Long-term subjective cognitive functioning following adjuvant systemic treatment: 7-9 years follow-up of a nationwide cohort of women treated for primary breast cancer

Background: There is growing concern among breast cancer (BC) patients and survivors about cognitive impairment following systemic treatments. The aim of the present study was to investigate the long-term effects of standard systemic adjuvant therapies on subjective cognitive impairment (SCI) in a large nationwide cohort of BC survivors 7-9 years after primary surgery. Methods: Participants were recruited from the nationwide Psychosocial Factors and Breast Cancer inception cohort of Danish women treated for primary BC. SCI was assessed with the Cognitive Failures Questionnaire and women allocated to systemic treatment according to nationwide standard protocols were compared with women who had not received any systemic treatments. Results: A total of 1889 recurrence-free survivors were eligible for analysis. No difference in SCI was found between survivors across standardized systemic treatment protocols when analyses were stratified by menopausal status and adjusted for possible sociodemographic and treatment-related confounders. The frequency of significant SCI in a subgroup of survivors in the age range 65-74 years was similar to 7%. Conclusions: No differences in long-term SCI at 7-9 years post surgery were found between women who had received systemic therapies and those who had not. Furthermore, the observed proportion of survivors with significant SCI was comparable to normative data. These results are important to communicate to patients, survivors, and clinicians alike, especially in the light of increasing concern about cognitive impairment following systemic therapies.