Clinical efficacy of dose escalation in 3-dimensional radiotherapy for patients with esophageal squamous cell carcinoma-multicenter retrospective analysis (3JECROG R-03) / 中华放射肿瘤学杂志

ABSTRACT

Objective:To evaluate the effect of definitive radiotherapy with different doses on overall survival (OS) and identify the prognostic factors of patients with non-metastatic esophageal squamous cell carcinoma (ESCC).Methods:Clinical data of 2 344 ESCC patients treated with definitive radiotherapy (RT) alone or chemoradiotherapy from 2002 to 2016 in 10 hospitals were collected and analyzed retrospectively. After the propensity score matching (PSM)(1 to 2 ratio), all patients were divided into the low-dose group (equivalent dose in 2 Gy fractions, EQD 2Gy<60 Gy; n=303) and high-dose group (EQD 2Gy≥60 Gy; n=606) based on the dose of radiation. Survival analysis was conducted by Kaplan- Meier method. Multivariate prognostic analysis was performed by Cox′s regression model. Results:The median follow-up time was 59.6 months. After the PSM, the 1-, 3- and 5-year overall survival (OS) rate was 66.5%, 34.7%, 27.2% in the low-dose group, 72.9%, 41.7% and 34.7% in the high-dose group, respectively ( P=0.018). The 1-, 3-and 5-year progression-free survival rate was 52.2%, 27.2%, 23.1% in the low-dose group, 58.3%, 38.1% and 33.9% in the high-dose group, respectively ( P=0.001). The outcomes of univariate analysis indicated that cervical/upper esophagus location, early (stage Ⅱ) AJCC clinical stage, node negative status, tumor length ≤5 cm, receiving intensity-modulated radiation therapy (IMRT), receiving concurrent chemotherapy and EQD 2Gy≥60 Gy were closely associated with better OS (all P<0.05). Multivariable analysis demonstrated that tumor location, regional lymph node metastasis, concurrent chemotherapy and EQD 2Gy were the independent prognostic factors for OS (all P<0.05). Conclusion:Three-dimensional conformal or IMRT with EQD 2Gy≥60 Gy yields favorable survival outcomes for patients with locally advanced ESCC.