Health-related quality of life and psychological distress of breast cancer patients after surgery during a phase III randomized trial comparing continuation of tamoxifen with switching to anastrozole after adjuvant tamoxifen for 1–4 years: N-SAS BC 03

To investigate whether the health-related quality of life (HRQOL) of patients switching from tamoxifen to anastrozole in a randomized trial is identical to that of those who continued tamoxifen after 1–4 years of adjuvant tamoxifen in Japanese postmenopausal breast cancer patients. Eligible patients for the randomized trial, the National Surgical Adjuvant Study of Breast Cancer 03, were recurrence-free postmenopausal women who had received definitive surgery for primary breast cancer with positive hormone receptor(s), and had been taking tamoxifen for 1–4 years postoperatively. They were randomly assigned to continue tamoxifen or to switch to anastrozole for a total duration of five years. Subjects were asked to reply to a self-administered QOL questionnaire survey to assess HRQOL (FACT-B [breast cancer scale], FACT-ES [endocrine symptom scale]) and psychological distress (CES-D: Center for Epidemiologic Studies Depression scale) at randomization (baseline), 3 months, 1, and 2 years after randomization, respectively. At baseline 694 patients (346 in the tamoxifen group and 348 in the anastrozole group) responded to the survey. The total scores of FACT-G, FACT-ES, and those of the FACT-G physical well-being subscale were statistically significantly better in the tamoxifen group than in the anastrozole group (P = 0.042, 0.038, and 0.005, respectively). However, there was no statistically significant difference between the treatment groups in the CES-D scores. Continuation of tamoxifen treatment after adjuvant tamoxifen for 1–4 years may provide Japanese breast cancer patients with better HRQOL than by switching to anastrozole.