Merkel Cell Carcinoma: Epidemiology, Target, and Therapy

Isolated limb perfusion as a treatment option for rare types of tumours

BACKGROUND

Isolated limb perfusion (ILP) is an established and effective treatment for advanced melanoma and soft tissue sarcomas of the extremities with a high overall response rate. The aim of this study was to describe our experience of ILP for more rare types of tumours.

METHODS

Patients with Merkel cell carcinoma (MCC) (n = 4), squamous cell carcinoma (SCC) (n = 2), B-cell lymphoma (n = 1), desmoid tumours (n = 3), pigmented villonodular synovitis (PVNS) (n = 1) and giant cell tumour (n = 1) were treated with ILP and analysed retrospectively.

RESULTS

The four patients with in-transit MCC had three complete responses (CR) and one partial response (PR); the two patients with SCC had one CR and one stable disease (SD); the patients with desmoid tumours had two PR and one SD. A CR was also observed for the patient with a giant cell tumour, but the patient with PVNS had a SD. The patient with cutaneous metastases of B-cell lymphoma showed a CR, however with rapid systemic progression. Local toxicity according to Wieberdink was grade II in 10 patients (83%) and grade III in two patients (17%).

CONCLUSIONS

These results show that ILP can be used as a treatment option also for more rare disease entities when other treatments have failed.

Phase I study of IMGN901, a CD56-targeting antibody-drug conjugate, in patients with CD56-positive solid tumors

Background IMGN901 is a CD56-targeting antibody-drug conjugate designed for tumor-selective delivery of the cytotoxic maytansinoid DM1. This phase 1 study investigated the safety, tolerability, pharmacokinetics, and preliminary activity of IMGN901 in patients with CD56-expressing solid tumors. Methods Patients were enrolled in cohorts of escalating IMGN901 doses, administered intravenously, on 3 consecutive days every 21 days. A dose-expansion phase accrued patients with small cell lung cancer (SCLC), Merkel cell carcinoma (MCC), or ovarian cancer. Results Fifty-two patients were treated at doses escalating from 4 to 94 mg/m(2)/day. The maximum tolerated dose (MTD) was determined to be 75 mg/m(2). Dose-limiting toxicities included fatigue, neuropathy, headache or meningitis-like symptoms, chest pain, dyspnea, and myalgias. In the dose-expansion phase (n = 45), seven patients received 75 mg/m(2) and 38 received 60 mg/m(2) for up to 21 cycles. The recommended phase 2 dose (RP2D) was established at 60 mg/m(2) during dose expansion. Overall, treatment-emergent adverse events (TEAEs) were experienced by 96.9 % of all patients, the majority of which were Grade 1 or 2. The most commonly reported Grade 3 or 4 TEAEs were hyponatremia and dyspnea (each 8.2 %). Responses included 1 complete response (CR), 1 clinical CR, and 1 unconfirmed partial response (PR) in MCC; and 1 unconfirmed PR in SCLC. Stable disease was seen for 25 % of all evaluable patients who received doses ≥60 mg/m(2). Conclusions The RP2D for IMGN901 of 60 mg/m(2) administered for 3 consecutive days every 3 weeks was associated with an acceptable tolerability profile. Objective responses were observed in patients with advanced CD56+ cancers.

Isolated limb perfusion in Merkel cell carcinoma offers high rate of complete response and durable local-regional control: Systematic review and institutional experience

INTRODUCTION

Hyperthermic isolated limb perfusion (HILP) has an established role in the management of melanoma, but its role for Merkel cell carcinoma (MCC) is less well defined.

METHODS

Retrospective review of our institutional experience with HILP for MCC was conducted (2009-2015). Literature search was performed through 04/2015 and 10 studies met inclusion criteria.

RESULTS

Four patients underwent HILP for MCC at our institution. There were no major complications and complete response was achieved in all patients. Early metastatic recurrence developed in two patients. The remaining two had no evidence of disease at last follow-up (36 months) or death (39 months). Systematic review identified an additional 12 pts that underwent HILP for MCC, for a total of 16 cases. Median age was 73 [IQR 69-78] years and 56% were men. Of the patients with reported follow-up, 12 (86%) had complete response, 1 had stable disease, and 1 partial response. Four patients developed local-regional recurrence and six distant metastases, all within 6 months. Overall median follow-up time was 15 [7-36] months.

