Treatment Options for Recurrent Anterior Skull Base Tumors

Malignancies of the anterior skull base are rare and recur in 40-80% of treated cases, varying with substantial variance according to histology, stage at primary diagnosis, and other factors. Most recurrences manifest within 2-5 years after primary treatment, but some histologies can relapse even decades after the first presentation. Management of recurrent anterior skull base tumors is challenging and a wide variety of treatment options are available. Similar to the primary setting, surgery is the mainstay of treatment. However, only few patients are likely to be suitable for salvage surgery after restaging. In this scenario, non-surgical options such as re-irradiation with photon or heavy particles may play a role, although the potential toxicity and benefits of treatment needs to be considered on a case-by-case basis. Moreover, stereotactic technologies are emerging as an adjunct valuable tool to minimize side effects. Chemotherapy is acquiring a relevant role in the primary treatment of sinonasal malignant lesions involving the anterior skull base in the neoadjuvant setting or in combination with radiotherapy, but evidence of its efficacy in the treatment of the recurrent/metastatic disease is very limited. The specific drugs employed vary considerably and need to be paralleled with the biology of the different histologies.