No abstract

9005 Background: ZOL (4 mg q 4 wk) is an established therapy for reducing the risk of debilitating skeletal-related events (SREs) in patients (pts) with bone metastases (mets) from BC. As BC treatments continue to improve pt survival, long-term SRE-reduction is increasingly important, and evaluation of modified ZOL dosing to retain efficacy with reduced adverse events (AEs) is warranted. Methods: ZOOM, a phase III prospective, randomized, open-label, multicenter study, assessed the safety and efficacy of quarterly (4 mg q 12 wk; Arm 1) vs monthly (4 mg q 4 wk; Arm 2) ZOL for ~1 yr in pts with BC who have ≥ 1 bone met, and have received ~1 yr of prior ZOL treatment (9 to 12 doses over ≤ 15 months; last dose ≤ 3 months prior). The primary endpoint was skeletal morbidity rate (SMR; number of SREs/pt/yr). Sample size to detect non-inferiority with 80% power (1-sided a = 0.025) was 420 pts. Secondary endpoints included time to first SRE, bone pain, bone marker (N-telopeptide of type I collagen; NTX) levels, and safety. Results: 425 pts were enrolled (209 in Arm 1; 216 in Arm 2); arms were well balanced for pt and disease characteristics, and anticancer therapies. SMR was similar between arms: 0.26 (95% confidence interval [CI] = 0.15, 0.37) in Arm 1 vs 0.22 (95% CI = 0.14, 0.29) in Arm 2; between-arms difference = 0.04 (upper limit of 1-tailed 97.5% CI = 0.17). Despite the proximity of 0.17 to the adjusted non-inferiority margin (0.19), the non-inferiority of Arm 1 vs 2 remains statistically significant. Safety analyses showed that ZOL was well tolerated. Renal AEs were reported in similar proportions of pts in both arms; 7 cases of osteonecrosis of the jaw were reported (1.65% overall; 4 cases in Arm 1 vs 3 in Arm 2). Conclusions: ZOOM is the first randomized trial to compare ZOL q 12 wk vs ZOL q 4 wk in BC pts after 1 yr of standard ZOL therapy. SMR was similar between arms. Limitations in study design suggest the need to confirm non-inferiority of ZOL q 12 wk in other ongoing phase III trials.

Chemotherapy-induced amenorrhea occurs in about 20-70% of premenopausal breast cancer patients. Chemotherapy-induced amenorrhea can affect choice of hormonal therapy, fertility, and quality of life of breast cancer survivors. We retrospectively analyzed the incidence of amenorrhea after adjuvant chemotherapy and the subsequent recovery of the menses in 145 breast cancer patients. Age, smoking, alcohol consumption, body mass index, chemotherapy regimen, previous hormonal therapies, and previous childbearing were analyzed as potential predictive factors of ovarian function recovery. Median age was 42 years at the beginning of adjuvant chemotherapy with 30.3% of patients below 40 years of age. The majority (87.6%) of patients received anthracycline-based chemotherapy, 35.2% of patients received a cyclophosphamide-methotrexate-5-fluorouracil regimen and 42.8% received a taxane. The incidence of chemotherapy-induced amenorrhea was 80, and 35.3% of these patients resumed menses after a median of 8 months. In multivariate analysis, younger age (<40 years, P=0.01) and taxane-based chemotherapy (P=0.03) were associated with increased probability of recovery of menses after chemotherapy-induced amenorrhea. In contrast, cyclophosphamide-methotrexate-5-fluorouracil-based chemotherapy (P=0.07) and previous childbearing (P=0.04) were associated with an increased probability of permanent chemotherapy-induced amenorrhea. Recovery of menses after chemotherapy-induced amenorrhea occurs more probably in younger women, with no pregnancies and receiving taxanes.

No abstract

No abstract