Early-stage Triple-negative Breast Cancer: Time to Optimize Personalized Strategies

Triple-negative breast cancer (TNBC) accounts for approximately 15%-20% of breast cancers diagnosed worldwide, which amounts to almost 200 000 cases each year. Although historically TNBC is considered difficult to treat with a poor prognosis, there is emerging evidence showing excellent response rates in a subset of TNBC patients. Attempts to de-escalate chemotherapy in hormone-receptor-positive (HR+) and HER2-neu amplified breast cancer subtypes have been successful. At present, robust strategies to personalize therapy in early-stage TNBC do not exist, and despite excellent response rates in a subset of patients, all patients are exposed to the same several cycles of cytotoxic chemotherapy. Personalizing therapy in TNBC represents a challenge due to the scarcity of treatment options outside of cytotoxic chemotherapy and limited predictive and prognostic biomarkers to tailor treatment. Recent developments in understanding TNBC biology have sparked interest in exploring treatment optimization and personalization with the goal of achieving excellent response rates and long-term clinical outcomes, while simultaneously reducing physical, psychological, and financial toxicities for select patients. Here, we provide an update on the current evidence to support future studies examining de-escalating chemotherapy in patients with low-risk TNBC and adjuvant intensification strategies to improve outcomes for patients who are at high risk for systemic failure despite current standard-of-care treatments.