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.
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).
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.
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.