Recurrence and mortality rates with different treatment approaches of Merkel cell carcinoma: a systematic review and meta-analysis
July 6, 2021
International Journal of Dermatology
July 6, 2021
This is a comprehensive analysis of 52 previously published studies across 1804 patients with Merkel cell carcinoma, addressing which approaches are most effective in preventing MCC recurrences. Because national databases do not capture recurrence data (only death) such studies must be done by local academic teams, as in these 52 studies. Recurrence rates were lower (39%) if radiation was also used as compared to if only surgery was used (55%). Addition of chemotherapy was associated with a higher chance of death. It is important to note that many of these patients were treated over a decade ago, when MCC management and risk assessment was less advanced. Nevertheless, this study reinforces major current recommendations: 1) many patients may benefit from the addition of radiation to initial surgery; and 2) chemotherapy should not routinely be used in early management of MCC.
Background: Comprehensive treatment recommendations for Merkel cell carcinoma are complex. We aimed to systematically review the published data on recurrence and mortality rates associated with various treatment approaches for Merkel cell carcinoma.
Methods: Search of MEDLINE, Embase, Web of Science, and Scopus from inception to August 2015. Studies were included that reported comparative survival and recurrence data for two or more treatment modalities. Two reviewers independently reviewed and abstracted recurrence and mortality rates. Event rates for individual treatment arms in each study were pooled and meta-analyzed across studies using a random-effects model.
Results: Fifty-two retrospective studies met inclusion criteria, revealing a total of 1,804 patients with primary Merkel cell carcinoma with data available for analyses. The recurrence rate was higher for surgery alone (55.0%) versus a combination of surgery and radiotherapy (39.0%) (odds ratio, 2.089; 95% CI, 1.374-3.177; P < 0.001). Combination therapy including surgery, radiotherapy, and chemotherapy had a higher mortality rate (44.6%) than did combined surgery and radiotherapy (23.2%) (odds ratio, 2.688; 95% CI, 1.196-6.037; P = 0.02).
Conclusions: The treatment of Merkel cell carcinoma with surgery plus adjuvant radiotherapy may produce lower recurrence rates.