tumors overexpressed Ki-67 was significantly shorter than that of patients whose recurrent tumors had low Ki-67 expression (3.6 vs. 9.5 years, p = 0.03). On multivariate analysis, a high proliferative index of the recurrent melanoma remained an independent predictor of worse overall survival, controlling for stage at initial diagnosis, disease-free survival, and stage at first recurrence [HR = 2.09 (95% CI 1.24-3.54), p = 0.006]. CONCLUSIONS: Our results demonstrate the prognostic relevance of tumor proliferation in recurrent melanoma patients. Data also support restratification of risk assessment upon recurrence that considers tumor biology in addition to clinical variables evaluated as part of the standard of care.

Clinical variables and primary tumor characteristics predictive of the development of melanoma brain metastases and post-brain metastases survival.

BACKGROUND: Melanoma patients who develop brain metastases (B-Met) have limited survival and are excluded from most clinical trials. In the current study, the authors attempted to identify primary tumor characteristics and clinical features predictive of B-Met development and post-B-Met survival. METHODS: A prospectively accrued cohort of 900 melanoma patients was studied to identify clinicopathologic features of primary melanoma (eg, thickness, ulceration, mitotic index, and lymphovascular invasion) that are predictive of B-Met development and survival after a diagnosis of B-Met. Associations between clinical variables present at the time of B-Met diagnosis (eg, extracranial metastases, B-Met location, and the presence of neurological symptoms) and post-B-Met survival were also assessed. Univariate associations were analyzed using Kaplan-Meier survival analysis, and the effect of independent predictors was assessed using multivariate Cox proportional hazards regression analysis. RESULTS: Of the 900 melanoma patients studied, 89 (10%) developed B-Met. Ulceration and site of the primary tumor on the head and neck were found to be independent predictors of B-Met development on multivariate analysis (P = .001 and P = .003, respectively). Clinical variables found to be predictive of post-B-Met survival on multivariate analysis included the presence of neurological symptoms (P = .008) and extracranial metastases (P = .04). Ulceration was the only primary tumor characteristic that remained a significant predictor of post-B-Met survival on multivariate analysis (P = .04). CONCLUSIONS: Primary tumor ulceration was found to be the strongest predictor of B-Met development and remained an independent predictor of decreased post-B-Met survival in a multivariate analysis inclusive of primary tumor characteristics and clinical variables. The results of the current study suggest that patients with ulcerated primary tumors should be prospectively studied to determine whether heightened surveillance for B-Met can improve clinical outcome.

Integrative genomics identifies molecular alterations that challenge the linear model of melanoma progression.

Superficial spreading melanoma (SSM) and nodular melanoma (NM) are believed to represent sequential phases of linear progression from radial to vertical growth. Several lines of clinical, pathologic, and epidemiologic evidence suggest, however, that SSM and NM might be the result of independent pathways of tumor development. We utilized an integrative genomic approach that combines single nucleotide polymorphism array (6.0; Affymetrix) with gene expression array (U133A 2.0; Affymetrix) to examine molecular differences between SSM and NM. Pathway analysis of the most differentially expressed genes between SSM and NM (N = 114) revealed significant differences related to metabolic processes. We identified 8 genes (DIS3, FGFR1OP, G3BP2, GALNT7, MTAP, SEC23IP, USO1, and ZNF668) in which NM/SSM-specific copy number alterations correlated with differential gene expression (P < 0.05; Spearman's rank). SSM-specific genomic deletions in G3BP2, MTAP, and SEC23IP were independently verified in two external data sets. Forced overexpression of metabolism-related gene MTAP (methylthioadenosine phosphorylase) in SSM resulted in reduced cell growth. The differential expression of another metabolic-related gene, aldehyde dehydrogenase 7A1 (ALDH7A1), was validated at the protein level by using tissue microarrays of human melanoma. In addition, we show that the decreased ALDH7A1 expression in SSM may be the result of epigenetic modifications. Our data reveal recurrent genomic deletions in SSM not present in NM, which challenge the linear model of melanoma progression. Furthermore, our data suggest a role for altered regulation of metabolism-related genes as a possible cause of the different clinical behavior of SSM and NM.