Brazilian study investigates the safety and efficacy of different chemotherapy regimens for the most aggressive form of breast cancer. 

The Role of Real-World Data in Oncology 

Medical research has increasingly incorporated real-world data to complement traditional randomized clinical trials. While clinical trials allocate patients randomly into different groups to assess a therapy’s efficacy in a controlled environment, real-world data is collected from patients undergoing routine clinical care, better reflecting the diversity of real-life patient populations. 

In oncology, real-world data is particularly valuable for implementing new therapies in urgent cases, such as triple-negative breast cancer (TNBC). This aggressive disease progresses rapidly and lacks the therapeutic targets present in other breast cancer subtypes (hormone receptors and HER2), limiting treatment options. 

The current standard treatment for stage II and III TNBC includes immunotherapy with pembrolizumab combined with chemotherapy. The chemotherapy regimen consists of carboplatin and paclitaxel, followed by anthracycline and cyclophosphamide (AC). However, a key question remains: which administration method of AC is more effective—AC every three weeks (q3w AC) or a more intensive dose-dense AC (ddAC)? 

Published in NPJ Breast Cancer, a Nature group journal, the Neo-Real study—led by the Instituto D’Or de Pesquisa e Ensino (IDOR) and the Brazilian Group for Breast Cancer Studies (GBECAM), with contributions from ten other Brazilian oncology centers—used real-world data to compare these two chemotherapy regimens. 

Neo-Real: Investigating the Best Therapeutic Approach 

The study followed 333 patients treated at ten oncology centers in Brazil from July 2020 to November 2023. The goal was to compare the efficacy and safety of two AC-based chemotherapy regimens in stage II and III TNBC patients who received neoadjuvant treatment (before surgery) with chemotherapy and immunotherapy. 

Patient data was collected through a standardized electronic record system (RedCap), ensuring high-quality and uniform data analysis. 

Comparing Treatment Outcomes 

Among the 279 patients who underwent tumor removal surgery, 65.4% of those who received ddAC achieved a pathologic complete response (pCR)—meaning no malignant cells were found in the removed tissue—compared to 58.7% of those who received q3w AC. However, researchers noted that this difference was not statistically significant to determine a superior regimen. 

In stage III TNBC patients, the intensified ddAC regimen showed a greater tendency for complete tumor eradication (59% vs. 40%), suggesting a potential benefit of this approach. However, further studies with larger populations are needed to confirm this effect. 

Regarding treatment safety, both regimens had similar discontinuation rates due to adverse effects. However, patients who received ddAC showed a higher tendency for severe side effects, such as febrile neutropenia (a dangerous drop in white blood cells accompanied by fever), highlighting the need for careful monitoring during treatment. 

The Impact of Real-World Data in the Fight Against Cancer 

The study underscores the importance of real-world data in medical research. Its findings align with those of KEYNOTE-522, the clinical trial that established the current standard treatment, reinforcing the complementarity of these two research approaches. 

While the real-world study did not find statistically significant differences between the chemotherapy regimens, the observed trend of better outcomes in stage III TNBC patients treated with ddAC suggests this regimen may offer benefits for this group. 

The researchers emphasize that further investigations are needed to confirm these findings and refine treatment guidelines for TNBC, ultimately expanding safe and effective options for patients.

Written by Maria Eduarda Ledo de Abreu.