Decision of adjuvant chemotherapy in intermediate risk luminal breast cancer patients: A prospective multicenter trial assessing the clinical and psychological impact of EndoPredict® (EpClin) use (UCBG 2–14)

Purpose: Genomic tests can identify ER-positive HER2-negative localized breast cancer patients who may not benefit from adjuvant chemotherapy. Such tests seem especially interesting in “intermediate” clinico-pathological risk categories. The psychological impact of the decision uncertainty in these women remains largely unexplored. We assessed the clinical and psychological impact of EndoPredict® (EpClin), a clinico-genomic test, in these patients. Methods: This multicenter, single arm prospective study (NCT02773004) enrolled patients for which adjuvant chemotherapy was uncertain, based on predefined criteria. The primary endpoint was the proportion of change between initial adjuvant decision and final administration of chemotherapy. Secondary endpoints included post-test (Day 17) and 1-year patient reported outcomes. Results: One third of 200 evaluable patients had a high EpClin score (≥3.32867; 10 years cumulative risk of distance failure ≥10%). The overall change rate of chemotherapy decision was 72/200 (35.8%, 95% CI 29.2–42.4). Chemotherapy was withdrawn in 57 cases (28.4% [22.2–34.8]) and added in 15 (7.5% [3.8–11.2]. 6 changes (8%) were based on patients’ decisions. Anxiety and distress levels increased at Day 17 when adding chemotherapy after the test result (p