BRAF inhibitor treatment of primary BRAF-mutant ameloblastoma with pathologic assessment of response

Oral Surg Oral Med Oral Pathol Oral Radiol. 2016 Jul;122(1):e5-7. doi: 10.1016/j.oooo.2015.12.016. Epub 2016 Feb 23.

Abstract

Objective: Molecular characterization of ameloblastoma has indicated a high frequency of driver mutations in BRAF and SMO. Preclinical data suggest that Food and Drug Administration-approved BRAF-targeted therapies may be immediately relevant for patients with ameloblastoma positive for the BRAF V600E mutation.

Methods: A neoadjuvant treatment regime of dabrafenib was given to a patient with recurrent BRAF-mutant mandibular ameloblastoma. The patient subsequently underwent left mandible composite resection of the tumor and pathologic evaluation of treatment response.

Results: The ameloblastoma had a slow but dramatic response with >90% tumor volume reduction. The inner areas of the tumor underwent degeneration and squamous differentiation, and intact ameloblastoma was present in the outer areas associated with bone.

Conclusions: Targeted neoadjuvant therapy for ameloblastoma may be useful in certain clinical settings of primary ameloblastoma. These might include tumors of advanced local stage when a neoadjuvant reduction could alter the extent of surgery and instances of local recurrence when surgical options are limited.

Publication types

  • Case Reports

MeSH terms

  • Aged, 80 and over
  • Ameloblastoma / diagnostic imaging
  • Ameloblastoma / drug therapy*
  • Ameloblastoma / genetics*
  • Ameloblastoma / surgery
  • Antineoplastic Agents / therapeutic use*
  • Humans
  • Imidazoles / therapeutic use*
  • Male
  • Mandibular Neoplasms / diagnostic imaging
  • Mandibular Neoplasms / drug therapy*
  • Mandibular Neoplasms / genetics*
  • Mandibular Neoplasms / surgery
  • Mutation
  • Neoadjuvant Therapy
  • Oximes / therapeutic use*
  • Polymerase Chain Reaction
  • Proto-Oncogene Proteins B-raf / genetics*
  • Tomography, X-Ray Computed

Substances

  • Antineoplastic Agents
  • Imidazoles
  • Oximes
  • Proto-Oncogene Proteins B-raf
  • dabrafenib