Experimental cancer treatments are
mainstream medical therapies intended to treat
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bl ...
by improving on, supplementing or replacing conventional methods (
surgery,
chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...
,
radiation
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes:
* ''electromagnetic radiation'', such as radio waves, microwaves, infrared, vi ...
, and
immunotherapy
Immunotherapy or biological therapy is the treatment of disease by activating or suppressing the immune system. Immunotherapies designed to elicit or amplify an immune response are classified as ''activation immunotherapies,'' while immunotherap ...
). However, researchers are
still trying to determine whether these treatments are safe and effective treatments. Experimental cancer treatments are normally available only to people who participate in formal research programs, which are called
''clinical trials''. Occasionally, a seriously ill person may be able to access an experimental drug through an
expanded access program. Some of the treatments have
regulatory approval for treating other conditions.
Health insurance and
publicly funded health care programs normally refuse to pay for experimental cancer treatments.
The entries listed below vary between theoretical therapies to unproven controversial therapies. Many of these treatments are alleged to help against only specific forms of cancer. It is not a list of treatments widely available at hospitals.
Studying treatments for cancer
The twin goals of research are to determine whether the treatment actually works (called
efficacy) and whether it is sufficiently safe. Regulatory processes attempt to balance the potential benefits with the potential harms, so that people given the treatment are more likely to benefit from it than to be harmed by it.
Medical research for cancer begins much like research for any disease. In organized studies of new treatments for cancer, the
pre-clinical development of drugs, devices, and techniques begins in laboratories, either with isolated cells or in small animals, most commonly rats or mice. In other cases, the proposed treatment for cancer is already in use for some other medical condition, in which case more is known about its safety and potential efficacy.
Clinical trial
Clinical trials are prospective biomedical or behavioral research studies on human subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel v ...
s are the study of treatments in humans. The first-in-human tests of a potential treatment are called
Phase I Phase 1, Phase I or Phase One may refer to:
Media
* Marvel Cinematic Universe: Phase One, six American superhero films from 2008–2012
* ''Phase One'' (Art Ensemble of Chicago album), 1971
* ''Phase One'' (Saga album), 1998
* ''Phase One'', r ...
studies. Early clinical trials typically enroll a very small number of patients, and the purpose is to identify major safety issues and the ''
maximum tolerated dose'', which is the highest dose that does not produce serious or fatal
adverse effect
An adverse effect is an undesired harmful effect resulting from a Pharmaceutical drug, medication or other Surgery#Definitions, intervention, such as surgery. An adverse effect may be termed a "side effect", when judged to be secondary to a main ...
s. The dose given in these trials may be far too small to produce any useful effect. In most research, these early trials may involve healthy people, but cancer studies normally enroll only people with relatively severe forms of the disease in this stage of testing. On average, 95% of the participants in these early trials receive no benefit, but all are exposed to the risk of adverse effects. Most participants show signs of
optimism bias (the irrational belief that they will beat the odds).
Later studies, called
Phase II Phase II, Phase 2 or Phase Two may refer to:
Media
* Marvel Cinematic Universe: Phase Two, six American superhero films from 2013–2015
* ''Star Trek: Phase II'', an unrealized television series based on the characters of Gene Roddenberry's ''S ...
and
Phase III studies, enroll more people, and the goal is to determine whether the treatment actually works. Phase III studies are frequently
randomized controlled trial
A randomized controlled trial (or randomized control trial; RCT) is a form of scientific experiment used to control factors not under direct experimental control. Examples of RCTs are clinical trials that compare the effects of drugs, surgical ...
s, with the experimental treatment being compared to the current best available treatment rather than to a
placebo
A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like Saline (medicine), saline), sham surgery, and other procedures.
In general ...
. In some cases, the Phase III trial provides the best available treatment to all participants, in addition to some of the patients receiving the experimental treatment.
Bacterial treatments
Chemotherapeutic drugs
A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via inhalat ...
have a hard time penetrating tumors to kill them at their core because these cells may lack a good blood supply . Researchers have been using
anaerobic bacteria, such as ''
Clostridium novyi'', to consume the interior of oxygen-poor tumours. These should then die when they come in contact with the tumor's oxygenated sides, meaning they would be harmless to the rest of the body. A major problem has been that bacteria do not consume all parts of the malignant tissue. However, combining the therapy with chemotherapeutic treatments can help to solve this problem.
Another strategy is to use anaerobic bacteria that have 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
Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated dig ...
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 nonpathogenic anaerobe ''
Clostridium sporogenes''.
