Faculty Bibliography

Patients with thick (>4 mm) primary melanomas have highly variable outcomes. Current staging criteria for these patients are based primarily on the presence of nodal disease, which often serves as the basis for adjuvant trial eligibility. Identification of novel biomarkers could help identify patients who may benefit from promising, new adjuvant therapies or, alternatively, spare patients with good prognoses the cost and potential toxicity of these drugs. We examined patients with thick primary melanoma to determine whether proliferation markers (mitotic index and Ki- 67) and other clinicopatholgical features were associated with survival. We studied 171 patients with thick primary melanomas; median thickness was 6.0 mm (median follow-up, 3.0 years). In clinically node-negative patients, Ki-67 expression was an independent predictor of worse RFS (HR 2.19, P = 0.024) and OS (HR 2.49, P = 0.028). In a separate model, moderate (>1 to <5 per mm²) and many (>5 per mm²) mitoses were each significantly associated with RFS (HR = 9.97, P = 0.035 and HR = 11.93, P = 0.025, respectively); and OS (HR = 12.79, P = 0.033 and HR = 18.68, P = 0.017, respectively). In the same model, natural log-transformed tumor thickness was also significantly associated with worse OS (HR 2.37, P = 0.009). In sum, we identified cell proliferation markers Ki-67 and mitotic index as independent predictors of survival in clinically nodenegative patients with thick primary melanoma. Greater tumor thickness was also an independent predictor of survival in this cohort. With further investigation, these measures may improve risk-stratification for patients with thick primary melanoma

Tumor infiltrating lymphocytes (TILs) in primary melanomas are thought to represent the host anti-tumor immune response, but controversy exists over whether TILs offer independent prognostication of survival. We studied a cohort of 1241 primary melanoma patients to assess the association of absent, non-brisk, 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 to histology alone in 15% of the cohort. To assess for inter-group 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%), non-brisk (n=330, 27%), and brisk (n=523, 42%). Patients with brisk TILs had improved recurrence-free survival (RFS) (P=.025) and overall survival (OS) (P=.006) compared to patients with non-brisk and absent TILs, for which there were no differences in RFS (P=.40) or OS (P=.41). TIL quantitation by immunohistochemistry did not improve prognostication compared to TIL grading on hematoxylin and eosin stained sections. Melanomas with non-brisk 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 to melanomas with non-brisk or absent TILs.

BACKGROUND: Age 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. METHODS: We 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 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. RESULTS: We 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. CONCLUSIONS: Older 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.

Despite major advances in the treatment of metastatic melanoma, treatment failure is still inevitable in most cases. Manipulation of key epigenetic regulators, including inhibition of Bromodomain and extra-terminal domain (BET) family members impairs cell proliferation in vitro and tumor growth in vivo in different cancers, including melanoma. Here, we investigated the effect of combining the BET inhibitor JQ1 with the BRAF inhibitor Vemurafenib in in vitro and in vivo models of BRAF-mutant melanoma. We performed cytotoxicity and apoptosis assays, and a xenograft mouse model to determine the in vitro and in vivo efficacy of JQ1 in combination with Vemurafenib against BRAF-mutant melanoma cell lines. Further, to investigate the molecular mechanisms underlying the effects of combined treatment, we conducted antibody arrays of in vitro drug-treated cell lines and RNA sequencing of drug-treated xenograft tumors. The combination of JQ1 and Vemurafenib acted synergistically in BRAF-mutant cell lines, resulting in marked apoptosis in vitro, with upregulation of proapoptotic proteins. In vivo, combination treatment suppressed tumor growth and significantly improved survival compared to either drug alone. RNA sequencing of tumor tissues revealed almost four thousand genes that were uniquely modulated by the combination, with several anti-apoptotic genes significantly down-regulated. Collectively, our data provide a rationale for combined BET and BRAF inhibition as a novel strategy for the treatment of melanoma.

