This is a randomized controlled trial comparing the effect on participation rates to colorectal cancer screening between an intervention arm (invitation letter to the screening program including a FIT test with or without prior notification) and a control arm with the standard of care (invitation letter to visit the GP who will deliver the FIT test).

The participation to the national screening program for colorectal cancer in France is low. In order to improve the performances of its organized program, the National Cancer Institute is planning to modify the invitation procedure. This is a pilot project and if an improvement in the program performances is reported, the invitation procedure may be scaled up.

Eligible individuals for colorectal cancer screening will be identified by the Regional Cancer Screening Coordinating Centre and randomized into the intervention or control arms. They will be followed for FIT test submission to the central laboratory (participation to screening). Those who did not send their test will receive reminder letters. Those who had a positive FIT test will be followed up for coloscopy referral, and result of the coloscopy. Comparison of the participation rates to screening program and to coloscopy among those with a positive FIT test will be compared between the two study arms.

Inclusion Criteria:

• Women and men aged 50 to 74 years old
• Living in the study area (Departments of Ardennes, Meurthe-et-Moselle, and Moselle, France)
• At moderate risk of colorectal cancer, i.e. eligible to the organised programme and receiving the first invitation of the screening round (not a reminder letter)

Exclusion Criteria:

• Outside the target age (less than 50 years old, or 75 years and more)
• Receiving the reminder letter
• At high or very high risk of colorectal cancer