435P - Efficacy and toxicity of different adjuvant chemotherapy administration methods and regimens in locoregionally advanced nasopharyngeal carcinoma

Background

Currently, adjuvant chemotherapy (AC) is administered intravenously or orally. Cisplatin plus fluorouracil (PF) and cisplatin plus gemcitabine (GP) are the preferred intravenous AC regimens. The oral AC regimens include capecitabine and S-1. Nonetheless, the optimal delivery method and regimen of AC for locoregionally advanced nasopharyngeal carcinoma (LA-NPC) remain controversial owing to the lack of direct head-to-head randomized controlled trials. This study aimed to evaluate the efficacy and toxicity of various AC regimens for treating LA-NPC, focusing on comparing intravenous and oral administration methods.

Methods

The patients received either intravenous AC regimens (PF or GP) or oral regimens (capecitabine or S-1) following concurrent chemoradiotherapy (CCRT). The primary endpoint was progression-free survival (PFS).

Results

A total of 229 patients were assigned to the oral administration group (127 patients received capecitabine and 102 received S-1), whereas 241 patients were assigned to the intravenous group (164 patients received the PF regimen and 77 received the GP regimen). There was no significant difference in PFS between the intravenous and oral groups (n=154 each) after PSM (3-year PFS rate: 76.3% vs. 73.9%; hazard ratio [HR], 0.803; 95% confidence interval [CI] 0.523-1.233, P=0.316). However, the GP regimen showed a superior 3-year PFS rate (89.1%) compared to PF (74.6%), capecitabine (76.0%), and S-1 (74.3%) regimen (P = 0.005, 0.012, 0.003, respectively), while multivariate analyses also demonstrated that the GP regimen (HR_PFS, 0.38; 95% CI 0.18–0.81, P=0.012) was associated with better survival. Additionally, the intravenous group, which included PF and GP, exhibited a higher incidence of grade 3-5 leukocytopenia (50.0% vs. 22.7%), neutropenia (30.5% vs. 18.2%), anemia (16.2% vs. 3.9%), hyponatremia (3.2% vs. 0), and hypokalemia (12.3% vs. 4.5%) than the oral group.

Conclusions

The GP regimen demonstrated improved efficacy and manageable toxicity, making it the optimal choice for AC in patients with LA-NPC. Further prospective trials are required to confirm these findings.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

H. Mai.

Funding

National Key Research and Development Program of China.

Disclosure

All authors have declared no conflicts of interest.