Selective lymphadenectomy in patients with Merkel cell (cutaneous neuroendocrine) carcinoma

The Role of Sentinel Lymph Node Biopsy in the Management of Merkel Cell Carcinoma: A Systematic Review and Meta-analysis

Background

Merkel cell carcinoma (MCC) is a rare cutaneous malignancy with high metastatic potential. Sentinel lymph node biopsy (SLNB) is used to assess locoregional spread, facilitate staging, and inform prognosis. Positive nodal status is associated with higher recurrence rates and reduced overall survival.

Methods

A systematic search was conducted. Eligible articles included patients diagnosed with MCC, who would be candidates for or who had SLNB. The Covidence tool was used for screening and data extraction, including additional treatments, disease-free survival, overall survival, and recurrence. Methodological quality was assessed using the Newcastle-Ottowa Scale criteria.

Results

SLNB was associated with increased likelihood of completion lymphadenectomy (223 versus 41), regional radiotherapy (2167 versus 808), and systemic chemotherapy (138 versus 31). Overall survival for patients undergoing SLNB was 81% at 2 years, 75% at 3 years, and 72% at 5 years (odds ratio: 0.79). Hazard ratio for positive SLNB versus negative was 3.36 (P < 0.001). Five-year disease recurrence was 23.3% in patients undergoing SLNB.

Conclusions

Lymph node metastases are associated with reduced overall survival and increased recurrence of MCC. Determining nodal status early can inform prognosis, facilitate staging, and determine need for adjuvant treatment. Adjuvant treatments are associated with reduced mortality and improved overall survival; SLNB is an important influencer of their use. Early prophylactic intervention should be considered in MCC in both positive and negative nodal status to improve overall outcomes. Widespread use of SLNB will allow more accurate assessment of the role of nodal status on adjuvant treatment and long-term outcomes.

Tissue sealants for the prevention of lymphoceles after radical inguinal lymph node dissection in patients with melanoma: A systematic review and individual patient data meta-analysis

BACKGROUND AND OBJECTIVES

Postoperative lymphoceles and further wound complications occur frequently after radical inguinal lymph node dissection (ILND). In various studies, tissue sealants have shown to reduce the incidence of postoperative morbidity.

METHODS

A systematic review and meta-analysis of randomized controlled trials (RCTs) investigating the effectiveness of tissue sealants in reducing the incidence of postoperative lymphoceles following ILND in patients with melanoma was conducted. Individual patient data was requested to pool the data for meta-analysis appropriately.

RESULTS

Thousand seven hundred twenty-nine manuscripts were screened for eligibility. Six RCTs published between 1986 and 2012 were identified including 194 patients for ILND. Only four RCTs were included in the meta-analysis. No study properly defined the term "lymphocele." Tissue sealants failed to influence the duration of drain placement (mean difference [MD] = -3.05 days; z = 1.18; P = 0.24), total drainage volume (MD = 598.39 mL; z = 1.49; P = 0.14), the incidence of postoperative seroma, wound infection and skin necrosis.

CONCLUSIONS

No improvement was identified with the use of tissue sealants, however, a valid comparison of the results of included trials was difficult owing to the lack of a definition of the term "lymphocele." Other surgical techniques and trials using validated endpoint definitions are required to reevaluate these findings.

Systematic review of sentinel lymph node biopsy in Merkel cell carcinoma of the head and neck

BACKGROUND

Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous neuroendocrine tumor arising on the head and neck in 40%-50% of patients. Between 20% and 40% will harbor subclinical nodal metastasis.

METHODS

Using search terms 'Merkel AND sentinel', MEDLINE, PUMED, and EMBASE databases were systematically reviewed for publications regarding sentinel lymph node biopsy (SLNB) in classification I and II MCC of the head and neck.

RESULTS

Twenty-nine publications encompassing 136 patients were included. The SLNB finding was positive in 42 patients (30.9%). Primary MCC was located on the malar/zygomatic (34.4%), forehead/frontal (13.5%), and nasal (13.5%) regions. Recurrence in an SLNB negative nodal basin result occurred in 10 patients (false negative rate of 19.2%). Site of primary MCC was not associated with a false-negative SLNB result; however, there was a non-statistically significant trend for increased frequency among midline lesions.

CONCLUSIONS

Sentinel lymph node biopsy (SLNB) is recommended for eligible patients with classification I and II head and neck MCC.

Sentinel lymph node biopsy in periocular merkel cell carcinoma: a case report

BACKGROUND

The National Comprehensive Cancer Network guidelines for Merkel cell carcinoma recommend performance of the sentinel lymph node biopsy in all patients with clinically negative nodal disease for staging and treatment. Nevertheless, sentinel lymph node biopsy in the periocular region is debated as tumors are typically smaller and lymphatic variability can make performance procedurally problematic.

CASE PRESENTATION

We present a case of a Caucasian patient in their seventies who presented with a 1.0 cm periocular Merkel cell carcinoma, who underwent Mohs surgery with a Tenzel flap repair, that was found to have a positive sentinel lymph node biopsy, but who, despite parotidectomy, selective neck dissection, and radiation, succumbed to the disease.

CONCLUSIONS

Evidence in both the site-specific and non-specific literature demonstrates: (1) Worsening prognosis with extent of lymph node burden, (2) improvements in our abilities to perform lymphoscintigraphy, (3) locoregional and distant metastatic disease in patients with tumor sizes ≤1 cm, and (4) significant rates of sentinel lymph node positivity in patients with tumor sizes ≤1 cm. Our case supports that sentinel lymph node biopsy should be considered in all clinically nodal negative periocular Merkel cell carcinoma, regardless of size, and despite limited site-specific studies on the subject.

