For thousands of patients each year, triple-negative breast cancer (TNBC) returns even after surgery and chemotherapy, presenting one of the most aggressive forms of the disease. Now, researchers are investigating whether vaccines could break the cycle and provide a new line of defense.
A recent review led by Cory Fines, a research fellow at Queen’s University Belfast (QUB), examines decades of vaccine efforts against TNBC and highlights why the cancer has remained resistant to conventional approaches. TNBC lacks the common drug targets found in many breast cancer therapies, making treatment especially challenging.
Without HER2 or hormone receptors, chemotherapy remains the mainstay, while newer immune-based therapies like checkpoint inhibitors offer benefits only for select patients. Drugs such as pembrolizumab, approved in 2021 for high-risk early-stage TNBC, show promise but primarily benefit tumors expressing PD-L1, leaving many patients without targeted options.
Cancer vaccines aim to train the immune system to recognize tumor-specific antigens and build long-lived memory T cells that respond quickly to disease recurrence. However, tumors evolve rapidly, and vaccination alone often falls short, prompting researchers to combine vaccines with therapies that enhance T cell activity.
Selecting the right target is a major hurdle. Personalized vaccines can match each patient’s tumor mutations but are costly and time-intensive. Shared targets could benefit more patients but require careful design to avoid harming healthy tissue. Among potential targets, the tumor-suppressor protein p53 has emerged as particularly promising. Mutated p53, found in up to 80% of TNBC tumors, accumulates in cells and may trigger immune recognition.
“While currently there are no approved TNBC vaccines, this review highlights many promising studies and points to an antigen, p53, which we believe is highly relevant for TNBC,” Fines said. His team advocates for a “guardian vaccine” approach, selecting p53 fragments that stimulate tumor-killing T cells rather than weaker immune responses.
Advances in mRNA technology have accelerated vaccine development. Unlike DNA vaccines, mRNA does not enter the nucleus, reducing risks and allowing faster production. Delivery systems, including lipid nanoparticles and dendritic cell-based platforms, are crucial to ensure the genetic material reaches immune cells intact.
Ongoing clinical trials are exploring how TNBC vaccines interact with surgery, chemotherapy, and the immune system. Experts caution that widespread use is still years away, as long-term safety and efficacy must be established.
The research underscores a growing optimism that combining precise targets like p53 with modern delivery methods could make vaccines a viable part of TNBC treatment in the future, potentially offering patients a much-needed guard against recurrence.
