Sentinel lymph node biopsy in patients with Merkel cell carcinoma: an emerging role and the Westmead hospital experience

Mucocutaneous toxicities from MEK inhibitors: a scoping review of the literature

BACKGROUND

MEK inhibitors cause a wide spectrum of mucocutaneous toxicities which can delay or interrupt life-saving therapy.

PURPOSE

To summarize the morphology, incidence, and clinical presentation of mucocutaneous toxicities from MEK inhibitors via a scoping review of the literature.

METHODS

We conducted a scoping review of the published literature, including clinical trials, retrospective and prospective studies, reviews, and case reports and series. All included literature was analyzed by a panel of pediatric and adult oncodermatologists.

RESULTS

Of 1626 initial citations, 227 articles met final inclusion criteria. Our review identified follicular reactions, ocular toxicities, xerosis, eczematous dermatitis, edema, and paronychia as the most common mucocutaneous side effects from MEK inhibitor therapy. Grade 1 and 2 reactions were the most prevalent and were typically managed while continuing treatment; however, grade 3 toxicities requiring dose reductions or treatment interruptions were also reported.

CONCLUSION

Mucocutaneous toxicities to MEK inhibitor therapy are common and most often mild in severity. Early recognition and treatment can mitigate disruptions in oncologic therapy.

Merkel Cell Carcinoma: A 28-Year Experience

OBJECTIVE

To evaluate the management and recurrence outcomes of head and neck Merkel cell carcinoma (HN-MCC) at a single institution.

STUDY DESIGN

A retrospective review of outcomes in patients with HN-MCC.

SETTING

A tertiary center from May 1990 to December 2018.

SUBJECTS AND METHODS

Electronic medical records of patients with HN-MCC were reviewed.

RESULTS

Sixty cases were included, with 67% (40 of 60) males and a mean age of 73.3 years. Imaging had a moderate sensitivity and specificity for detection of occult disease when compared with histopathologic analysis. Forty-two percent (25 of 60) of patients underwent neck dissection, and 12% (7 of 60) had a sentinel lymph node biopsy (SLNB). There was a high rate of negative SLNB findings. The majority of patients were treated with surgery alone (29 of 60), followed by a cohort (21 of 60) treated with surgery plus adjuvant treatment, and 10 of 60 patients were treated with radiation therapy with or without chemotherapy. Recurrence-free survival was 50%, 45%, and 42% at 1, 2, and 5 years.

CONCLUSIONS

We report higher recurrence rates and higher negative SLNB result rates than other studies. Our results affirm that imaging may not be a substitute for SLNB and that it had an intermediate ability to identify the occult disease. Traditional predictors, including SLNB and cervical node pathology, may not identify patients at risk for recurrence in HN-MCC. We report similar recurrence rates in patients who had treatment of the cervical nodes by radiation therapy or neck dissection as compared with those who did not receive neck treatment.

Expression of 15-lipoxygenase-1 in Merkel cell carcinoma is linked to advanced disease

BACKGROUND

The purpose of this study was to determine whether the expression of 15-lipoxygenase-1 (ALOX15) in primary tumour specimens predicts lymph node metastasis and subsequently clinical outcome in Merkel cell carcinoma (MCC) patients.

METHODS

A retrospective medical chart review of 33 patients was performed between 1994 and 2014. Eleven out of 33 (33%) Patients with primary MCC stages I and II were categorised as group I. Twenty two out of 33 (67%) Patients with regional lymph node metastases and/or distant metastases were defined as group II. All available tumour samples were immunostained for ALOX15, Podoplanin and MCPyV large T-protein antibody.

RESULTS

ALOX15 expression was observed in 19/23 (83%) primary tumour samples and in all lymph node metastasis. Primary tumours in patients with stage III and IV disease showed a higher expression rate of ALOX15 compared to patients with early stage disease (11/12 (92%) and 8/11 (73%), respectively). In group I, five patients (45%) were MCPyV positive, whereas in group II, 15 patients (68%) were MCPyV positive. The median lymphatic vessel density in ALOX15 negative group I primary tumour samples was lower compared to the median lymphatic vessel density in ALOX15 positive group I primary tumour probes (2.7 range, 1-4.3 vs 4.7 range, 4.0-7.3). Furthermore, all 17 samples of MCC metastases showed ALOX15 expression with a median lymphatic vessel density (not lymph node metastases) of 5.3 (range 2.0-7.3).

