Radiotherapy is one of the main treatments for locally advanced esophageal carcinoma (EC). The accuracy of the existing imaging methods in diagnosing and predicting therapeutic efficacy is disappointing, which increases the difficulty in clinical decision-making. In this study, based on a continuous cohort of EC treated with radiotherapy, the clinical and pathological factors of the patients are used to classify them into the appropriate therapeutic group. By multiple liquid biopsy technologies, combining with radiomics, we intend to construct prediction models of prognosis, therapeutic effect and toxicity. The aim of this RWS is to provide appropriate individualized regimen, further optimize the treatment mode based on precision radiotherapy and improve the outcome and quality of life of EC patients.

Radiotherapy is one of the main treatments for locally advanced esophageal squamous cell carcinoma (ESCC). The guidelines recommend neoadjuvant concurrent chemoradiotherapy plus surgery for resectable or potentially resectable patients; for unresectable patients, definitive chemoradiotherapy is the standard treatment. However, due to the complexity of the biological behavior of esophageal cancer (EC) and individual differences, fully complying with guideline recommendations in clinical practice is difficult and idealized. The results of prospective clinical trials are difficult to meet the demand of clinical diagnosis and treatment, thus, carrying out high-quality real-world study (RWS) is necessary.

Three-dimensional conformal radiotherapy (3DCRT) for unresectable EC yields 5-year OS rates of 34%-45.6%, which is an improvement over the rates reported in the RTOG 85-01 and 94-05 studies. Even so, there is still room for improvement of local control rate and overall survival. The accuracy of the existing imaging methods [computed tomography (CT), magnetic resonance imaging (MRI), endoscopic ultrasonography (EUS), endoscopic ultrasonography (EUS), as well as positron-emission tomography (PET)-CT, etc.] in diagnosing and predicting therapeutic efficacy is disappointing, which increases the difficulty in clinical decision-making. It is worthy to investigate an appropriate individualized radiation regimen based on different treatment sensitivity.

In this study, based on a continuous cohort of EC treated with radiotherapy, the clinical and pathological factors of the patients are used to classify them into the appropriate therapeutic group. Collect the blood and saliva samples before, during and after radiotherapy; the remaining diagnostic biopsy tissue samples. By using multiple liquid biopsy technologies [microbial flora, circulating tumor DNA (ctDNA), genome, RNA, and immunophenotype, ect.], combining with radiomics, construct prediction models of prognosis, therapeutic effect and toxicity. The aim of this RWS is to provide appropriate individualized regimen, further optimize the treatment mode based on precision radiotherapy and improve the outcome and quality of life of EC patients.

Inclusion Criteria:

• Pathology proved esophageal cancer
• ECOG PS ≤3
• Signed Informed consent

Exclusion Criteria:

• Pregnant and lactating women
• Others that researchers consider inappropriate

Patients with esophageal cancer who are acceptable and tolerable to radiotherapy