CONCLUSION

Among a highly selective group of patients, regional perfusion for MCC is safe and has a high complete response rate. HILP is an acceptable therapeutic modality for obtaining durable loco-regional control but early distant metastatic disease remains a significant cause of mortality. J. Surg. Oncol. 2016;114:187-192. © 2016 Wiley Periodicals, Inc.

Genomic portfolio of Merkel cell carcinoma as determined by comprehensive genomic profiling: implications for targeted therapeutics

Merkel cell carcinoma is an ultra-rare cutaneous neuroendocrine cancer for which approved treatment options are lacking. To better understand potential actionability, the genomic landscape of Merkel cell cancers was assessed. The molecular aberrations in 17 patients with Merkel cell carcinoma were, on physician request, tested in a Clinical Laboratory Improvement Amendments (CLIA) laboratory (Foundation Medicine, Cambridge, MA) using next-generation sequencing (182 or 236 genes) and analyzed by N-of-One, Inc. (Lexington, MA). There were 30 genes harboring aberrations and 60 distinct molecular alterations identified in this patient population. The most common abnormalities involved the TP53 gene (12/17 [71% of patients]) and the cell cycle pathway (CDKN2A/B, CDKN2C or RB1) (12/17 [71%]). Abnormalities also were observed in the PI3K/AKT/mTOR pathway (AKT2, FBXW7, NF1, PIK3CA, PIK3R1, PTEN or RICTOR) (9/17 [53%]) and DNA repair genes (ATM, BAP1, BRCA1/2, CHEK2, FANCA or MLH1) (5/17 [29%]). Possible cognate targeted therapies, including FDA-approved drugs, could be identified in most of the patients (16/17 [94%]). In summary, Merkel cell carcinomas were characterized by multiple distinct aberrations that were unique in the majority of analyzed cases. Most patients had theoretically actionable alterations. These results provide a framework for investigating tailored combinations of matched therapies in Merkel cell carcinoma patients.

Palliative radiotherapy for Merkel cell carcinoma: single-centre experience and review of the literature

Background and purpose

Merkel cell carcinoma is a rare and aggressive primary cutaneous neuroendocrine carcinoma with a high risk of loco-regional and distant metastasis. It is predominantly seen in the elderly, on the head and neck or extremities. Although treated primarily with surgery, some patients are too frail. A World Health Organization performance status of two or more with co-existing medical co-morbidities, or the site of the disease adjacent to a critical structure, can prevent surgical management. In this cohort of patients, primary palliative radiotherapy has been found to achieve excellent tumour regression and improve quality of life. A new palliative split-course hypofractionated regime has been used in North Middlesex University Hospital in this cohort of patients. The purpose of this case series was to provide supporting evidence on the efficacy of this dose and fractionation regime and review the literature for the palliative management of Merkel cell carcinoma.

Materials and methods

In total, four patients were treated with the palliative split-course hypofractionated regime. The regime consisted of an initial 20 Gray in 5 fractions over 1 week, a 2-week gap and then a further 20 Gray in 5 fractions over 1 week. Tolerability and response to treatment were evaluated by history and clinical examination.

Results and conclusion

The split-course hypofractionated regime was well tolerated, achieved excellent tumour regression and improved quality of life in all four patients. Since then, a further three patients have been successfully treated with the above regime. This case series demonstrates the efficacy of this dose and fractionation in a select group of patients too frail for radical management and adds to the evidence base for the optimal palliative management of Merkel cell carcinoma.

Reversal of epigenetic silencing of MHC class I chain-related protein A and B improves immune recognition of Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a virally associated cancer characterized by its aggressive behavior and strong immunogenicity. Both viral infection and malignant transformation induce expression of MHC class I chain-related protein (MIC) A and B, which signal stress to cells of the immune system via Natural Killer group 2D (NKG2D) resulting in elimination of target cells. However, despite transformation and the continued presence of virally-encoded proteins, MICs are only expressed in a minority of MCC tumors in situ and are completely absent on MCC cell lines in vitro. This lack of MIC expression was due to epigenetic silencing via MIC promoter hypo-acetylation; indeed, MIC expression was re-induced by pharmacological inhibition of histone deacetylases (HDACs) both in vitro and in vivo. This re-induction of MICs rendered MCC cells more sensitive to immune-mediated lysis. Thus, epigenetic silencing of MICs is an important immune escape mechanism of MCCs.