CONCLUSION

In the current study, we were able to show ALOX15 expression in the primary MCC sample and the metastasis sample. Based on the findings of the current study, expression rate of ALOX15 in primary MCC and metastases is possibly linked to an increased lymphatic vessel density.

Merkel cell carcinoma: emerging biology, current approaches, and future directions

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine cutaneous cancer that predominantly occurs in patients who are older, and is associated with a high rate of distant failure and mortality. Current management strategies that incorporate surgery and radiotherapy achieve high rates of locoregional control, but distant failure rates remain problematic, highlighting the need for new effective systemic therapies. Chemotherapy can achieve high response rates of limited duration in the metastatic setting, but its role in definitive management remains unproven. Recent developments in our knowledge about the biology of MCC have led to the identification of new potential therapeutic targets and treatments. A key finding has been the discovery that a human polyomavirus may be a causative agent. However, emerging data suggests that MCC may actually be two distinct entities, viral-associated and viral-negative MCC, which is likely to have implications for the management of MCC in the future and for the development of new treatments. In this review, we discuss recent discoveries about the biology of MCC, current approaches to management, and new therapeutic strategies that are being investigated.

Sentinel lymph node biopsy in Merkel cell carcinoma: a 15-year institutional experience and statistical analysis of 721 reported cases

Merkel cell carcinoma (MCC) is a rare aggressive cutaneous neuroendocrine malignancy that frequently metastasizes to the regional lymphatic basin. Pathological assessment of regional lymph nodes with sentinel lymph node biopsy (SLNB) in patients without clinical involvement has permitted more accurate staging and more appropriate management. Nonetheless, concerns have been raised regarding the accuracy of this technique and its prognostic implications. We conducted a review of previously published data analysing the positive and false negative rates of SLNB in MCC. A search of the Medline and Embase databases to April 2015 identified 36 published studies between 1997 and 2015 comprising 692 patients. With the addition of 29 patients treated at our own institution, we conducted an analysis of 721 patients. Among this cumulative cohort, SLNBs were performed from 736 regional sites with 29·6% recorded as positive. Regional metastasis occurred in 45 cases following a negative SLNB, for a false negative rate of 17·1%. Adjuvant regional radiotherapy in the setting of a negative SLNB did not affect regional recurrence (P = 0·31), providing credence to emerging evidence that regional therapy can be safely omitted in the setting of a negative SLNB. Distant relapse was noted far more frequently following a positive rather than negative SLNB (17·6% vs. 7·3%, P < 0·001).

Lack of clinical impact of 18 F-fluorodeoxyglucose positron emission tomography with simultaneous computed tomography for stage I and II Merkel cell carcinoma with concurrent sentinel lymph node biopsy staging: A single institutional experience from Westmead Hospital, Sydney

BACKGROUND/OBJECTIVE

¹⁸ F-fluorodeoxyglucose (FDG) positron emission tomography with simultaneous computed tomography (PET-CT) FDG PET-CT plays an important clinical role in the staging and management of Merkel cell carcinoma (MCC) although its role in stage I and II disease relative to a sentinel lymph node biopsy (SLNB) is undefined. This study aimed to compare the clinical impact of FDG PET-CT and SLNB on management in stage I and II MCC.

METHODS

This was a retrospective observational study. Between 2000 and 2014, 65 patients with biopsy-proven MCC (all stages) underwent a staging FDG PET-CT as part of their investigations in Westmead Hospital, Sydney. Since 2006, 26 patients have had an SLNB and of these, 16 underwent both an SLNB and FDGPET-CT. All 16 patients had a histological diagnosis consistent with MCC without clinical evidence of regional or distant metastases prior to SLNB and FDG PET-CT (stages IB and IIB). These patients were assessed with respect to MCC staging and the subsequent change of patient management post-SLNB and FDG PET-CT.

