Radiation monotherapy as regional treatment for lymph node‐positive Merkel cell carcinoma

Abstract

BACKGROUND:Merkel cell carcinoma (MCC) is an aggressive cutaneous malignancy with a high risk of lymph node involvement. To the authors' knowledge, few data have been published to date regarding the optimal regional therapy for lymph node‐positive patients. This cohort study was performed to analyze the outcomes of patients with lymph node‐positive MCC treated with lymph node irradiation as definitive therapy compared with completion lymphadenectomy (CLND).METHODS:Fifty patients with lymph node involvement of MCC at presentation and adequate follow‐up data were included in this analysis. Forty‐three of these patients were enrolled and followed prospectively. Twenty‐six patients presented with microscopic lymph node disease, and 24 patients presented with palpable lymph node involvement.RESULTS:Regional control for patients with microscopically involved lymph nodes was 100% regardless of treatment modality—definitive lymph node irradiation (n = 19) or CLND ± radiotherapy (n = 7) with median follow‐up of 18 months. Patients with clinically positive lymph nodes had 2‐year regional recurrence‐free survival rate of 78% and 73% in the definitive lymph node irradiation (n = 9) and CLND ± radiotherapy (n = 15) groups, respectively (P = .8) with a median follow‐up of 16 months.CONCLUSIONS:To the best of the authors' knowledge, the current study is the largest series published to date of radiation monotherapy as regional treatment for lymph node‐positive MCC. Lymph node irradiation alone to positive regional lymph nodes was found to confer an excellent regional control rate that was comparable to CLND for both microscopic and palpable lymph node disease. There was no difference noted with regard to overall survival. Given their similar efficacy, the choice between these lymph node therapies may be based on the clinical scenario and anticipated side effect profiles. Cancer 2010. © 2010 American Cancer Society.

Merkel Cell Carcinoma: Current Management and Controversies

“…Fang et al [40] showed high rates of local control in lymph node basins for pathologically involved nodes treated with primary radiotherapy compared with lymphadenectomy AE radiotherapy. Those with 'microscopic' regional disease (n ¼ 26) who received either radiotherapy alone (n ¼ 19), lymph node dissection alone (n ¼ 3) or both (n ¼ 4), had 2 year regional recurrence-free survival of 100%.…”

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

“…However, it is unknown if this treatment should consist of radiotherapy and/or surgery. In the study by Fang et al, 42 after a positive SLNB result, 19 patients received radiotherapy to the lymph node basin, 3 underwent completion lymphadenectomy, and 4 underwent both completion lymphadenectomy and radiotherapy, and no patients developed regional disease recurrence. The authors of this study concluded that in terms of regional disease control completion lymphadenectomy was comparable with radiotherapy.…”

Merkel cell carcinoma: The prognostic implications of an occult primary in stage IIIB (nodal) disease

“…Although most clinicians recommend surgery to achieve pathological staging [3][4][5] this is not always undertaken and there is evidence that radiotherapy alone may be efficacious for macroscopic nodal disease. 2,6,7 There is also evidence that adjuvant radiotherapy after surgery is associated with improved locoregional control [8][9][10][11] and survival, 12 however this has been challenged by others. 13 Similarly, the role of chemotherapy is currently under investigation.…”

“…1,2 Because of the rarity of this tumor and the lack of prospective clinical trials, controversies exist regarding the optimal staging 3 and treatment 4 of this disease.…”