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5‐year follow‐up of a randomized controlled trial of immediate versus delayed zoledronic acid for the prevention of bone loss in postmenopausal women with breast cancer starting letrozole after tamoxifen: N03CC (Alliance) trial
Author(s) -
WagnerJohnston Nina D.,
Sloan Jeff A.,
Liu Heshan,
Kearns Ann E.,
Hines Stephanie L.,
Puttabasavaiah Suneetha,
Dakhil Shaker R.,
Lafky Jacqueline M.,
Perez Edith A.,
Loprinzi Charles L.
Publication year - 2015
Publication title -
cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.052
H-Index - 304
eISSN - 1097-0142
pISSN - 0008-543X
DOI - 10.1002/cncr.29327
Subject(s) - medicine , zoledronic acid , letrozole , breast cancer , bone mineral , osteoporosis , surgery , randomized controlled trial , tamoxifen , cancer
BACKGROUND Postmenopausal women with breast cancer receiving aromatase inhibitors are at an increased risk of bone loss. The current study was undertaken to determine whether upfront versus delayed treatment with zoledronic acid (ZA) impacted bone loss. This report described the 5‐year follow‐up results. METHODS A total of 551 postmenopausal women with breast cancer who completed tamoxifen treatment and were undergoing daily letrozole treatment were randomized to either upfront (274 patients) or delayed (277 patients) ZA at a dose of 4 mg intravenously every 6 months. In the patients on the delayed treatment arm, ZA was initiated for a postbaseline bone mineral density T‐score of <‐2.0 or fracture. RESULTS The incidence of a 5% decrease in the total lumbar spine bone mineral density at 5 years was 10.2% in the upfront treatment arm versus 41.2% in the delayed treatment arm ( P <.0001). A total of 41 patients in the delayed treatment arm were eventually started on ZA. With the exception of increased NCI Common Toxicity Criteria (CTC) grade 1/2 elevated creatinine and fever in the patients treated on the upfront arm and cerebrovascular ischemia among those in the delayed treatment arm, there were no significant differences observed between arms with respect to the most common adverse events of arthralgia and back pain. Osteoporosis occurred less frequently in the upfront treatment arm (2 vs 8 cumulative cases), although this difference was not found to be statistically significant. Bone fractures occurred in 24 patients in the upfront treatment arm versus 25 patients in the delayed treatment arm. CONCLUSIONS Immediate treatment with ZA prevented bone loss compared with delayed treatment in postmenopausal women receiving letrozole and these differences were maintained at 5 years. The incidence of osteoporosis or fractures was not found to be significantly different between treatment arms. Cancer 2015;121:2537–2543 . © 2015 American Cancer Society .