INTRODUCTION: Inflammatory breast cancer (IBC) is an aggressive and rare cancer with a poor prognosis and a need for novel targeted therapeutic strategies. Preclinical IBC data showed strong activation of the phosphatidylinositide-3-kinase/mammalian target of rapamycin (mTOR) and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathways, and expression of inflammatory cytokines and tumor-associated macrophages (TAMs). PATIENTS AND METHODS: Archival tumor tissue from 3 disease types (IBC treated with neoadjuvant chemotherapy [NAC], n = 45; invasive ductal carcinoma [IDC] treated with NAC [n = 24; 'treated IDC'; and untreated IDC [n = 27; 'untreated IDC']) was analyzed for the expression of biomarkers phospho-S6 (pS6) (mTOR), phospho-JAK2 (pJAK2), pSTAT3, interleukin (IL)-6, CD68 (monocytes, macrophages), and CD163 (TAMs). Surrounding nontumor tissue was also analyzed. RESULTS: Biomarker levels and surrogate activity according to site-specific phosphorylation were shown in the tumor tissue of all 3 disease types but were greatest in IBC and treated IDC and least in untreated IDC for pS6, pJAK2, pSTAT3, and IL-6. Of 37 IBC patients with complete biomarker data available, 100% were pS6-positive and 95% were pJAK2-positive. In nontumor tissue, biomarker levels were observed in all groups but were generally greatest in untreated IDC and least in IBC, except for JAK2. CONCLUSION: IBC and treated IDC display similar levels of mTOR and JAK2 biomarker activation, which suggests a potential mechanism of resistance after NAC. Biomarker levels in surrounding nontumor tissue suggested that the stroma might be activated by chemotherapy and resembles the oncogenic tumor-promoting environment. Activation of pS6 and pJAK2 in IBC might support dual targeting of the mTOR and JAK/STAT pathways, and the need for prospective studies to investigate combined targeted therapies in IBC.

BACKGROUND: Median overall survival (OS) of patients with melanoma brain metastases (MBM) is usually 6 months or less. There are rare reports of patients with treated MBM who survived for years. These outlier cases represent valuable opportunities to study the somatic and germline factors that may have influenced patient outcome and led to extended survival. CASE PRESENTATION: Here we report the clinical scenario of a 67 year old man with a recurrent brain metastasis from melanoma who has survived over 12 years post-resection. We review the literature relating to clinical and molecular variables associated with long term survival post-brain metastasis. We present the somatic characteristics of this individual patient's tumor as well as an analysis of inherited genetic variants related to immune function. The patient's resected brain tumor is BRAF V600E mutated, NRAS wild type (WT), and TERT C250T mutated. The patient is a carrier of germline variants in immunomodulatory loci associated with prolonged survival. CONCLUSIONS: Our data suggest that genetic variants in immunomodulatory loci may partially contribute to this patient's unusually favorable outcome and should not be overlooked. With further and future investigation, knowledge of inherited single nucleotide polymorphisms (SNPs) may provide clinicians with more individualized prognostic information for melanoma patients, with potential implications for surveillance strategies and therapeutic interventions.

PURPOSE: Brain metastasis is the major cause of mortality among melanoma patients. A molecular prognostic test that can reliably stratify patients at initial melanoma diagnosis by risk of developing brain metastasis may inform the clinical management of these patients. EXPERIMENTAL DESIGN: We performed a retrospective, cohort-based study analyzing genome-wide and targeted microRNA expression profiling of primary melanoma tumors of three patient cohorts (n= 92, n= 119, n= 45) with extensive clinical follow up. We used Cox regression analysis to establish a microRNA-based signature that improves the ability of the current clinicopathologic staging system to predict the development of brain metastasis. RESULTS: Our analyses identified a 4-microRNA (miR-150-5p, miR-15b-5p, miR-16-5p, and miR-374b-3p) prognostic signature that, in combination with stage, distinguished primary melanomas that metastasized to the brain from non-recurrent and non-brain-metastatic primary tumors (training cohort: C-index=81.4%, validation cohort: C-index=67.4%, independent cohort: C-index=76.9%). Corresponding Kaplan-Meier curves of high- vs. low-risk patients displayed a clear separation in brain-metastasis-free and overall survival (training: p<0.001, p<0.001, validation: p=0.033, p=0.007, independent: p=0.021, p=0.022, respectively). Finally, of the microRNA in the prognostic model, we found that the expression of a key lymphocyte miRNA, miR-150-5p, which is less abundant in primary melanomas metastatic to brain, correlated with presence of CD45+ tumor infiltrating lymphocytes. CONCLUSIONS: A prognostic assay based on the described miRNA expression signature combined with the currently used staging criteria may improve accuracy of primary melanoma patient prognoses and aid clinical management of patients, including selection for adjuvant treatment or clinical trials of adjuvant therapies.

Sentinel lymph node biopsy is the current standard procedure used to stage patients with breast cancer. The best histological method in evaluating sentinel nodes is highly debated among institutions and is thus not standardized. The optimal histological analysis is a balance between comprehensive evaluation of the sentinel nodes and cost effectiveness. One commonly used approach is serial sectioning and alternately staining with hemotoxylin and eosin and AE1/AE3 cytokeratin immunohistochemistry analysis. We report 2 cases of metastatic carcinoma demonstrating negative staining for AE1/AE3. This observation highlights a rare but potential pitfall to this commonly used strategy in assessing sentinel lymph node biopsies in breast cancer.