Targeted therapies against breast cancer: Clinical perspectives, obstacles and new opportunities

Breast cancer is a multifaceted, heterogeneous disease that manifests in the mammary gland. According to the WHO, more than 2.3 million cases are diagnosed each year, making it the most common malignancy among adults. The primary treatment of tumors includes chemotherapy, surgical resection, and radiotherapy. Although chemotherapy plays an irreplaceable role in tumor treatment, the drugs used generally show poor bioavailability, instability, lack of targeting, and toxicity. The major challenge facing chemotherapy regimens against cancers includes dose-limiting side effects on healthy tissues. A published meta-analysis indicated that only 0.7 % of the drug reaches the target. Thus, developing new therapies for the treatment of cancer is the need of the hour. The advent of drug resistance has been one of the major challenges facing researchers. Over the years, extensive investigations in the fields of cancer biomedical research and nanotechnology have evolved. Nanomedicine drugs have become an excellent alternative for the treatment of breast cancer, including Doxil (R), Abraxane (R), and other products widely used clinically. This review highlights potential strategies for the treatment of breast cancer and includes clinical trials data on available therapies. The role of immunotherapies including monoclonal anti-bodies, and the status of cancer vaccines have also been addressed in this work.