Cancer. A word that fills people with dread. A powerful, devastating word that has destroyed so many lives of cancer victims, their families and loved ones. A word that scientists and doctors are actively and fervently working towards making just a memory.
Every year there are new breakthroughs in oncology research and cancer treatments. Unfortunately a lot of these experimental treatments take years to develop and to run them through the required clinical trials, and they still don’t always pan out in the end. This top ten list, however, is going to walk you through some of the most exciting experimental cancer treatments currently being tested or administered in pre-clinical trials. Scientists are the most hopeful about these experimental cancer treatments right now and explain why they might be viable options for cancer patients. Some of these treatments are still in the early stages of development, whereas others are currently in pre-clinical and clinical trials to test how viable they are as treatments.
Radiation therapies are any number of therapies that utilize different forms of radiation to try and cause cancerous tumors to go into remission.
Hyperthermia Therapy is an experimental form of cancer therapy that utilizes localized or whole-body administration of heat. Intense heating will cause denaturation and coagulation of cellular proteins, rapidly killing the cells within a tumor. What this means is the protein cells will lose their quaternary structure, tertiary structure and secondary structure which causes cell disruption and cell death. A mild heat-treatment in combination of other stresses can also cause apoptosis of the cell, which means the cell dies and creates fragments which are called apoptotic bodies, which can be cleaned up by phagocytic cells. Phagocytic cells engulf these apoptotic bodies which destroys them, rendering them unable to cause damage to surrounding cells.
Hyperthermia Therapy is very exciting because, if it turns out to be a viable treatment, this will destroy the cancerous tumors from the inside out and hinder its ability to infect more healthy cells. This therapy type is currently in the very early stages of development, as scientists need to dial in how much heat is needed to destroy these cells.
The application of heat to treat certain medical conditions, including possible tumors, has a very long history. Ancient Greeks, Romans, and Egyptians used heat to treat breast masses; this is still a recommended self-care treatment for breast engorgement. Medical practitioners in ancient India used regional and whole-body hyperthermia as treatments for various medical maladies as well. During the 19th century, tumor shrinkage after a high fever caused by infections was reported in a small number of cases. Because of this, properly conducted clinical trials were conducted in the early 1970’s using hyperthermia therapy in an attempt to reduce or kill cancerous growths in patients. The ancient usage of hyperthermia treatment, the reported cases of tumor-shrinkage in the early 19th century and the clinical trials performed in the 1970’s comprise the basis for today’s treatments utilizing hyperthermia therapy.
Fact: More than 30% of cancer could be prevented, mainly by not using tobacco, having a healthy diet, being physically active and moderating the use of alcohol. In developing countries up to 20% of cancer deaths could be prevented by immunization against the infection of HBV and HPV.
Non-Invasive Cancer Treatments
Non-Invasive Cancer Treatments are experimental treatments that don’t require doctors to create an incision into a patient and it doesn’t require them to remove any tissue. These treatments are exciting because they will cause shorter recovery times for patients, and can be used in scenarios where invasive treatment might not be a choice.
One of these experimental treatments uses radio waves to heat up tiny metals that are implanted into cancerous tissue. Gold nanoparticles or carbon nanotubes are the most likely candidates for the metal implanted into the cancerous tissue due to their heat-conducting abilities and a lower risk of causing metal poisoning or other detrimental effects. This treatment is currently in pre-clinical trials, but it has shown a lot of promise as a treatment option.
Another non-invasive experimental treatment is known as Tumor Treating Fields. This is where doctors apply an electric field through a tumor region using electrodes external to the body. Successful trials have shown that this process is more effective than chemotherapy and that there are no side-effects and only negligible time spent away from normal daily activities will be required. This treatment is still in the early development stages for many forms of cancer.
High-Intensity Focused Ultrasound (HIFU) is also currently being tested for viability in many places around the world. HIFU has been successfully used to treat cancer by destroying tumors of the bone, brain, breast, liver, pancreas, rectum, kidney, testes, and prostate. Several thousand patients in China, Hong Kong and Korea have been treated with various types of tumors. HIFU is an early stage medical technology that is in various stages of development worldwide to treat a range of disorders. Therapeutic applications use ultrasound to deliver heat or agitation into the body which can be used to target and destroy cancerous cells. High-energy therapeutic ultrasound, such as the kind used in HIFU, could increase higher-density anti-cancer drug load and nanomedicines to target tumor sites by 20x fold higher than traditional target cancer therapy, which is absolutely astounding.
Fact: There are more than 100 types of cancer; any part of the human anatomy can be affected by cancer.
