Importance: There are no global screening recommendations for esophageal squamous cell carcinoma (ESCC). Endoscopic screening has been investigated in high incidence areas of China since 1970's. But up until now there no apparent evidence that would lead to a reduction in disease morbidity and mortality.

Objective: To evaluate whether endoscopic screening and early intervention program could reduce the incidence or mortality of ESCC.

Design: Community-based, controlled cohort study among 45 386 residents, Endoscopy screening was completed from November 1999 to May of 2000. Subjects in intervention group were examined once during intervention period. The study follow-up concluded in December 2009.

Setting: High risk area of ESCC in China

Participants:Cluster sampling from communities with high rates of esophageal cancer. A set of villages with was selected as the study intervention community. Age 40 to 69 years residents were selected as an eligible population. Another set of villages was select as the control population. Buffer villages were set up between intervention and control group.

Intervention: Endoscopy with Lugol's iodine staining and early treatment on precancerous lesions was undergone for the intervention group.

Main Outcome(s) and Measure(s): Incidence and mortality ESCC

Inclusion Criteria:

• local residents
• Men and women aged 40 to 69 years
• no contraindications for endoscopic examinations (e.g. history of reaction of iodine or lidocaine), and who were mentally and physically competent to provide written informed consent.
• informed consent

Exclusion Criteria:

• Not local residents
• age younger than 40 yrs and older than 69 yrs
• History of reaction of iodine or lidocaine
• contraindications for endoscopic examinations