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).

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.

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Merkel cell carcinoma is an aggressive neoplasm.

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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.

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

Regional nodal relapse in surgically staged Merkel cell carcinoma

PURPOSE

The nodal relapse pattern of surgically staged Merkel cell carcinoma (MCC) with/without elective nodal radiotherapy (RT) was studied in a single institution.

METHOD

A total of 51 patients with MCC, 33% UICC stage I, 14% II, 53% III (4 lymph node metastases of unknown primary) were eligible. All patients had surgical staging: 23 patients sentinel node biopsy (SNB), 22 patients SNB followed by lymphadenectomy (LAD) and 6 patients LAD. In all, 94% of the primary tumors (PT) were completely resected; 57% of patients received RT, 51% of known PT sites, 33% (8/24 patients) regional RT to snN0 nodes and 68% (17/27 patients) to pN+ nodes, mean reference dose 51.5 and 50 Gy, respectively. Mean follow-up was 6 years (range 2-14 years).

RESULTS

A total of 22% (11/51) patients developed regional relapses (RR); the 5-year RR rate was 27%. In snN0 sites (stage I/II), relapse occurred in 5 of 14 nonirradiated vs. none of 8 irradiated sites (p = 0.054), resulting in a 5-year RR rate of 33% versus 0% (p = 0.16). The crude RR rate was lower in stage I (12%, 2/17 patients) than for stage II (43%, 3/7 patients). In stage III (pN+), RR appeared to be less frequent in irradiated sites (18%, 3/14 patients) compared with nonirradiated sites (33%, 3/10 patients, p = 0.45) with 5-year RR rates of 23% vs. 34%, respectively.

DISCUSSION

Our data suggest that adjuvant nodal RT plays a major role even if the sentinel nodes were negative.

CONCLUSION

Adjuvant RT of the lymph nodes in patients with stage IIa tumors and RT after LAD in stage III tumors is proposed and should be evaluated prospectively.

Diagnosis and management of merkel cell carcinoma of the head and neck: current trends and controversies

Merkel cell carcinoma is an aggressive neuroendocrine cutaneous malignancy with a predilection for regional and distant metastasis. This malignancy presents most commonly on the head and neck of elderly Caucasian males, with a higher prevalence in the immunosuppressed. A high index of suspicion must be maintained due to the often asymptomatic presentation. Lip tumors, scalp tumors, local invasion, nodal metastasis, distant metastasis, and lymphovascular invasion are poor prognostic factors. Up to 8.7% of patients present with distant metastasis, and PET-CT is an accurate staging tool with a 90% sensitivity. Combined aggressive surgical resection with adjuvant radiotherapy affords the best regional control rates. The regional lymphatics must be addressed with either sentinel lymph node biopsy, surgery, or elective radiation due to the risk of occult metastasis. Addition of chemotherapy has no proven benefit in locoregional control.

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.

Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare, clinically aggressive cutaneous neuroendocrine neoplasm with a high mortality rate. Though the etiology is not precisely known, Merkel cell polyomavirus DNA has been found recently in a large percentage of MCC tumors. Other suggested risk factors include sun exposure, immunosuppression, and a history of prior malignancy. Work up of patients with MCC most notably includes nodal staging via clinical examination or sentinel lymph node biopsy. The prognosis for most patients with MCC is poor, and the rarity of MCC precludes the prospective, randomized clinical trials necessary to elucidate optimum treatment protocols. Most published data support the use of a multimodality approach centered around surgical excision with negative margins, sentinel lymph node biopsy to establish the presence or absence of nodal metastases, adjuvant radiothearpy to decrease the risk of recurrence, and systemic chemotherapy in the case of widespread disease.

Role of sentinel lymph node biopsy in the management of merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare and typically aggressive form of skin cancer. It most commonly affects the elderly and has a predilection for the sun-exposed skin of the head and neck region. Other etiological factors include immune suppression, organ transplantation, and polyoma virus infection. MCC has a propensity to spread to regional lymphatics with a high locoregional recurrence rate. Since its discovery in 1972, treatment paradigms have shifted, with no consensus on optimal management strategies. Currently, standard of care includes surgical intervention to the primary and locoregional site with adjuvant radiotherapy for high-risk disease. In this paper, we discuss the history, pathology, and epidemiology of this rare disease with a focus on the evidentiary basis of treatment protocols. The use of sentinel lymph node biopsy as a management option will be the focus of this paper.

Merkel cell carcinoma of unknown primary origin

BACKGROUND

Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor of the skin. MCC from an unknown primary origin (MCCUP) can present a diagnostic and therapeutic challenge. We describe our single-institution experience with the diagnosis and management of MCCUP presenting as metastases to lymph nodes.

METHODS

After institutional review board approval, our institutional database spanning the years 1998-2010 was queried for patients with MCCUP. Clinicopathologic variables and outcomes were assessed.

RESULTS

From a database of 321 patients with MCC, 38 (12%) were identified as having nodal MCCUP. Median age was 67 years, and 79% were men. Nodal basins involved at presentation were cervical (58%), axillary/epitrochlear (21%), or inguinal/iliac (21%). CK20 staining was positive in 93% of tumors tested, and all were negative for thyroid transcription factor-1. Twenty-nine patients (76%) underwent complete regional lymph node dissection (LND): 3 had LND alone, ten had LND and adjuvant radiotherapy, and 16 underwent LND followed by chemoradiotherapy. Definitive chemoradiotherapy without surgery was provided to six patients (16%), while radiotherapy alone was provided to three (8%). Recurrence was observed in 34% of patients. Median recurrence-free survival was 35 months. Ten patients (26%) died, five of disease and five of other causes. The median overall survival was 104 months.

