Sung Won Han

Serum‐based miRNAs in the prediction and detection of recurrence in melanoma patients

Identification of primary melanoma patients at the highest risk of recurrence remains a critical challenge, and monitoring for recurrent disease is limited to costly imaging studies. We recently reported our array‐based discovery of prognostic serum miRNAs in melanoma. In the current study, we examined the clinical utility of these serum‐based miRNAs for prognosis as well as detection of melanoma recurrence.

Immunologic heterogeneity of tumor-infiltrating lymphocyte composition in primary melanoma

Tumor-infiltrating lymphocytes (TILs) in primary melanomas are thought to represent the host antitumor immune response, but controversy exists over whether TILs offer independent prognostication of survival. We studied a cohort of 1241 patients with primary melanoma to assess the association of absent, nonbrisk, and brisk TIL grade with survival outcomes. We tested whether quantitative TIL counts using immunohistochemical lymphocyte markers CD3, CD45, and FOXP3 add prognostic value to TIL grading compared with histology alone in 15% of the cohort. To assess for intergroup immunologic heterogeneity among TIL grades, we investigated differential expression of 594 immunoregulatory genes in 67 primary melanomas. On histologic evaluation of 1241 primary melanomas, TILs were graded as absent (n=388, 31%), nonbrisk (n=330, 27%), and brisk (n=523, 42%). Patients with brisk TILs had improved recurrence-free survival (P=.025) and overall survival (P=.006) compared with patients with nonbrisk and absent TILs, for which there were no differences in recurrence-free survival (P=.40) or overall survival (P=.41). TIL quantitation by immunohistochemistry did not improve prognostication compared with TIL grading on hematoxylin and eosin-stained sections. Melanomas with nonbrisk and absent TILs share similar immunoregulatory gene expression profiles. In contrast, melanomas with brisk TILs demonstrate upregulation of T-cell activation pathways and inhibition of upstream immune checkpoint regulators. The presence of TILs in primary melanomas represents a heterogeneous group, and caution in prognostic interpretation is warranted. Melanomas with brisk TILs are defined by an immunostimulatory gene expression profile and improved prognosis compared with melanomas with nonbrisk or absent TILs.

Hedgehog pathway blockade inhibits melanoma cell growth in vitro and in vivo.

Previous reports have demonstrated a role for hedgehog signaling in melanoma progression, prompting us to explore the therapeutic benefit of targeting this pathway in melanoma. We profiled a panel of human melanoma cell lines and control melanocytes for altered expression of hedgehog pathway members and determined the consequences of both genetic and pharmacological inhibition of the hedgehog pathway activator Smoothened (SMO) in melanoma, both in vitro and in vivo. We also examined the relationship between altered expression of hedgehog pathway mediators and survival in a well-characterized cohort of metastatic melanoma patients with prospectively collected follow up information. Studies revealed that over 40% of the melanoma cell lines examined harbored significantly elevated levels of the hedgehog pathway mediators SMO, GLI2, and PTCH1 compared to melanocytes (p < 0.05). SMO inhibition using siRNA and the small molecule inhibitor, NVP-LDE-225, suppressed melanoma growth in vitro, particularly in those cell lines with moderate SMO and GLI2 expression. NVP-LDE-225 also induced apoptosis in vitro and inhibited melanoma growth in a xenograft model. Gene expression data also revealed evidence of compensatory up-regulation of two other developmental pathways, Notch and WNT, in response to hedgehog pathway inhibition. Pharmacological and genetic SMO inhibition also downregulated genes involved in human embryonic stem cell pluripotency. Finally, increased SMO expression and decreased expression of the hedgehog pathway repressor GLI3 correlated with shorter post recurrence survival in metastatic melanoma patients. Our data demonstrate that hedgehog pathway inhibition might be a promising targeted therapy in appropriately selected metastatic melanoma patients.

Impact of aging on host immune response and survival in melanoma: an analysis of 3 patient cohorts.

