According to the U.S. National Cancer Institute's Surveillance Epidemiology and End Results (SEER) database for the year 2008, the most recent year for which incidence data are available, 11,958,000 Americans have invasive cancers. Cancer is the second most common cause of death in the United States, behind only heart disease, and accounts for one in four deaths. It has been estimated that approximately 1600 Americans die of cancer each day. In addition to the medical, emotional and psychological costs of cancer, cancer has significant financial costs to both the individual and society. It is estimated by the National Institutes of Health that the overall costs of cancer in 2010 was $263.8 billion. In addition, it is estimated that another $140.1 billion is lost in productivity due to premature death.
Cancer treatments today include surgery, hormone therapy, radiation, chemotherapy, immunotherapy, targeted therapy, and combinations thereof. Surgical removal of cancer has advanced significantly; however, there remains a high chance of recurrence of the disease. Hormone therapy using drugs such as aromatase inhibitors and luteinizing hormone-releasing hormone analogs and inhibitors has been relatively effective in treating prostate and breast cancers. Radiation and the related techniques of conformal proton beam radiation therapy, stereotactic radiosurgery, stereotactic radiation therapy, intraoperative radiation therapy, chemical modifiers, and radio sensitizers are effective at killing cancerous cells, but can also kill and alter surrounding normal tissue. Chemotherapy drugs such as aminopterin, cisplatin, methotrexate, doxorubicin, daunorubicin and others alone and in combinations are effective at killing cancer cells, often by altering the DNA replication process. Biological response modifier (BRM) therapy, biologic therapy, biotherapy, or immunotherapy alter cancer cell growth or influence the natural immune response, and involve administering biologic agents to a patient such as an interferons, interleukins, and other cytokines and antibodies such as rituximab and trastuzumab and even cancer vaccines such as Sipuleucel-T.
Recently, new targeted therapies have been developed to fight cancer. These targeted therapies differ from chemotherapy because chemotherapy works by killing both cancerous and normal cells, with greater effects on the cancerous cells. Targeted therapies work by influencing the processes that control growth, division, and the spread of cancer cells and signals that cause cancer cells to die naturally. One type of targeted therapy includes growth signal inhibitors such as trastuzumab, gefitinib, imatinib, centuximab, dasatinib and nilotinib. Another type of targeted therapy includes angiogenesis inhibitors such as bevacizumab that inhibit cancers from increasing surrounding vasculature and blood supply. A final type of targeted therapy includes apoptosis-inducing drugs that are able to induce direct cancer cell death.
Although all of these treatments have been effective to one degree or another, they all have drawbacks and limitations. In addition to many of the treatments being expensive, they also are often too imprecise or the cancers are able to adapt to them and become resistant.
Thus, there is a great need for additional cancer treatments. In particular, there is a need for treatments for cancers that have become resistant to other forms of treatment.