The Benefits From Extended Adjuvant Therapy After5Years Of Adjuvant Endocrine Therapy: A Meta-analysis Using Update Date From6Randomized Clinical Trials

Objective A meta-analysis evaluates the extended adjuvant endocrinetherapy for follow-up4years Overall survival,4years disease-free survival and4years Recurrence rate of the patients with breast cancer who were disease-freeat the end of5years endocrine therapy by RevMan5.0and STATA10.0sorwares.Methods Search all of the RCT on extended endocrine therapy for breastcancer in MEDLINE, EMBASE,CBM, VIP, CNKI, SD databases, andHandsearch recent issues of relevant journals, textbooks,annals and relevantconference abstracts，eview articles. Search strategy:pubmed:extended ANDbreast cancer AND endocrine therapy AND randomized controlled trial. Allsearches were conducted for the period between1978and November2011．Ameta-analysis was completed by collecting numerical data based on inclusionand exclusion criteria from all papers available. Two reviewers assessed thedocuments quality separately and cross check them. RevMan5.0and STATA10.0sorwares were used for statistical analysis.Result The meta-analysis included6trials. A total of9271patients were included in the analysis. The results of meta-analysis were listed as followes：①There was no statistically significant different between extended endocrinetherapy and placebo or Observation on overall survival、disease-free survival orrecurrence rate（P>0.05）;②Subgroup analysis, follow-up4years overallsurvival was worse with tamoxifen than with placebo or Observation，andfollow-up4years recurrence rate was higher. There was statistically significantdifferent between tamoxifen and placebo or Observation on follow-up4yearsoverall survival [OR=0.64,95%CI(0.46,0.89),P=0.008] or recurrence rate[OR=1.51,95%CI(1.15,2.14), P=0.005];③Subgroup analysis, Aromataseinhibitors improved follow-up4years disease-free survival and decreasedfollow-up4years recurrence rate in the patients. There was statisticallysignificant different between Aromatase inhibitors and placebo or Observationon follow-up4years disease-free survival [OR=1.46,95%CI(1.20,1.77),P=0.001] or recurrence rate [OR=0.64,95%CI(0.53,0.77), P<0.0001], andnon-statistically significant different on follow-up4years overall survival[OR=0.97,95%CI (0.77,1.17). P=0.64];④Subgroup analysis,the extendedendocrine therapy statistically decreased follow-up4years overall survival in thenode negetive breast cancer[OR=0.68；95%CI(0.50,0.93)，P=0.01].Conclusion Achieved5years tamoxifen with stabled disease followed byextended endocrime therapy could not improve patient’s survival and recurrencerate，but subgroup analysis showed：Aromatase inhibitors as extended therapyresulted in statistically significant improvement in follow-up4years DFS，andstatistically significant decreased the follow-up4years recurrence rate；tamoxifen as extended therapy resulted in statistically significant decreasedfollow-up4years OS，and increased the follow-up4years recurrence rate；extended endocrine therapy statistically decreased follow-up4years overall survival in the node negetive breast cancer。...