BackgroundAge has been reported as an independent prognostic factor for melanoma-specific survival (MSS). We tested the hypothesis that age impacts the host anti-tumor immune response, accounting for age-specific survival outcomes in three unique melanoma patient cohorts.MethodsWe queried the U.S. population-based Surveillance, Epidemiology, and End Results Program (SEER), the prospective tertiary care hospital-based Interdisciplinary Melanoma Cooperative Group (IMCG) biorepository, and the Cancer Genome Atlas (TCGA) biospecimen database to test the association of patient age at time of melanoma diagnosis with clinicopathologic features and survival outcomes. Age groups were defined as ≤45 (young), 46–65 (intermediate), and >65 (older). Each age group in the IMCG and TCGA cohorts was stratified by tumor infiltrating lymphocyte (TIL) measurements and tested for association with MSS. Differential expression of 594 immunoregulatory genes was assessed in a subset of primary melanomas in the IMCG and TCGA cohorts using an integrative pathway analysis.ResultsWe analyzed 304, 476 (SEER), 1241 (IMCG), and 292 (TCGA) patients. Increasing age at melanoma diagnosis in both the SEER and IMCG cohorts demonstrated a positive correlation with tumor thickness, ulceration, stage, and mortality, however age in the TCGA cohort did not correlate with mortality. Older age was associated with shorter MSS in all three cohorts. When the young age group in both the IMCG and TCGA cohorts was stratified by TIL status, there were no differences in MSS. However, older IMCG patients with brisk TILs and intermediate aged TCGA patients with high lymphocyte scores (3–6) had improved MSS. Gene expression analysis revealed top pathways (T cell trafficking, communication, and differentiation) and top upstream regulators (CD3, CD28, IFNG, and STAT3) that significantly changed with age in 84 IMCG and 43 TCGA primary melanomas.ConclusionsOlder age at time of melanoma diagnosis is associated with shorter MSS, however age’s association with clinicopathologic features is dependent upon specific characteristics of the study population. TIL as a read-out of the host immune response may have greater prognostic impact in patients older than age 45. Recognition of age-related factors negatively impacting host immune responses may provide new insights into therapeutic strategies for the elderly.

Outcomes in Melanoma Patients Treated with BRAF/MEK-Directed Therapy or Immune Checkpoint Inhibition Stratified by Clinical Trial versus Standard of Care

Objectives: Since 2011, metastatic melanoma treatment has evolved with commercial approval of BRAF- and MEK-targeted therapy and CTLA-4- and PD-1-blocking antibodies (immune checkpoint inhibitors, ICI). While novel therapies have demonstrated improved prognosis in clinical trials, few studies have examined the evolution of prognosis and toxicity of these drugs among an unselected population. We assess whether survival and toxicity reported in trials, which typically exclude most patients with brain metastases and poor performance status, are recapitulated within a commercial access population. Methods: 182 patients diagnosed with stage IV melanoma from July 2006 to December 2013 and treated with BRAF- and/or MEK-targeted therapy or ICI were prospectively studied. Outcomes and clinicopathologic differences between trial and commercial cohorts were assessed. Results: Patients receiving commercial therapy (vs. on trial) had poorer prognostic features (i.e., brain metastases) and lower median overall survival (mOS) when assessed across all treatments (9.2 vs. 17.5 months, p = 0.0027). While toxicity within trial and commercial cohorts did not differ, patients who experienced toxicity had increased mOS (p < 0.001), irrespective of stratification by trial status or therapy. Conclusion: Metastatic melanoma patients receiving commercial treatment may represent a different clinical population with poor prognostic features compared to trial patients. Toxicity may prognosticate treatment benefit.

Computer-assisted measurement of primary tumor area is prognostic of recurrence-free survival in stage IB melanoma patients

Current staging guidelines are insufficient to predict which patients with thin primary melanoma are at high risk of recurrence. Computer-assisted image analysis may allow for more practical and objective histopathological analysis of primary tumors than traditional light microscopy. We studied a prospective cohort of stage IB melanoma patients treated at NYU Langone Medical Center from 2002 to 2014. Primary tumor width, manual area, digital area, and conformation were evaluated in a patient subset via computer-assisted image analysis. The associations between histologic variables and survival were evaluated using Cox proportional hazards model. Logistic regressions were used to build a classifier with clinicopathological characteristics to predict recurrence status. Of the 655 patients with stage IB melanoma studied, a subset of 149 patient tumors (63 recurred, 86 did not recur) underwent computer-assisted histopathological analysis. Increasing tumor width (hazard ratios (HR): 1.17, P=0.01) and digital area (HR: 1.08, P<0.01) were significantly associated with worse recurrence-free survival, whereas non-contiguous conformation (HR: 0.57, P=0.05) was significantly associated with better recurrence-free survival. The novel histopathological classifier composed of digital area, conformation, and baseline variables effectively distinguished recurrent cases from non-recurrent cases (AUC: 0.733, 95% confidence interval (CI): 0.647–0.818), compared to the baseline classifier alone (AUC: 0.635, 95% CI: 0.545–0.724). Primary tumor cross-sectional area, width, and conformation measured via computer-assisted analysis may help identify high-risk patients with stage IB melanoma.

Corrigendum to “Immunologic heterogeneity of tumor-infiltrating lymphocyte composition in primary melanoma” (Hum Pathol 2016;57:116-25)

Department of Medicine, New York University School of Medicine, New York, NY, USA 10016 Interdisciplinary Melanoma Cooperative Group, New York University School of Medicine, New York, NY, USA 10016 Department of Population Health, New York University School of Medicine, New York, NY, USA 10016 Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, NY, USA 10016 Department of Surgery, New York University School of Medicine, New York, NY, USA 10016 Department of Biostatistics, New York University School of Medicine, New York, NY, USA 10016 Department of Pathology, New York University School of Medicine, New York, NY, USA 10016