Drug therapies
HAMLET (human alpha-lactalbumin made lethal to tumor cells)
HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a molecular complex derived from human
breast milk
Breast milk (sometimes spelled as breastmilk) or mother's milk is milk produced by mammary glands located in the breast of a human female. Breast milk is the primary source of nutrition for newborns, containing fat, protein, carbohydrates (lac ...
that kills tumor cells by a process resembling programmed cell death (
apoptosis). , it had been tested in humans with skin
papillomas and
bladder cancer
Bladder cancer is any of several types of cancer arising from the tissues of the urinary bladder. Symptoms include blood in the urine, pain with urination, and low back pain. It is caused when epithelial cells that line the bladder become ma ...
.
[
]
p53 activation therapy
Several drug therapies are being developed based on
p53, the
tumour suppressor gene that protects the cell in response to damage and stress. It is analogous to deciding what to do with a damaged car: p53 brings everything to a halt, and then decides whether to fix the cell or, if the cell is beyond repair, to destroy the cell. This protective function of p53 is disabled in most cancer cells, allowing them to multiply without check. Restoration of p53 activity in tumours (where possible) has been shown to inhibit tumour growth and can even shrink the tumour.
As p53 protein levels are usually kept low, one could block its degradation and allow large amounts of p53 to accumulate, thus stimulating p53 activity and its antitumour effects. Drugs that utilize this mechanism include
nutlin and MI-219, which are both in phase I
clinical trials
Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, dietar ...
. , there are also other drugs that are still in the preclinical stage of testing, such as RITA and MITA.
BI811283
BI811283
BI 811283 is a small molecule inhibitor of the Aurora B kinase protein being developed by Boehringer Ingelheim for use as an anti-cancer agent. BI 811283 is currently in the early stages of clinical development and is undergoing first in human tr ...
is a
small molecule
Within the fields of molecular biology and pharmacology, a small molecule or micromolecule is a low molecular weight (≤ 1000 daltons) organic compound that may regulate a biological process, with a size on the order of 1 nm. Many drugs are ...
inhibitor
Inhibitor or inhibition may refer to:
In biology
* Enzyme inhibitor, a substance that binds to an enzyme and decreases the enzyme's activity
* Reuptake inhibitor, a substance that increases neurotransmission by blocking the reuptake of a neurotra ...
of the
aurora B kinase protein being developed by
Boehringer Ingelheim for use as an
anti-cancer agent
This is a list of antineoplastic agents used to treat cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do no ...
. , BI 811283 is currently in the early stages of
clinical development and is undergoing first-in-human trials in patients with
solid tumors and
Acute Myeloid Leukaemia.
[
]
Itraconazole treatment
Itraconazole, sometimes abbreviated ITZ, is an
antifungal medication used to treat a number of
fungal infections
Fungal infection, also known as mycosis, is disease caused by fungi. Different types are traditionally divided according to the part of the body affected; superficial, subcutaneous, and systemic. Superficial fungal infections include common ti ...
. Recent research works suggest itraconazole (ITZ) could also be used in the treatment of cancer by inhibiting the
hedgehog pathway
The Hedgehog signaling pathway is a signaling pathway that transmits information to embryonic cells required for proper cell differentiation. Different parts of the embryo have different concentrations of hedgehog signaling proteins. The pathway ...
in a similar way to
Sonidegib.
Gene therapy
Introduction of
tumor suppressor gene
A tumor suppressor gene (TSG), or anti-oncogene, is a gene that regulates a cell during cell division and replication. If the cell grows uncontrollably, it will result in cancer. When a tumor suppressor gene is mutated, it results in a loss or re ...
s into rapidly dividing cells has been thought to slow down or arrest tumor growth.
Adenoviruses are a commonly utilized vector for this purpose. Much research has focused on the use of adenoviruses that cannot reproduce, or reproduce only to a limited extent, within the patient to ensure safety via the avoidance of
cytolytic
Cytolysis, or osmotic lysis, occurs when a cell bursts due to an osmotic imbalance that has caused excess water to diffuse into the cell. Water can enter the cell by diffusion through the cell membrane or through selective membrane channels ...
destruction of noncancerous cells infected with the vector. However, new studies focus on adenoviruses that can be permitted to reproduce, and destroy cancerous cells in the process, since the adenoviruses' ability to infect normal cells is substantially impaired, potentially resulting in a far more effective treatment.
Another use of gene therapy is the introduction of
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...
s into these cells that make them susceptible to particular chemotherapy agents; studies with introducing
thymidine kinase
Thymidine kinase is an enzyme, a phosphotransferase (a kinase): 2'-deoxythymidine kinase, ATP-thymidine 5'-phosphotransferase, EC 2.7.1.21. It can be found in most living cells. It is present in two forms in mammalian cells, TK1 and TK2. Cer ...
in
glioma
A glioma is a type of tumor that starts in the glial cells of the brain or the spine. Gliomas comprise about 30 percent of all brain tumors and central nervous system tumours, and 80 percent of all malignant brain tumours.