CONCLUSIONS

Nodal MCCUP is a rare disease affecting primarily elderly white men. Recurrence is observed in approximately one-third of patients, with a 104 month median overall survival after a multimodal treatment approach consisting of surgery along with adjuvant chemotherapy and radiotherapy in the majority of patients.

Merkel cell carcinoma: an Australian perspective and the importance of addressing the regional lymph nodes in clinically node-negative patients

BACKGROUND

Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous malignancy. Nodal status has prognostic significance.

OBJECTIVE

We sought to analyze for factors predictive of survival and explore the significance of lymph node status and indication for sentinel lymph node biopsy in patients with MCC.

METHODS

A review was undertaken of 136 patients presenting with MCC at our institution between 1980 and 2008. Patient and tumor characteristics, treatment, and patterns of relapse were analyzed.

RESULTS

Ninety patients presented with stage I disease, and 46 presented with stage II disease. The median follow-up time was 21 months. In all, 74 patients developed relapse with the commonest site of relapse in the regional lymph nodes. A total of 24 patients developed nodal relapse without prior treatment of the nodal basin. The 5-year survival was 62% and the median disease-free interval was 16 months. Radiotherapy was associated with a better disease-free survival (P < .001) and overall survival was worse as the number of involved lymph nodes increased (P = .03).

LIMITATIONS

This was a retrospective review with a prolonged accrual time.

CONCLUSION

A high rate of nodal relapse occurred in patients with stage I disease who had undergone treatment of the primary site only. These patients may have benefited from sentinel lymph node biopsy and subsequent treatment of the nodal basin if micrometastatic disease was present, as the number of involved nodes impacted negatively on survival. Conversely, sentinel lymph node biopsy may be used to select those patients with clinical stage I disease who may avoid elective nodal treatment. Radiotherapy should have a routine role in the management of MCC.

Radiation therapy in the management of Merkel cell carcinoma: current perspectives

Merkel cell carcinoma (MCC) is a rare cutaneous neuroendocrine neoplasm with a propensity for metastatic spread. When managing MCC, surgical excision is often the initial treatment. As MCC is generally radiosensitive, many institutions include adjuvant radiation therapy (RT) in their standard treatment protocols. In the absence of prospective randomized clinical trials, a number of retrospective reports suggest that adjuvant RT can improve local and regional recurrence rates. Here, we provide an overview of recent studies on the use of RT in MCC treatment and explore the limits of the current knowledge. Ultimately, the benefits and risks associated with using RT in the treatment of MCC remain poorly described and merit more rigorous investigation.

Recurrence and survival in patients undergoing sentinel lymph node biopsy for merkel cell carcinoma: analysis of 153 patients from a single institution

BACKGROUND

Merkel cell carcinoma (MCC) is a cutaneous neuroendocrine neoplasm with propensity for lymphatic spread. The rarity of MCC has limited analysis of factors associated with a positive sentinel lymph node biopsy (SLNB) and survival.

METHODS

Review of a prospective MCC database was performed. Factors associated with SLNB positivity were analyzed. Univariate and multivariate analyses of factors associated with recurrence and survival were performed using the cumulative incidence (CI) function, treating death from other causes as a competing risk.

RESULTS

From 1996 to 2010, a total of 153 patients with localized MCC underwent SLNB, of whom 45 (29%) were positive. Factors associated with SLNB positivity were primary tumor size (25% ≤2 cm vs. 45% >2 cm; P = 0.02) and presence of lymphovascular invasion (LVI) (55% LVI positive vs. 4% LVI negative; P < 0.01). SLNB-positive patients were more likely to receive radiation or chemotherapy (60% vs. 7%, P < 0.01). With median follow-up of 41 months, there were 16 nodal/distant recurrences (10%), 11 deaths from MCC (7%), and 27 death from other causes (18%). The 2-year CIs of recurrence or death from MCC were 12% and 6%, respectively. There was no difference in recurrence or death from MCC between SLNB-positive and -negative patients. The 2-year CIs of recurrence or death from MCC for LVI-positive patients were 30% and 15%, respectively. No LVI-negative patient experienced recurrence of disease or died of MCC.

DISCUSSION

SLNB identifies occult nodal metastases in 29% of patients with localized MCC. Predictors of SLNB positivity are tumor size and presence of lymphovascular invasion (LVI). Patients with SLNB-positive disease are more likely to receive further treatment; however, sentinel lymph node (SLN) status is not associated with recurrence or survival. In contrast, LVI is strongly associated with both recurrence and survival.

Features predicting sentinel lymph node positivity in Merkel cell carcinoma

PURPOSE

Merkel cell carcinoma (MCC) is a relatively rare, potentially aggressive cutaneous malignancy. We examined the clinical and histologic features of primary MCC that may correlate with the probability of a positive sentinel lymph node (SLN).

METHODS

Ninety-five patients with MCC who underwent SLN biopsy at the University of Michigan were identified. SLN biopsy was performed on 97 primary tumors, and an SLN was identified in 93 instances. These were reviewed for clinical and histologic features and associated SLN positivity. Univariate associations between these characteristics and a positive SLN were tested for by using either the χ(2) or the Fisher's exact test. A backward elimination algorithm was used to help create a best multiple variable model to explain a positive SLN.

