Prospective memory in breast cancer survivors treated with endocrine therapy: findings from an ecological virtual reality task.

OBJECTIVE

Cognitive effects of endocrine therapy (ET) in breast cancer are often subtle and may escape detection by standard neuropsychological assessments. Prospective memory (PM)-the ability to carry out intended actions-is particularly sensitive to mild cognitive changes, and crucial for autonomy and treatment adherence. This study examined the impact of ET, administered without chemotherapy, on PM using a virtual reality (VR)-based paradigm.

METHOD: Thirty-eight postmenopausal breast cancer survivors treated with ET (ET+) or without ET (ET-), and 21 healthy controls were evaluated. To isolate the cognitive effects of ET, none of the patients had received chemotherapy. Participants completed standardized neuropsychological tests, self-report questionnaires, and a VR-based PM task assessing recall of event-based (EB) and time-based (TB) intentions after short (10-min) and long (10 h) delays.

RESULTS

Despite preserved performance on standard neuropsychological measures, ET+ patients showed significantly lower PM performance than ET- patients, specifically for TB intentions after the short delay (p.adj = .002). The prospective component of these TB intentions was particularly less frequently retrieved (p.adj = .014), despite preserved storage.

CONCLUSIONS

This study provides preliminary evidence suggesting that ET, independent of chemotherapy-related neurotoxicity, may be associated with alterations in PM. The pattern of PM performance in ET+ patients suggests a disruption in self-initiated retrieval processes during early consolidation, when memory traces remain labile and vulnerable to interference. The use of an immersive VR-based PM paradigm revealed subtle cognitive changes not captured by conventional assessments, underscoring the clinical value of ecologically valid tools.