Invitation to CRC Screening programme (Basque Country, Spain). Extension to cohort 70 - 74 years old

Abstract Background The Colorectal Cancer Screening Programme (BCSP) approved in 2008 by the Basque Countr’s Parliament, started as a pilot study in 2009, inviting residents 50-69 y (586,700). By 2013 target population had been invited at least once. In 2024, the Health Authority approved extend to 74 (778.000 residents). The screening process is with a biennial Faecal Immunochemical Test (FIT) and colonoscopy in FIT positive Objectives To analyze the impact on health system by the extension to 74y and to compare it to target population of the previous programme Methods Retrospective study of the results of invitations to men and women 70/74y to the BSCP. Participation and positivity rate of FIT and quality indicator of colonoscopy calculated by sex and compared to population invited under 70s Results The increase of eligible population over 70y was 18.6% and 19.4% of colonoscopies required. From 2024, august to december 19,766 people (men 44.2%; women 55.8%) were invited, with a total participation rate of 77.6% (77.3% men / 77.8% women) p > 0.001. The FIT positivity rate was 6.7%, with significant differences between sex (8.3% men / 5.8% women) P < 0.001. CRC 5.8% and advanced lesions 51.6%. The only statistically significant differences between sexes in colonoscopies were found on the advanced neoplasia. Comparing the results of the invitation of the population over 70 y to the 50-69 cohort: 1) participation rate 70.4% 2) positive rate 4.2% 3) CRC 2.8% and advanced lesions 36.3% higher in all of them in the older group. There were no differences between the two cohorts regarding colonoscopy quality indicators: extension, colonic cleansing, complications, and adherence to colonoscopy (95%) nor the rest of the colonoscopy findings Conclusions Despite the effort required to address the increase in the invitation and the colonoscopies required, the response has been positive and this will have an impact on the reduction of interval cancer FIT and the incidence and mortality by CRC. Key messages • Inviting to the BCSP over 70 years old impact on the reduction of interval cancer FIT. • Inviting to the BCSP over 70 years old impact on the reduction of incidence and mortality.