Outcome of early stage Merkel carcinoma treated by exclusive radiation: a study of 53 patients

Abstract

Purpose Early stage Merkel cell carcinoma (MCC) is a rare and aggressive primary skin cancer. The standard of care for MCC is broad excision and adjuvant external beam radiation therapy (EBRT). However, for some patients, anesthesia is contraindicated, while others run the risk of serious aesthetic sequelae. In such cases, exclusive radiotherapy is an interesting alternative to surgery. Though limited data is available, this study evaluates exclusive radiotherapy for MCC, using data from the largest retrospective study to date. Methods All patients who were followed in our center between 1989 and 2019 for histologically proven early stage MCC were included in the study. They were treated either by surgery with a 2-cm clear margin followed by adjuvant radiotherapy (RT) or by exclusive RT. Survival rates with adjuvant and exclusive EBRT were analyzed using Cox model and Fine and Gray model depending on the type of survival. p value < 0.05 was considered significant. Results Eighty-four patients treated for MCC were included. Fifty-three of them (63.1%) were treated by exclusive RT, and 31 (36.9%) had surgical excision followed by adjuvant RT. Local relapse rate was 13.7% (95% CI 8.0–43.7) in the RT monotherapy group (group A) and 25.8% (95% CI 10.3–56.2) in the surgery + RT group (group B) (p = 0.42). No statistical difference was found for nodal relapse (p = 0.81), metastatic relapse (p = 0.10), disease free survival (p = 0.83) or overall survival (p = 0.98). Conclusion Our study suggests that exclusive radiotherapy for early Merkel cell carcinoma leads to a similar oncological outcome as combined treatment, with fewer aesthetic sequelae. The approach is interesting for elderly patients with comorbidities or patients for whom surgery would cause significant functional or aesthetic sequelae.

The Role of Histone Post-Translational Modifications in Merkel Cell Carcinoma

“…The identification of novel PTMs may improve early MCC diagnosis and therapy monitoring. MCC onset, progression and metastasis is often rapid ( 32 ) and early tumor identification, as well as expeditious diagnostic workup and therapy initiation are crucial. Thus, research for novel PTMs to be employed in the clinic should be a priority ( 106 ).…”

“…Moreover, some patients are not responders and/or develop therapy resistance. Surgery and radiation therapies are adopted for local and nodal MCC ( 31 , 32 ), while systemic therapy is preferred for extensive, metastatic, and recurrent tumor. Even when early diagnosed, patients may not be eligible for surgery/radiotherapy due to other comorbidities.…”

Merkel Cell Carcinoma: An Immunotherapy Fairy-Tale?

“…Sometimes, radical excision may not be feasible, especially in the head/neck region and in elderly patients with poor performance status. In these cases, exclusive radiotherapy should be considered (54)(55)(56). In a retrospective trial published in 2021 (55), a total of 84 patients who were treated with either surgery with wide margins (2 cm) plus adjuvant RT (31, 36.9%) or RT alone (53, 63.1%) were analyzed.…”

“…In these cases, exclusive radiotherapy should be considered (54)(55)(56). In a retrospective trial published in 2021 (55), a total of 84 patients who were treated with either surgery with wide margins (2 cm) plus adjuvant RT (31, 36.9%) or RT alone (53, 63.1%) were analyzed. In these two groups, the local relapse rate was 13.7% in the RT group and 25.8% in the surgery plus RT group, without a statistically significant difference in terms of local or distant relapse and in OS.…”

Effects of surgery on survival of patients aged 75 years or older with Merkel cell carcinoma

“…Surgery is widely used clinically, but its outcome may be influenced by the location and size of the lesions, postoperative sequelae, and contraindications to anesthesia. 9 The typical surgical rate is not yet clear. However, according to National Comprehensive Cancer Network (NCCN) guidelines, the standard treatment for patients with primary MCC is surgical removal followed by adjuvant radiation therapy.…”