Successful BRAF/MEK-inhibition in a young patient with BRAF V600E-mutated extrapancreatic acinar cell carcinoma (HIPO-021)

ABSTRACT: Pancreatic acinar cell carcinoma (PAC) is a rare but dismal disease with a peak incidence rate around 60 to 70 years of age. Treatment options in case of metastatic disease are limited and often follow chemotherapeutic regimens for pancreatic ductal adenocarcinoma. Even though recurrent genomic alteration like BRAF fusions and defects in genes involved in homologous DNA repair mechanisms have been described, there are little reports about the clinical outcome of targeted treatment. Here we describe the case of a 27-year-old male patient with a BRAF V600E-mutated PAC who was successfully treated with a combination of BRAF- and MEK inhibitors.The patient presented to our clinic with abdominal pain and weight loss. Imaging showed massive retroperitoneal disease without contact to visceral organs and mediastinal lymphadenopathy. Because of an inconclusive histology and elevated AFP levels initially a germ cell tumor was suspected, and the patient received PEI chemotherapy without success. Since a second biopsy was consistent with pancreatic-type acinar cell carcinomatreatment was changed to FOLFIRINOX in analogy to pancreatic ductal adenocarcinoma, leading to stable disease on imaging and decreasing AFP levels.Extensive molecular characterization of the tumor within the Molecularly Aided Stratification for Tumor Eradication Research (MASTER) precision oncology program revealed a somatic BRAFV600E and a germline PALB2 stopgain mutation. The patient was hence switched to BRAF/MEK inhibition with almost complete response on consecutive imaging and a remarkable improvement in his general condition.Conclusion: Molecular and genetic analyses including assessment of BRAF alterations can offer targeted treatment options for patients with acinar cell carcinoma of the pancreas and are therefore recommended in this patient cohort.

PROVIDER: EGAS00001004282 | EGA |

REPOSITORIES: EGA