Neoadjuvant chemotherapy combined with endocrine therapy for hormone receptor-positive breast cancer: A systematic review and meta-analysis

BACKGROUND: This study aimed to conduct a comparative analysis of the efficacy and safety of neoadjuvant chemotherapy combined with endocrine therapy against the backdrop of single neoadjuvant chemotherapy or endocrine therapy, specifically in the context of hormone receptor-positive (HR+) breast cancer treatment. METHODS: We conducted a thorough literature search across several databases, including China National Knowledge Infrastructure, Wanfang, Weipu, Chinese Journal Full-text Database, PubMed, Web of Science, Cochrane Library, and EMBASE, adhering to the guidelines outlined in the PRISMA statement. Our specific focus was on identifying randomized controlled trials that directly compared the combined approach of neoadjuvant chemotherapy and endocrine therapy with single chemotherapy or endocrine therapy in the context of treating HR+ breast cancer. Subsequently, we utilized statistical packages implemented in R software to perform comparative analyses of key clinical indicators, encompassing the complete response, objective response rate (ORR), disease control rate, pathological complete response (pCR), and adverse reactions. RESULTS: A total of 11 randomized controlled trials, involving 1359 patients, all of whom met our inclusion criteria and were thus included in our comprehensive analysis. Within this cohort, 688 patients (50.63%) administered neoadjuvant chemotherapy combined with endocrine therapy (NCET), 642 patients (47.24%) received neoadjuvant chemotherapy (NCT) alone, while 29 patients (2.13%) underwent neoadjuvant endocrine therapy (NET) alone. The results of our meta-analysis revealed that NCET exhibited a statistically significant enhancement in both ORR and pCR (P < .05). Nonetheless, when compared to NCT or NET, NCET did not yield a significant impact on complete response, disease control rate, and safety (P > .05). In addition, NCET demonstrated a significant improvement in ORR among patients with HR+, HER2-negative breast cancer (P < .05). However, it was also linked to a heightened incidence of serious adverse reactions within this particular patient subgroup (P < .05). CONCLUSION: The combination of Neoadjuvant chemotherapy and endocrine therapy stands out as a significant contributor to enhancing the ORR and pCR for HR+ breast cancer patients. For breast cancer patients with HER2- status, NCET demonstrates a remarkable improvement in ORR but is also associated with the emergence of adverse reactions.