There is a war being waged. It is being called a war on cancer, but it may be a slight misnomer, because cancer is not one disease; it is a formidable army of many diseases. The war, using multiple different approaches, is making much progress on what does turn out to be many different cancers. It is a war on cancers.
So far, it has not been one size fits all. Some cancers have been conquered or almost conquered while others like pancreatic cancer have barely benefited from multiple therapeutic attempts. (Source 1)
Until recent years, the standard armory in the war on cancer included surgery, radiation and chemotherapy. Surgery can be disfiguring or compromise a bodily function in an effort to take enough tissue to include the entire cancer. Radiation not only destroys cancer cells; it is also harmful to normal cells. For example, brain and head and neck radiation can affect swallowing, taste, vision, and lead to rampant dental decay (Source 3). Chemotherapy can vary in its side effects from minimal to significant, because it targets rapidly dividing cells. Cancer cells rapidly divide, but some normal cells also have a high rate of division and are also affected. Young children with leukemia, thanks to the early commitments of people like Danny Thomas, have a good success rate of survival (Source 4). The chemotherapy infusion into the brain can, however, have a permanent impact on brain function (Source 5). Both radiation and chemotherapy can also lead to causing future cancers different from the targeted cancer (Source 2). So, while the old therapies have had some success in life extension, the side effects and discomfort they bring will hopefully someday be looked at as archaic and will be replaced with even more successful therapies having more limited side effects.
In fact, recent years have seen the development of new, specifically targeted therapies with less side effects. There has been a revolution in therapeutic approaches, which are specific at the genetic and/or molecular level at destroying cancer cells or preventing their development altogether while minimizing damage to normal cells.
Here are some examples of successful therapeutic approaches:
T-cell therapies range from stimulating the individual’s own immune cells (the T-cells) that should have destroyed the cancer cells to actually extracting some of a person’s immune cells (drawing blood), altering them to recognize specific molecular markers on the specific cancer that a person has, and reinjecting those cells. The persons own re-engineered T cells will find the cancer cells and destroy them. Juno therapeutics reported the best results in history of cancer therapy for terminal patients using this technology. In a clinical, they reported that 91% of terminal cancer patients with a blood based cancer who had failed all other therapies were in complete remission with no signs of cancer cells (Source 6).
Small molecule therapy inhibition of cancer protein production
There is an array of small molecules that can inhibit the development of cancer at different points of a cell’s manufacture of the molecule that directly leads to a cell becoming cancerous. As an example, a company based on technology from City of Hope has 3 different small molecule platforms, each focused on several different cancer targets, and each targeting the inhibition of the formation of the cancer molecule (from gene to ribosome, where the molecule is made) at three different places in the process. That company expects to begin human clinical trials in a few months. Their first target will be ovarian cancer (Source 7). Should that succeed subsequent targets will include breast, liver, pancreatic cancers and multiple myeloma. In each case the treatment target will be very specific.
Gene deletion (Source 8)
An exciting new area where the gene that leads to production of the errant molecule that causes a cell to be a cancer cell is excised and replaced by the gene leading to production of the normal molecule not causing a cell to be cancerous.
Antibodies (Source 9)
Antibodies have shown to have positive effect on certain targeted cancers and have led to life extension. Antibodies are specific in their recognition of targets.
Nano molecular carrier molecules (Source 10).
A new arena, where a carrier molecule delivers chemotherapeutic agents, molecules and/or antibodies specifically into targeted cancer cells. The goal is to create better effectiveness against the cancer cells and minimize side effects. Some carrier molecules also hold the promise of carrying therapies into the brain, which often presents a barrier to other therapies.
Inhibition of Inhibition
There are mechanisms that cancer cells utilize to protect themselves from being destroyed by the body’s natural defenses. Approaches like check point inhibitors are now being utilized to destroy the defenses of cancer cells against therapies and allow a patient’s own immune response and delivered therapies to be more successful in destroying cancer cells. (Source 11)
Multiple other approaches including stem cell therapy, technologies to slow the aging process (there appears to be a relationship between aging and certain cancers), and multiple others are being developed and may hold promise in the war on cancers.
In each case, there is specificity: specific markers, specific genes, specific molecules specific antibodies, specific targets. With specificity also comes the hope of less side-effects and less discomfort to the patients. The success of each of these therapeutic approaches can vary with the target or marker and cancer type. Hopefully, one size fits all approach will someday be developed and the war on cancer will be won. Until then, scientists will continue their work to win the smaller wars against specific cancers. The hope for those (like my own brother) who have what today are deemed as incurable cancers, is that they can be sustained long enough on therapies that slow down or halt cancer progression, giving the opportunity for one of the exciting new therapeutic approaches to become a reality and win the battle and ultimately the War on Cancers.
Source 1: http://www.cancer.org/acs/groups/cid/documents/webcontent/003131-pdf.pdf
Source 2: http://www.cancer.org/acs/groups/cid/documents/webcontent/002043-pdf.pdf
Source 3: http://www.cancer.org/acs/groups/cid/documents/webcontent/003028-pdf.pdf
Source 4: http://www.cancer.org/acs/groups/cid/documents/webcontent/003095-pdf.pdf
Source 5: http://www.cancernetwork.com/oncology-journal/overview-chemotherapy-related-cognitive-dysfunction-or-chemobrain
Source 6: http://ir.junotherapeutics.com/phoenix.zhtml?c=253828&p=irol-newsArticle&ID=2038302
Source 7: http://www.pnas.org/content/113/18/4970.abstract
Source 8: http://www.pnas.org/content/102/12/4542.full.pdf
Source 9: http://www.nature.com/nrc/journal/v12/n4/pdf/nrc3236.pdf
Source 10: http://mct.aacrjournals.org/content/5/8/1909.full.pdf+html
Source 11: http://www.cancer.org/acs/groups/cid/documents/webcontent/003013-pdf.pdf