Merkel Cell Carcinoma: Current Issues Regarding Diagnosis, Management, and Emerging Treatment Strategies

Merkel cell carcinoma (MCC) is a rare but aggressive cutaneous tumor with a predilection for the head and neck of elderly Caucasian patients. Although much less common than melanoma, MCC has higher rates of sentinel lymph node involvement, local and regional recurrences, and mortality. The majority of MCC cases have been linked to the relatively newly discovered Merkel cell polyomavirus, which is a ubiquitous constituent of the skin flora. Recent discoveries regarding viral integration and carcinogenesis and the immunologic features of MCC have expanded the understanding of MCC. These discoveries have led to the development and application of emerging therapies such as somatostatin analogs, immune checkpoint inhibition, adoptive cell therapy, and other exciting possibilities for targeted therapy.

Clinically amyopathic dermatomyositis: clinical features, response to medications and malignancy-associated risk factors in a specific tertiary-care-centre cohort

BACKGROUND

Clinically amyopathic dermatomyositis (CADM) is a subset of dermatomyositis (DM) characterized by the typical DM cutaneous manifestations but without myositis. There is a relative paucity of characterized cases of CADM in the peer-reviewed medical literature.

OBJECTIVES

To characterize the clinical features, response to medications and malignancy-associated risk factors of patients with CADM with available baseline data seen at a single tertiary-care centre.

METHODS

A retrospective review was undertaken of 44 patients with CADM with available clinical and serological data prior to onset of treatment.

RESULTS

Patients with CADM comprised 18% of all patients with DM with baseline data available at our institution. Although the majority of patients showed improvement with the first prescribed treatment, most required additional medications to control their CADM. Six of 44 patients had an associated malignancy. Photosensitivity and periungual erythema were found to be associated with absence of malignancy (P = 0·03 and P = 0·02, respectively). Patients with malignancy-associated CADM were found to be more likely to have a cutaneous response with the first prescribed treatment than patients without malignancy (P = 0·04).

CONCLUSIONS

CADM represents a significant subset of the DM population. As with classic DM, the cutaneous manifestations of CADM often represent a therapeutic challenge. A subset of patients with CADM has underlying malignancies, and these may differ from those typically associated with classic DM. Differences in serological abnormalities, cutaneous manifestations and response to first treatment among patients with CADM with and without malignancy were found, and suggest distinct pathophysiologies among CADM subsets. Characterization of this cohort expands the knowledge about this unique DM subset.

Effect of the dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor NVP-BEZ235 against human Merkel cell carcinoma MKL-1 cells

Merkel cell carcinoma (MCC) is an aggressive skin cancer with an increasing incidence. Aberrant activation of the phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is common in human cancers and has been revealed to play an important function in cell proliferation, metabolism and tumorigenesis. In the present study, NVP-BEZ235, a dual PI3K/mTOR inhibitor, was revealed to be effective in inhibiting proliferation and inducing cell cycle arrest in MKL-1 cells. Additional investigations revealed that NVP-BEZ235 attenuated PI3K/Akt/mTOR signaling and upregulated the levels of the cell cycle inhibitors p21 and p27. Overall, the present results possess considerable implications for future development of dual PI3K/mTOR inhibitor as potential agents in the management of MCC.

Both tumor depth and diameter are predictive of sentinel lymph node status and survival in Merkel cell carcinoma

BACKGROUND

The purposes of this study were 1) to determine the impact of primary tumor-related factors on the prediction of the sentinel lymph node (SLN) status and 2) to identify clinical and pathologic factors associated with survival in Merkel cell carcinoma (MCC).