Signs and symptoms ...
s, making them susceptible to
aciclovir, are in their experimental stage.
Epigenetic options
Epigenetics
In biology, epigenetics is the study of stable phenotypic changes (known as ''marks'') that do not involve alterations in the DNA sequence. The Greek prefix '' epi-'' ( "over, outside of, around") in ''epigenetics'' implies features that are " ...
is the study of heritable changes in gene activity that are not caused by changes in the DNA sequence, often a result of environmental or dietary damage to the
histone
In biology, histones are highly basic proteins abundant in lysine and arginine residues that are found in eukaryotic cell nuclei. They act as spools around which DNA winds to create structural units called nucleosomes. Nucleosomes in turn ar ...
receptors within the cell. Current research has shown that epigenetic pharmaceuticals could be a putative replacement or adjuvant therapy for currently accepted treatment methods such as
radiation
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes:
* ''electromagnetic radiation'', such as radio waves, microwaves, infrared, vi ...
and
chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...
, or could enhance the effects of these current treatments.
It has been shown that the epigenetic control of the proto-onco regions and the tumor suppressor sequences by conformational changes in histones directly affects the formation and progression of cancer.
Epigenetics also has the factor of reversibility, a characteristic that other cancer treatments do not offer.
Some investigators, like
Randy Jirtle
Randy Jirtle (born November 9, 1947) is an American biologist noted for his research in epigenetics, the branch of biology that deals with inherited information that does not reside in the nucleotide sequence of DNA. Jirtle retired from Duke Uni ...
, PhD, of Duke University Medical Center, think epigenetics may ultimately turn out to have a greater role in disease than genetics.
Telomerase deactivation therapy
Because most malignant cells rely on the activity of the protein
telomerase
Telomerase, also called terminal transferase, is a ribonucleoprotein that adds a species-dependent telomere repeat sequence to the 3' end of telomeres. A telomere is a region of repetitive sequences at each end of the chromosomes of most e ...
for their immortality, it has been proposed that a drug that inactivates telomerase might be effective against a broad spectrum of malignancies. At the same time, most healthy tissues in the body express little if any telomerase, and would function normally in its absence. Currently,
inositol hexaphosphate, which is available over-the-counter, is undergoing testing in cancer research due to its telomerase-inhibiting abilities.
A number of research groups have experimented with the use of
telomerase inhibitors in
animal models, and as of 2005 and 2006 phase I and II
human clinical trials are underway.
Geron Corporation is currently conducting two clinical trials involving telomerase inhibitors. One uses a vaccine (
GRNVAC1) and the other uses a lipidated oligonucleotide (
GRN163L).
Radiation therapies
Photodynamic therapy
Photodynamic therapy (PDT) is generally a non-invasive treatment using a combination of light and a photosensitive drug, such as 5-ALA, Foscan, Metvix,
padeliporfin (Tookad, WST09, WST11), Photofrin, or
Visudyne. The drug is triggered by light of a specific wavelength.
Hyperthermiatic therapy
Localized and whole-body application of heat has been proposed as a technique for the treatment of malignant tumours. Intense heating will cause
denaturation and coagulation of
cellular protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...
s, rapidly killing cells within a tumour.
More prolonged moderate heating to temperatures just a few degrees above normal (39.5 °C) can cause more subtle changes. A mild heat treatment combined with other stresses can cause cell death by
apoptosis. There are many biochemical consequences to the
heat shock response
The heat shock response (HSR) is a cell stress response that increases the number of molecular chaperones to combat the negative effects on proteins caused by stressors such as increased temperatures, oxidative stress, and heavy metals. In a n ...
within the cell, including slowed cell division and increased sensitivity to ionizing
radiation therapy
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Rad ...
. The purpose of overheating the tumor cells is to create a lack of oxygen so that the heated cells become overacidified, which leads to a lack of nutrients in the tumor. This in turn disrupts the metabolism of the cells so that cell death (apoptosis) can set in. In certain cases chemotherapy or radiation that has previously not had any effect can be made effective. Hyperthermia alters the cell walls by means of so-called heat shock proteins. The cancer cells then react very much more effectively to the cytostatics and radiation. If hyperthermia is used conscientiously it has no serious side effects.
There are many techniques by which heat may be delivered. Some of the most common involve the use of focused
ultrasound
Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies fr ...
