The KEYNOTE-522 trial is a significant study in the field of oncology, particularly for the treatment of early triple-negative breast cancer (TNBC), a subtype of breast cancer that lacks estrogen receptors, progesterone receptors, and excess HER2 protein, and is known for its aggressive nature and limited treatment options. The trial evaluated the efficacy of adding pembrolizumab, an immune checkpoint inhibitor that targets the PD-1/PD-L1 pathway, to the standard neoadjuvant (pre-surgery) chemotherapy regimen for patients with early TNBC. Pembrolizumab is designed to help the immune system recognize and fight cancer cells. The trial found that adding pembrolizumab significantly improved the rate of pathological complete response (pCR), which refers to the absence of any detectable cancer cells in tissue samples after treatment when examined under a microscope. A pCR is often associated with a better prognosis and can be an early indicator of long-term treatment effectiveness. Furthermore, the trial reported an absolute improvement in event-free survival (EFS), which measures the time after treatment when the patient has no signs of cancer recurrence, progression, or death from any cause. This suggests that when used in combination with chemotherapy, pembrolizumab increases the likelihood of a favorable response to treatment and potentially improves long-term outcomes for patients with early TNBC. These results have important implications for the treatment of early TNBC and support the integration of pembrolizumab into the standard treatment regimen, offering new hope for patients with this challenging cancer subtype. Pic by freepik. source:  https://www.annalsofoncology.org/article/S0923-7534(24)00077-2/fulltext?rss=yes