METHODS

An institutional review board-approved, retrospective review of patients with MCC treated between 1988 and 2011 at a single center was performed. Patients were categorized into 5 groups: 1) negative SLN, 2) positive SLN, 3) clinically node-negative but SLN biopsy not performed, 4) regional nodal disease without a known primary tumor, and 5) primary MCC with synchronous clinically evident regional nodal disease. Factors predictive of the SLN status were analyzed with logistic regressions, and overall survival (OS) and disease-specific survival (DSS) were analyzed with Cox models and competing risk models assuming proportional hazards, respectively.

RESULTS

Three hundred seventy-five patients were analyzed, and 70% were male; the median age was 75 years. The median tumor diameter was 1.5 cm (range, 0.2-12.5 cm), and the median tumor depth was 4.8 mm (range, 0.3-45.0 mm). One hundred ninety-one patients underwent SLN biopsy, and 59 (31%) were SLN-positive. Increasing primary tumor diameter and increasing tumor depth were associated with SLN positivity (P = .007 and P = .017, respectively). Age and sex were not associated with the SLN status. Immunosuppression, increasing tumor diameter, and increasing tumor depth were associated with worse OS (P = .007, P = .003, and P = .025, respectively). DSS differed significantly by group and was best for patients with a negative SLN and worst for those with primary MCC and synchronous clinically evident nodal disease (P = .018).

CONCLUSION

For patients with MCC, increasing primary tumor diameter and increasing tumor depth are independently predictive of a positive SLN, worse OS, and worse DSS. Tumor depth should be routinely reported when primary MCC specimens are being evaluated histopathologically.

Disruption of BRD4 at H3K27Ac-enriched enhancer region correlates with decreased c-Myc expression in Merkel cell carcinoma

Pathologic c-Myc expression is frequently detected in human cancers, including Merkel cell carcinoma (MCC), an aggressive skin cancer with no cure for metastatic disease. Bromodomain protein 4 (BRD4) regulates gene transcription by binding to acetylated histone H3 lysine 27 (H3K27Ac) on the chromatin. Super-enhancers of transcription are identified by enrichment of H3K27Ac. BET inhibitor JQ1 disrupts BRD4 association with super-enhancers, downregulates proto-oncogenes, such as c-Myc, and displays antitumor activity in preclinical animal models of human cancers. Here we show that an enhancer proximal to the c-Myc promoter is enriched in H3K27Ac and associated with high occupancy of BRD4, and coincides with a putative c-Myc super-enhancer in MCC cells. This observation is mirrored in tumors from MCC patients. Importantly, depleted BRD4 occupancy at the putative c-Myc super-enhancer region by JQ1 correlates with decreased c-Myc expression. Thus, our study provides initial evidence that super-enhancers regulate c-Myc expression in MCC.

[A 73-year-old female patient after liver and kidney transplantation with dull pain in the epigastrium and recurrent epistaxis]

A 73-year-old female patient who had received a liver and kidney transplantation presented with symptomatic pancytopenia and right-sided upper abdominal pain. The histological investigation of a bone marrow biopsy showed the extremely rare manifestation of a disseminated Merkel cell carcinoma with infiltration of the bone marrow and suppression of hematopoiesis. Also a Coombs test positive hemolytic anemia did not show a significant response to high-dose steroid therapy. Palliative chemotherapy with carboplatin and etoposide at reduced dosage had to be terminated due to deterioration of the patient's general condition. The patient died 2 days after initiation of chemotherapy.

Merkel Cell Carcinoma with a Suppressor of Fused (SUFU) Mutation: Case Report and Potential Therapeutic Implications

Introduction

Merkel cell carcinoma is a neuroendocrine malignancy. Suppressor of fused (SUFU) is a tumor suppressor oncogene that participates in the Hedgehog (Hh) signaling pathway. The aim of the study was to describe a patient whose Merkel cell carcinoma demonstrated a SUFU genomic alteration.