RESULTS

SLN positivity was significantly associated with the clinical size of the lesion, greatest horizontal histologic dimension, tumor thickness, mitotic rate, and histologic growth pattern. Two competing multivariate models were generated to predict a positive SLN. The histologic growth pattern was present in both models and combined with either tumor thickness or mitotic rate.

CONCLUSION

Increasing clinical size, increasing tumor thickness, increasing mitotic rate, and infiltrative tumor growth pattern were significantly associated with a greater likelihood of a positive SLN. By using the growth pattern and tumor thickness model, no subgroup of patients was predicted to have a lower than 15% to 20% likelihood of a positive SLN. This suggests that all patients presenting with MCC without clinical evidence of regional lymph node disease should be considered for SLN biopsy.

A review of the epidemiology and treatment of Merkel cell carcinoma

Merkel cell carcinoma is a very rare and aggressive neoplasm. Due to its rarity, therapeutic guidelines are not well established, especially for regionally advanced disease. Articles in English, French, Italian, Portuguese, and Spanish from the last 20 years were identified in MEDLINE and reviewed. The key word "Merkel" was used for the search, relevant articles were selected, and their references were examined. The most important articles related to epidemiology, genesis and treatment were reviewed. The incidence of Merkel cell carcinoma is increasing due to the advancing age of the population, higher rates of sun exposure and an increasing number of immunocompromised individuals. With regard to etiology, the recently described Merkel Cell polyomavirus is thought to play a role. Either local or regional surgical intervention remains the standard of care, but adjuvant radiotherapy or radiotherapy as a primary treatment have been discussed as reasonable therapeutic options. An update on this rare neoplasia is essential because of its increasing incidence and changing treatment options.

Updated Review of the Pathogenesis and Management of Merkel Cell Carcinoma

Background:

Merkel cell carcinoma is a rare, aggressive, malignant cutaneous tumor of the elderly or immunosuppressed individuals that usually appears on sun-exposed areas of the body. Its pathogenesis is still debated, and, currently, no standardized treatment exists.

Objective:

To provide a current updated review of the most relevant data concerning the pathogenesis and management of Merkel cell carcinoma.

Methods:

Using relevant MeSH terms, we performed a review of the literature on these subjects from 1980 to June 2009.

Results and Conclusion:

The current management of Merkel cell carcinoma is based on surgical excision as the majority of patients present with localized disease, whereas up to 30% have regional lymph node metastases. In these cases, the best outcome is achieved with multidisciplinary management that includes radiotherapy. Chemotherapy is part of the treatment in advanced cases and is mandatory for distant metastatis. Given that a recent work showed the presence of a previously unknown polyomavirus, which the authors called Merkel cell polyomavirus, the therapeutical approach to Merkel cell carcinoma could be reconsidered in the future.

Intraoperative Imprint Cytology for Evaluation of Sentinel Lymph Nodes from Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous malignancy. Intraoperative imprint cytology (IIC) can potentially avoid second operations for completion lymphadenectomy when nodal metastases are found during nodal staging with sentinel lymph node biopsy (SLN). This represents the first series of IIC for MCC we are aware of and our initial experience. Patients with biopsy-proven MCC underwent SLN (at the time of wide excision) using a double indicator technique with “technetium sulfur colloid and isosulfan blue. SLN were identified and bisected and touch imprints of each half were made. One half was air-dried and stained with Diff-Quick and the other was fixed with 95 per cent alcohol and stained with hematoxylin and eosin (H&E). Paraffin-embedded sections were examined by H&E. Eighteen patients underwent successful SLN mapping procedures. IIC was negative in 84.2 per cent (16) cases. Three false-negatives occurred with IIC, but there were no false-positives, making the sensitivity 33 per cent and the specificity 100 per cent. Two of four patients with positive pathology-confirmed SLN also had positive IIC. SLN mapping has usefulness in patients with MCC. IIC is feasible and accurate in evaluating the SLN. IIC is a practical diagnostic tool when intraoperative analysis of SLN biopsy is desired for MCC.

A comprehensive overview of radioguided surgery using gamma detection probe technology

The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology.

Management of merkel cell carcinoma: the roles of lymphoscintigraphy, sentinel lymph node biopsy and adjuvant radiotherapy

BACKGROUND

Merkel cell carcinoma (MCC) is an uncommon, highly aggressive skin malignancy with a propensity to recur locally and regionally. However, its optimal treatment is uncertain. In this study, we aimed to assess the roles of lymphoscintigraphy and sentinel node (SN) biopsy, as well as radiotherapy, in the treatment of MCC.

PATIENTS AND METHODS

A retrospective analysis of 17 patients diagnosed with MCC (median age 74 years) over a 7-year period (median follow-up 16 months) was performed.

RESULTS

Of 11 patients. 3 had a positive SN biopsy and, despite adjuvant radiotherapy, 2 of these 3 developed regional lymph node (RLN) recurrence. Of the remaining 8 patients who had a negative SN biopsy, however, 5 also had RLN recurrences. There were 9 patients who received adjuvant radiotherapy (RT) to the primary site, with no in-field recurrences; and 8 who received RT to their RLN field, with only 2 developing regional nodal recurrences-both were SN biopsy positive. During the follow-up period, 2 patients died, only 1 due to MCC.

