Long-term effects of aromatase inhibitor withdrawal on bone mineral density in early breast cancer patients: 10-year follow-up results of the BREX study.

PURPOSE: We aimed to provide long-term bone mineral density (BMD) data on early breast cancer patients of the BREX (Breast Cancer and Exercise) study. The effects of exercise and adjuvant endocrine treatment 10 years after randomization were analyzed, with special emphasis on aromatase inhibitor (AI) therapy discontinuation at 5 years. METHODS: The BREX study randomized 573 pre- and postmenopausal breast cancer patients into a 1-year supervised exercise program or a control group. 372 patients were included into the current follow-up analysis. BMD (g/cm2) was measured by dual-energy X-ray absorptiometry at lumbar spine (LS), left femoral neck (FN), and the total hip. Separate groups were displayed according to baseline menopausal status, and whether the patient had discontinued AI therapy at 5 years or not. RESULTS: The BMD change from 5 to 10 years did not significantly differ between the two randomized arms. AI discontinuation at 5 years had statistically significant BMD effects. The FN BMD continued to decrease in patients who discontinued AI therapy during the first 5-year off-treatment, but the decrease was three-fold less than in patients without AI withdrawal (- 1.4% v. - 3.8%). The LS BMD increased (+ 2.6%) in patients with AI withdrawal during the first 5 years following treatment discontinuation, while a BMD decrease (-1.3%) was seen in patients without AI withdrawal. CONCLUSION: This study is to our knowledge the first to quantify the long-term impact of AI withdrawal on BMD. Bone loss associated with AI therapy seems partially reversible after stopping treatment. TRIAL REGISTRATION: http://www. CLINICALTRIALS: gov/ (Identifier Number NCT00639210).

Isometric endurance test of the cervical flexor muscles - Reliability and normative reference values.

OBJECTIVE: To obtain reference values for the isometric endurance test (IET) of the cervical flexor muscles, investigate its reproducibility, and compare the results with the maximal isometric strength test (MIST) of the cervical flexor muscles. DESIGN: Cross-sectional non-comparative study with single group repeated measurements. METHODS: Altogether 219 healthy females aged 20-59 years volunteered to participate in the study. The IET was performed in the supine position and MIST seated. The reproducibility was evaluated by the intraclass correlation coefficient (ICC) and an analysis described by Bland and Altman. The relationship between the two measuring methods was evaluated by Pearson's correlation coefficient. RESULTS: The mean (SD) IET time was 60 (33) seconds with no significant differences between the age groups of each decade. The ICC for intrarater repeatability was 0.80. However, the Bland-Altman analysis suggested moderate variation in repeated measurements. Pearson's correlation coefficient between the IET and MIST was 0.56. CONCLUSION: Normative reference values for the IET are presented. Although the ICC showed good repeatability, one should consider that the change at follow-up visits has to be considerable to be clinically relevant. The correlation between the endurance time and maximal flexion strength was moderate. Thus IET of the cervical flexor muscles may be used in the clinic like the Biering-Sorenson test has been used to assess fatigue of the trunk extensor muscles.