Partial Response to Dual BRAF and MEK Inhibition in a Patient with BRAF-Mutant Pancreatic Acinar Cell Carcinoma Refractory to Chemotherapy: A Case Report and Review of the Literature

Introduction: Pancreatic Acinar Cell Carcinoma (PACC) is a rare subgroup of pancreatic neoplasms that has a better prognosis compared to Pancreatic Ductal Adenocarcinoma (PDAC). The more indolent evolution of the PACC makes surgical resection the standard treatment for localized disease. In metastatic disease, treatment is not well established. BRAF mutations have been detected in up to 13% of PACC, however, treatment with BRAF and/or MEK inhibitors has not yet been studied.

Case report: We present the case of a 73-year-old man, who has the diagnosis of BRAF-mutated metastatic PACC refractory to chemotherapy regimens. He underwent the combination of dabrafenib (selective BRAF inhibitor) and trametinib (selective MEK inhibitor) and had a partial response after 2 and 6 months from initiation of treatment.

Discussion: This case suggests the hypothesis that the block of the RAS‐RAF‐MAPK pathway with the combination of dabrafenib and trametinib may be an option in patients with BRAF-mutated refractory metastatic PACC.  However, other studies are currently evaluating combinations of BRAF and MEK inhibitors in non-melanoma and non-colorectal cancer BRAF-mutated tumors, that can help confirm the activity of dual MEK/BRAF inhibition as a standard approach in BRAF-mutant PACC.