Even as monotherapy, neoadjuvant endocrine therapy (NET) is associated with similar response rates as neoadjuvant combination chemotherapy in treating estrogen receptor-positive (ER+) breast cancer, but with significantly lower toxicity. This according to a meta-analysis of 3,490 unique patients to evaluate the effect of NET on the response rate and the rate of breast conservation surgery (BCS) for ER+ breast cancer. Researchers found:
• NET as chemotherapy with aromatase inhibitors had a similar clinical response rate (OR, 1.08), radiological response rate (OR, 1.38), and BCS rate (OR, 0.65), compared with combination therapy, but with lower toxicity.
• Aromatase inhibitors were associated with a significantly higher clinical response rate (OR, 1.69), radiological response rate (OR, 1.49), and BCS rate (OR, 1.62), compared with tamoxifen.
• Dual combination therapy with growth factor pathway inhibitors was associated with a higher radiological response rate (OR, 1.59), but not clinical response rate (OR, 0.76), compared with endocrine monotherapy.
Citation: Spring LM, Gupta A, Reynolds KL, et al. Neoadjuvant endocrine therapy for estrogen receptor-positive breast cancer. A systematic review and meta-analysis. [Published online ahead of print June 30, 2016]. JAMA Oncol. doi:10.1001/jamaoncol.2016.1897.