2247 - Comparative Study of Immunotherapy Combined with High-Dose vs. Standard-Dose Concurrent Chemoradiotherapy for Locally Advanced Cervical Esophageal Squamous Cell Carcinoma

Purpose/Objective(s): The optimal treatment strategy and radiotherapy dose for locally advanced cervical esophageal squamous cell carcinoma (LAEC) remain controversial. This study aimed to evaluate the comparative clinical efficacy of immunotherapy combined with high-dose radiotherapy (HD-RT) versus standard-dose radiotherapy (SD-RT) concurrent chemoradiotherapy in LAEC patients.

Materials/Methods: Clinical data from 42 patients diagnosed with LAEC (?A, ?B, ?A) who were treated at the Department of Radiation Oncology, Chongqing University Cancer Hospital from Jan. 2021 to Dec. 2022 were retrospectively analyzed. Patients were divided into two groups (n=21 each) based on radiation dose: the study group received HD-RT (60Gy/30f), while the control group received SD-RT (50.4Gy/28f). For the study group, induction therapy consisted of two cycles of tislelizumab combined with albumin-bound paclitaxel and cisplatin (q3w), followed by concurrent chemoradiotherapy with HD-RT plus albumin-bound paclitaxel and cisplatin (q3w), and subsequent maintenance therapy with tislelizumab for one year. The control group received SD-RT concurrently with six cycles of albumin-bound paclitaxel and cisplatin. Local regional control (LRC), progression-free survival (PFS), and overall survival (OS) were evaluated using the Kaplan-Meier survival curve. Between-group comparisons and univariate analyses were performed using the log-rank test, and independent prognostic factors were identified using Cox proportional hazards regression modeling.

Results: The median follow-up duration was 28.4 months, with a 100% follow-up rate. In the study group, the 1- and 2-year LRC rates were 72.6% (95% CI 64.5–80.1) and 59.6% (95% CI 42.2–71.6); the 1- and 2-year PFS rates were 67.8% (95% CI 52.4–74.6) and 58.9% (95% CI 45.6–69.4); the 1- and 2-year OS rates were 64.5% (95% CI 60.6–72.7) and 48.5% (95% CI 40.6–58.4), respectively. In the control group, the 1- and 2-year LRC rates were 60.6% (95% CI 55.4–66.7) and 52.2% (95% CI 42.2–63.5); the 1- and 2-year PFS rates were 54.5% (95% CI 50.5–60.4) and 42.6% (95% CI 35.5–50.4); the 1- and 2-year OS rates were 55.8% (95% CI 47.6–63.8) and 30.5% (95% CI 26.3–35.1), respectively. Univariate analysis revealed that T stage, N stage, TNM stage, immunotherapy, and radiotherapy dose were significantly associated with OS, PFS, and LRC (all P<0.05). Multivariate Cox regression analysis indicated that immunotherapy and radiotherapy dose were independent prognostic factors for OS, PFS, and LRC in LAEC patients (all P<0.05).

Conclusion: For LAEC patients, immunotherapy combined with HD-RT superior survival benefits compared with SD-RT concurrent chemoradiotherapy. Immunotherapy and radiotherapy dose are independent prognostic factors for LRC, PFS, and OS in LAEC patients.