RESULTS

The SLNB identified occult lymph node metastases in 10 patients (63%), with FDG PET-CT positive in only one patient (6%). Of the six SLNB-negative patients, none demonstrated additional metastases on the FDG PET-CT.

CONCLUSIONS

In patients with stage I and II MCC, FDG PET-CT is less sensitive than an SLNB in detecting occult metastatic lymph nodes. The routine use of FDG PET-CT in these patients may not be justified.

A systematic review of patients with Merkel cell carcinoma of the head and neck and a negative sentinel lymph node biopsy

Background

A negative sentinel lymph node biopsy (SLNB) from patients with head and neck Merkel cell carcinoma (HNMCC) may allow the patient to avoid further adjunctive therapies. However, there is considerable regional variability of lymphatic drainage from primary sites involving the head and neck, and Merkel cell carcinoma (MCC) has aggressive biologic behavior.

Objective

The primary aim of this systematic review was to document the incidence of regional recurrence and mortality from HNMCC patients after a negative SLNB.

Methods

A systematic search of the English literature was conducted via Ovid Medline and Embase from inception until 2013 and the Cochrane Central Register of Controlled Trials from 1991 to January 2014.

Results

Twenty-three studies, with a total of 81 patients matched the inclusion criteria. The incidence of regional recurrence from the entire cohort was 12.3%, and there was a 5% mortality rate. The mean follow-up time, excluding the 30 patients who did not have individual follow-up times specified, was 32.8 months.

Limitations

This review included studies had variable follow-up durations and treatments for MCC.

Conclusions

Despite negative pathologic staging of the neck using SLNB in HNMCC patients, there is still a high incidence of regional recurrence and mortality, over a short follow-up period.

•

Merkel cell carcinoma is an aggressive neoplasm.

•

Patients with a negative sentinel lymph node biopsy from head and neck Merkel cell carcinoma showed a high incidence of future regional lymph node involvement.

•

In this context, a negative sentinel lymph node biopsy is not necessarily reassuring for the patient or the clinician.

Merkel cell carcinoma in East Yorkshire: A case series and literature review of current management

INTRODUCTION

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine tumour of the skin. The incidence is rising and it is associated with sun exposure and immunosuppression. Our aim was to perform a 10-year retrospective review of MCC treated in East Yorkshire and to examine disease progression, surgical and adjuvant management, and outcomes.

METHODS

A 10-year retrospective review was undertaken of patients identified through the histopathology database. Case notes and digital patient records were examined for patient demographics, disease characteristics, management and outcome. Disease stage was calculated using the 2010 AJCC TNM classification.

RESULTS

Thirty-seven patients with complete records were included. Twenty-one patients were male and 16 female, with mean age 76.7 years at presentation. Pre-malignant or malignant skin changes were documented in 15 patients, and immunosuppression in 15 patients. Mean duration of lesion was 17.5 weeks. Following diagnosis 22/37 patients underwent further surgery with 11 patients undergoing sentinel lymph node (LN) biopsy. LN disease was palpable at presentation in 8 patients. Three year survival is 40%.

CONCLUSIONS

There is no standardised management of MCC and randomised trials are challenging due to relatively small numbers. There has been little progress made in terms of improving survival. Development of a national database for patients with this condition would allow prospective data collection and more accurate assessment of current treatment protocols and their efficacy.

LEVEL OF EVIDENCE

IV.

The important role of radiation treatment in the management of Merkel cell carcinoma

Merkel cell carcinoma is an aggressive, radiosensitive cutaneous neuroendocrine tumour. In this review, the roles of radiation therapy and chemoradiation in the management of Merkel cell carcinoma are described and discussed, and guidelines for patient management are presented. Radiation treatment may be indicated for definitive (> 55 Gy) or adjuvant (> 50 Gy) treatment of the primary tumour site and for prophylactic (> 50 Gy), adjuvant (> 50 Gy) or definitive (> 55 Gy) treatment of the regional lymph node field. If a patient presents with positive margins after initial biopsy or resection, definitive radiation therapy or chemoradiation may be an alternative to further surgery and, importantly, results in less delay than re-resection followed by adjuvant radiation treatment. Given the rarity of this tumour, patients should be enrolled on prospective databases and clinical trials, and managed in a multidisciplinary clinical setting wherever possible.