CONCLUSION

The results suggest that SN status may not be an accurate predictor of loco-regional recurrence in MCC. However, they strongly reinforce previous reports that radiotherapy, both locally and to regional nodes, provides effective infield disease control.

A comprehensive review of the treatment of Merkel cell carcinoma

Merkel cell carcinoma (MCC) is an uncommon but malignant cutaneous neuroendocrine carcinoma with a high incidence of local recurrence, regional lymph node metastases, and subsequent distant metastases. The etiology of MCC remains unknown. It usually occurs in sun-exposed areas in elderly people, many of whom have a history of other synchronous or metachronous sun-associated skin lesions. The outcome for most patients with MCC is generally poor. Surgery is the mainstay of treatment. The role of adjuvant therapy has been debated. However, data from recent development support a multimodality approach, including surgical excision of primary tumor with adequate margins and sentinel lymph node dissection followed by postoperative radiotherapy in most cases, as current choice of practice with better locoregional control and disease-free survival. Patients with regional nodal involvement or advanced disease should undergo nodal dissection followed by adjuvant radiotherapy and, perhaps, systemic platinum-based chemotherapy in most cases.

Merkel cell carcinoma: critical review with guidelines for multidisciplinary management

Merkel cell carcinoma (MCC) is a relatively rare cutaneous malignancy that occurs predominantly in the older white population. The incidence of MCC appears to have tripled during the past 20 years; an increase that is likely to continue because of the growing number of older Americans. The pathogenesis of MCC remains largely unknown. However, ultraviolet radiation and immunosuppression are likely to play a significant pathogenetic role. Many questions currently remain unanswered regarding the biologic behavior and optimal treatment of MCC. Large, prospective, randomized studies are not available and are unlikely to be performed because of the rarity of the disease. The objective of this review was to provide a comprehensive reference for MCC based on a critical evaluation of the current data. The authors investigated the importance of sentinel lymph node biopsy as a staging tool for MCC to assess the status of the regional lymph node basin and to determine the need for additional therapy to the lymph node basin. In an attempt to standardize prospective data collection with the intention to define prognostic indicators, the authors also present histopathologic profiles for primary MCC and sentinel lymph nodes. The controversies regarding the appropriate surgical approach to primary MCC, the use of adjuvant radiation therapy, and the effectiveness of adjuvant chemotherapy were examined critically. Finally, the authors have provided treatment guidelines based on the available evidence and their multidisciplinary experience.

Sentinel node biopsy in oral squamous cell carcinoma

The clinical utility of sentinel node biopsy techniques for cutaneous melanoma has led multiple investigators to study the applicability of this approach to other solid tumors, including cancers of the upper aerodigestive tract, and especially the oral cavity. Preliminary data indicate that it may be useful for early oral cancers, with the exception of floor of mouth tumors, where technical challenges related to the proximity of the lymphatic basin remain a problem. A multi-institutional pathologic validation trial, involving sentinel node biopsy followed by completion selective neck dissection, has completed accrual. While central step sectioning and immunohistochemistry remain to be completed and analyzed, routine pathologic techniques provided negative predictive values of 96% for oral cancer excluding floor of mouth lesions. Subsequent trials need to involve clinical follow-up and evaluation for recurrence in the neck. We believe this technique may ultimately play a role in the management of early oral cancer.

Merkel cell carcinoma of the head and neck: is adjuvant radiotherapy necessary?

BACKGROUND

Controversy exists regarding the optimal management of patients with Merkel cell carcinoma. The primary aim of this study was to determine whether combined treatment with surgery and radiotherapy improves outcome in a multi-institutional cohort of patients with Merkel cell carcinoma of the head and neck. The secondary aims were to determine by stage, which patients derive benefit from combined therapy and to identify predictors for survival on multivariable analysis.

METHODS

A retrospective analysis of 110 patients with Merkel cell carcinoma of the head and neck was performed. Data were collected from 3 tertiary care institutions (Westmead Hospital, Sydney, Australia; Princess Margaret Hospital, Toronto, Canada; Royal Prince Alfred Hospital, Sydney). There were 78 males and 32 females, median age was 70 years, and mean follow-up of survivors was 2.3 years. Sixty-six patients underwent combined treatment, and 44 patients had either surgery or radiotherapy alone. Analysis by stage was performed using 2 staging systems.

RESULTS

Local and regional control at 5 years was 84% and 69%, respectively. Combined treatment improved both local (p = .009) and regional control (p = .006). Overall and disease-specific survival at 5 years was 49% and 62%, respectively. Combined treatment was associated with significantly better disease-free survival on univariable analysis (p = .013) When analyzed by stage, patients with stage IIb (primary >1 cm, node negative) disease who underwent combined treatment had improved disease-free (p = .005) and disease-specific survival (p = .035). Predictors of survival on multivariable analysis were age >70 years (HR 6.19, p < .001), primary tumor size >1 cm (HR 7.55, p < .001), number of nodal metastases divided into none, <or= 2 and >2 (HR 3.71 per stratum, p < .001). When analyzed with age and disease stage, treatment modality trended toward significance as a predictor of disease-specific (p = .081) and overall survival (p = .076). Disease stage was the most powerful independent predictor on Cox regression (HR 5.43 per stratum, p < .001).

CONCLUSIONS

Merkel cell carcinoma is an aggressive cutaneous malignancy. Age and disease stage are the most important predictors of survival. Combined surgery and radiotherapy improves both locoregional control and disease-free survival. Patients with stage II disease appear to derive the greatest benefit from adjuvant radiotherapy, including improved disease specific survival.

