Neoadjuvant Toripalimab and Radiotherapy Treatment in N+ HR+ Breast Cancer

Breast cancer is a leading malignancy among women globally, with early diagnosis and treatment being crucial for better outcomes. Over 90% of breast cancer patients are diagnosed at an early stage, and approximately two-thirds have the hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) subtype. Despite this, these patients often exhibit resistance to neoadjuvant chemotherapy, with a pathologic complete response (pCR) rate of only 5-15%, which is significantly lower compared to other subtypes and is associated with poor prognosis. This indicates the necessity for optimizing current treatment strategies. In recent years, significant advancements have been made in the application of immunotherapy for breast cancer. The studies demonstrated that the addition of immune checkpoint inhibitors to neoadjuvant chemotherapy for patients with high-risk early-stage HR+/HER2- breast cancer significantly improved pCR rates. Building on these findings, this study proposes a novel strategy of dose-intensified radiation to the tumor (tumor boost) during the neoadjuvant immuno-chemotherapy phase. The advantage of this approach is that it can activate the immune system while the tumor tissue is still intact, providing a rich source of tumor antigens, which aids in enhancing the immune system's recognition and destruction of cancer cells. Toripalimab is an optimal immunotherapy agent to study, as this agent has recently been approved by the FDA for use in multiple tumor types. It is therefore ready to be tested for efficacy in other disease sites and in combination with other treatments. This study will provide valuable insights into the potential of immunotherapy in combination with radiotherapy to improve outcomes for patients with lymph nodes-positive, high-risk HR+/HER2- breast cancer.