Recent updates in systemic therapy of breast cancer: A brief narrative review

Abstract

Breast cancer is the most common malignancy and the leading cause of cancer-related deaths in women globally. Systemic therapy of breast cancer has evolved rapidly in the past few years. In this brief review, we aim to summarize the potentially practice-changing recent updates in the management of breast cancer. We searched the PubMed database for randomized clinical trials for breast cancer treatment conducted over the past 2 years. In addition, abstracts and results of studies reported at major oncology meetings were evaluated. A total of 95 randomized clinical trials were included to prepare this review. Multiple new therapeutic options for almost all subsets of breast cancer have emerged in the past 2 years. Most importantly, for hormone-receptor-positive breast cancer, addition of abemaciclib to endocrine therapy in the adjuvant setting and alpelisib for PIK3CA-mutant refractory advanced disease have been shown to improve the survival outcomes. Addition of pembrolizumab or atezolizumab to neoadjuvant chemotherapy has significantly increased the pathological complete response rate for early triple-negative breast cancer, while adjuvant metronomic capecitabine for 1 year has led to improved disease-free survival. Moreover, adjuvant adotrastuzumab emtansine fared better than trastuzumab in the management of residual disease after neoadjuvant treatment for human epidermal growth factor receptor 2 (HER2)-positive breast cancer, while tucatinib and neratinib have shown meaningfully improved progression-free survival in HER2-positive advanced disease, including patients with cranial nervous system involvement. Expanding access to these advances is soon expected to transform the way we treat breast cancers.