Prognostic significance of sentinel lymph node mapping in Merkel cell carcinoma: systematic review and meta-analysis of prognostic studies

Aim. To assess through a systematic review and meta-analysis of the literature the prognostic implication of sentinel lymph node mapping in Merkel cell carcinoma (MCC). Materials and Methods. PubMed and SCOPUS databases were searched by using “Merkel AND sentinel” as keywords. All studies with prognostic information regarding SLN mapping in cN0 MCC patients were included. Hazard ratio (HR) for overall survival (OS) and disease free survival (DFS) was used as effect size. Results. SLN biopsy predicted better DFS and OS as compared to the nodal observation in cN0 MCC patients (pooled HR for DFS: 1.61 (95% CI: 1.05–2.46), P = 0.028; pooled HR for OS: 1.08 (95% CI: 0.55–2.10), P = 0.8). Pathologically negative SLN (SLN−) patients had better OS (pooled HR: 4.42 (95% CI: 1.82–10.7), P = 0.0009) and DFS (pooled HR: 2.58 (95% CI: 1.78–3.73)) as compared to SLN+ patients. Conclusion. SLN mapping can provide strong prognostic information regarding OS and DFS in cN0 MCC patients. More importantly, SLN mapping can improve DFS and possibly OS in cN0 MCC patients as compared to nodal observation. As MCC is a rare tumor, large multicenter prospective studies are still needed to validate the survival benefit of SLN mapping.

Role of sentinel lymph node biopsy in patients with Merkel cell carcinoma: statistical analysis of 403 reported cases

BACKGROUND

Merkel cell carcinoma (MCC) is a rare cutaneous malignancy with a high rate of nodal metastasis. Sentinel lymph node biopsy (SLNB) is used in MCC and other cancers to identify regional node micrometastases in patients with clinically negative nodes; however, whether SLN status is associated with recurrence or prognosis in MCC is unclear.

METHODS

A statistical analysis was performed of 397 published cases of MCC with SLNB results from 22 reports and 6 new cases, in order to elucidate any correlation between SLN status and recurrence, and to determine false-negative rates for SLNB.

RESULTS

Of these 403 cases, 128 (31.8 %) had positive SLNs; 16 of these 128 (12.5 %) developed recurrence (6 nodal, 10 distant). Of 275 patients with negative SLNs, 27 (9.8 %) developed recurrence (19 nodal, 8 distant). Patients with positive SLNs had a greater risk of distant metastasis (OR 2.82; P = 0.037; 95 % CI 1.089-7.347). The false-negative rate for SLNB in all 403 patients was 12.9 %. Use of the immunohistochemical approach to diagnosis of micrometastasis with anti-CK20 antibody did not affect the false-negative rate.

CONCLUSIONS

Patients with positive SLNs had a greater risk of distant metastasis in MCC; positive SLN was an important prognostic factor in MCC. Further studies using standardized, more-sensitive techniques to examine entire SLNs may decrease the false-negative rate, and improve the significance of SLNB in MCC.

Shared decision-making in treatment of Merkel cell carcinoma

An 82-year-old woman presented with an asymptomatic mass, rapidly growing on her left cheek for the previous 3 months. Punch biopsy of the tumour was performed, and the pathology was compatible with Merkel cell carcinoma. A resection margin of more than 1 cm would involve left oral commissura, potentially damaging speech, eating and drinking ability. The patient had a strong wish of keeping surgery simple in order to maintain quality of life. Tumour excision was performed with 1 cm resection margin, and postoperatively the patient was referred to adjuvant radiation therapy. Sensibility of upper and lower lip remained unaffected, while motor innervation of left upper lip was impaired. Despite this, the patient's ability to talk and eat was unaffected. Surgery, with adjunctive radiation therapy, is the first-line of treatment for the primary tumour. The option for a more conservative treatment is not first choice, but can be considered upon individual assessment.

