Comparison of risedronate versus placebo in preventing anastrozole-induced bone loss in women at high risk of developing breast cancer with osteopenia

TY - JOUR

T1 - Comparison of risedronate versus placebo in preventing anastrozole-induced bone loss in women at high risk of developing breast cancer with osteopenia

AU - Sestak, Ivana

AU - Blake, Glen M.

AU - Patel, Rajesh

AU - Coleman, Robert E.

AU - Cuzick, Jack

AU - Eastell, Richard

PY - 2019/7

Y1 - 2019/7

N2 - Anastrozole has been shown to prevent breast cancer in postmenopausal women at high risk of the disease, but has been associated with substantial accelerated loss of bone mineral density (BMD) and increased fractures. Here, we investigate the effect of risedronate on BMD after 5 years of follow-up in the IBIS-II prevention trial. 1410 women were enrolled in the bone sub-study and stratified into three strata according to the lowest baseline T-score at spine or femoral neck. The objective was to compare the effect of oral risedronate (35 mg weekly) versus placebo in osteopenic women in stratum II who were randomised to anastrozole in the main study. 258 osteopenic, postmenopausal women at high risk of developing breast cancer for whom baseline and follow-up bone mineral density measurements were available. 5-year mean BMD change at the lumbar spine for osteopenic women randomised to anastrozole and risedronate was −0.4% compared to −4.2% for those not on risedronate (P < 0.0001) but not significantly different between risedronate users and non-users at the hip (P = 0.2). 5-year mean PINP change was −20% for those randomised to anastrozole and risedronate compared to 3% for those not on risedronate but on anastrozole (P < 0.0001). Our results confirm the bone loss associated with the use of anastrozole and show that anastrozole-induced BMD loss in the spine can be controlled with risedronate treatment. However, our results suggest that weekly oral risedronate is unable to completely prevent anastrozole induced bone loss at the hip.

AB - Anastrozole has been shown to prevent breast cancer in postmenopausal women at high risk of the disease, but has been associated with substantial accelerated loss of bone mineral density (BMD) and increased fractures. Here, we investigate the effect of risedronate on BMD after 5 years of follow-up in the IBIS-II prevention trial. 1410 women were enrolled in the bone sub-study and stratified into three strata according to the lowest baseline T-score at spine or femoral neck. The objective was to compare the effect of oral risedronate (35 mg weekly) versus placebo in osteopenic women in stratum II who were randomised to anastrozole in the main study. 258 osteopenic, postmenopausal women at high risk of developing breast cancer for whom baseline and follow-up bone mineral density measurements were available. 5-year mean BMD change at the lumbar spine for osteopenic women randomised to anastrozole and risedronate was −0.4% compared to −4.2% for those not on risedronate (P < 0.0001) but not significantly different between risedronate users and non-users at the hip (P = 0.2). 5-year mean PINP change was −20% for those randomised to anastrozole and risedronate compared to 3% for those not on risedronate but on anastrozole (P < 0.0001). Our results confirm the bone loss associated with the use of anastrozole and show that anastrozole-induced BMD loss in the spine can be controlled with risedronate treatment. However, our results suggest that weekly oral risedronate is unable to completely prevent anastrozole induced bone loss at the hip.

KW - Anastrozole

KW - Bone marker

KW - Bone mineral density

KW - Breast cancer risk

KW - Osteopenia

KW - Risedronate

UR - http://www.scopus.com/inward/record.url?scp=85064807581&partnerID=8YFLogxK

U2 - 10.1016/j.bone.2019.04.016

DO - 10.1016/j.bone.2019.04.016

M3 - Article

AN - SCOPUS:85064807581

SN - 8756-3282

VL - 124

SP - 83

EP - 88

JO - Bone

JF - Bone

ER -