Do Local Excision Margins Influence Survival in Merkel Cell Carcinoma?
Posted: Friday, April 30, 2021
Brian C. Baumann, MD, of Washington University School of Medicine, St. Louis, and colleagues investigated whether adjuvant radiotherapy and clinical local excision margin size were associated with overall survival among patients with Merkel cell carcinoma. Published in JAMA Dermatology, their findings demonstrated that there was, in fact, a correlation between improved overall survival and larger excision size.
The investigators analyzed data on 6,156 patients from the National Cancer Database who had localized stage I or II Merkel cell carcinoma. All participants underwent local excision but may or may not have received adjuvant radiotherapy. Patients were excluded from analysis if they were administered systemic therapy (chemotherapy or immunotherapy), underwent Mohs surgery, or died within 90 days of surgery.
The median follow-up was 35 months. When compared with surgical margins of 1.0 cm or smaller, margins larger than 1.0 cm seemed to be associated with overall survival improvement (hazard ratio [HR] = 0.88), regardless of tumor subsite. This also held true at 5 years after surgery; patients with margins larger than 1.0 cm had an 89.8% overall survival rate, whereas those with smaller margins had a survival rate of 76.7%. The median overall survival for patients with margins of 1.0 or smaller, 1.1 cm to 2.0 cm, and larger than 2.0 cm was 69, 95, and 91 months, respectively.
Hazard ratios for patients receiving adjuvant radiotherapy with margins of 1.0 cm or smaller (0.75), 1.1 to 2.0 cm (0.77), and larger than 2.0 cm (0.66) suggested an association between adjuvant radiotherapy and significant improvements in overall survival. Additionally, patients with local excision margins of 1.0 cm or smaller who received radiotherapy had a similar overall survival as those with larger lesions who did not receive radiotherapy (HR = 0.80).
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.