Merkel Cell Carcinoma – treatment news

Niels Junker | Apr 2020 | Dermatologi | Onkologi /hematologi |

Niels Junker
Staff Physician, Ph.D.,
Department of Oncology,
Herlev Hospital

As previously described in the Danish journal BestPractice Onkologi in August 2017, Merkel cell carcinomas (MCC) are a very aggressive skin-associated cancer type. They are characterized by being rapidly proliferative with an extremely high risk of spread and rapidly declining survival odds parallel to regional and remote spread. For patients with resectable local or regional (lymph nodes) disease, the adjuvant oncological option is radiotherapy. There is a survival benefit for patients with local disease (stages I+II) whereas there is an increased locoregional control for patients who had radical surgery for nodal disease (stage III). The lack of effect in terms of survival in the case of nodal disease suggests an early tendency to systemic microscopic disease as soon as lymph node involvement occurs.1 Historically, patients with non-resectable locally advanced or disseminated MCC have been treated with chemotherapy. Despite the fact that MCC is highly chemo-sensitive with a high first line response rate of 56%, the prognosis is very poor with an average PFS of 2-4 months and OS trending towards zero within 12 months.2,3 With the introduction of immune checkpoint inhibitors blocking the PD-1/L1 axis, the early data from three phase II studies showed signs of a response rate similar to the historical chemotherapy data but with fewer adverse effects – and  for the first time with a survival benefit as well! Below is presented still unpublished data from studies evaluating the rationale for immunotherapy at the early stages with nodal involvement as well as an update on the promising studies for patients with non-resectable locally advanced or disseminated MCC. Immunotherapy in an adjuvant and neoadjuvant setting In order to answer the question of whether immunotherapy plays an early role (locoregional or non-detectable disease) in MCC patients, a number of studies have been initiated with various immune checkpoint inhibitors, and...