[Gene therapy for breast cancer]

Area of Science:

• Oncology
• Gene Therapy
• Hematopoietic Stem Cell Transplantation

Context:

• Advanced breast cancer presents significant treatment challenges.
• Current gene therapy strategies include oncogene suppression, immune enhancement, suicide gene transfer, and drug resistance gene therapy.
• Multidrug resistance (mdr1) gene therapy is being investigated as a protective measure against high-dose chemotherapy.

Purpose:

• To evaluate the safety and efficacy of multidrug resistance (mdr1) gene therapy in patients with advanced breast cancer.
• To assess the in vivo enrichment of mdr1-transduced hematopoietic stem cells following high-dose chemotherapy and docetaxel treatment.
• To determine the therapeutic potential of combining mdr1 gene therapy with high-dose chemotherapy and autologous peripheral blood stem cell transplantation (PBSCT).

Summary:

• A clinical study involving advanced breast cancer patients undergoing high-dose chemotherapy and autologous PBSCT with mdr1-transduced hematopoietic cells was initiated.
• Two patients received docetaxel treatment post-transplantation, demonstrating in vivo enrichment of mdr1-transduced cells.
• Both treated patients achieved complete remission with no observed adverse effects related to the mdr1 gene transduction.

Impact:

• mdr1 gene therapy, combined with high-dose chemotherapy and PBSCT, offers a potentially effective treatment for advanced breast cancer.
• This approach may enhance treatment tolerance by protecting bone marrow from chemotherapy-induced toxicity.
• The findings support further clinical investigation of mdr1 gene therapy in breast cancer and potentially other malignancies.