Role of chemotherapy after curative esophagectomy in squamous cell carcinoma of the thoracic esophagus: A propensity score-matched analysis

Abstract

Background: The efficacy of postoperative treatment of squamous cell carcinoma of the esophagus has not yet been determined. In this retrospective study, we investigated whether postoperative adjuvant chemotherapy (POCT) confers a survival benefit on patients who undergo curative esophagectomy.

Methods: A total of 782 patients were enrolled in our study. The patients were divided into surgery alone (S) and surgery plus postoperative chemotherapy (S + POCT) groups. Propensity score matching (PSM) was used to eliminate the differences in baseline characteristics. The primary endpoint was overall survival (OS), which was calculated by the Kaplan-Meier method and compared with the log-rank test. A Cox proportional hazards model was used to identify factors influencing the prognosis.

Results: Of 782 patients, 343 (43.9%) underwent S alone, and 439 (56.1%) underwent S + POCT before PSM. The five-year OS rates were 42.3% and 47.8% in the S and S + POCT groups (p = 0.080), respectively. After PSM (296 patients per group), the five-year OS rates were 48.7% and 56.2% in the S and S + POCT groups (p = 0.025), respectively. For different cycles of POCT, patients with more than three cycles had a better survival than those with less than three cycles. The significant predictive factors for OS were pN stage (HR = 1.861, 95% CI: 1.310-2.645, p = 0.001), number of dissected nodes (HR = 0.621, 95% CI: 0.494-0.781, p < 0.001) and POCT received (HR = 0.699, 95% CI: 0.559-0.875, p = 0.002), which were identified by multivariate Cox regression analyses in the matched samples.

Conclusions: POCT appears to improve the OS rate of patients with ESCC after resection, and at least four chemotherapy cycles are necessary. These conclusions warrant further confirmation in large-scale multicenter randomized controlled trials.

Keywords: chemotherapy cycles; esophageal squamous cell carcinoma; metastasis-positive lymph nodes; postoperative adjuvant chemotherapy.