Narrow excision margins are appropriate for Merkel cell carcinoma when combined with adjuvant radiation: Analysis of 188 cases of localized disease and proposed management algorithm

Increased risk of recurrence and disease-specific death following delayed postoperative radiation for Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is often treated with surgery and postoperative radiation therapy (PORT). The optimal time to initiate PORT (Time-to-PORT [ttPORT]) is unknown.

PURPOSE

We assessed if delays in ttPORT were associated with inferior outcomes.

METHODS

Competing risk regression was used to evaluate associations between ttPORT and locoregional recurrence (LRR) for patients with stage I/II MCC in a prospective registry and adjust for covariates. Distant metastasis and death were competing risks.

RESULTS

The cohort included 124 patients with median ttPORT of 41 days (range: 8-125 days). Median follow-up was 55 months. 17 (14%) patients experienced a LRR, 14 (82%) of which arose outside the radiation field. LRR at 5 years was increased for ttPORT >8 weeks vs ≤ 8 weeks, 28.0% vs 9.2%, P = .006. There was an increase in the cumulative incidence of MCC-specific death with increasing ttPORT (HR = 1.14 per 1-week increase, P = .016).

LIMITATIONS

The relatively low number of LRRs limited the extent of our multivariable analyses.

CONCLUSIONS

Delay of PORT was associated with increased LRR, usually beyond the radiation field. This is consistent with the tendency of MCC to spread quickly via lymphatics. Initiation of PORT within 8 weeks was associated with improved locoregional control and MCC-specific survival.

Exploring diagnosis and therapeutic complexities of an aggressive Merkel cell carcinoma: A case report and review of the literature

Merkel cell carcinoma (MCC) is an aggressive and rare cutaneous neuroendocrine carcinoma that predominantly affects the sun-damaged skin of the head and neck region, extremities, and trunk of older white individuals. Microscopically, MCC is characterized by nests or sheets of uniform small round blue cells with scant cytoplasm, granular nuclei with a salt-and-pepper chromatin pattern, high proliferative activity, and occasional necrosis. They are usually positive for epithelial and neuroendocrine markers, particularly for cytokeratin 20 and AE1/AE3 in a paranuclear dot-like staining. We herein contribute by reporting a case of MCC affecting the auricular pavilion of a 66-year-old female patient from Campinas, Brazil. Additionally, a review of the current literature is also included to analyze all the cases that have been reported in the English-language literature, totalizing 27 cases of MCC on the external ear. The 5-year overall survival rate for individuals with localized MCC is 50% and the most common treatment choice is the combination of surgery with adjuvant radiotherapy and sentinel lymph node biopsy.

Moderne Diagnostik und Therapie des Merkelzellkarzinoms

Das Merkelzellkarzinom (MCC) ist ein seltener, aggressiver Hauttumor mit epithelialer und neuroendokriner Differenzierung, dessen Inzidenz in den letzten Jahrzehnten deutlich zugenommen hat. Risikofaktoren sind fortgeschrittenes Lebensalter, heller Hauttyp, UV‐Exposition und Immunsuppression. Pathogenetisch wird ein durch das Merkelzell‐Polyomavirus (MCPyV) hervorgerufener Typ von einem UV‐induzierten Typ mit hoher Tumormutationslast unterschieden.

Klinisch präsentiert sich das MCC als meist schmerzloser, schnell wachsender, rötlich‐violetter Tumor mit glänzender Oberfläche, der bevorzugt im Kopf‐Hals‐Bereich und an den distalen Extremitäten lokalisiert ist. Eine sichere Diagnose kann nur anhand histologischer und immunhistochemischer Merkmale gestellt werden. Bei Erstdiagnose weisen 20%–26% der Patienten lokoregionäre Metastasen und 8%–14% Fernmetastasen auf, weshalb eine Ausbreitungsdiagnostik unabdingbar ist. Bei fehlenden klinischen Hinweisen auf Metastasen wird eine Sentinel‐Lymphknotenbiopsie empfohlen.

