Bisphosphonates (Again and More)
You may be interested in this commentary by Dr Bedart and colleagues at the Jules Bordet Institute in Brussels. This was recently published in the Journal of Clinical Oncology, and, after the quote, I will post the link if you want to read more.
While waiting for this new and exciting knowledge to emerge, should clinicians routinely incorporate bisphosphonates into adjuvant therapy? A single randomized trial contingent on 137 DFS events is insufficient to change the current standard of care. The open-label design of the ABCSG-12 trial may have introduced bias favoring the earlier detection of bone metastases in the standard therapy arm, and longer follow-up is required to establish the stability of these early efficacy results. Moreover, concerns that the effect of zoledronic acid treatment may have been driven by the experimental anastrozole and goserelin arm—and concerns about the administration of endocrine therapy for only the nonstandard duration of 3 years—in this study suggest that it is too early to treat all patients with early-stage breast cancer with adjuvant bisphosphonate therapy. Reserving final judgment until the results of the NSABP B-34 and AZURE trials are available is prudent, although the delay in presentation of the efficacy analyses raises concern that the event rates may be lower than anticipated, or there may not be significant differences in outcome with the addition of a bisphosphonate. Nevertheless, on the basis of the striking treatment effect and minimal toxicity observed in the ABCSG-12 trial, it is certainly reasonable to discuss the benefits of early rather than late administration of zoledronic acid every 6 months in premenopausal women receiving adjuvant ovarian suppression to prevent treatment-related bone loss and subsequent fractures and possibly reduce the risk of breast cancer relapse.