A propensity score–matched analysis to evaluate the benefit of adjuvant therapy on disease progression of esophageal squamous cell carcinoma after R0 esophagectomy.

Abstract

e16071 Background: The impact of adjuvant therapy (AT) on patients’ disease progression with esophageal squamous cell carcinoma (ESCC) after R0 resection remains controversial in clinical practice. The study aims to evaluate the benefits of AT on recurrence or death through propensity score (PS) matched analyses. Methods: A cohort of patients who have undergone R0 esophagectomy without neoadjuvant therapy for ESCC was identified at the tertiary hospital in China between 2013 and 2020. Patients’ demographic, clinical, surgical, pathological and follow-up data were retrieved from a prospectively maintained database. PS for each patient was calculated by the generalized linear regression model including all potential confounders (age, sex, body mass index, smoking history, alcohol consumption, Eastern Cooperative Oncology Group performance score, baseline comorbidities, hospitalization days, tumor location, size, pathological stage T, N and differentiation grade). PS was stratified into four groups (PS < 0.20, 0.20≤PS < 0.30, 0.30≤PS < 0.40, and PS≥0.40) based on distributions. Patients with and without AT were matched by the nearest neighbor PS with caliper 0.05 to evaluate rates of recurrence-free survival (RFS) for overall patients and patients across four PS groups. RFS was defined as the time from date of curative surgery to the time of recurrence or death. Results: In total, 523 patients were identified and 162 (30.9%) of those patients received AT. A total of 312 (60.0%) patients experienced recurrence or death with a median follow-up of 4.15 years (interquartile range: 2.92-4.73 years). Patients with younger ages, shorter hospitalization, larger tumor size, advanced pathological T and N stages, poorly differentiated tumors were more likely to receive AT (all p < 0.05). The mean PS was 0.39 (standard deviation [SD] 0.16) for AT group and 0.27 (SD 0.15) for non-AT group. A total of 274 patients (137 AT and 137 non-AT) were matched. Before matching, AT group tended to have a worse RFS compared with non-AT group (median RFS: 1.84 years vs 2.67 years, p = 0.06). However, after PS matching, AT group showed a significantly better RFS compared with non-AT group (median RFS: 2.41 vs. 1.89 years, p = 0.02). In the subgroup analyses, the benefits of AT were mostly consistent with the whole group, except for patients with PS < 0.20 where AT tended to have worse RFS. Moreover, for PS≥0.40 subgroup, a significantly better RFS was observed in AT group compared with non-AT group (median RFS: 3.52 vs. 1.53 years, p < 0.01). Conclusions: Adjuvant therapy had a benefit on delaying disease progression for Chinese patients with ESCC after R0 esophagectomy, especially for patients with a higher PS score.