Evaluation of real-world treatment outcomes in patients with distant metastatic Merkel cell carcinoma following second-line chemotherapy in Europe.

Jürgen C Becker,Friedegund Meier,Katharina Kähler,Claudia Pföhler,Peter Mohr,Ivonne Kellner,Felix Kiecker,Carola Berking,Lisa Mahnke,Christoph Helwig,Thomas K Eigentler,Murtuza Bharmal,Selma Ugurel,Gabriele Haas,Eva Lorenz,Dirk Schadendorf,Dina Oksen

doi:10.18632/oncotarget.19218

Abstract

Background and aimsMerkel cell carcinoma (MCC) is a rare, aggressive skin cancer; few treatments exist for patients with advanced disease. Once tumors metastasize to distant sites, patients generally receive chemotherapy, but response duration and progression-free survival (PFS) are typically short. Few studies have assessed the efficacy of second-line chemotherapy for metastatic MCC. Here, we studied outcomes in patients who received ≥ 2 lines of chemotherapy for metastatic MCC.Materials and methodsPatients in an MCC-specific registry diagnosed with stage IV MCC between November 1, 2004, and September 15, 2015, and treated with second-line or later chemotherapy were analyzed retrospectively. Patient records, including baseline characteristics, immunocompetent status, and responses to prior chemotherapy, were evaluated. Patients meeting eligibility criteria were followed through December 31, 2015.ResultsOf 29 patients with metastatic MCC and immunocompetent status who had received ≥ 2 lines of chemotherapy, 3 achieved a partial response, for an objective response rate (ORR) of 10.3% (95% CI, 2.2–27.4). In the overall population including patients with immunocompetent and immunocompromised status (n = 34), the ORR was 8.8% (95% CI, 1.9–23.7). The median duration of response was 1.9 months (range, 1.3–2.1 months; 95% CI, 1.3–2.1). In the immunocompetent population, median PFS and overall survival were 3.0 months (95% CI, 2.5–6.0) and 5.3 months (95% CI, 4.3–6.0), respectively.ConclusionsThe low response rates and limited durability confirm previous reports of the ineffectiveness of second-line or later chemotherapy in patients with metastatic MCC and provide a benchmark for assessing clinical benefit of new treatments.

Highlights

Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer that is more prevalent in elderly and immunocompromised patients [1, 2]
Median progression-free survival (PFS) and overall survival were 3.0 months and 5.3 months, respectively
Reflecting the survival benefit observed in these patients, occult nodal disease and clinically detected nodal disease with unknown primary tumor were classified as stage IIIA in the most recent American Joint Committee on Cancer staging (AJCC) system update [10]

Summary

Introduction

Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer that is more prevalent in elderly and immunocompromised patients [1, 2]. Further evidence of immune involvement in MCC comes from cases of nodal disease found in the absence of a primary tumor; this suggests that cell-mediated responses may be able to clear primary tumors in some patients [10, 11]. Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer; few treatments exist for patients with advanced disease. Once tumors metastasize to distant sites, patients generally receive chemotherapy, but response duration and progression-free survival (PFS) are typically short. We studied outcomes in patients who received ≥ 2 lines of chemotherapy for metastatic MCC

Methods

Results

Conclusion