Wesentliche Säulen der Therapie sind die Operation, die adjuvante oder palliative Strahlentherapie und in fortgeschrittenen inoperablen Stadien die medikamentöse Tumortherapie. Die Einführung von Immuncheckpoint‐Inhibitoren führte zu einem Paradigmenwechsel, da sich hiermit ein wesentlich langfristigeres Ansprechen und bessere Überlebensraten als mit Chemotherapie erreichen lassen. Zur Therapie des metastasierten MCC ist in Deutschland der PD‐L1‐Inhibitor Avelumab zugelassen, aber auch die PD‐1‐Antikörper Pembrolizumab und Nivolumab werden mit Erfolg eingesetzt. Adjuvante und neoadjuvante Therapiekonzepte, Immunkombinationstherapien und zielgerichtete Therapien als Monotherapie oder in Kombination mit Immuncheckpoint‐Inhibitoren befinden sich in klinischer Prüfung.

Modern diagnostics and treatment of Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer with epithelial and neuroendocrine differentiation, the incidence of which has increased substantially during the last decades. Risk factors include advanced age, fair skin type, UV exposure, and immunosuppression. Pathogenetically, a type caused by the Merkel cell polyomavirus is distinguished from a UV-induced type with a high tumor mutational burden. Clinically, MCC presents as a mostly painless, rapidly growing, reddish-violet tumor with a shiny surface, which is preferentially localized in the head-neck region and at the distal extremities. A reliable diagnosis can only be made based on histological and immunohistochemical features. At initial diagnosis, 20-26% of patients show locoregional metastases and 8-14% distant metastases, making staging examinations indispensable. If there is no clinical evidence of metastases, a sentinel lymph node biopsy is recommended. Essential columns of therapy are surgery, adjuvant or palliative radiotherapy and, in advanced inoperable stages, medicamentous tumor therapy. The introduction of immune checkpoint inhibitors has led to a paradigm shift, as they provide a considerably longer duration of response and better survival rates than chemotherapy. The PD-L1 inhibitor avelumab is approved for treatment of metastatic MCC in Germany, but the PD-1 antibodies pembrolizumab and nivolumab are also used with success. Adjuvant and neoadjuvant treatment concepts, immune combination therapies and targeted therapies as monotherapy or in combination with immune checkpoint inhibitors are in the clinical trial phase.

Primary tumor site for localized Merkel cell carcinoma drives different management strategies without impacting oncologic outcomes

BACKGROUND AND PURPOSE

Clinically localized Merkel cell carcinoma (MCC) has been associated with high rates of disease relapse. This study examines how primary tumor anatomic site drives patterns of care and outcomes in a large cohort treated in the contemporary era.

MATERIALS AND METHODS

Patterns of care and associated outcomes were evaluated for clinically Stage I-II MCC patients treated at our institution with adjuvant radiation therapy (RT) to the primary site and/or regional nodal basin as a component of their curative intent therapy between 2014-2021.

RESULTS

Of 80 patients who met inclusion criteria, the primary tumor anatomic site was head and neck (HN) for 42 (53%) and non-head and neck (NHN) for 38 (47%). Primary tumor risk factors were similar between cohorts. Fewer patients with HN tumors had wide local excision (WLE; HN-81% vs. NHN-100% p < 0.01). Of those undergoing WLE, patients with HN tumors received higher dose adjuvant RT (>50 Gy: HN-70% vs. NHN-8%; p < 0.01). Patients with HN tumors were less likely to undergo sentinel lymph node biopsy (HN-62%vs. NHN-100%; p < 0.01) and more likely to have elective nodal RT (HN-48% vs. NHN-0%). Despite varying management strategies, there was no significant difference in local recurrence-free survival (3-yr LRFS HN-94% vs. NHN-94%; p = 0.97), nodal recurrence-free survival (3-yr NRFS HN-89% vs. NHN-85%; p = 0.71) or overall recurrence-free survival (3-yr RFS 73% HN vs. 80% NHN; p = 0.44).

CONCLUSIONS

Among patients with primary MCC who had RT as a component of their initial treatment strategy, anatomically-driven heterogeneous treatment approaches were associated with equally excellent locoregional disease control.

