Case of a Patient With Pancreatic Cancer With Sporadic Microsatellite Instability Associated With a BRAF Fusion Achieving Excellent Response to Immunotherapy

JCO Precis Oncol. 2023 Jun:7:e2200650. doi: 10.1200/PO.22.00650.

Kathrin Heinrich^{1

2}, Laura E Fischer¹, Enrico N De Toni³, Daniel Markwardt³, Daniel Roessler³, Georg Beyer³, Michael Günther⁴, Steffen Ormanns⁴, Frederick Klauschen^{2

4}, Wolfgang G Kunz⁵, Stefan Fröhling^{6

7}, Tilman Brummer^{8

9

10}, Volker Heinemann^{1

2}, C Benedikt Westphalen^{1

2}

¹ Department of Medicine III and Comprehensive Cancer Centre (CCC), LMU University Hospital Munich, Munich, Germany.
² German Cancer Consortium (DKTK), Partner Site Munich, Munich, Germany.
³ Department of Medicine II and Comprehensive Cancer Centre (CCC), LMU University Hospital Munich, Munich, Germany.
⁴ Institute of Pathology, Ludwig Maximilians University (LMU), Munich, Germany.
⁵ Department of Radiology and Comprehensive Cancer Center (CCC Munich LMU), University Hospital, LMU Munich, Munich, Germany.
⁶ Department of Translational Medical Oncology, National Center for Tumor Diseases (NCT) and German Cancer Research Center (DKTZ), Heidelberg, Germany.
⁷ DKTK, Heidelberg, Germany.
⁸ Institute of Molecular Medicine, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
⁹ Comprehensive Cancer Center Freiburg (CCCF), Medical Center, University of Freiburg, Freiburg, Germany.
¹⁰ German Cancer Consortium (DKTK), Partner Site Freiburg and German Cancer Research Center (DKFZ), Heidelberg, Germany.

Abstract

In this case report, we discuss a case of pancreatic cancer bearing a BRAF fusion, leading to MAPK activation, MLHph, and finally MSI.