Investigation of the RB1-SOX2 axis constitutes a tool for viral status determination and diagnosis in Merkel cell carcinoma.

MCC (Merkel cell carcinoma) is an aggressive neuroendocrine cutaneous neoplasm. Integration of the Merkel cell polyomavirus (MCPyV) is observed in about 80% of the cases, while the remaining 20% are related to UV exposure. Both MCPyV-positive and -negative MCCs-albeit by different mechanisms-are associated with RB1 inactivation leading to overexpression of SOX2, a major contributor to MCC biology. Moreover, although controversial, loss of RB1 expression seems to be restricted to MCPyV-negative cases.The aim of the present study was to assess the performances of RB1 loss and SOX2 expression detected by immunohistochemistry to determine MCPyV status and to diagnose MCC, respectively.Overall, 196 MCC tumors, 233 non-neuroendocrine skin neoplasms and 70 extra-cutaneous neuroendocrine carcinomas (NEC) were included. SOX2 and RB1 expressions were assessed by immunohistochemistry in a tissue micro-array. Diagnostic performances were determined using the likelihood ratio (LHR).RB1 expression loss was evidenced in 27% of the MCC cases, 12% of non-neuroendocrine skin tumors and 63% of extra-cutaneous NEC. Importantly, among MCC cases, RB1 loss was detected in all MCPyV(-) MCCs, while MCPyV( +) cases were consistently RB1-positive (p < 0.001). SOX2 diffuse expression was observed in 92% of the MCC cases and almost never observed in non-neuroendocrine skin epithelial neoplasms (2%, p < 0.0001, LHR + = 59). Furthermore, SOX2 diffuse staining was more frequently observed in MCCs than in extra-cutaneous NECs (30%, p < 0.001, LHR + = 3.1).These results confirm RB1 as a robust predictor of MCC viral status and further suggest SOX2 to be a relevant diagnostic marker of MCC.

A high neutrophil to lymphocyte ratio prior to BRAF inhibitor treatment is a predictor of poor progression-free survival in patients with metastatic melanoma.

Some studies have shown that a high neutrophil/lymphocyte ratio (NLR) ≥4 before initiating ipilimumab treatment is an independent prognostic indicator of poor survival in patients with metastatic melanoma (MM). To determine whether the NLR before starting BRAF inhibitor (BRAFi) treatment in patients with (MM) is associated with progression-free survival (PFS). This retrospective study included 49 patients consecutively receiving BRAFi for MM between July 2012 and December 2014. Cox proportional hazards regression was used to analyse the relationship between NLR and other factors, such as lactate dehydrogenase (LDH), performance status, BRAFi as first- or second-line therapy, and corticosteroid intake with PFS. The NLR before starting BRAFi was significantly associated with PFS based on univariate analysis and multivariate analysis adjusted for potential confounding factors, such as LDH activity, ulceration, performance status, first-line therapy, and corticosteroid intake. A high NLR (continuous variable) was associated with short PFS (HR: 1.35; 95% CI: 1.07-1.70; p = 0.01), and NLR ≥4 was associated with shorter PFS (HR: 3.24; 95% CI: 1.30-8.12; p = 0.01). Corticosteroid intake was not associated with short PFS based on multivariate analysis. An NLR >4, before starting BRAFi treatment, is an independent prognostic indicator of poor progression-free survival.

Differentiating Merkel cell carcinoma of lymph nodes without a detectable primary skin tumor from other metastatic neuroendocrine carcinomas: The ELECTHIP criteria.

BACKGROUND: Merkel cell carcinoma (MCC) can present as a cutaneous tumor or a lymph node metastasis without a primary tumor. MCC presenting without a primary tumor (MCCWOPT) can be misinterpreted on histologic examination as lymph node metastasis (LNM) from another neuroendocrine carcinoma (LNMNEC). However, this distinction is crucial for therapeutic management. OBJECTIVE: To determine the discriminative criteria for the differential diagnosis of MCCWOPT, LNM from cutaneous MCC, and LNMNECs. METHODS: Clinical, morphologic, and immunohistochemical data (expression of cytokeratins AE1, AE3, 7, 19, and 20; chromogranin A, synaptophysin, thyroid transcription factor-1 [TTF-1]), as well as the presence of Merkel cell polyomavirus (by immunohistochemistry and PCR) were compared in patients with MCCWOPT (n = 17), LNM from a cutaneous MCC (n = 11), and LNMNEC (n = 20; 8 lung, 7 thyroid, 3 digestive tract, 2 other). RESULTS: MCC (including MCCWOPT and LNM from a cutaneous MCC) differed from LNMNEC by 7 discriminative criteria: 1) elderly age, 2) location of the tumor, 3) extent of the disease, 4) cytokeratin expression, 5) TTF-1 expression, 6) histologic type, and 7) Merkel cell polyomavirus detection, summarized under the acronym ELECTHIP. All MCC patients had ≥5 of the ELECTHIP criteria, whereas all patients with LNMNEC (except 1) had <3 criteria. LIMITATIONS: The discriminant ability of the ELECTHIP criteria should be validated in a second independent set. CONCLUSION: MCCWOPT can be distinguished from other LNMNEC by the ELECTHIP criteria.

