Analysis of tumor recurrence following anterior skull base surgery

In order to elucidate the predictive factors for tumor recurrence following skull base surgery and the significance of salvage surgery in cases of recurrence, we retrospectively surveyed the incidence, site, and time of local recurrences in 20 patients who underwent either anterior or anterolateral skull base surgery for malignant tumors invading the anterior cranial fossa between 1989 and 1995 at the University of Tokyo Hospital. Nineteen patients underwent total resections of malignancies, with recurrences and/or metastases occurring in 13. Local recurrences occurred at the skull base in 5 patients (group A), outside the skull base in 4 patients (group B), and in both locations in 2 patients (group C). The mean time interval between surgery and recurrence was 29 months in group A, and 4.2 months in groups B and C. The local recurrence-free rates were 51% at 1 year and 34% at 5 years. Both brain and/or dural invasion and a microscopic positive surgical margin were proven to be predictive factors for tumor recurrences. The 3-year local recurrence-free rate was 20% in patients with dural invasions and 83% in those without. The incidence of recurrence-free patients was 79% in cases with negative margins, with no patient being recurrence-free in positive cases. All recurrences found more than 6 months after the initial surgery resulted in patients being salvaged successfully by a second operation.