3477 - Efficacy and Safety of Neoadjuvant Therapies in Locally Advanced Esophageal Squamous Cell Carcinoma: A Comprehensive Retrospective Analysis

Purpose/Objective(s): This study aims to compare the efficacy and safety of neoadjuvant chemoradiotherapy (NCRT), chemotherapy (NCT), and chemoimmunotherapy (NCIT) in patients with locally advanced esophageal squamous cell carcinoma (LAESCC). It also explores factors that may affect survival outcomes.

Materials/Methods: A retrospective cohort analysis was conducted on 625 patients treated at our hospital from 2016 to 2022. Patients received NCRT, NCT, or NCIT followed by radical esophagectomy. To adjust for confounders, the inverse probability of treatment weighting (IPTW) were employed. Survival data were analyzed using the Kaplan-Meier method, while prognostic factors were assessed using the multivariate Cox regression analysis.

Results: Among the 625 patients, 50 received NCRT, 444 received NCT, and 131 received NCIT. Before IPTW adjustment, significant differences were observed among the three groups in factors such as age, cTNM stage, surgical approaches and number of neoadjuvant therapy cycles. After IPTW, these differences were mitigated, allowing for a balanced comparison.

Histopathological analysis revealed that the pCR rates of NCRT, NCT and NCIT groups were 25.8%, 5.8% and 9.3%, while the MPR rates were 45.2%, 29.0% and 49.3%, respectively.

Before IPTW, the 4-year DFS rates in the three groups were 54%, 58%, and 76.1%, respectively (P=0.011), and the 4-year OS rates were 56.8%, 61.8%, and 89.9%, respectively (P<0.001). The 4-year DFS rates in the three groups after IPTW were 56.7%, 58.8%, and 81.5%, respectively (P<0.001), and the 4-year OS rates were 60.4%, 62.5%, and 91.4%, respectively (P<0.001).

Multivariate analysis identified independent prognostic factors for DFS as gender, ypTNM stage, MPR, pCR, number of lymph nodes dissected, and postoperative adjuvant therapy. In the multivariate analysis of OS, neoadjuvant therapy, gender, tumor location, ypTNM stage, MPR, pCR, number of lymph nodes dissected, and postoperative adjuvant therapy were independent prognostic factors.

The incidence of grade 3 or grade 4 leukopenia in the three groups was 14.6%, 1.8%, and 3.2%, respectively (P=0.033).

The incidence of recurrent laryngeal nerve injury in the three groups was 0%, 16.8%, and 25.2%, respectively (P=0.009), and the incidence of postoperative pneumonia in the three groups was 20.6%, 12.2%, and 3.9%, respectively (P=0.009). While the incidence of overall postoperative complication in the three groups was 21.4%, 32.1%, and 34.5%, respectively (P=0.367). The incidence of anastomotic leakage in the three groups was 0.8%, 4.7%, and 5.4%, respectively (P=0.096).

Conclusion: For resectable LAESCC, NCRT may achieve a higher pCR rate, but NCIT appears to be associated with better survival outcomes. All three neoadjuvant treatment modalities were clinically well-tolerated. The survival benefit of NCIT deserves further exploration.