A possible form of gene therapy is the introduction of enzymes into cancerous cells that make them susceptible to particular chemotherapy agents; introducing thymidine kinase in gliomas, which make them susceptible to Aciclovir is the current study being worked on into this form of experimental treatment. Thymidine kinase have a key function in the synthesis of DNA and, due to this function, it plays a key role in cell division as well, as they are part of the unique reaction chain to introduce thymidine into the DNA. Aciclovir (ACV) also known as Acyclovir is an antiviral medication primarily used in the treatment of herpes simplex virus infections, chickenpox and shingles. This treatment is thought to be highly effective, but it is still in its early developmental stages and, as such, it could take some time before it even reaches clinical trials. Scientists are hopeful that this form of treatment will prove to be effective however, which they base on the amount of research that has currently gone into it.
The basis of gene therapy is the introduction of tumor suppressor genes into rapidly dividing cells, which is thought by most scientist to slow down or arrest tumor growth. Adenoviruses are a commonly utilized vector for the purpose of hindering tumor growth. Adenoviruses represent the largest non-enveloped virus group currently known. Due to how Adenoviruses behave and their cell structure, they have long been a popular viral vector for gene therapy due to their ability to affect both replicating and non-replicating cells, accommodate large transgenes, and code for proteins without integrating into the host cell genome. More specifically, Adenoviruses are used as a vehicle to administer targeted therapy in form of recombinant DNA or proteins. This makes Adenoviruses one of the most viable vectors for gene therapy currently known.
Fact: In 2008, 7.6 million people died of cancer – 13% of all deaths worldwide.
Immunotherapy uses the body’s natural defense mechanisms to fight off cancerous cells. These treatments are often less toxic and often more effective than other forms of therapy.
Immunotherapeutic vaccines are a form of vaccine that gives your body the tools it needs to fight off cancer. Sipuleucel-T (Provenge) is currently the only FDA approved Immunotherapeutic vaccine in use. Sipuleucel-T is used for individuals with advanced prostate cancer that are no longer benefiting from or responding to other forms of cancer treatment such as hormone therapy. With this treatment immune system cells are removed from the patient’s blood and are sent to a lab. At the lab, the cells are exposed to chemicals that turn them into special immune cells called dendritic cells. The dendritic cells are then exposed to a protein called prostatic acid phosphatase (PAP), which should produce an immune response against prostate cancer cells. This form of treatment is currently available to the public with great results. Currently a form of this treatment is in works for various other forms of cancer such as lung and bladder cancers, but these treatments are currently in the early development stages; scientists are hopeful that when the experimental treatments are put into clinical trials they will have the same success rate for eradicating other forms of cancer as it currently has had with eradicating prostate cancer.
One form of immunotherapy is to use Monoclonal antibodies to treat cancer. Normal antibodies are specific proteins that stick to other proteins called antigens. Once antibodies attach to an antigen, they signal other antibodies to attach to it as well, and they all attack it to destroy it. Monoclonal antibodies (mAbs) are antibodies designed by researchers to attack specific antigens, such as the ones found in cancer. Once designed, researchers produce a large number of these Monoclonal antibodies in a lab and introduce them into a patient’s body to fight off cancerous cells. For this to work, researchers first have to identify the right antigen to attack. For cancer, this is not always easy, and so far mAbs have proven to be more useful against some cancers than others. This is still being investigated by researchers to work against a wider range of cancers.
Fact: Cancers of major public health relevance such as breast, cervical and colorectal cancer can be cured if detected early and treated adequately.
Adoptive Cell Transfer Therapies
Adoptive cell transfers involves removing immune system cells (usually white blood cells) from a patient’s body, re-engineering them to teach them how to fight against specific forms of cancerous cells and then re-infusing them back into the patient’s body. These experimental cancer treatments have to be specifically tailored to each patient, making them resource-intensive and thus not as easily scalable as other forms of cancer treatment. Adoptive cell transfers are used for various other treatments, as it’s the main way to improve a cell’s functionality, particularly its ability to fight off illnesses. Trials of this therapy began in the 1990’s but really accelerated in 2010. There have been numerous examples of highly promising results with tumor-specific, adoptive cellular immunotherapy in early clinical trials, but such treatments are not yet widely available at this time. Scientists are currently working on how to make this a more accessible treatment option for patients.
The basis for Adoptive Cell Transfer Therapies were first discovered in the 1960’s when lymphocytes were discovered to be the mediators of allograft rejection in animals. Attempts to use T-cells to treat transplanted murine tumors required cultivating and manipulating T-cells in cultures. Syngeneic lymphocytes were transferred from rodents heavily immunized against the tumor to inhibit growth of small established tumors, becoming the first example of an Adoptive Cell Transfer (ACT). A lymphocyte is the main type of cell found in lymph nodes, hence the name. They are subtype of the white blood cell found in invertebrates, and include Natural Killer Cells, T-Cells and B-Cells. Allografts is what transferring cells from one organism to another is called. Lymphocytes and Allografts are the basis for Adoptive Cell Transfer Therapies, and even though ACTs have been theorized and researched since the 1960’s, it’s just now becoming a viable treatment option for cancer reduction in patients.