The Evolving Treatment Landscape of Merkel Cell Carcinoma

OPINION STATEMENT

Merkel cell carcinoma (MCC) has a high risk of recurrence and requires unique treatment relative to other skin cancers. The patient population is generally older, with comorbidities. Multidisciplinary and personalized care is therefore paramount, based on patient preferences regarding risks and benefits. Positron emission tomography and computed tomography (PET-CT) is the most sensitive staging modality and reveals clinically occult disease in ~ 16% of patients. Discovery of occult disease spread markedly alters management. Newly diagnosed, localized disease is often managed with sentinel lymph node biopsy (SLNB), local excision, primary wound closure, and post-operative radiation therapy (PORT). In contrast, metastatic disease is usually treated systemically with an immune checkpoint inhibitor (ICI). However, one or more of these approaches may not be indicated. Criteria for such exceptions and alternative approaches will be discussed. Because MCC recurs in 40% of patients and early detection/treatment of advanced disease is advantageous, close surveillance is recommended. Given that over 90% of initial recurrences arise within 3 years, surveillance frequency can be rapidly decreased after this high-risk period. Patient-specific assessment of risk is important because recurrence risk varies widely (15 to > 80%: Merkelcell.org/recur) depending on baseline patient characteristics and time since treatment. Blood-based surveillance tests are now available (Merkel cell polyomavirus (MCPyV) antibodies and circulating tumor DNA (ctDNA)) with excellent sensitivity that can spare patients from contrast dye, radioactivity, and travel to a cancer imaging facility. If recurrent disease is locoregional, management with surgery and/or RT is typically indicated. ICIs are now the first line for systemic/advanced MCC, with objective response rates (ORRs) exceeding 50%. Cytotoxic chemotherapy is sometimes used for debulking disease or in patients who cannot tolerate ICI. ICI-refractory disease is the major problem faced by this field. Fortunately, numerous promising therapies are on the horizon to address this clinical need.

Merkel cell carcinoma: a forty-year experience at the Peter MacCallum Cancer Centre

BACKGROUND

Merkel cell carcinoma (MCC) is a rare but highly aggressive neuroendocrine skin malignancy, with Australia having the highest reported incidence in the world. There is currently a lack of consensus regarding optimal management of this disease.

METHODS

This was a retrospective audit conducted by reviewing existing medical records of MCC patients presenting to the Peter MacCallum Cancer Centre (PMCC) between 1980 and 2018. The primary endpoint was locoregional recurrence. The secondary endpoints were distant recurrence, disease-free survival (DFS) and overall survival (OS).

RESULTS

A total of 533 patients were identified. Locoregional recurrence occurring at one, two and 5 years was 24, 31 and 32%, respectively. The estimated 5-year OS and DFS were 46% (95% Confidence Interval [CI] 41-51%) and 34% (95% CI 30-39%) respectively. Older age at diagnosis (hazard ratio [HR] per year = 1.07, 95% CI 1.06-1.07, p < 0.001), and larger primary tumour diameter (HR =1.16, 95% CI 1.03-1.31, p = 0.019) were associated with worse OS on multivariable analysis. Positive or negative histopathological margin status was not associated with OS or DFS differences in patients treated with post-operative radiotherapy.

CONCLUSIONS

In our study, about a third of patients developed locoregional recurrence, distal recurrence or both, and there appears to be no change over the last four decades. If treated with adjuvant radiotherapy, there is no difference in OS or DFS with positive surgical margins. Findings should influence future guidelines.

Merkel Cell Carcinoma-Update on Diagnosis, Management and Future Perspectives

MCC is a rare but highly aggressive skin cancer. The identification of the driving role of Merkel cell polyomavirus (MCPyV) and ultraviolet-induced DNA damage in the oncogenesis of MCC allowed a better understanding of its biological behavior. The presence of MCPyV-specific T cells and lymphocytes exhibiting an 'exhausted' phenotype in the tumor microenvironment along with the high prevalence of immunosuppression among affected patients are strong indicators of the immunogenic properties of MCC. The use of immunotherapy has revolutionized the management of patients with advanced MCC with anti-PD-1/PD L1 blockade, providing objective responses in as much as 50-70% of cases when used in first-line treatment. However, acquired resistance or contraindication to immune checkpoint inhibitors can be an issue for a non-negligible number of patients and novel therapeutic strategies are warranted. This review will focus on current management guidelines for MCC and future therapeutic perspectives for advanced disease with an emphasis on molecular pathways, targeted therapies, and immune-based strategies. These new therapies alone or in combination with anti-PD-1/PD-L1 inhibitors could enhance immune responses against tumor cells and overcome acquired resistance to immunotherapy.

