Improvement of treatment outcomes after implementation of comprehensive pharmaceutical care in breast cancer patients receiving everolimus and exemestane.

Combination therapy with everolimus and an aromatase inhibitor such as exemestane is an effective treatment option for advanced or recurrent breast cancer. However, the therapy is often limited because of the occurrence of severe adverse events (AEs), including oral mucositis, interstitial lung disease, diarrhea, and rash. Therefore, early management of AEs is extremely important to obtain maximum treatment outcome. We investigated here the effects of comprehensive pharmaceutical care for prevention of severe AEs on patient's quality-of-life (QOL) and continuation of therapy. QOL was assessed every month based on the five-level version of EuroQol-5-Dimension (EQ-5D-5L). AEs were graded according to the Common Terminology Criteria for Adverse Events (ver 4.0). Implementation of comprehensive pharmaceutical care remarkably reduced the incidence of severe oral mucositis as compared with those without such interventions. EQ-5D-5L health states were almost constant during 6 months after intervention, ranging from 0.850 to 0.889. Median time to treatment failure (TTF) was significantly longer after intervention than before [224.0 days, 95% confidence interval (CI): 117-331 days versus 34 days, 21-47 days, hazard ratio (HR): 0.027, 95% CI: 0.005 - 0.154, p<0.001]. These findings suggest that our comprehensive pharmaceutical care is highly effective for enhancing treatment outcome by maintaining patient's QOL.