MO13-5 Clinical features and prognosis of patients with unresectable locally advanced or metastatic olfactory neuroblastoma

Abstract

Olfactory neuroblastoma is especially rare cancer of the nasal cavity, with an incidence of 0.03 per 100,000 in Japan. Combining surgery, chemotherapy, and radiotherapy are offered to manage this tumor, but no standard treatment has been established. We retrospectively reviewed patients with unresectable locally advanced or metastatic olfactory neuroblastoma who received chemotherapy between January 2015 and August 2020 at the National Cancer Center Hospital (Tokyo, Japan). A total of 10 patients were identified, with a median age of 46.5 (range 30-73). There were 5 men and 5 women each. Seven patients presented initially unresectable disease and three patients presented with recurrent disease after surgery. Among unresectable cases, modified Kadish staging C/D was 4/3, most patients underwent chemotherapy followed by radiotherapy. Vincristine, doxorubicin and etoposide (VDC)/platinum (cisplatine or carboplatine) and etoposide/others were administrated in 4/3/1 patient, respectively. Regimen change from cisplatin to carboplatin was occurred in 3 patients, one was hearing impairment, and the others was due to Syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Response rate was 75% (95% confidence interval [CI] 30-95) with VDC and 33% (95% CI 10-70) with platinum-based chemotherapy (p=0.52, Fisher's exact test). Median progression-free survival of initial chemotherapy was 14.2 months (95% CI 1.1-NE). Overall survival from the initiation of chemotherapy for unresectable disease was 36.7 months (95% CI 11.7-36.7). In the clinical setting, multimodal therapeutic approach is necessary in case of unresectable olfactory neuroblastoma. In some cases, VDC or platinum-based therapy showed relatively better response in spite of a late recurrence. Therefore, long term follow-up is mandatory.