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document
Reversal of skeletal effects of endocrine treatments in the Intergroup Exemestane Study . The adjuvant use of aromatase inhibitors in breast cancer is associated with adverse effects on bone health . We previously reported a decline in bone mineral density ( BMD ) following the switch from tamoxifen to exemestane in the Intergroup Exemestane Study ( IES ) . Here we report effects of endocrine treatment withdrawal on BMD , bone turnover markers ( BTM ) and fracture rates . 4,724 patients took part in IES , and 206 patients were included in a bone sub-study . BMD and BTM were assessed pre-randomization , during and after the end of treatment ( EOT ) . To evaluate treatment withdrawal effects , 12- and 24-month post EOT BMD results are available for 122 and 126 patients , respectively . Similar patient numbers had BTM measured post EOT . Following treatment withdrawal , the differences in BMD observed between the two endocrine strategies were partially reversed . At 24 months from EOT , spine BMD increased by 1.53 % ( 95 % CI 0.63-2.43 ; p = 0.001 ) after stopping exemestane and fell by 1.93 % ( 95 % CI -2.91 to 0.95 ; p = 0.0002 ) following tamoxifen withdrawal . A similar pattern of changes was observed at the hip . At 2 years post EOT , BMD changes from baseline were similar with both treatment strategies . Corresponding inverse changes in BTM were seen , with an increase following tamoxifen withdrawal and a reduction after exemestane . A higher number of fractures occurred during exemestane treatment , but fracture rates were similar after treatment withdrawal . With the switch strategy used in IES , the on treatment adverse bone effects of exemestane are reversed . Ongoing monitoring of BMD is therefore not routinely required .
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Intervention_Pharmacological
aromatase inhibitors
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Intervention_Pharmacological
tamoxifen
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Intervention_Pharmacological
exemestane
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Intervention_Pharmacological
endocrine treatment
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Intervention_Pharmacological
tamoxifen
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Intervention_Pharmacological
exemestane
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Intervention_Pharmacological
exemestane
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Outcome_Other
effects
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Outcome_Physical
spine BMD
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Outcome_Physical
BMD changes
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Outcome_Physical
inverse changes in BTM
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Outcome_Physical
number of fractures occurred
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Outcome_Physical
fracture rates
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Outcome_Adverse-effects
adverse bone effects
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Participant_Sample-size
4,724
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Participant_Sample-size
206