Abstract 421P
Background
Locally advanced nasoethmoidal squamous cell carcinoma (SCC) is rare, and often unsuitable for surgical resection. Data on the potential clinical benefits of combining induction chemotherapy (IC) and sequential definitive chemoradiotherapy for this condition is limited.
Methods
We retrospectively investigated T4 nasoethmoidal SCC patients who underwent proton or photon chemoradiotherapy with curative intent at the National Cancer Center Hospital East between April 2014 and May 2022. Patients were categorized into three groups based on IC regimen: no IC (No-IC), paclitaxel plus carboplatin plus cetuximab (IC-PCE), and docetaxel plus cisplatin plus S-1 (IC-TPS).
Results
Twenty-five patients were analyzed (No IC, 9; IC-PCE, 10; and IC-TPS, 6). All patients exhibited a performance status of 0 or 1, with a median age of 58 years (range: 28-73) at the initiation of treatment. The IC-PCE group had the highest ratio of Stage IVB to IVA patients. IC-PCE and IC-TPS yielded objective responses in eight (80%) and two (33%) patients, respectively. During IC-TPS, five patients (83%) experienced a total of nine grade 3/4 adverse events, and two (20%) experienced one grade 3 event each during IC-PCE. All subjects completed proton beam therapy (65–70 GyE, n=20) or intensity-modulated radiation therapy (70 Gy, n=5), with median relative to dose intensity of concurrent cisplatin reaching 100% in all groups. After completion of planned treatment, complete responses were observed in 22 patients, and three patients in the No IC or IC-TPS group showed a partial response. On median follow-up of 42 months, 3-year recurrence-free survival (RFS) rate was 90.0% in the IC-PCE group and 33.3% in the remaining groups. Of note, the IC-PCE group had significantly better RFS (median RFS: IC-PCE, not reached; IC-TPS, 24.1 months; No IC, 16.8 months; log-rank p-value, 0.023), despite no differences in overall survival, time-to-locoregional progression, or time-to-distant metastasis.
Conclusions
Sequential IC-PCE followed by concurrent chemoradiotherapy with cisplatin appears promising as an effective therapeutic strategy for T4 nasoethmoidal SCC.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.