Are oral bisphosphonates effective in improving lumbar bone mineral density in breast cancer survivors with osteopenia or osteoporosis?

OBJECTIVE: Breast cancer survivors with osteoporosis or osteopenia are commonly encountered in primary care and gynaecology practices. Our objective was to determine whether treatment with oral bisphosphonates (alendronate or cyclic etidronate) was more effective than calcium with vitamin D in improving lumbar spine bone mineral density (BMD) within one year in breast cancer survivors. METHODS: Breast cancer survivors with at least one year of clinical follow-up were identified from the prospective observational Canadian Database of Osteoporosis and Osteopenia (CANDOO). Analysis of covariance was used to examine the effects of bisphosphonate therapy on change in lumbar spine BMD at one year compared with the effects of calcium with vitamin D (analysis adjusted for baseline L2-L4 BMD, current tamoxifen use, number of prevalent vertebral fractures [VFs], and time since diagnosis of breast cancer, and age). RESULTS: Eighteen patients took calcium and vitamin D, 25 took cyclic etidronate, and 27 took oral alendronate. Adjusted one-year BMD increases for alendronate and cyclic etidronate compared to calcium and vitamin D were as follows: alendronate 4.53% (95% confidence interval [CI] 1.26%, 7.81%, P = 0.008), and cyclic etidronate 1.85% (-1.55%, 5.25%, P = 0.280). BMD increases were significantly greater in patients with prevalent VF compared to those without VF (P = 0.025). In contrast, time since diagnosis of breast cancer was significantly associated with a decrease in BMD (P = 0.002). We were unable to detect any effect of current tamoxifen use, baseline lumbar spine BMD, or age on changes in BMD at one year. CONCLUSION: Treatment with alendronate was associated with significantly greater improvements in lumbar spine BMD within one year in breast cancer survivors when compared with treatment with cyclic etidronate or calcium and vitamin D.

Are there differences between men and women prescribed bisphosphonate therapy in canadian subspecialty osteoporosis practices?

OBJECTIVE: To determine if there are differences between men and women referred for treatment of osteoporosis in Canada. METHODS: We performed an observational study of 1588 patients (163 men, 1425 women), 50 years of age and older, who were prescribed cyclic etidronate or alendronate for treatment of osteoporosis or osteopenia and had at least 2 years of followup registered in the Canadian Database for Osteoporosis and Osteopenia Patients (CANDOO). Comparisons of characteristics between men and women were performed using Pearson chi-square test, Student's t test, or a Kruskal-Wallis test, whichever was most appropriate. RESULTS: Mean baseline femoral neck and lumbar spine bone mineral densities were significantly higher in men than women at both the femoral neck and lumbar spine (p < 0.05, respectively). Men had double the rate of prevalent vertebral fractures (44%, 72/163) compared to women (22%, 315/1425; p < 0.001) and triple the rate of multiple prevalent vertebral fractures (10%, 17/163) compared to women (3%, 37/1425, p < 0.001). Furthermore, men were twice as likely as women to sustain a fracture within 2 years of starting treatment during observation in the CANDOO study (men: 4%, 7/163, women: 2%, 24/1425, p = 0.033). CONCLUSION: Osteoporosis may be under-recognized in men until the condition is at an advanced stage. A form of gender bias may exist in recognition and treatment (or referral for treatment) of osteoporosis in men.