Lymphatic mapping for Merkel cell carcinoma

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: 30-year experience from a single institution

BACKGROUND

Merkel cell carcinoma (MCC) is a rare cutaneous malignancy. Few single-institution series have been reported.

METHODS

Review of MCC patients treated at our institution between 1980 and 2010. Patient, tumor, and treatment variables were analyzed to determine MCC-specific outcomes.

RESULTS

We identified 161 patients with MCC. There was a 2.5-fold increase in cases over the last decade. Median length of follow-up was 36 months. Stage at diagnosis was I in 35 %, II in 21 %, IIIa in 12 %, IIIb in 23 %, and IV in 9 %. The 5-year MCC-specific survival rates were 87, 63, 42, and 0 % for stages I, II, III, and IV, respectively. Death from the disease occurred in 10 % of patients with T1 and in 50 % with larger lesions. One-third of patients presented with nodal disease. Sentinel lymph node biopsy (SLNB) identified micrometastases in 9 out of 27 (33 %) early-stage patients. Recurrence developed in 56 % of SLNB-positive and 39 % of SLNB-negative patients. Half of patients recurred after a median time of 9 months. Proportions of first recurrence location were distant (52 %), nodal (27 %), and local (21 %). Adjuvant treatments did not improve recurrence or survival rates. One-third of patients died of the disease.

CONCLUSIONS

SLNB identifies micrometastasis in one-third of early-stage patients. Negative SLNB may predict for improved but not necessarily favorable outcome. Initial tumor size and clinical nodal disease predict for poor outcome. High recurrence rates warrant the development of more effective adjuvant therapies, and better markers of recurrence and treatment response for MCC are needed.

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 Case of Merkel Cell Carcinoma: Treated with Wide Excision and Adjuvant Radiotherapy

Merkel cell carcinoma is a rare aggressive primary cutaneous neuroendocrine skin cancer arising from the basal epidermis. Although the majority of patients with non-melanoma skin cancer are cured by local treatment, patients with Merkel cell carcinoma have a poor outcome characterized by locoregional and distant relapse. No standard treatment protocol for Merkel cell carcinoma exists. But, there is mounting evidence that combined treatment, incorporating adjuvant radiotherapy, improves the outcome (locoregional control and disease-free survival) compared with surgery alone in most patients. Herein we report a case of Merkel cell carcinoma treated with wide local excision and post-operative radiotherapy.

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.

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.

Selective sentinel lymphadenectomy for malignant melanoma, Merkel cell carcinoma, and squamous cell carcinoma

To date, selective sentinel lymphadenectomy (SSL) should be considered a standard approach for staging patients with primary invasive melanoma greater than or equal to 1 mm. It is imperative that the multidisciplinary team master the techniques of preoperative lymphoscintigraphy, intraoperative lymphatic mapping, and postoperative pathologic evaluation of the sentinel lymph nodes (SLNs). An SLN is defined as a blue, "hot" and any subsequent lymph node greater than 10% of the ex vivo count of the hottest lymph node. Any enlarged or indurated lymph node in the nodal basin should be excised. Frozen sections are not recommended. For extremity melanoma, delayed SSL may be performed. Preoperative lymphoscintigraphy for extremity melanoma may be done the night before so that the surgery can be scheduled as the first case of the following day. Every surgeon who uses blue dye should be aware of the potential adverse reaction to isosulfan blue and treatment for such a potential fatal reaction. A complete lymph node dissection is done if the SLN is found to be positive. Elective lymph node dissection (ELND) should not be done if an SSL can be performed as a staging procedure. SSL has further been applied to stage the nodal basin for Merkel cell carcinoma and high-risk squamous cell carcinoma. It is important for investigators involved with the SSL to follow the clinical outcome of these patients, so that the role of SSL can be further defined.

Immunostaining for cytokeratin 20 improves detection of micrometastatic Merkel cell carcinoma in sentinel lymph nodes

BACKGROUND

Sentinel lymph node biopsy (SLNBx) can identify Merkel cell carcinoma (MCC) micrometastasis.

OBJECTIVE

We attempted to examine the effectiveness of immunostaining and identify antibodies most appropriate for evaluation of SLNBxs for MCC.

METHODS

Histopathologic material from 10 patients with MCC who had SLNBx was reviewed.

