ASTRO 2020: Is Nodal Radiation Therapy of Benefit in Merkel Cell Carcinoma?
Posted: Friday, November 13, 2020
Patients with locally advanced, lymph node–positive Merkel cell carcinoma seem to benefit from nodal radiation therapy, according to Neal Andruska, MD, PhD, of the Washington University School of Medicine, St. Louis, and colleagues. The results of this retrospective analysis, which were presented during the 2020 American Society for Radiation Oncology (ASTRO) Annual Meeting (Abstract 2002), support a more liberal use of regional lymph node radiation therapy in this patient population.
This analysis focused on 72 patients with locally advanced Merkel cell carcinoma who were treated between 2006 and 2019. Those enrolled had a history of lymph node dissection, nodal radiation therapy, lymph node dissection followed by adjuvant nodal radiation therapy, or observation.
Regional recurrence–free survival (hazard ratio = 0.07; P = .004), distant recurrence–free survival (hazard ratio = 0.28; P = .01), disease-free survival (hazard ratio = 0.23; P = .002), and disease-specific survival (hazard ratio = 0.22; P = .02) seemed to improve as a result of nodal radiation therapy. Patient outcomes did not appear to significantly differ after treatment with single-modality lymph node dissection or nodal radiation therapy.
Nodal radiation therapy improved disease-free survival and disease-specific survival in high-risk patients (those with extracapsular extension, multiple involved lymph nodes, or bulkier lymph nodes) who underwent lymph node dissection. According to the investigators, the benefit of nodal radiation therapy seemed to increase with a higher disease burden. After adjustments were made for age and these adverse factors, adjuvant radiation therapy appeared to significantly improve regional recurrence–free survival (hazard ratio = 0.03; P = .003), distant recurrence–free survival (hazard ratio = 0.16; P = .01), disease-free survival (hazard ratio = 0.10; P = .0007), and disease-specific survival (hazard ratio = 0.18; P = .046).
Disclosure: For full disclosures of the study authors, visit www.redjournal.org.