Clinicopathological features, MCPyV status and outcomes of Merkel cell carcinoma in solid-organ transplant recipients: a retrospective, multicentre cohort study

BACKGROUND

The proportion of Merkel cell carcinomas (MCCs) in solid-organ transplant recipients (SOTR) harbouring Merkel cell polyomavirus (MCPyV) is unknown, as are factors affecting their outcomes.

OBJECTIVE

To describe clinicopathological features of MCC in SOTR, investigate the tumoral MCPyV-status and identify factors associated with tumour outcomes.

METHODS

Retrospective, international, cohort-study. MCPyV-status was investigated by immunohistochemistry and polymerase chain reaction.

RESULTS

A total of 30 SOTR and 44 consecutive immunocompetent patients with MCC were enrolled. SOTR were younger at diagnosis (69 vs. 78 years, P < 0.001). Thirty-three percent of SOTR MCCs were MCPyV-positive vs. 91% of immunocompetent MCCs (P = 0.001). Solid-organ transplantation was associated with an increased cumulative incidence of progression (SHR: 3.35 [1.57-7.14], P = 0.002), MCC-specific mortality (SHR: 2.55 [1.07-6.06], P = 0.034) and overall mortality (HR: 3.26 [1.54-6.9], P = 0.002). MCPyV-positivity and switching to an mTOR inhibitor (mTORi) after MCC diagnosis were associated with an increased incidence of progression (SHR: 4.3 [1.5-13], P = 0.008 and SHR: 3.6 [1.1-12], P = 0.032 respectively) in SOTR.

LIMITATIONS

Retrospective design and heterogeneity of SOTR cohort.

CONCLUSIONS

MCPyV appears to play a less prominent role in the aetiopathogenesis of MCC in SOTR. SOTR have a worse prognosis than their immunocompetent counterparts and switching to an mTORi after the diagnosis of MCC does not improve progression.

Evidence from Clinical Studies Related to Dermatologic Surgeries for Skin Cancer

Simple Summary

Although significant progress in pharmacotherapy for skin cancer has been made in the past several years, surgical removal of primary skin cancer is still the first choice of treatment unless distant metastases are evident. In the surgical treatment of primary skin tumors, the surgical margin is critical not only for reducing the possibility of tumor recurrence but also for minimizing the cosmetic and functional complications associated with wide local excision. In contrast, dermatologic surgeries including lymph node dissection and skin graft can cause various complications, and these complications are frequently associated with significant morbidity and discomfort. In this review, we summarize the evidence from previous clinical studies regarding the optimal surgical margin for skin cancer and the methods for diminishing the complications associated with dermatologic surgery.

Abstract

Despite the significant progress made in the past several years in pharmacotherapies for skin cancer, such as BRAF/MEK inhibitors, immune checkpoint inhibitors, and Hedgehog pathway inhibitors, surgical removal of primary skin cancer is still the first choice of treatment unless distant metastases are evident. In cases of lymph node metastases with clinically palpable lymphadenopathy, lymph node dissection (LND) is typically performed for most skin cancers. In the surgical treatment of primary skin tumors, the surgical margin is critical not only for reducing the possibility of tumor recurrence but also for minimizing the cosmetic and functional complications associated with wide local excision. In contrast, dermatologic surgery can cause various complications. Although skin graft is frequently used for reconstruction of the surgical defect, extensive graft necrosis may develop if optimal stabilization of the graft is not obtained. LND also sometimes causes complications such as intraoperative or postoperative bleeding and postoperative lymphoceles. Moreover, as in other types of surgery, surgical site infection, intraoperative anxiety, and intraoperative and postoperative pain may also develop. These complications are frequently associated with significant morbidity and discomfort. In this review, we summarize the evidence from previous clinical studies regarding the optimal surgical margin for skin cancer and the methods for diminishing the complications associated with dermatologic surgery.

