[Olfactory neuroblastoma: the Hokkaido University experience]

Olfactory neuroblastoma is such a rare malignancy that no consensus has been reached on its management. We analyzed 17 patients with olfactory neuroblastoma treated between April 1980 and March 2004--9 men and 8 women, aged 16 to 76 years old(mean: 50.4 years). Follow-up of current survivors was 1 year 8 months to 16 years 6 months (average: 7 years 9 months). Initially, 2 were treated with surgery alone, 5 with surgery and radiotherapy, and 2 with a combination of these and chemotherapy. Without surgery, radiotherapy alone was conducted in 3 and combined of radiation and chemotherapy in 5. Three of the 5 patients treated with surgery and radiotherapy survive without locoregional recurrence as do 2 with chemotherapy added. All 5 initially treated with craniofacial resection survived more than 5 years. Combined radiotherapy and chemotherapy without surgery was effective in 2. 5- and 10-year overall survival for all patients were 75.5% and 64.7%. Overall 5-year survival of 8 patients with low-grade tumors was 87.5% and of 6 with high-grade tumors 33.3%. In conclusion, combined craniofacial resection plus radiotherapy and chemotherapy seemed to improve survival. Histopathological grading is a prognostic factors.