Fact: About 70% of all cancer deaths occur in low- and middle-income countries.
Treatments that fall under the drug therapies category involve using man-made or natural drugs to promote cancer recovery.
Dichloroacetate (DCA) has been found in lab studies to reduce tumors in vivo in lab rats, and has a plausible scientific mechanism behind it: DCA appears to reactivate suppressed mitochondria in some types of oxygen-starved tumor cells, and thus promotes apoptosis. Apoptosis, as stated earlier, is a perfect way to rid the body of cancerous cells due to the way the body disposes of what is left over after apoptosis. Because this drug was tested for various other applications, we now know it is a relatively safe, available and inexpensive drug. This drug can also be taken orally, which is very convenient for a lot of patients. This drug, however, has only gone through a pre-clinical trial that consisted of five patients. Doctors have stated that four out of the five were probably extended due to the drug, but until it goes to full clinical trials we won’t know the extent of its cancer-fighting properties.
DCA is an acid, an analogue of acetic acid, in which 2 of the 3 hydrogen atoms of the methyl group have been replaced by chlorine atoms. Like the other chloroacetic acids, it has various practical applications because it inhibits what’s known as pyruvate dehydrogenase kinase which is a kinase enzyme. Pyruvate dehydrogenase kinase (PDK) has been shown to have increased activity in hypoxic cancer cells, which are cancer cells that have a decreased oxygen flow. Because DCA inhibits PDK, it shows potential as a viable treatment for hypoxic cancer cells in patients. Pre-clinical trials have shown that it inhibits cancerous growths in vitro in animals. DCA can only be administered in a carefully controlled laboratory setting, however, as improper usage or dosage can easily cause liver damage or other complications, so taking DCA without a doctor’s orders or not following a doctor’s orders exactly is something that is strongly discouraged for general cancer patients.
Fact: One-fifth of all cancers worldwide are caused by a chronic infection, for example human papillomavirus (HPV) causes cervical cancer and hepatitis B virus (HBV) causes liver cancer.
Quercetin is a dietary supplement that makes for an excellent free-radical-scavenging antioxidant and it also promotes apoptosis in cancerous cells. In vitro it has been proven to have anti-tumor proclivities in both oral cancer and leukemia. Cultured skin and prostate cancer cells showed significant mortality (compared to nonmalignant cells) when treated with a combination of quercetin and ultrasound. Interestingly enough, ultrasound promotes topical absorption of up to 1,000% making a topical Quercetin and ultrasound combination to be a possible option for experimental cancer treatment. Quercetin is found in most fruits, vegetables, leaves and grains, which is why a diet high in these items can be very advantageous for many cancer patients. When taken orally, such as eating products that naturally contain it, it can be a helpful supplement to other cancer treatments, but doctors are trying to find a way to create a topical ointment that will work against cancerous cells to use in combination with ultrasound therapy. The topical ointment is still in early development, but the food items that contain this antioxidant are readily available on the market.
Some foods containing Quercetin are as follows: capers (canned or fresh), black plums, cranberries, fennel, radish leaves, dill, cilantro, red onions, kale, sweet potato, blueberries, Red Delicious apples, broccoli and black or green teas. A diet high in these foods as a supplement can sometimes help inhibit cancerous growths. This should by no means be used as a cancer treatment replacement, only as a supplement. Quercetin has the capability to inhibit cancerous cells from multiplying, but it isn’t as effective on its own as other treatments. Popular treatment options involving Quercetin are usually radiation therapy or Adoptive Cell Transfer Therapies that utilize a diet rich in Quercetin as a complimenting supplement.
Fact: Tobacco use is the single largest preventable cause of cancer in the world causing 22% of cancer deaths.
Combination Opdivo and Yervoy
Doctors at Memorial Sloan Kettering Cancer Center offered a 49-year old patient with melanoma growths an experimental combination of two drugs: Opdivo and Yervoy, both of which are manufactured by Bristol-Myers Squibb. Both of these drugs are new medications that boost the immune system so it can attack cancerous growths. Three weeks after the first dose, the patient’s melanoma growths had disappeared completely. Afterwards, doctors launched a 142-patient study on the effects of Opdivo and Yervoy when taken in combination. An astounding 22% of the study group had what’s known as a complete response to the drugs; that is to say that their cancerous growths completely disappeared. This drug combination, however, boosts a high toxicity rate along with it’s high success rate, so scientists are currently looking into ways to combat the toxicity they cause in patients. These drugs are still currently in the clinical trial phase, but should be readily available to advanced case patients in the near future; cases where the toxicity chance is more preferable to letting the unresponsive cancer continue to spread.
