Overall Survival With Radiotherapy and Chemotherapy for Merkel Cell Carcinoma
Posted: Thursday, December 23, 2021
Radiotherapy may yield improved overall survival rates, whereas chemotherapy may be associated with worse overall survival for patients with Merkel cell carcinoma, according to Thomas J. Quinn, MD, of Beaumont Health, Royal Oak, Michigan, and colleagues. This retrospective, population-based study, which focused on data from the Surveillance, Epidemiology, and End Results (SEER) program, was published in the journal Cureus.
From 1980 to 2016, a total of 5,002 patients with Merkel cell carcinoma were included in the analysis. Criteria for inclusion were indicated chemotherapy and radiotherapy status, single primary tumor with known primary tumor location, and known surgery type. Of those included, 648 (13%) had received chemotherapy, and 4,354 (87%) had no previous chemotherapy or their chemotherapy status was unknown. Just over half (51%) of the patients received radiotherapy. Definitive surgical resection was performed on most patients, with 9.5% having undergone no surgery.
Most patients presented with either localized or regionally confined disease, with 7.8% presenting with distant metastases. The median age at diagnosis was 76. The median follow-up was nearly 15 years. Overall survival for patients treated with chemotherapy was worse (hazard ratio [HR] = 1.22, 95% confidence interval [CI] = 1.1–1.35, P < .001), whereas overall survival for patients treated with radiotherapy was improved (HR = 0.9, 95% CI = 0.83–0.97, P = .008).
An exploratory subgroup analysis did not yield any overall survival improvement with chemotherapy. Notably, there was no apparent association between chemotherapy and worse overall survival in the highest risk patients who were older than 80 and had distant metastases and no definitive surgery. The authors recognized that this could be due to limited power within this subgroup.
“Future database analyses exploring the impact of immunotherapy as well as the interaction between radiotherapy and immunotherapy in Merkel cell carcinoma are warranted,” the authors concluded.
Disclosure: The study authors reported no conflicts of interest.
