China National Cancer Early Screening Trial: Lung and Colorectal Cancer

Interventions: Group A:Annual LDCT (5 rounds) and colonoscopy for any year (first year is recommended);Group B:Biennial LDCT (3 rounds) and annual FIT (5 rounds), those who have FIT positive results will undertake colonoscopy;Group C:To inform the participants of high risk of lung cancer and recommend them to undertake lung cancer screening in other regular medical institutions; To recommend colonoscopy for any year (first year is recommended), and those who are unwilling to undertake colonoscopy will receive FIT screening (5 rounds), those Primary outcome(s): lung cancer mortality;colorectal cancer mortality Study Design: Parallel