Case Study

The Hh signaling pathway is involved in the pathogenesis of several tumors, including nevoid basal cell carcinoma syndrome that is associated with an alteration of the patched-1 (PTCH1) gene. Targeted molecular therapy against smoothened (SMO) with vismodegib has been shown to be an effective therapeutic intervention for patients with PTCH-1 mutation. The reported patient was presented with metastatic Merkel cell carcinoma. Analysis of his tumor, using a next-generation sequencing-based assay, demonstrated a genomic aberration of SUFU protein, a component of the Hh signaling pathway that acts downstream to SMO and, therefore, is unlikely to be responsive to vismodegib. Of interest, arsenic trioxide or bromo and extra C-terminal inhibitors impact signals downstream to SUFU, making this aberration conceivably druggable. His tumor has initially been managed with chemotherapy (carboplatin and etoposide) and subsequent radiation therapy is planned.

Conclusion

The pathogenesis of Merkel cell carcinoma is multifactorial, and related to ultraviolet radiation exposure, immunosuppression, and Merkel cell polyomavirus. We report a patient with a mutation in SUFU, a potentially actionable component of the Hh signaling pathway.

Electronic supplementary material

The online version of this article (doi:10.1007/s13555-015-0074-5) contains supplementary material, which is available to authorized users.

Cytokeratin 20-negative Merkel cell carcinoma is infrequently associated with the Merkel cell polyomavirus

Merkel cell carcinoma is a rare, highly aggressive cutaneous neuroendocrine carcinoma most commonly seen in sun-damaged skin. Histologically, the tumor consists of primitive round cells with fine chromatin and numerous mitoses. Immunohistochemical stains demonstrate expression of neuroendocrine markers. In addition, cytokeratin 20 (CK20) is expressed in ∼95% of cases. In 2008, Merkel cell carcinoma was shown to be associated with a virus now known as Merkel cell polyomavirus in ∼80% of cases. Prognostic and mechanistic differences between Merkel cell polyomavirus-positive and Merkel cell polyomavirus-negative Merkel cell carcinoma may exist. There has been the suggestion that CK20-negative Merkel cell carcinomas less frequently harbor Merkel cell polyomavirus, but a systematic investigation for Merkel cell polyomavirus incidence in CK20-negative Merkel cell carcinoma has not been done. To test the hypothesis that Merkel cell polyomavirus is less frequently associated with CK20-negative Merkel cell carcinoma, we investigated 13 CK20-negative Merkel cell carcinomas from the files of the Cleveland Clinic and the University of Michigan for the virus. The presence or absence of Merkel cell polyomavirus was determined by quantitative PCR performed for Large T and small T antigens, with sequencing of PCR products to confirm the presence of Merkel cell polyomavirus. Ten of these (77%) were negative for Merkel cell polyomavirus and three (23%) were positive for Merkel cell polyomavirus. Merkel cell polyomavirus is less common in CK20-negative Merkel cell carcinoma. Larger series and clinical follow-up may help to determine whether CK20-negative Merkel cell carcinoma is mechanistically and prognostically unique.

Merkel cell carcinoma in the left groin: A case report and review of the literature

Merkel cell carcinoma (MCC) is a relatively rare but aggressive primary neuroendocrine carcinoma of the skin. MCC frequently occurs on sun-exposed areas in elderly Caucasian patients and has a propensity for local recurrence, regional lymph node invasion and distant metastases. However, MCC occurring on sites that are not sun-exposed in Asian patients is extremely uncommon. The current study describes the case of a 66-year-old Chinese male who presented with an asymptomatic, smooth lesion in the left inguinal region, which was initially diagnosed as a malignant lymphoma. Upon histological and immunohistochemical analysis, the tumor was consistent with the diagnosis of an MCC. In conclusion, due to its low incidence rate and lack of characteristic clinical manifestations, the final diagnosis of MCC relies on the analysis of histological findings and immunohistochemical markers following lesion biopsy or resection. The present study aimed to report a case of MCC and present a brief literature review in order to bring attention to the diagnosis of this condition.

The consequences for human health of stratospheric ozone depletion in association with other environmental factors

Ozone depletion, climate and human health.