Opdivo is what is known as a programmed death receptor which blocks antibodies and is used for the treatment of unresectable or metastatic melanoma and metastatic squamous non-small-cell lung carcinoma. In contrast to traditional chemotherapies and targeted anti-cancer therapies, which exert their effects by direct cytotoxic or tumor growth inhibition, nivolumab acts by inducing the immune system to attack the tumor.
Yervoy is a monoclonal antibody (mAbs) that works to activate the immune system by targeting CTLA-4, a protein receptor that downregulates the immune system. It was approved by the U.S. FDA in 2011 for the treatment of melanoma, a type of skin cancer and is currently undergoing clinical trials for use in treating non-small cell lung carcinoma, small cell lung cancer, bladder cancer and metastatic hormone-refractory prostate cancer.
Fact: About 70% of all cancer deaths occur in low- and middle-income countries.
Bacterial Therapies and Virotherapy
Researchers have been using anaerobic bacteria, such as Clostridium Novyi, to consume the interior of oxygen-poor tumors in patients. These tumors then die when they come in contact with the tumor’s oxygenated sides, meaning the cancerous cells within the tumor would then be harmless to the rest of the body. A major problem with using Clostridium Novyi has been that the bacteria does not consume all parts of the malignant tissue. However, by combining this therapy with chemotherapeutic treatments the problem can be mitigated if not completely solve this problem. This works because anaerobic bacteria can grow with or without the presence of air (whereas aerobic bacteria must have oxygen to grow), so Clostridium Novyi can grow in oxygen-poor tumors. This is important because tumor-induced tissue hypoxia can cause even more complications than a normal tumor would. Hypoxia is when tissue is getting less oxygen than what it needs, causing the body to have an even harder time fighting off infections, cancerous cells and can cause necropsy of tissue.
Another cancer fighting strategy that is being used in treatments for cancer patients involves utilizing anaerobic bacteria that has been transformed with an enzyme that can convert a non-toxic prodrug into a toxic drug. With the proliferation of the bacteria in the necrotic and hypoxic areas of the tumor, the enzyme is expressed solely in the tumor. Thus, a systemically applied prodrug is metabolised to the toxic drug only in the tumor. This has been demonstrated to be effective with the non-pathogenic anaerobe Clostridium Sporogenes. Clostridium Sporogenes is also being researched as a vehicle for delivering cancer-treating drugs into tumors in patients. Researchers hope to continue utilizing and researching these anaerobic bacterium for new cancer-treatment vectors in an effort to kill off hypoxic tumors in patients.
Fact: Worldwide, the 5 most common types of cancer that kill women are (in the order of frequency): breast, lung, stomach, colorectal and cervical. In many developing countries, cervical cancer is the most common cancer.
Genetically-Modified Poliovirus Therapy
This therapy which utilizes genetically-modified Poliovirus samples is an extremely new treatment option for cancer patients. Researchers at The Preston Robert Tisch Brain Tumor Center at Duke University modified the poliovirus with portion of a cold-causing rhinovirus which removed the intrinsic disease-causing properties of the poliovirus. This genetically-modified virus has been dubbed the “PVS-RIPO” virus and it works by being directly infused into a patient’s tumor (such as a brain tumor). Once inside the tumor, PVS-RIPO then proceeds to infect and kill the cancerous cells. PVS-RIPO has remarkable cancer regression capabilities on its own, but it’s real power lies in the fact that it alerts your body’s natural defense mechanisms into fighting against the cancerous cells as well. The human immune system is trained to fight against viral infections and, as such, it recognizes the now infected cancer cells as being viral in nature and it attacks them. The body doesn’t normally attack cancer cells on its own due to the fact that cancer cells have a sort of “shield” around them that causes the immune system to not be able to “see” it properly.
The PVS-RIPO poliovirus was invented by Matthias Gromeier, MD, Associate Professor of Surgery, Associate Professor in Molecular Genetics and Microbiology, and Associate Professor of Medicine at Duke University School of Medicine, more than 2 decades ago, when he discovered that many cancer cells, including glioblastoma cells, produce the poliovirus receptor Necl-5/CD155. Glioblastoma multiforme (GBM), also known as glioblastoma and grade IV astrocytoma, is the most common and aggressive form of cancer that begins within the brain. People that suffer from this form of cancer almost never recover, but with the help of PVS-RIPO, sufferers may now have a chance to fight against this type of cancer.
Fact: Worldwide, the 5 most common types of cancer that kill men are (in order of frequency): lung, stomach, liver, colorectal and esophagus.
Experimental cancer treatments are medical therapies designed to improve, supplement or replace traditional cancer treatments (surgery, chemotherapy and radiation) in an attempt to reduce or remove cancerous growths. As you can see, all of the listed treatments are very exciting in nature and, if they become viable, can hopefully help us eradicate cancer.