Cognitive performance in breast cancer survivors: a ten-year follow-up

Abstract Background Cognitive impairment (CI) has been widely reported as a frequent non-fatal cancer outcome. 15% to 25% of breast cancer (BCa) patients may have CI; however long-term variations of cognitive performance during and after the cessation of the treatments remains unclear. The present study aims to describe the evolution of cognitive performance in BCa survivors that are still in follow-up at breast cancer clinic, 10 years after diagnosis. Methods 506 women with BCa admitted to the Portuguese Institute of Oncology, Porto, in 2012, were evaluated with the Montreal Cognitive Assessment (MoCA) before any treatment, after one, three, five, and ten years. Patients with a MoCA score ≤1.5 standard deviation below the mean of age- and education-specific norms were considered to have probable cognitive impairment (PCI). The 10-year follow up started in October 2022, and is still in progress (as of March, 118 were evaluated). All women that are still being followed at IPO-Porto for consultations and treatments were evaluated with MoCA assessment. Results PCI prevalence at the 10 years was 43.0% (95%Confidence Interval: 34.1%-52.7%). Several pathways for cognitive performance were identified throughout the 10-year follow-up: 58 women (49.2%) never had PCI at baseline assessment or during follow-up; 19 women (16.1%) had PCI at baseline, from whom 5 (4.2%) had PCI in all evaluations, 2 (1.7%) did not have PCI in any follow up evaluation, 2 (1.7%) had PCI during follow up, but not at 10 years and 3 (2.5%) had PCI again only at the 10-year follow-up; 5 women (4.2%) did not have PCI at baseline but had PCI at least once during follow-up but not at 10 years, and 24.6% had PCI for the first time at 10 years. Conclusions The results show a high prevalence of PCI 10 years after diagnosis with a significant part being new cases. These results highlight the need for including regular assessments of cognitive performance as a part of the clinical follow-up of BCa survivors. Key messages • There is a high prevalence of cognitive deficits in breast cancer suvivors 10 years after diagnosis. • Including cognitive evaluations of breast cancer survivors during clinical follow up are recommended.