different therapies exist to treat cancer – systemic therapies, like chemotherapy, attack both normal and cancerous cells, while targeted therapies inhibit or solicit molecular pathways – acting on specific molecular targets that are associated with the cancer.
different types of targeted therapies exist
hormone targeted therapies slow or stop the growth of hormone sensitive tumours. they work by preventing hormones such as estrogen, progesterone and testosterone from binding to receptors that proliferate the growth of cancer cells.
signal transduction inhibitors block inappropriate cell response from the environment – they block signals that tell cells to divide too quickly and too much. one example is the breast cancer drug trastuzumab [herceptin] – a protein on the outside of the cells called her2 receptors picks up the signals telling the cells to grow and divide. this type of targeted therapy attaches to the protein receptors to stop or slow the cell division.
gene expression modulators modify the function of proteins that control gene expression. this type of targeted therapy changes the proteins that control the abnormal gene instruction of cancer cells.
apoptosis inducers – apoptosis is a natural process of healthy cell death when they are old or damaged. cancer cells do not go through apoptosis. these types of targeted therapies cause cancer cells to go through normal cell death.
angiogenesis inhibitors is a type of targeted therapy that blocks the growth of blood vessels that feed the cancer cells. some angiogensis inhibitors target vascular endothelial growth factor [vegf] or other substances that trigger blood vessel growth. these targeted therapies target the blood vessels that provide oxygen and nutrients to the cancer cells.
immunotherapies – immunotherapies are a type of targeted therapy that uses the immune system to destroy cancer cells. immuno-oncology [IO] is still a relatively new area in cancer treatment and currently include immune checkpoint inhibitors and chimeric antigen receptor t-cell therapy [CAR-T]. studies are currently underway in immuno-oncology that include stimulatory checkpoint molecules, adoptive cell therapies [including CAR-Ts, natural killer cells (NKs) and tumour infiltrating lymphocytes (TILs) ]
targeted therapies slow the growth of cancer, destroy cancer cells and relieve symptoms caused by cancer. because targeted therapies, unlike systemic therapies, act on specific markets they are associated with decreased side effects. targeted therapies are also associated with improved quality of life and improved survival.
targeted therapies are a cornerstone of precision medicine and a focus of anticancer drug development. in order to access targeted therapies, biomarker testing or genomic profiling must be performed. find out more about biomarkers here and here.
precision medicine awareness month runs throughout the month of november – follow @cancercolab, @coloncanada and @lymphomacanada to learn more about precision medicine and its impact on cancer care and learn more here