Characterization of functional domains in the Merkel cell polyoma virus Large T antigen

Merkel cell polyomavirus (MCPyV)--positive Merkel cell carcinoma (MCC) tumor cell growth is dependent on the expression of a viral Large T antigen (LT) with an intact retinoblastoma protein (RB)-binding site. This RB-binding domain in MCPyV-LT is--in contrast to other polyomavirus LTs (e.g., SV40)--embedded between two large MCPyV unique regions (MUR1 and MUR2). To identify elements of the MCPyV-LT necessary for tumor cell growth, we analyzed the rescue activity of LT variants following knockdown of the endogenous LT in MCC cells. These experiments demonstrate that nuclear localization is essential for LT function, but that a motif previously described to be a nuclear localization sequence is neither required for nuclear accumulation of truncated MCPyV-LT nor for promotion of MCC cell proliferation. Furthermore, large parts of the MURs distal to the RB binding domain as well as ALTO--a second protein encoded by an alternative reading frame in the MCPyV-LT mRNA--are completely dispensable for MCPyV-driven tumor cell proliferation. Notably, even MCPyV-LTs in which the entire MURs have been removed are still able to promote MCC cellular growth although rescue activity is reduced which may be due to MUR1 being required for stable LT expression in MCC cells. Finally, we provide evidence implying that--while binding to Vam6p is not essential--HSC-70 interaction is significantly involved in mediating MCPyV-LT function in MCC cells including growth promotion and induction of E2F target genes.

Skin cancer in kidney transplant recipients

Morbidity and mortality due to skin cancer is excessively high in renal transplant recipients compared to the general population. This epidemiologic difference is mainly due to the severe immunosuppression that enhances ultraviolet-induced DNA damage and leads to reactivation of potential oncogenic viruses. The most common skin cancer in transplant recipients is squamous cell carcinoma followed by basal cell carcinoma, while in the general population this ratio is reversed. Melanoma and cutaneous lymphoma are relatively rare although they occur more frequently in transplant patients than in the general population. Notably some tumors, such as Kaposi's sarcoma, are seldom encountered in the general population while they are frequently observed in transplant recipients. Local recurrences and visceral spreading are not so uncommon and pose a major issue for quality of life and overall prognosis of these patients. Timely diagnosis is essential and may be challenging, since the accuracy of clinical diagnosis is modest; thus skin biopsy is an essential tool for appropriate management. In this review, we describe the most common types of skin cancer in renal transplant recipients, with a focus on pathogenic issues that account for the different epidemiology and clinical expression of these neoplasms in this population.

Melanotic and non-melanotic malignancies of the face and external ear - A review of current treatment concepts and future options

Skin has the highest incidence and variety of tumors of all organs. Its structure is of great complexity, and every component has the potential to originate a skin neoplasm (SN). Because of its exposed nature, skin is vulnerable to carcinogenic stimuli such as UV radiation. Various entities can cause SN. Nonmelanotic skin cancers (NMSC) are the most common of all cancers, with over one million cases diagnosed annually in the US. Basal cell carcinoma (BCC) accounts for approximately 80% of all NMSC, most of the remaining 20% being squamous cell carcinoma (SCC). The skin of the head and neck is the most common site for tumors, accounting for more than 80% of all NMSC. BCC, SCC, and malignant melanomas (MM) represent 85-90% of all SN. Merkel cell tumors (MCC), lymphoepithelioma-like carcinomas of the skin (LELCS), dermato-fibro-sarcomas, leiomyosarkomas, and Kaposi-sarcomas are less frequent in the facial skin region and the external ear. Based on data from the German Federal Cancer Registry (2003/2004), 140,000 people in Germany were affected by SN (100,000 BCC, 22,000 SCC, 22,000 MM). This number increases considerably if malignant precursors, such as actinic keratosis, are included. Each year, the frequency of SN diagnosis rises by 3-7%. Among all known malignant tumors, MM exhibits the highest rate of increase in incidence. In the past, SN was primarily diagnosed in people aged 50 years or older. However, recently, the risk for developing SN has shifted, and younger people are also affected. Early diagnosis is significantly correlated with prognosis. Resection of SN creates defects that must be closed with local or microvascular flaps to avoid functional disturbing scar formation and deflection of the nose, eyelids, or lips. All therapeutic strategies for SN, the current standard for adjuvant and systemic treatment, and the management of the increasing number of patients under permanent blood thinner medication are described with regard to the treatment of SN.