Prolonged Response to Dabrafenib/Trametinib in Grade 3 Metastatic Pancreatic Neuroendocrine Tumor (NET G3) with BRAF V600E Mutation

Treatment of metastatic pancreatic neuroendocrine tumors (pancNETs), particularly grade 2 (G2) and grade 3 (G3), often presents a dilemma in choosing from multiple similarly efficacious therapies. Data on targeted therapies for these tumor types is limited, and this report presents BRAF-targeted therapy as a therapeutic option for metastatic pancNET G3.

This is a case report of a patient with G3 pancNET metastatic to the liver, lung, lymph node, and scalp (soft tissue) treated with dabrafenib/trametinib (D/T) in the presence of a BRAF V600E mutation detected in tumor tissue.

This patient has demonstrated an ongoing partial response to therapy at all involved sites for nearly 15 months with minimal side effects attributable to D/T.

Dabrafenib/trametinib therapy for BRAF-mutated metastatic pancNETs provides a novel treatment option and, especially in the G3 setting, should be considered a first-line option. Tumor testing for actionable mutations should be undertaken at the time of diagnosis and/or progression to identify novel therapeutic avenues in these rare tumors.