[Neoadjuvant chemotherapy in the treatment of locally advanced olfactory neuroblastoma in 25 cases].

Objective: To evaluate the efficacy of neoadjuvant chemotherapy (NACT) in the treatment of locally advanced olfactory neuroblastoma (ONB), and to explore the factors related to the efficacy of NACT. Methods: A total of 25 patients with ONB who underwent NACT in Beijing TongRen Hospital from April 2017 to July 2022 were retrospectively analyzed. There were 16 males and 9 females, with an average age of 44.9 years (ranged 26-72 years). There were 22 cases of Kadish stage C and 3 cases of stage D. After multiple disciplinary team(MDT) discussion, all patients were treated sequentially with NACT-surgery-radiotherapy. Among them, 17 cases were treated with taxol, cis-platinum and etoposide (TEP), 4 cases with taxol, nedaplatin and ifosfamide (TPI), 3 cases with TP, while 1 case with EP. SPSS 25.0 software was used for statistical analysis, and survival analyses were calculated based on the Kaplan-Meier method. Results: The overall response rate of NACT was 32% (8/25). Subsequently, 21 patients underwent extended endoscopic surgery and 4 patients underwent combined cranial-nasal approach. Three patients with stage D disease underwent cervical lymph node dissection. All patients received postoperative radiotherapy. The mean follow-up time was 44.2 months (ranged 6-67 months). The 5-year overall survival rate was 100.0%, and the 5-year disease-free survival rates was 94.4%. Before NACT, Ki-67 index was 60% (50%, 90%), while Ki-67 index was 20% (3%, 30%) after chemotherapy [M (Q1, Q3)]. The change of Ki-67 before and after NACT was statistically significant (Z=-24.24, P<0.05). The effects of age, gender, history of surgery, Hyams grade, Ki-67 index and chemotherapy regimen to NACT were analyzed. Ki-67 index≥25% and high Hyams grade were related to the efficacy of NACT (all P<0.05). Conclusions: NACT could reduce Ki-67 index in ONBs. High Ki-67 index and Hyams grade are clinical indicators sensitive to the efficacy of NACT. NACT-surgery-radiotherapy is effective for patients with locally advanced ONB.