Adjuvant Radiation Therapy Is Associated With Improved Survival in Merkel Cell Carcinoma of the Skin

Purpose

Merkel cell carcinoma (MCC) is a rare cutaneous malignancy. Because of the absence of randomized studies, the real benefit of adjuvant radiation therapy in MCC is unclear. The aim of this study was to better define the role of adjuvant radiation therapy in the management of MCC.

Methods

The Surveillance, Epidemiology, and End Results (SEER) survey from the National Cancer Institute was queried from 1973 through 2002. Retrospective analysis was performed. The end point of the study was overall survival.

Results

There were 1,665 cases of MCC in the SEER registry. Presentation by stage were 55% stage I, 31% stage II, and 6% stage III. Eight percent of the cases could not be staged because of incomplete data. Surgical intervention was a component of therapy in 89% of the cases (n = 1,487). The median survival for the entire cohort was 49 months, and median follow-up was 40 months. Adjuvant radiation was a component of therapy in 40% of the surgical cases. The median survival for those patients receiving adjuvant radiation therapy was 63 months compared with 45 months for those treated without adjuvant radiation. The use of radiation was associated with an improved survival for patients with all sizes of tumors, but the improvement with radiation use was particularly prominent when analyzing those patients with primary lesions larger than 2 cm.

Conclusion

The use of adjuvant radiation therapy is associated with improved survival in patients with MCC. Prospective evaluation of adjuvant radiation therapy in this setting is warranted.

Predictors of survival and recurrence in the surgical treatment of merkel cell carcinoma of the extremities

PURPOSE

Merkel cell carcinoma (MCC) is a rare and aggressive malignancy that originates within the extremities in about 40% of cases. Treatment approaches to this tumor have not been standardized. The purpose of this study was to examine treatment approaches to extremity MCC and to determine predictors of recurrence and patient survival.

METHODS

A retrospective review of 38 consecutive patients with surgically treated extremity MCC was performed. Patient demographics, histologic tumor stage and location and pre-existing malignancies were recorded. Patients were treated by wide-local excision (WLE) or Mohs' technique. Clinically negative regional lymph nodes were either observed (n = 16) or staged with elective lymphadenectomy or sentinel lymph node dissection (SLND) (n = 17), and clinically positive nodes underwent therapeutic node dissection (n = 5). Adjuvant radiotherapy (n = 21) and chemotherapy (n = 6) were noted, as well as time to tumor recurrence and overall patient survival. Predictors of recurrence and survival were analyzed using Kaplan-Meier method and log rank test.

RESULTS

There was no difference in local recurrence rates when comparing Mohs' technique to WLE for the treatment of primary tumors. Although there was no survival advantage to lymph node dissection, lymph node status was effective in predicting the risk of regional recurrence. Radiation reduced the local recurrence rate (HR = 0.29, 95% CI [0.10, 0.85]), but did not lead to improved overall survival.

CONCLUSION

Margin-negative excision of the MCC remains the mainstay of treatment. Surgical staging, preferably with SLND, identifies patients that may develop regional recurrence. This study further supports the important role of adjuvant radiation therapy in improving locoregional tumor control in the patients with MCC.

Isolated Tibial Metastasis from Merkel Cell Carcinoma

Merkel cell carcinoma is a rare but aggressive neuroendocrine tumor of the skin with high propensity for local, regional and distant soft tissue metastasis not only at initial presentation but also after timely and satisfactory wide-margin surgery. Bone metastases account for 10% of all cases and have been reported involving the calvarium, facial bones and spine related to the head and neck preferential location of this soft tissue malignancy. Appendicular skeletal dissemination is uncommon with only a few cases reported in the radiological literature. We present a case of isolated tibial metastasis from Merkel cell carcinoma occurring 19 months after a technically adequate head and neck tumor resection and lymphadenectomy.

Merkel cell carcinoma: a report of 34 cases and literature review

BACKGROUND

Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer, with unclear histogenesis. To date there is no consensus on the optimal treatment of this neoplasm, with controversy surrounding the use of radiotherapy and chemotherapy. There are also limited data on biological behaviour and prognosis, with reported survival ranging from 31% at three years to 74% at five years.

METHOD

The medical records of 34 patients with a diagnosis of primary MCC, treated at two NHS trusts in Birmingham and Coventry, were reviewed. An extensive review of the English literature was also performed.

RESULTS

MCC occurred predominantly in Caucasians (97%) with a mean age of 75 years. Identified risk factors were a previous history of SCC (37%), BCC (18%) and AK (20%). Ten percent of patients showed evidence of immunocompromise. Most tumours were located on the extremity, where they reached a mean size of 2.1cm. Fifty percent had regional metastasis during the course of their disease. A sub group analysis of the excision margins showed that a 2-cm excision margin, extending to the deep fascia, resulted in a 50% incomplete excision rate and a 33% local recurrence rate. In contrast a 3-cm margin including deep fascia resulted in no incomplete excisions and a 10.5% local recurrence rate Prognosis was poor with a 40% 3-year survival. Combining the data from two trusts has produced a relatively large series and highlighted differences in patient characteristics and management between the units. We advocate a 3-cm excision margin, including fascia wherever possible, combined with post-operative radiotherapy to offer the best chance of local control. Survival is fairly dismal and in keeping with the aggressive nature of this tumour. The respective roles of radiotherapy and chemotherapy remain controversial.

