Impact of different age ranges on the benefits and harms of the breast cancer screening programme by the EU-TOPIA tool

Background The recommendation for the implementation of mammography screening in women aged 45-49 and 70-74 is conditional with moderate certainty of the evidence. The aim of this study is to simulate the long-term outcomes (2020-50) of using different age range scenarios in the breast cancer screening programme of the Valencia Region (Spain), considering different programme participation rates.Methods Three age range scenarios (S) were simulated with the EU-TOPIA tool, considering a biennial screening interval: S1, 45-69 years old (y); S2, 50-69 y and S3, 45-74 y. Simulations were performed for four participation rates: A = current participation (72.7%), B = +5%, C = +10% and D = +20%. Considered benefits: number (N degrees) of in situ and invasive breast cancers (BC) (screen vs. clinically detected), N degrees of BC deaths and % BC mortality reduction. Considered harms: N degrees of false positives (FP) and % overdiagnosis.Results The results showed that BC mortality decreased in all scenarios, being higher in S3A (32.2%) than S1A (30.6%) and S2A (27.9%). Harms decreased in S2A vs. S1A (N degrees FP: 236 vs. 423, overdiagnosis: 4.9% vs. 5.0%) but also benefits (BC mortality reduction: 27.9% vs. 30.6%, N degrees screen-detected invasive BC 15/28 vs. 18/25). In S3A vs. S1A, an increase in benefits was observed (BC mortality reduction: 32.2% vs. 30.6%), N degrees screen-detected in situ B: 5/2 vs. 4/3), but also in harms (N degrees FP: 460 vs. 423, overdiagnosis: 5.8% vs. 5.0%). Similar trends were observed with increased participation.Conclusions As the age range increases, so does not only the reduction in BC mortality, but also the probability of FP and overdiagnosis.