ABSTRACT
BACKGROUND: Informing patients about chemotherapy-related cognitive symptoms (CRCS) may increase perceived cognitive symptoms. This longitudinal randomized study evaluated this Adverse Information Effect (AIE) in breast cancer patients and examined whether self-affirmation (SA) can reduce AIEs (ClinicalTrials.gov identifier: NCT04813965). PATIENTS AND METHODS: Before (neo) adjuvant chemotherapy, 160 newly diagnosed breast cancer patients were randomly allocated to receive: standard information on side-effects (control), standard information with additional information about CRCS (information), or standard and additional information with a subsequent self-affirmative text (information+SA). Online-questionnaires assessed the perceived frequency (MOS-cog) and severity (MDASI-cog) of cognitive symptoms before chemotherapy (baseline, T0), and 2.5-months (T1) and 6.5-months (T2) post-chemotherapy. Higher scores indicate less frequent, and more severe symptoms, respectively. Baseline-to-follow-up analyses using a mixed-effects modeling approach compared groups over time. RESULTS: At T0-T2, 148, 140 and 133 patients responded, respectively (attrition rates: 8%, 5%, 5%). Frequency (ES = -0.36, P =.003) and severity (ES = 0.54, P <.001) of symptoms worsened from baseline to T1, without differences between groups. At T2, symptom frequency remained stable for informed (ES=-0.3, P =.021) and self-affirmed (ES=-0.3, P =.019) patients, but returned to baseline levels for controls. At T2, symptom severity remained increased for informed patients (ES = 0.3, P =.006), but normalized for self-affirmed patients (ES = 0.2, P =.178) and controls. CONCLUSION: No AIEs occurred until T2. The initial overall increase in perceived cognitive symptoms recovered at T2 for controls, but not for patients who received additional information about CRCS. Self-affirmation attenuated these longer-term AIEs for the perceived severity but not the frequency of symptoms.