Diagnosis and treatment of Merkel cell carcinoma: European consensus-based interdisciplinary guideline - Update 2022

Merkel cell carcinoma (MCC) is a rare skin cancer, accounting for less than 1% of all cutaneous malignancies. It is found predominantly in white populations and risk factors include advanced age, ultraviolet exposure, male sex, immunosuppression, such as AIDS/HIV infection, haematological malignancies or solid organ transplantation, and Merkel cell polyomavirus infection. MCC is an aggressive tumour with 26% of cases presenting lymph node involvement at diagnosis and 8% with distant metastases. Five-year overall survival rates range between 48% and 63%. Two subsets of MCC have been characterised with distinct molecular pathogenetic pathways: ultraviolet-induced MCC versus virus-positive MCC, which carries a better prognosis. In both subtypes, there are alterations in the retinoblastoma protein and p53 gene structure and function. MCC typically manifests as a red nodule or plaque with fast growth, most commonly on sun exposed areas. Histopathology (small-cell neuroendocrine appearance) and immunohistochemistry (CK20 positivity and TTF-1 negativity) confirm the diagnosis. The current staging systems are the American Joint Committee on Cancer/Union for international Cancer control 8th edition. Baseline whole body imaging is encouraged to rule out regional and distant metastasis. For localised MCC, first-line treatment is surgical excision with postoperative margin assessment followed by adjuvant radiation therapy (RT). Sentinel lymph node biopsy is recommended in all patients with MCC without clinically detectable lymph nodes or distant metastasis. Adjuvant RT alone, eventually combined with complete lymph nodes dissection is proposed in case of micrometastatic nodal involvement. In case of macroscopic nodal involvement, the standard of care is complete lymph nodes dissection potentially followed by post-operative RT. Immunotherapy with anti-PD-(L)1 antibodies should be offered as first-line systemic treatment in advanced MCC. Chemotherapy can be used when patients fail to respond or are intolerant for anti-PD-(L)1 immunotherapy or clinical trials.

Merkel Cell Carcinoma, the Impact of Clinical Excision Margins and Mohs Micrographic Surgery on Recurrence and Survival: A Systematic Review

BACKGROUND

When treating Merkel cell carcinoma (MCC), the relation between wide local excision (WLE) margin and recurrence or survival is unclear. Mohs micrographic surgery (MMS) is an alternative surgical option for MCC, but it is unknown whether the local recurrence rate differs between MMS and WLE.

OBJECTIVE

To systematically assess the available literature to determine the recurrence and survival rates when treating MCC with MMS and different clinical excision margins.

MATERIALS AND METHODS

The MEDLINE, EMBASE, and CENTRAL databases were searched. Two independent reviewers selected studies that defined clear excision margins and either recurrence or survival. When possible, individual cases were extracted from case series and included in the analyses. Other studies were reviewed narratively.

RESULTS

Overall, 1108 studies were identified; of which, 19 case series (168 cases) and 12 cohort studies were eligible. None of the cohort studies showed significant differences in recurrence or survival for either excision margins or MMS. Equally, logistic and Cox regression analyses of the case series revealed no significant differences in recurrence or survival between different excision margins and MMS.

CONCLUSION

Synthesis of the available data does not indicate differences in recurrence and/or survival rates for MCC between different clinical excision margins and MMS.

Merkel cell carcinoma in the hand. Report of two cases

Merkel-cell-carcinoma of the hand is rare. The Pathological and Immunohistochemical diagnosis helps us to focus the treatment. Immunotherapy has shown beneficial effects in unresectable/advanced/metastatic stages. The quantification of antibodies against Merkel-cell-polyomavirus (MCPyV) can be a useful for prognosis and follow-up. A wide margin in surgery and the sentinel node are the first option with Radiotherapy.

