Long-term Outcomes By Neoadjuvant Efficacy Indexes In HR+ And HR+/HER2+ Breast Cancer:A Systematic Review And Meta-analysis

Objective: The meta-analysis is provided to identify the best prognostic neoadjuvant efficacy indexes among pathological complete response(pCR),residual cancer burden(RCB),preoperative endocrine prognostic index(PEPI),and Ki-67 index change in patients with hormone receptor positive(HR+)and HR+/ human epidermal growth factor receptor 2 positive(HR+/HER2+)breast cancer after neoadjuvant systemic therapy for prognosis prediction.Methods: PubMed,Web of Science,Embase,and Wiley Online Library databases were systematically searched and reference lists of retrieved articles were searched for related publications.Eligible studies examined patients with stage I to III HR+ breast cancer who received neoadjuvant therapy.All studies were clinical trials or cohort studies that reported one or more neoadjuvant efficacy indexes and long-term outcome.Study characteristics,neoadjuvant efficacy indexes,and survival data were then extracted.“Event-free survival”(EFS)was used as an umbrella term for all survival endpoints,as well.Furthermore,to assess the optimal neoadjuvant efficacy indexes for HR+ and HR+/HER2+ breast cancer,relative risk(RR)values determined by fixed-effects meta-analysis were compared.Results: Our analysis finally included 21 publications,among which twelve studies provided EFS using pCR,ten using RCB,and five using PEPI.Ki-67 change was excluded because of the few amount of studies eligible after systematic review.For HR+ patients,PEPI possessed the greatest prognostic value(RR: 0.24,95%confidence interval [CI]: 0.13–0.44),followed by RCB(RR: 0.33,95% CI:0.25–0.43),and pCR(RR: 0.46,95% CI: 0.37–0.56).For HR+/HER2+ patients,RCB(RR: 0.24,95% CI: 0.13–0.44)exhibited better prognostic value than pCR(RR: 0.50,95% CI: 0.33–0.78).Conclusion: These findings show that PEPI is the best prognostic indicator for HR+patients,and RCB is the optimal for HR+/HER2+ patients.A focus on improving the PEPI(especially for patients with HR+ breast cancer)and improving the RCB(especially for patients with HR+/HER2+ breast cancer)in patients receiving neoadjuvant therapy should be considered when designing future clinical trials of neoadjuvant regimens.There is also a need to develop more accurate predictive models for use in clinical settings.