Zoledronic acid (ZA) prevents aromatase inhibitor (Al)-associated bone loss in postmenopausal women with early breast cancer -36-month follow-up of the Z-FAST study

New results from the use of bisphosphonates in cancer patients

“…Patients were randomized to either immediate or delayed zoledronic acid (initiated only when T-score decreased below À2.0 or at occurrence of a nontraumatic fracture). Even at an early 12 months of follow-up, a 5.2% difference in BMD between groups was reported (P < 0.0001), and subsequent updates of these trials at 36 months of follow-up demonstrated continuing efficacy with the immediate treatment strategy [36,37].…”

The evolving role of zoledronic acid in early breast cancer

“…Patients in the upfront group received zoledronic acid concurrently with letrozole, and those in the delayed group received zoledronic acid only after a postbaseline BMD T-score ≤ −2.0 or after experiencing a nontraumatic fracture. After a median follow-up of 36 months in the Z-FAST trial (N = 602), patients in the upfront zoledronic acid group had improved BMD compared with baseline, and those in the delayed group had lost BMD, resulting in a significant 6.7% difference in lumbar spine BMD between the upfront and delayed groups (p < 0.0001) 45. Similar bone-protective effects of upfront versus delayed zoledronic acid were seen after 36 months in the ZO-FAST trial (9.3% difference in lumbar spine BMD, p < 0.0001; N = 1065),46 and after 12 months in the E-ZO-FAST trial (5.4% difference in lumbar spine BMD, p < 0.0001; N = 527) 26.…”

“…Zoledronic acid (4 mg every 6 months) was well tolerated in patients receiving adjuvant endocrine therapy, with transient infusion-site reaction and mild flu-like symptoms (arthralgia and pyrexia) being the most common adverse events 26,45,46,49. Among the 4 phase III trials, osteonecrosis of the jaw (ONJ) was suspected in 6 of 3998 patients; however, only 1 case (<0.05%) has been confirmed by the ONJ Adjudication Committee 26,45,46,49.…”

“…Among the 4 phase III trials, osteonecrosis of the jaw (ONJ) was suspected in 6 of 3998 patients; however, only 1 case (<0.05%) has been confirmed by the ONJ Adjudication Committee 26,45,46,49. In the same 4 trials, only 3 patients were suspected to have renal function impairment related to bisphosphonate treatment 26,45,46,49. In the adjuvant therapy setting, adverse events related to bisphosphonate therapy are mild and easily manageable, and the risk of rare adverse events can be further reduced with preventive measures and proper patient surveillance 51,52…”