Scientific and clinical developments in Merkel cell carcinoma: A polyomavirus-driven, often-lethal skin cancer

Merkel cell carcinoma (MCC) is a primary neuroendocrine skin cancer that recurs in ~40% of cases. Merkel cell polyomavirus (MCPyV) and ultraviolet (UV)-induced mutations are two major causative factors of MCC. Virus-positive MCCs express polyomavirus oncoproteins that are highly immunogenic yet are required for ongoing tumor growth. Virus-negative MCCs have a high burden of UV-DNA mutations that encode tumor-specific UV-neoantigens. Thus, both UV- and virus-induced MCCs are highly immunogenic, enabling diverse T-cell targeted therapies. Optimal MCC management is challenging given its rarity, aggressive nature, rapidly evolving care guidelines, and fundamental differences in management compared to other skin cancers. MCC is often managed aggressively with extensive surgery, radiotherapy or systemic therapy, frequently leading to toxicities that might have been avoidable while still achieving optimal disease control. Thus, multi-disciplinary care is crucial for providing patients with the best possible outcomes. The outlook for many patients with advanced MCC has progressed remarkably over the past decade due to PD-1 pathway blocking agents that provide durable benefit for a substantial subset of MCC patients. The management of early-stage MCC has also improved due to better approaches to integrate surgery and radiotherapy. Prognostic accuracy and ongoing surveillance have advanced due to stage-specific recurrence data and sophisticated "liquid biopsies" that allow early detection of disease recurrence. Here we summarize both recent striking progress and pressing challenges such as PD-(L)1-refractory MCC, and management of MCC patients with immune dysfunction. We also highlight diverse resources to allow providers to take advantage of recent progress in this fast-moving field.

Merkel Cell Carcinoma: An Immunotherapy Fairy-Tale?

Merkel cell carcinoma (MCC) is a rare, highly aggressive, neuroendocrine cutaneous tumor. The incidence of MCC is growing worldwide, and the disease-related mortality is about three-fold higher than melanoma. Since a few years ago, very little has been known about this disease, and chemotherapy has been the standard of care. Nowadays, new discoveries about the pathophysiology of this neoplasm and the introduction of immunotherapy allowed to completely rewrite the history of these patients. In this review, we provide a summary of the most important changes in the management of Merkel cell carcinoma, with a focus on immunotherapy and a landscape of future treatment strategies.

Updates on the diagnosis, current and future therapeutic options in Merkel-cell carcinoma

Merkel-cell carcinoma (MCC) is a rare and extremely aggressive nonmelanocytic cutaneous neuroendocrine carcinoma. Historically, it has been associated with limited therapy options and poor prognosis. While its incidence has been rising over the last two decades, recent discoveries and a better understanding of its pathogenesis, viral association and immunologic features have allowed for the emergence of new therapies. Surgical excision with or without radiotherapy remains the first-line therapy for primary lesions without evidence of metastatic disease. The majority of MCC cases are regrettably diagnosed at advanced stages and oftentimes require systemic therapy. There have been several significant advances in the treatment of MCC in the last decade. Among these have been the development of immune checkpoint inhibitors targeting the programmed death protein-1 (PD-1)/programmed death ligand-1 (PDL-1). Despite recent success of immunotherapy, nearly 50% of patients diagnosed with MCC still succumb to the disease. Fortunately, there has been a number of new targeted therapies that hold great promise. Among them are phosphatidylinositide-3kinase (Pl3K) inhibitors, adoptive T-cell immunotherapy, activated NK-92 cells infusions and therapeutic vaccines. Additional emerging therapeutic targets include cellular ubiquitin-specific processing protease 7 (Usp7) that restricts viral replication and IFN genes (STING), activation of which promotes an antitumor inflammatory response.

Multimodal Strategy in Localized Merkel Cell Carcinoma: Where Are We and Where Are We Heading?

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine tumor of the skin whose incidence is rising. Multimodal treatment is crucial in the non-metastatic, potentially curable setting. However, the optimal management of patients with non-metastatic MCC is still unclear. In addition, novel insights into tumor biology and newly developed treatments (e.g., immune checkpoint inhibitors) that dramatically improved outcomes in the advanced setting are being investigated in earlier stages with promising results. Nevertheless, the combination of new strategies with consolidated ones needs to be clarified. We reviewed available evidence supporting the current treatment recommendations of localized MCC with a focus on potentially ground-breaking future strategies. Advantages and disadvantages of the different treatment modalities, including surgery, radiotherapy, chemotherapy, and immunotherapy in the non-metastatic setting, are analyzed, as well as those of different treatment modalities (adjuvant as opposed to neoadjuvant). Lastly, we provide an outlook of remarkable ongoing studies and of promising agents and strategies in the treatment of patients with non-metastatic MCC.