RESULTS

Twenty-three SLNBxs from 10 patients appeared tumor-free in routine hematoxylin-eosin (H&E)-stained sections. However, tumor cells were detected in immunostained sections from 5 (22%) of 23 SLNBxs in 4 (40%) of 10 patients. Immunostains with pancytokeratin (panCK), cytokeratin-20 (CK-20), neurofilament protein, and chromogranin A were used for all primary and SLNBx specimens. All 5 (100%) micrometastatic foci stained strongly for CK-20 and panCK. Background normal lymph node tissue also stained for panCK but not for CK-20.

CONCLUSION

Examination of H&E sections alone is insufficient for excluding micrometastatic MCC in sentinel lymph nodes. We observed the greatest sensitivity and specificity with anti-CK-20 antibody in identifying micrometastatic MCC in sentinel lymph nodes.

A meta-analysis of the prognostic significance of sentinel lymph node status in Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma is an aggressive cutaneous neoplasm with a high propensity to metastasize to lymph nodes.

OBJECTIVE

The objective of this study was to determine the prognostic significance of sentinel lymph node status in patients with Merkel cell carcinoma.

METHODS

A meta-analysis of case series of patients with Merkel cell carcinoma managed with sentinel lymph node biopsy was performed.

RESULTS

Forty of 60 patients (67%) had a biopsy-negative sentinel lymph node; 97% of this group had no recurrence at 7.3 months median follow-up. Twenty patients (33%) had a biopsy-positive sentinel lymph node; 33% of this group experienced local, regional, or systemic recurrence at 12 months median follow-up. Risk of recurrence or metastasis was 19-fold greater in biopsy-positive patients (odds ratio, 18.9; p = 0.005). None of 15 biopsy-positive patients who underwent therapeutic lymph node dissection experienced a regional recurrence; 3 of 4 who did not receive therapeutic lymphadenectomy experienced regional recurrence.

CONCLUSION

Sentinel lymph node positivity is strongly predictive of a high short-term risk of recurrence or metastasis in patients with Merkel cell carcinoma. Therapeutic lymph node dissection appears effective in preventing short-term regional nodal recurrence. Aggressive adjuvant treatment should be considered for patients with positive sentinel lymph nodes.

Merkel cell carcinoma of the skin

BACKGROUND

Neuroendocrine/Merkel cell carcinoma (MCC) of the skin is an uncommon tumour. Currently, there are only limited data available on the natural history, prognostic factors, and patient management of MCC.

OBJECTIVES

To review our experience and build the largest database from the literature.

METHODS

Twenty-eight cases from the London Regional Cancer Center were combined with 633 cases obtained from the literature searched in English, French, German, and Chinese for the years 1966 to 1998. The database included age, sex, initial disease status at presentation to the clinic, site of primary, any coexisting disease, any previous irradiation, sizes of primary/nodal/distant metastases, management details, and final disease status. A new modified staging system was used: stage Ia (primary disease only, size > 2 cm), stage Ib (primary disease only, size > 2 cm); stage II (regional nodal disease), and stage III (beyond regional nodes and/or distant disease).

RESULTS

Age > 65 years, male sex, size of primary > 2 cm, truncal site, nodal/distant disease at presentation, and duration of disease before presentation (< or =3 months) were poor prognostic factors. Surgery was the initial treatment of choice and it significantly improved overall survival (p =.004).

CONCLUSIONS

We identified poor prognostic factors that may necessitate more aggressive treatment. The suggested staging system, incorporating primary tumour size, accurately predicted outcomes.

Lymphatic mapping with sentinel node biopsy in pediatric patients

BACKGROUND/PURPOSE

Lymphatic mapping with sentinel node biopsy is used widely in adult melanoma and breast cancer to determine nodal status without the morbidity associated with elective lymph node dissection. This technique can be used in children to determine lymph node status with limited dissection and accurate interpretation. The authors report their initial experience.

METHODS

The charts of patients who underwent lymphatic mapping with sentinel node biopsy were reviewed retrospectively. Lymphoscintigraphy was performed in patients with truncal lesions 24 hours before surgery to determine the draining nodal basin (for surgical mapping). The tumors were injected 1 hour preoperatively with technetium sulfur colloid and in the operating room with Lymphazurin blue. The draining basin was examined using a radioisotope detector. The blue nodes with high counts were localized and removed. If nodal metastases were identified, lymph node dissection was recommended. Four patients were injected only with Lymphazurin blue.

