P-glycoprotein in breast cancer

摘要: Resistance to cytotoxic chemotherapy is a major impediment the successful treatment of breast cancer. Adjuvant chemotherapy, though given under theoretically optimal conditions low tumor bulk [1], often fails eradicate micrometastasis. Once metastasis grossly evident, most cancers have intrinsic resistance single-agent chemotherapy. The response rate such advanced disease doxorubicin less than 40%; vinca alkyloids only 21% [2,3]. Though higher initial rates can be achieved with combination [4], essentially all will become resistant therapy. This might occur either through outgrowth subclones selection pressure [5], or induction phenotype in surviving cancer cells. In case, this frequently includes component cross-resistance unrelated agents, as second-line marked by lower and brief durations [6].