Merkel cell carcinomas infiltrated with CD33+ myeloid cells and CD8+ T cells are associated with improved outcome.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare tumor of the skin that has an aggressive behavior. Immunity is the main regulator of MCC development, and many interactions between lymphocytes and tumor cells have been proven. However, the impact of tumor-infiltrating myeloid cells needs better characterization. OBJECTIVE: To characterize tumor-infiltrating myeloid cells in MCC and their association with other immune effectors and patient outcome. METHODS: MCC cases were reviewed from an ongoing prospective cohort study. In all, 103 triplicate tumor samples were included in a tissue microarray. Macrophages, neutrophils, and myeloid-derived suppressor cells were characterized by the following markers: CD68, CD33, CD163, CD15, CD33, and human leukocyte antigen-DR. Associations of these cell populations with programmed cell death ligand 1 expression, CD8 infiltrates, and vascular density were assessed. Impact on survival was analyzed by log-rank tests and a Cox multivariate model. RESULTS: The median density of macrophages was 216 cells/mm2. CD68+ and CD33+ macrophage densities were associated with CD8+ T-cell infiltrates and programmed cell death ligand 1 expression. In addition, MCC harboring CD8+ T cell infiltrates and brisk CD33+ myeloid cell infiltrates were significantly and independently associated with improved outcomes (recurrence-free and overall survival). LIMITATIONS: Sampling bias and the retrospective design were potential study limitations. CONCLUSION: Infiltration of CD33+ myeloid cells and CD8+ T lymphocytes defines a subset of MCC associated with improved outcome.

High-frequency ultrasound imaging for cutaneous neurofibroma in patients with neurofibromatosis type I.

Neurofibromas (NFs) are benign tumours arising from a nerve sheath, which are present in nearly all patients with neurofibromatosis type 1 (NF1). High-frequency ultrasound (HFU) systems, using frequencies over 20 MHz, were developed to improve visualization of skin tumours by means of increased resolution. To describe NFs by using HFU in patients with NF1. Anonymized HFU (25-MHz) images of NFs were randomized. Initially, two dermatologist investigators, with experience in HFU imaging of the skin, together described the ultrasound images and established eight criteria for NFs. The same task was then repeated by two other dermatologists, also with experience in HFU imaging of the skin, independently, to establish inter-observer agreement. A total of 108 NFs in 29 patients were included. Superficial and subcutaneous NFs were hypoechoic with a round to spindle shape. Plexiform NFs were ill-defined, consisting of multiple hypoechoic linear zones. Good to excellent inter-observer agreement was found for six of the eight criteria (k>0.6). This is the first series describing HFU skin imaging of NFs in patients with NF1. Lateral extension that may correspond to involvement of an adjacent nerve seems to be specific to NFs.

A high neutrophil-to-lymphocyte ratio as a potential marker of mortality in patients with Merkel cell carcinoma: A retrospective study.

BACKGROUND: The prognostic relevance of a high blood neutrophil-to-lymphocyte ratio (NLR) has been reported in many cancers, although, to our knowledge, not investigated in patients with Merkel cell carcinoma (MCC) to date. OBJECTIVE: We assessed whether the NLR at baseline was associated with specific survival and recurrence-free survival in MCC. METHODS: We retrospectively included MCC cases between 1999 and 2015 and collected clinical data, blood cell count at baseline, and outcome. A Cox model was used to identify factors associated with recurrence and death from MCC. RESULTS: Among the 75 patients included in the study, a high NLR at baseline (NLR ≥4) was associated with death from MCC in univariate (hazard ratio 2.76, 95% confidence interval 1.15-6.62, P = .023) and multivariate (hazard ratio 3.30, 95% confidence interval 1.21-9.01, P = .020) analysis, but not with recurrence. LIMITATIONS: Because of the retrospective design, we excluded patients with missing data and not all confounding factors that may influence the NLR were available. CONCLUSION: A high NLR at baseline was independently associated with specific mortality in patients with MCC. The NLR seems to constitute an easily available and inexpensive prognostic biomarker at baseline.