Lymphatic mapping and sentinel node biopsy in Merkel's cell carcinoma

AIM

The purpose of this study was to determine the predictive value of lymphatic mapping with selective lymphadenectomy in patients with Merkel's cell carcinoma.

METHODS

Eight patients with biopsy proven Merkel's cell carcinoma underwent sentinel node biopsy. Lymphoscintigraphy was performed the day before surgery following intradermal injection of 74-111MBq of 99mTc-nanocolloid divided into four doses around the biopsy scar. Dynamic and static images were obtained.

RESULTS

At least one sentinel node was visualized in all patients. The sentinel node was intra-operatively identified with the aid of a hand-held gamma probe in all cases and patent blue dye in six out of eight cases. During surgery, all sentinel nodes were successfully harvested. Metastatic cell deposits were subsequently identified in three patients (37.5%) and they underwent regional lymphadenectomy. No additional involved lymph nodes were identified. No recurrence has been reported in a median follow-up of 4.6 years (range: 8 months-10 years).

CONCLUSIONS

In conclusion, sentinel node biopsy in patients with Merkel's cell carcinoma appears to be a reliable staging technique.

Lymphatic mapping and sentinel lymphadenectomy for 106 head and neck lesions: contrasts between oral cavity and cutaneous malignancy

OBJECTIVES

The objectives of this prospective series were to present our results in 106 sequential cases of lymphatic mapping and sentinel lymph node biopsy (SLNB) in the head and neck region and contrast the experience in oral cancer with that for cutaneous lesions.

HYPOTHESES

SLNB has an acceptably low complication rate in the head and neck. Lymphatic mapping and gamma probe-guided lymphadenectomy can improve the management of malignancies of the head and neck by more accurate identification of the nodal basins at risk and more accurate staging of the lymphatics. For appropriately selected patients, radionuclide lymphatic mapping may safely allow for minimally invasive sentinel lymphadenectomy without formal completion selective lymphadenectomy.

METHODS

One hundred six patients underwent intralesional radionuclide injection and radiologic lymphoscintigraphy (LS) on Institutional Review Board-approved protocols and 103 of these underwent successful SLNB. These included 35 patients with malignant melanoma, 10 cutaneous squamous cell carcinomas, four lip cancers, eight Merkel cell carcinomas, two rare cutaneous lesions, and 43 oral cancers. Mean follow up was 24 months. Patients with oral cavity malignancy underwent concurrent selective neck dissection after narrow-exposure sentinel lymph node excision. In this group, the SLNB histopathology could be correlated with the completion neck specimen histopathology. Patients with cutaneous malignancy underwent SLNB alone and only received regional lymphadenectomy based on positive histology or clinical indications. Data were tabulated for anatomic drainage patterns, complications, histopathology, and patterns of cancer recurrence.

RESULTS

Surgical complications were rare. No temporary or permanent dysfunction of facial or spinal accessory nerves occurred with sentinel node biopsy. Lymphatic drainage to areas dramatically outside of the expected lymphatic basins occurred in 13.6%. Predictive value of a negative sentinel node was 98.2% for cutaneous malignancies (based on regional recurrence) and 92% with oral cancer (based on pathologic correlation). Gross tumor replacement of lymph nodes and redirection of lymphatic flow represented a significant technical issue in oral squamous cell carcinoma. Sixteen percent of patients with oral cancer were upstaged from N0 to N1 after extended sectioning and immunohistochemistry of the sentinel node.

CONCLUSIONS

LS and SLNB can be performed with technical success in the head and neck region. Complications are minimal. More accurate staging and mapping of lymphatic drainage may improve the quality of standard lymphadenectomy. The potential for minimally invasive surgery based on this technology exists, but there is a small risk of missing positive disease. Whether the failure rate is greater than that of standard lymphadenectomy without gamma probe guidance is not known. New studies need to focus on refinements of technique and validation of accuracy as well as biologic correlates for the prediction of metastases.

Merkel cell cancer of the skin

Merkel cell carcinoma (MCC) is a rare malignant cutaneous tumor of the elderly with rapidly growing skin nodules found predominantly on sun-exposed areas of the body. The vast majority of patients present with localized disease, while up to 30% have regional lymph node metastases. Despite local excision and the incidence of local recurrence, regional lymph node metastases and distant metastases is high and usually occurs within 2 years of primary diagnosis. The optimal treatment for patients with MCC remains unclear. The best outcome is achieved with multidisciplinary management including surgical excision of primary tumor with adequate margins and post-operative radiotherapy (RT) to control local and regional disease. Patients with regional nodal metastases should be treated with lymph node dissection plus RT. Adjuvant chemotherapy (CT) should be considered as part of the initial management. In case of metastatic disease CT based on regimens used for small-cell lung cancer is the standard treatment of care.

Lymphoscintigraphic drainage of acral limb skin to interval sentinel lymph nodes in healthy subjects

BACKGROUND AND OBJECTIVES

In the literature, drainage to epitrochlear and popliteal sentinel lymph nodes (SLN) are analyzed for whole or distal extremity (below elbow or knee) melanomas that are not topographically homogeneous with respect to tendency of drainage to interval SLNs. We hypothesize that acral (hand and foot) skin has a uniform frequency of drainage to interval SLNs, which is higher than reported for distal extremity melanomas.

METHODS

One hundred healthy subjects were enrolled. Fifty subjects had standard four extremity lymphoscintigraphies by radiocolloid injection into an interdigital web space as in lymphodynamic studies. On another 50 subjects, either targeted upper (n = 25) or lower (n = 25) extremity lymphoscintigraphies were performed utilizing injection sites that likely drain to interval SLNs. Acral skin drainage to interval SLNs was analyzed for interindividual variability and injection site dependence.