RESULTS

Thirteen children (7 girls, 6 boys; mean age, 7 years) underwent lymphatic mapping with sentinel node biopsy. The tumor types were as follows: 8 malignant melanoma (6 extremity, 2 truncal), 1 malignant peripheral nerve sheath tumor, 1 alveolar soft part sarcoma, and 3 rhabdomyosarcoma. A mean of 2.4 nodes (range, 1 to 6) were removed from each patient. Six patients had a positive sentinel node. Formal lymph node dissection was performed on 4 of the 6 patients, 1 of whom had further nodal disease with 2 of 13 nodes containing micrometastases. One of the 6 patients refused lymph node dissection and adjuvant therapy; the final patient had rhabdomyosarcoma, a malignancy for which lymph node dissection is not indicated. Pulmonary metastasis developed 26 months after diagnoses in the patient with alveolar soft part sarcoma and a negative sentinel node. This patient was injected only with Lymphazurin blue at the time of sentinel node biopsy and refused adjuvant therapy. There have been no other recurrences. There were no complications related to lymphatic mapping or sentinel node biopsy.

CONCLUSIONS

Lymphatic mapping with sentinel node biopsy, using both technetium-labeled sulfur colloid and Lymphazurin blue, can be performed safely in pediatric skin and soft tissue malignancies. Further study with long-term follow-up will determine the utility and accuracy of this technique in pediatric malignancies.

Lymphatic mapping for Merkel cell carcinoma

Merkel cell trabecular carcinoma of the skin has a prognosis poorer than expected for a small skin lesion. An early diagnosis and prompt treatment can contribute to improve survival in cases of this aggressive skin tumor. A wide local excision is indicated for localized disease. Elective lymph node dissection is controversial. The authors report a rare case of Merkel cell tumor treated with wide local excision and sentinel lymph node biopsy.

Lymphoscintigraphy, sentinel lymph node biopsy, and Mohs micrographic surgery in the treatment of Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive cutaneous malignancy with a high incidence of occult nodal metastases. MCC is believed to be similar in natural history to thick or ulcerated melanomas in its propensity for locoregional recurrence and early lymph node metastasis. Studies have shown that nodal status is statistically correlated to survival in MCC. Radiolocalization and superselective lymph node biopsy is a recent technique that has been proven to be of great value in evaluating the status of occult lymph node disease in malignant melanoma and breast cancer patients.

OBJECTIVE

In previously untreated patients, an orderly progression of metastases is observed for both cutaneous carcinomas and malignant melanomas and is anticipated for MCC. METHODS/RESULTS. We present two patients with MCC of the head and neck who underwent simultaneous Mohs micrographic surgery and sentinel lymph node biopsy with intraoperative radiolocalization.

CONCLUSION

Sentinel lymph node biopsy and intraoperative lymphoscintigraphy may prove to be a useful technique in evaluating occult nodal involvement and in limiting the potentially unnecessary morbidity of more comprehensive lymph node dissections in MCC patients who do not yet have metastatic involvement.

Intraoperative lymphatic mapping and sentinel lymph node biopsy for Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma is a rare cutaneous neoplasm which commonly spreads to the regional lymph nodes. The feasibility of identifying the sentinel node in patients with clinically node-negative Merkel cell carcinoma was evaluated.

METHODS

Sentinel lymphatic mapping was performed in 18 patients with stage 1 Merkel cell carcinoma using the combination of isosulphan blue dye and 99mTc-radiolabelled sulphur colloid. Patients with tumour metastasis in the sentinel node underwent complete dissection of the remainder of the lymph node basin.

RESULTS

Eighteen patients underwent removal of 35 sentinel nodes. Two patients demonstrated metastatic disease in the sentinel lymph nodes; complete dissection of the involved nodal basin revealed no additional positive nodes suggesting that the sentinel lymph node had been identified. The node-negative patients received no further surgical therapy, with no evidence of recurrent disease in the sentinel nodal basin at a median of 7 months' follow-up.

CONCLUSION

Sentinel node biopsy is feasible in patients with Merkel cell carcinoma. It can be used to stage patients and provides important prognostic information. In those with subclinical nodal disease, it may direct early regional lymphadenectomy but the effect of such surgery on survival remains unclear.