Association Between Surgical Margins Larger Than 1 cm and Overall Survival in Patients With Merkel Cell Carcinoma

Importance

Current recommendations regarding the size of local excision (LE) margins for Merkel cell carcinoma (MCC) have not been well established.

Objective

To assess whether larger clinical LE margins and receipt of adjuvant radiotherapy are associated with improvements in overall survival (OS) among patients with localized MCC.

Design, Setting, and Participants

This large multicenter retrospective cohort study used records from the National Cancer Database to identify adult patients with localized stage I or stage II MCC who underwent LE between January 1, 2004, and December 31, 2015. Data were analyzed from August 1, 2020, to January 25, 2021.

Exposures

Local excision margin size and adjuvant radiotherapy.

Main Outcomes and Measures

Overall and net survival were assessed using Cox multivariable regression analysis.

Results

A total of 6156 patients with localized MCC (median age at diagnosis, 77 years [range, 27-90 years]; 2500 women [40.6%]). In the multivariable regression analysis, LE clinical margins larger than 1.0 cm were associated with improvements in OS (HR, 0.88; 95% CI, 0.81-0.95; P < .001) compared with margins of 1.0 cm or smaller, regardless of tumor subsite. At 5 years after surgery, LE margins of 1.0 cm or smaller were associated with a net survival of 76.7%, while LE margins larger than 1.0 cm were associated with a net survival of 89.8% (P < .001). Stratification of LE margins into 3 subgroups indicated that LE margins of 1.1 to 2.0 cm (HR, 0.87; 95% CI, 0.76-0.99; P = .047) and larger than 2.0 cm (HR, 0.84; 95% CI, 0.72-0.98; P = .03) were associated with improvements in OS compared with margins of 1.0 cm or smaller. In patients with less aggressive disease (ie, those who were immunocompetent and had tumors ≤1.0 cm, no lymphovascular invasion, and negative pathologic margins), LE margins larger than 1.0 cm were also associated with improvements in OS (HR, 0.87; 95% CI, 0.78-0.97; P = .01). Among patients who received adjuvant radiotherapy, larger LE margins were associated with improvements in OS (HR, 0.87; 95% CI, 0.76-0.98; P = .03). Receipt of adjuvant radiotherapy was also associated with improvements in OS within the 3 LE margin subgroups. Patients who received adjuvant radiotherapy and had LE margins of 1.0 cm or smaller (HR, 0.81; 95% CI, 0.74-0.89; P < .001) experienced OS that was comparable to that in patients who did not receive adjuvant radiotherapy and had LE margins larger than 1.0 cm (HR, 0.80; 95% CI, 0.71-0.89; P = .87).

Conclusions and Relevance

In this study, LE clinical margins larger than 1.0 cm were associated with improvements in OS, and these improvements were independent of tumor subsite, receipt of adjuvant radiotherapy, positive pathologic margins, or adverse pathologic features for stage I to stage II MCC. Patients with LE margins of 1.0 cm or smaller who received adjuvant radiotherapy experienced OS that was similar to that of patients with larger LE margins who did not receive radiotherapy. The combination of LE clinical margins larger than 1.0 cm and adjuvant radiotherapy was associated with the highest OS.

Cutaneous Malignancies of the Head and Neck

Cutaneous malignancies (CMs), or skin cancers, are the most common cancer worldwide, with a quarter million cases diagnosed annually in the United States alone. The best described risk factor for CM is ultraviolet radiation from sunlight, and therefore most of these cancers develop in sun-exposed skin, including the head and neck. Beginning with melanoma, immunotherapy has increasingly been used over the past decade for treatment of unresectable CM, and immune checkpoint inhibitors are now Food and Drug Administration-approved for first-line treatment of unresectable melanoma, Merkel cell carcinoma, and cutaneous squamous cell carcinoma, and second-line for basal cell carcinoma.

