Alternative cancer treatments
Since the 1940s, medical science has developed chemotherapy, radiation therapy, adjuvant therapy and the newer targeted therapies, as well as refined surgical techniques for removing cancer. Before the development of these modern, evidence-based treatments, 90% of cancer patients died within five years. With modern mainstream treatments, only 34% of cancer patients die within five years. However, while mainstream forms of cancer treatment generally prolong life or permanently cure cancer, most treatments also have side effects ranging from unpleasant to fatal, such as pain, blood clots, fatigue, and infection. These side effects and the lack of a guarantee that treatment will be successful create appeal for alternative treatments for cancer, which purport to cause fewer side effects or to increase survival rates despite evidence to suggest a 2–5 fold increase in death with alternative medicines.
Telomerase
Immunotherapy successfully treats some kinds of cancer, such as melanoma. This treatment involves manipulating a human’s immune system to destroy cancerous cells. Humans have two major antigen identifying lymphocytes: CD8+ cytotoxic T-lymphocytes (CTL) and CD4+ helper T-lymphocytes that can destroy cells. Antigen receptors on CTL can bind to a 9-10 amino acid chain that is presented by the major histocompatibility complex (MHC) as in Figure 4. HTERT is a potential target antigen. Immunotargeting should result in relatively few side effects since hTERT expression is associated only with telomerase and is not essential in almost all somatic cells. GV1001 uses this pathway. Experimental drug and vaccine therapies targeting active telomerase have been tested in mouse models, and clinical trials have begun. One drug, imetelstat, is being clinically researched as a means of interfering with telomerase in cancer cells. Most of the harmful cancer-related effects of telomerase are dependent on an intact RNA template. Cancer stem cells that use an alternative method of telomere maintenance are still killed when telomerase's RNA template is blocked or damaged.