Enhancing decision-making about adjuvant chemotherapy in early breast cancer following EndoPredict testing.

Objective: Chemotherapy side-effects can be substantial. There is increasing recognition that some oestrogen receptor positive (ER +ve), human epidermal growth factor receptor 2 negative (HER2 -ve) patients with breast cancer derive no benefit from chemotherapy and experience only iatrogenic harm. Gene expression profiling tests help refine recurrence risk and likely chemotherapy benefit. EndoPredict® is one such test, which classifies risks of distant recurrence as low or high in patients treated with surgery and adjuvant endocrine therapy alone. We compared treatment decisions pre-test and post-test results, patients' anxiety, decisional conflict, and oncologists' confidence about the decisions made.

Methods: Fourteen oncologists in 7 UK hospitals saw 149 pts judged to have equivocal indications for chemotherapy. Provisional treatment decisions were recorded then reconsidered when EPClin results were available. Pre-test and post-test results, patients completed State/Trait Anxiety Inventories (STAI), and the decisional conflict scale. Oncologists also recorded basic clinical details, their agreement with, and confidence about treatment decisions.

Results: Sixty-seven percent patients initially prescribed endocrine alone with high risk result upgraded to endocrine+chemotherapy (E + C); 83% prescribed E + C and had low risk scores, downgraded to E. None of 46 patients initially favouring E alone, who were low risk, changed decisions. Oncologists' confidence about decisions was significantly increased following the results (P = 0.002). Patients with downgraded treatment decisions had significantly lower anxiety scores (P = 0.045); those upgraded had increased scores (P = 0.001). Overall decisional conflict and uncertainty fell significantly post-test (P < 0.022).

Conclusions: EndoPredict scores increased oncologists' and patients' decision-making confidence, generally improving the matching of risk with therapy decisions.