Previous studies have shown geographic disparities in the detection of colorectal adenomas in Côte-d'Or, with an impact of the distance from the general practitioner and an ecological deprivation index (EDI). On the other hand, the extremely low detection rates for these lesions in everyday practice before the implementation of organized screening for colorectal cancer in the Côte-d'Or were shown. One of the aims of this screening is to reduce socio-geographic inequalities in access to care and prevention. Yet, participation in screening also varies depending on the socio-economic level. In this context, the Côte-d'Or Polyps Registry, the only body to have data for the pre-screening period (before 2003), will make it possible to determine whether the implementation of organized screening led to the elimination of socio-geographic disparities concerning the detection of adenomas.

Inclusion Criteria:

• The study population will include all patients residing in Côte d'Or with a first colorectal adenoma (including in situ carcinomas) diagnosed between 01/01/1997 and 31/12/2008

Exclusion Criteria:

• Absence of address
• history (or suspected history) of previously resected adenoma
• personal history of colorectal cancer or colorectal cancer discovered in the year following resection of the adenoma (because the cancer was probably not seen at the initial colonoscopy)
• familial polyposis or known HNPCC
• chronic inflammatory bowel disease

Patients residing in Côte d'Or with a first colorectal adenoma (including in situ carcinomas) diagnosed between 01/01/1997 and 31/12/2008.