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document
Assessment of osteopontin in early breast cancer : correlative study in a randomised clinical trial . INTRODUCTION Osteopontin ( OPN ) is a malignancy-associated glycoprotein that contributes functionally to tumor aggressiveness . In metastatic breast cancer , we previously demonstrated that elevated OPN in primary tumor and blood was associated with poor prognosis . METHODS We measured OPN in plasma by ELISA , and in tumors by immunohistochemistry , in 624 ( 94 % ) and 462 ( 69 % ) , respectively , of 667 postmenopausal women with hormone responsive early breast cancer treated by surgery followed by adjuvant treatment with tamoxifen +/- octreotide in a randomized trial ( NCIC CTG MA.14 ; National Cancer Institute of Canada Clinical Trials Group Mammary.14 ) . RESULTS Plasma OPN was measured in 2,540 samples ; 688 at baseline and 1,852 collected during follow-up . Mean baseline plasma OPN was 46 ng/ml ( range 22.6 to 290 ) which did not differ from normal levels . Mean percentage OPN tumor cell positivity was 33.9 ( 95 % CI : 30.2 to 37.9 ) . There was no correlation between plasma and tumor OPN values . In multivariate analysis , neither was associated with event-free survival ( EFS ) , relapse-free survival ( RFS ) , overall survival ( OS ) , bone RFS or non-bone RFS . An exploratory analysis in patients with recurrence showed higher mean OPN plasma levels 60.7 ng/ml ( 23.9 to 543 ) in the recurrence period compared with baseline levels . CONCLUSIONS The hypothesis that OPN tumor expression would have independent prognostic value in early breast cancer was not supported by multivariate analysis of this study population . Plasma OPN levels in women with hormone responsive early breast cancer in the MA.14 trial were not elevated and there was no evidence for prognostic value of plasma OPN in this defined group of patients . However , our finding of elevated mean OPN plasma level around the time of recurrence warrants further study . TRIAL REGISTRATION NCT00002864 , http : //clinicaltrials.gov/show/NCT00002864 .
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Intervention_Pharmacological
Osteopontin
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Intervention_Pharmacological
OPN
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Intervention_Pharmacological
immunohistochemistry
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Intervention_Surgical
surgery
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Intervention_Pharmacological
tamoxifen +/- octreotide
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Outcome_Physical
Plasma OPN
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Outcome_Physical
Mean baseline plasma OPN
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Outcome_Physical
Mean percentage OPN tumor cell positivity
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Outcome_Other
between plasma and tumor OPN values
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Outcome_Mortality
with event-free survival ( EFS ) , relapse-free survival ( RFS ) , overall survival ( OS ) , bone RFS or non-bone RFS
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Outcome_Physical
that OPN tumor expression
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Outcome_Other
population
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Outcome_Physical
Plasma OPN levels
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Outcome_Other
elevated mean OPN plasma level
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Participant_Condition
early breast cancer :
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Participant_Sample-size
624 ( 94 % )
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Participant_Sample-size
462
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Participant_Sample-size
667
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Participant_Condition
postmenopausal
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Participant_Sex
women
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Participant_Condition
breast cancer
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Participant_Sample-size
2,540 samples
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Participant_Sex
women
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Participant_Condition
early breast cancer