Completion Lymph Node Dissection or Radiation Therapy for Sentinel Node Metastasis in Merkel Cell Carcinoma
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For sentinel lymph node (SLN) metastasis from Merkel cell carcinoma (MCC), the benefit of completion lymph node dissection (CLND) versus radiation therapy (RT) is unclear. This study compares outcomes for patients with SLN metastasis undergoing CLND or RT. We also evaluated positive non-SLNs as a prognostic factor.
Using a prospective database, we identified MCC patients with SLN metastasis who underwent CLND or RT. At our institution, CLND was recommended for patients with acceptable perioperative risk, while therapeutic RT was offered to those with high perioperative risk. Primary outcomes were MCC-specific survival (MCCSS), disease-free survival (DFS), nodal recurrence-free survival (NRFS), and distant recurrence-free survival (DRFS).
From 2006 to 2017, 163 patients underwent CLND (n = 137) or RT (n = 26). Median follow-up was 1.9 years. CLND had no significant differences for MCCSS (5-year survival 71% vs. 64%, p = 1.0), DFS (52% vs. 61%, p = 0.8), NRFS (76% vs. 91%, p = 0.3), or DRFS (65% vs. 75%, p = 0.3) compared with RT. Patients with positive non-SLNs (n = 44) had significantly worse MCCSS (5-year survival 39% vs. 87%, p < 0.001), DFS (35% vs. 60%, p = 0.005), and DRFS (54% vs. 71%, p = 0.03) compared with negative non-SLNs (n = 93). Multivariate analysis showed positive non-SLNs were independently associated with MCCSS, DFS, and DRFS.
CLND and RT may have similar outcomes for MCC patients with SLN metastasis when treatment aligns with our institutional practices. For patients undergoing CLND, positive non-SLNs is an important prognostic factor associated with poor survival and distant recurrence. This high-risk group should be considered for adjuvant systemic therapy trials.
The authors would like to acknowledge Sherry Fu for her role as the database manager for our institutional Merkel Cell Carcinoma database.
Dr. Lee is a National Research Service Award postdoctoral fellow supported by the National Cancer Institute (5T32 CA009672-23). This project was supported by a Clinical and Translational Science Award provided to the Michigan Institute for Clinical & Health Research grant support (CTSA: UL1TR002240).
- 5.Merkel Cell Carcinoma. Version 1.2018. Clinical Practice Guidelines in Oncology. National Comprehensive Cancer Network. Last updated 18 Sep 2017. Available at: https://www.nccn.org/professionals/physician_gls/default.aspx#site. Accessed 27 Apr 2018.
- 18.Adjuvant Avelumab in Merkel Cell Cancer (ADAM). NCT03271372. Available at: https://clinicaltrials.gov/ct2/show/NCT03271372. Accessed 23 Apr 2018.
- 25.Harms KL, Healy MA, Nghiem P, et al. Analysis of Prognostic Factors from 9387 Merkel Cell Carcinoma Cases Forms the Basis for the New 8th Edition AJCC Staging System. Ann Surg Oncol. 2016;23(11):3564–3571.Google Scholar