Impact of delayed screening invitations on screen-detected and interval cancers in the Dutch colorectal cancer screening programme: individual-level data analysis

Objective: To assess the impact of delayed invitation on screen-detected and interval colorectal cancers (CRC) within a faecal immunochemical testing (FIT)-based CRC screening programme. Design: All individuals that participated in 2017 and 2018 with a negative FIT and were eligible for CRC screening in 2019 and 2020 were included using individual-level data. Multivariable logistic regression analyses were used to assess the association between either the different time periods (ie, ' before', ' during' and ' after' the first COVID-19 wave) or the invitation interval on screen-detected and interval CRCs. Results: Positive predictive value for advanced neoplasia (AN) was slightly lower during (OR=0.83) and after (OR=0.92) the first COVID-19 wave, but no significant difference was observed for the different invitation intervals. Out of all individuals that previously tested negative, 84 (0.004%) had an interval CRC beyond the 24 months since their last invitation. The time period of invitation as well as the extended invitation interval was not associated with detection rates for AN and interval CRC rate. Conclusion: The impact of the first COVID-19 wave on screening yield was modest. A very small proportion of the FIT negatives had an interval CRC possibly due to an extended interval, which potentially could have been prevented if they had received the invitation earlier. Nonetheless, no increase in interval CRC rate was observed, indicating that an extended invitation interval up to 30 months had no negative impact on the performance of the CRC screening programme and a modest extension of the invitation interval seems an appropriate intervention

Personalised surveillance for serrated polyposis syndrome: results from a prospective 5-year international cohort study

Background and aims: Serrated polyposis syndrome (SPS) is associated with an increased risk of colorectal cancer (CRC). International guidelines recommend surveillance intervals of 1-2 years. However, yearly surveillance likely leads to overtreatment for many. We prospectively assessed a surveillance protocol aiming to safely reduce the burden of colonoscopies. Methods: Between 2013 and 2018, we enrolled SPS patients from nine Dutch and Spanish hospitals. Patients were surveilled using a protocol appointing either a 1-year or 2-year interval after each surveillance colonoscopy, based on polyp burden. Primary endpoint was the 5-year cumulative incidence of CRC and advanced neoplasia (AN) during surveillance. Results: We followed 271 SPS patients for a median of 3.6 years. During surveillance, two patients developed CRC (cumulative 5-year incidence 1.3%[95% CI 0% to 3.2%]). The 5-year AN incidence was 44% (95% CI 37% to 52%), and was lower for patients with SPS type III (26%) than for patients diagnosed with type I (53%) or type I and III (59%, p<0.001). Most patients were recommended a 2-year interval, and those recommended a 2-year interval were not at increased risk of AN: AN incidence after a 2-year recommendation was 15.6% compared with 24.4% after a 1-year recommendation (OR 0.57, p=0.08). Conclusion: Risk stratification substantially reduced colonoscopy burden while achieving CRC incidence similar to previous studies. AN incidence is considerable in SPS patients, but extension of surveillance intervals was not associated with increased AN in those identified as low-risk by the protocol. We identified SPS type III patients as low-risk group that might benefit from even less frequent surveillance