How we treat Merkel cell carcinoma: within and beyond current guidelines

Merkel cell carcinoma (MCC) is an aggressive skin cancer associated with a high risk of local recurrence and distant metastasis. Optimal care of this potentially life-threatening cancer is critical but challenging because: physicians are often unfamiliar with its management due to rarity, and MCC management remains controversial, in part because it is rapidly evolving across multiple specialties. While guidelines offer a broad overview of management, they are often not sufficient when making decisions for individual patients. Herein, we present a literature review as well as practical approaches adopted at our institutions for staging, surveillance and therapy of MCC. Each of these areas are discussed in light of how they can be appropriately customized for prevalent but challenging situations. We also provide representative examples of MCC patient scenarios and how they were managed by a multidisciplinary team to identify suitable evidence-based, individualized treatment plans.

Merkel cell carcinoma (MCC) is a skin cancer with a high risk of recurrence and distant spread. Optimal care of this cancer is important. However, management is challenging because it is rare and its treatment is continuously evolving across multiple specialties. While treatment guidelines offer a broad overview of management, they are often not detailed enough to provide appropriate patient-specific assistance. Herein, we present a review of recent studies and our suggestions relevant to MCC staging, surveillance and treatment options. Each of these areas are discussed in light of how they can be appropriately customized for challenging situations often encountered by practitioners. We also provide representative examples of MCC patient scenarios and how they were managed by a multidisciplinary team to identify evidence-based, individualized treatment plans.

Merkel cell carcinoma of the eyelid and periocular region: A review

Merkel cell carcinoma (MCC) is a rare primary cutaneous neuroendocrine carcinoma with a high mortality rate. It typically affects elderly Caucasians, with a slight predilection for males. It is associated with chronic sun exposure and/or immunosuppression. Almost half of all cases occur on the head or neck and an estimated 2.5%–10% arise on the eyelids or periocular skin. It ranks as the 5^th most common malignant tumor at these sites, preceded in frequency by basal cell, squamous cell and sebaceous carcinoma, as well as melanoma. Its clinical presentation as a violaceous nodule/plaque lacks specificity, and it can be mistaken for cysts, chalazia or basal cell carcinomas. Sub-specialized histopathological and immunohistochemical evaluations are required for diagnosis. Clinical staging defines the extent of disease and governs management. This includes surgery and adjuvant radiotherapy for localized tumors and of late, immunotherapy for metastatic disease. Significant advances in our understanding of the dual etiopathogenesis (Merkel cell polyomavirus- and Ultraviolet radiation-induced) and the biology of the neoplasm have been achieved in recent years. Issuing from the tumor's known susceptibility to host immunity, a recent therapeutic breakthrough has occurred whereby immune checkpoint inhibition has been shown to mitigate advanced disease. These factors and the increased global incidence of the tumor have brought it to the forefront of medical attention. This review provides a clinically relevant update on MCC, with special reference to cases arising on the eyelid/periocular region.

Narrow resection margins are not associated with mortality or recurrence in patients with Merkel cell carcinoma: A retrospective study

BACKGROUND

Wide local excision constitutes the standard of care for Merkel cell carcinoma, but the optimal margin width remains controversial.

OBJECTIVES

To assess whether narrow margins (0.5-1 cm) were associated with outcome.

METHODS

Patients were recruited from a retrospective French multicentric cohort and included if they had had excision of primary tumor with minimum lateral margins of 0.5 cm. Factors associated with mortality and recurrence were assessed by multivariate regression.

RESULTS

Among the 214 patients included, 58 (27.1%) had undergone excision with narrow margins (0.5-1 cm) versus 156 (72.9%) with wide margins (>1 cm). During a median follow-up of 50.7 months, cancer-specific survival did not differ between groups (5-year specific survival rate 76.8% [95% confidence interval 61.7%-91.9%] and 76.2% [95% confidence interval 68.8%-83.6%], respectively). Overall survival, any recurrence-free survival, and local recurrence-free survival did not significantly differ between groups. Cancer-specific mortality was associated with age, male sex, American Joint Committee on Cancer stage III, and presence of positive margins.

LIMITATIONS

Retrospective design, heterogenous baseline characteristics between groups.

CONCLUSION

Excision with narrow margins was not associated with outcome in this cohort, in which most patients had clear margins and postoperative radiation therapy. Residual tumor, mostly found on deep surgical margins, was independently associated with prognosis.