RESULTS

There was considerable interindividual variability in drainage of each injection site to interval SLNs. Hand skin had a uniform 50% frequency of drainage to epitrochlear-midhumeral SLNs with both injection sites. This frequency was higher than the epitroclear SLN frequencies reported for distal extremity melanomas. Foot skin had 10% and 90% frequencies of drainage to popliteal SLNs from standard and targeted injection sites, respectively. Foot skin largely simulates the tendency of drainage reported for distal extremity melanomas while lateral heel represents a limited zone that almost uniformly drains to popliteal SLNs.

CONCLUSIONS

Despite dissimilarities between hand and foot, acral skin drainage to interval SLNs is high enough to obligate a thorough interval SLN exploration in acral primaries.

Impact of sentinel lymph node biopsy in patients with Merkel cell carcinoma: results of a prospective study and review of the literature

PURPOSE

Merkel cell carcinoma (MCC) is the most aggressive of the cutaneous malignancies, showing a propensity to spread to regional lymph nodes (LNs). The aim of this prospective study was to examine the feasibility and clinical impact of sentinel lymph node biopsy (SLNB) in this cutaneous malignancy.

METHODS

The study population comprised 23 patients with stage I MCC (median age 70 years, range 50-85 years). Lymphoscintigraphic mapping with( 99 m)Tc-nanocolloid was performed in all patients. Sentinel lymph nodes (SLNs) were identified, excised and analysed in serial sections by conventional histopathology and cytokeratin-20 immunohistochemistry.

RESULTS

Metastatic disease was determined in the SLNs of 11 patients (47.8%). Elective lymph node dissection (ELND) was performed in eight of these 11 patients, four of whom had additional positive LNs. During follow-up (median 36.1 months, range 3-79 months), seven of the 23 patients (30%) relapsed: four had a local recurrence and three, in-transit metastases. Recurrence developed in two SLN-negative patients with local LN metastases and in one SLN-positive patient with distant metastases. This patient died, representing the only tumour-related death in our sample. Median survival was 49.1 and 35.5 months for SLN-negative and SLN-positive patients, respectively. This difference was not statistically significant (p=0.3452).

CONCLUSION

SLNB allows for exact nodal staging in patients with MCC. Whether additional ELND is of further benefit remains unclear.

A case report of Merkel cell carcinoma on chronic lymphocytic leukemia: differential diagnosis of coexisting lymphadenopathy and indications for early aggressive treatment

BACKGROUND

Chronic lymphocytic leukemia (CLL) is a monoclonal disorder, characterized by a progressive proliferation of functionally incompetent B lymphocytes. There is increased evidence of association between CLL and skin cancers, including the uncommon Merkel cell carcinoma (MCC).

CASE PRESENTATION

A case report of an 84-year old male, who presented with an aggressively recurrent form of MCC on the lower lip, on the background of an 8-year history of untreated CLL. During the recurrences of MCC, coexisting regional lymphadenopathy, posed a problem in the differential diagnosis and treatment of lymph node involvement. Histopathology and immunoistochemistry showed that submandibular lymphadenopathy coexisting with the second recurrence of MCC, was due to B-cell small lymphocytic lymphoma. The subsequent and more aggressive recurrence of the skin tumor had involved the superficial and deep cervical lymph nodes. Surgical excision followed by involved field radiation therapy has been proven effective for both malignancies.

CONCLUSION

MCC has a high incidence of regional lymphadenopathy at presentation (12-45%) and even when it arises on the background of chronic leukemia, lymphadenopathy at presentation should be managed agressively with elective lymph node dissection. We overview the postulated correlation between Merkel tumor and CCL, the differential diagnosis of regional lymphadenopathy during the recurrences of the skin tumor and the strategies of treatment.

Merkel cell carcinoma: prognosis and treatment of patients from a single institution

PURPOSE

Merkel cell carcinoma (MCC) is an uncommon cutaneous malignancy. Most reports consist of single-institution experiences of fewer than 30 patients. The natural history of MCC is poorly defined.

PATIENTS AND METHODS

A review was performed of Memorial Sloan-Kettering Cancer Center's MCC database, identifying 251 patients who had been treated between 1970 and 2002. Patient, tumor, and treatment-related factors were analyzed for their association with recurrence and survival.

RESULTS

The average follow-up for all patients was 40 months and 46 months for patients alive at last follow-up. The 5-year disease-specific survival rate was 64%. Disease stage was the only independent predictor of survival (stage I, 81%; stage II, 67%; stage III, 52%; stage IV, 11%; P = .001). Pathologic staging of the draining nodal basin was performed in 71 (40%) of 177 patients who presented with clinically negative nodes, and 16 of these patients (23%) were found to have node-positive disease. Pathologic nodal staging was associated with improved stage-specific survival probabilities (clinical node-negative, 75% v pathologic node-negative disease, 97%; P = .009) and decreased nodal recurrence (44% v 11%, P < .001). The median time to recurrence was 9 months, and 102 patients (43%) recurred. Local recurrence developed in 8% of patients after margin-negative excision.

CONCLUSION

These data demonstrate that the natural history of MCC is variable and dependent on the stage of disease at presentation. Pathologic nodal staging identifies a group of patients with excellent long-term survival. After margin-negative excision and pathologic nodal staging, local and nodal recurrence rates are low.