Sentinel lymph node biopsy in nonmelanoma skin cancer patients

The management of lymph nodes in nonmelanoma skin cancer patients is currently still debated. Merkel cell carcinoma (MCC), squamous cell carcinoma (SCC), pigmented epithelioid melanocytoma (PEM), and other rare skin neoplasms have a well-known risk to spread to regional lymph nodes. The use of sentinel lymph node biopsy (SLNB) could be a promising procedure to assess this risk in clinically N0 patients. Metastatic SNs have been observed in 4.5-28% SCC (according to risk factors), in 9-42% MCC, and in 14-57% PEM. We observed overall 30.8% positive SNs in 13 consecutive patients operated for high-risk nonmelanoma skin cancer between 2002 and 2011 in our institution. These high rates support recommendation to implement SLNB for nonmelanoma skin cancer especially for SCC patients. Completion lymph node dissection following positive SNs is also a matter of discussion especially in PEM. It must be remembered that a definitive survival benefit of SLNB in melanoma patients has not been proven yet. However, because of its low morbidity when compared to empiric elective lymph node dissection or radiation therapy of lymphatic basins, SLNB has allowed sparing a lot of morbidity and could therefore be used in nonmelanoma skin cancer patients, even though a significant impact on survival has not been demonstrated.

A practical update of surgical management of merkel cell carcinoma of the skin

The role of surgeons in the treatment of Merkel cell carcinoma (MCC) of the skin is reviewed, with respect to diagnosis and treatment. Most of the data in the literature are case reports. Surgery is the mainstay of treatment. A wide local excision, with sentinel node (SLN) biopsy, is the recommended treatment of choice. If SLN is involved, nodal dissection should be performed; unless patient is unfit, then regional radiotherapy can be given. Surgeons should always refer patients for assessment of the need for adjuvant treatments. Adjuvant radiotherapy is well tolerated and effective to minimize recurrence. Adjuvant chemotherapy may be considered for selected node-positive patients, as per National Comprehensive Cancer Network guideline. Data are insufficient to assess whether adjuvant chemotherapy improves survival. Recurrent disease should be treated by complete surgical resection if possible, followed by radiotherapy and possibly chemotherapy. Generally results of multimodality treatment for recurrent disease are better than lesser treatments. Future research should focus on newer chemotherapy and molecular targeted agents in the adjuvant setting and for gross disease.

Merkel cell carcinoma of the head and neck: a single institutional experience

Merkel cell carcinoma (MCC) is a rare cutaneous malignancy occurring mostly in older immunocompromized Caucasian males. A growing incidence of MCC has been reported in epidemiological studies. Treatment of MCC usually consists of surgical excision, pathological lymph node evaluation, and adjuvant radiotherapy. This paper reports the experience of a single tertiary center institution with 17 head and neck Merkel cell carcinoma patients. Median followup for the cohort was 37.5 months. After five years, recurrence-free survival, disease specific survival, and overall survival were 85%, 90%, and 83%, respectively. Our limited data support the use of adjuvant radiotherapy. We also report two cases of MCC located at the vestibule of the nose and two cases of spontaneous regression after diagnostic biopsy. About 40% of our patients were referred to our center for surgical revision and pathological lymph node evaluation. Increased awareness of MCC and an interdisciplinary approach are essential in the management of MCC.

A review of radiotherapy for merkel cell carcinoma of the head and neck

Merkel cell carcinoma of the head and neck (MCCHN) presents a clinical challenge due to its aggressive natural history, unpredictable lymphatic drainage, and high degree of treatment related morbidity. Histological examination of the regional lymph nodes is very important in determining the optimal treatment and is usually achieved by sentinel lymph node biopsy. Radiotherapy plays a critical role in the treatment of most patients with MCCHN. Surgery with adjuvant radiotherapy to the primary tumour site is associated with high local control rates. If lymph nodes are clinically or microscopically positive, adjuvant radiotherapy is indicated to decrease the risk of regional recurrence. The majority of locoregional recurrences occur at the edge or just outside of the radiation field, reflecting both the inherent radiosensitivity of MCC and the importance of relatively large volumes to include “in-transit” dermal lymphatic pathways. When surgical excision of the primary or nodal disease is not feasible, primary radiotherapy alone should be considered as a potentially curative modality and confers good loco-regional control. Concurrent chemoradiotherapy is well tolerated and may further improve outcomes.