(FUS or
HIFU),
microwave
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequency, frequencies between 300 MHz and 300 GHz respectively. Different sources define different fre ...
heating,
induction heating,
magnetic hyperthermia, and direct application of heat through the use of heated saline pumped through catheters. Experiments with carbon nanotubes that selectively bind to cancer cells have been performed. Lasers are then used that pass harmlessly through the body, but heat the nanotubes, causing the death of the cancer cells. Similar results have also been achieved with other types of nanoparticles, including gold-coated nanoshells and nanorods that exhibit certain degrees of 'tunability' of the absorption properties of the nanoparticles to the wavelength of light for irradiation. The success of this approach to cancer treatment rests on the existence of an 'optical window' in which biological tissue (i.e., healthy cells) are completely transparent at the wavelength of the laser light, while nanoparticles are highly absorbing at the same wavelength. Such a 'window' exists in the so-called near-infrared region of the electromagnetic spectrum. In this way, the laser light can pass through the system without harming healthy tissue, and only diseased cells, where the nanoparticles reside, get hot and are killed.
Magnetic Hyperthermia makes use of magnetic nanoparticles, which can be injected into tumours and then generate heat when subjected to an alternating magnetic field.
One of the challenges in thermal therapy is delivering the appropriate amount of heat to the correct part of the patient's body. A great deal of current research focuses on precisely positioning heat delivery devices (catheters, microwave, and ultrasound applicators, etc.) using ultrasound or
magnetic resonance imaging, as well as of developing new types of nanoparticles that make them particularly efficient absorbers while offering little or no concerns about toxicity to the circulation system. Clinicians also hope to use advanced imaging techniques to monitor heat treatments in real time—heat-induced changes in
tissue are sometimes perceptible using these imaging instruments. In
magnetic hyperthermia or magnetic fluid hyperthermia method, it will be easier to control temperature distribution by controlling the velocity of
ferrofluid injection and size of
magnetic nanoparticles.
Noninvasive cancer heat treatment
Heat treatment involves using radio waves to heat up tiny metals that are implanted in cancerous tissue.
Gold nanoparticles or
carbon nanotube
A scanning tunneling microscopy image of a single-walled carbon nanotube
Rotating single-walled zigzag carbon nanotube
A carbon nanotube (CNT) is a tube made of carbon with diameters typically measured in nanometers.
''Single-wall carbon nan ...
s are the most likely candidate. Promising preclinical trials have been conducted,
[
] although clinical trials may not be held for another few years.
Another method that is entirely non-invasive referred to as
Tumor Treating Fields has already reached clinical trial stage in many countries. The concept applies an
electric field through a tumour region using electrodes external to the body. Successful trials have shown the process effectiveness to be greater than chemotherapy and there are no side-effects and only negligible time spent away from normal daily activities. This treatment is still in very early development stages for many types of cancer.
High-intensity focused ultrasound (HIFU) is still in investigatory phases in many places around the world.
In China it has CFDA approval and over 180 treatment centres have been established in China, Hong Kong, and Korea. HIFU has been successfully used to treat cancer to destroy tumours of the bone, brain, breast, liver, pancreas, rectum, kidney, testes, and prostate. Several thousand patients have been treated with various types of tumours. HIFU has CE approval for palliative care for bone metastasis. Experimentally, palliative care has been provided for cases of advanced pancreatic cancer. High-energy therapeutic ultrasound could increase higher-density anti-cancer drug load and nanomedicines to target tumor sites by 20x fold higher than traditional target cancer therapy.
Cold atmospheric plasma treatment
Cold atmospheric plasma or CAP for short is an emerging modality for the treatment of solid tumors Recently, cold atmospheric plasma (CAP) indicated promising anti-neoplastic effects on several tumors, e.g. melanoma, glioma, and pancreatic cancer cells
, 6, 7
The comma is a punctuation mark that appears in several variants in different languages. It has the same shape as an apostrophe or single closing quotation mark () in many typefaces, but it differs from them in being placed on the baseline o ...
and therefore could be an efficient method for anti-cancer treatment in clinical urology in the future. One example of an experimental technology utilizing Cold Atmospheric plasma i
Theraphi
Electromagnetic treatments
Tumor Treating Fields is a novel FDA-approved cancer treatment therapy that uses alternating electric field to disturb the rapid cell division exhibited by cancer cells.
Complementary and alternative treatments
Complementary and alternative medicine (CAM) treatments are the diverse group of medical and healthcare systems, practices, and products that are not part of conventional medicine and have not been proven to be effective.
''Complementary medicine'' usually refers to methods and substances used along with conventional medicine, while ''alternative medicine'' refers to compounds used instead of conventional medicine.
What Is CAM?
National Center for Complementary and Integrative Health
The National Center for Complementary and Integrative Health (NCCIH) is a United States government agency which explores complementary and alternative medicine (CAM). It was initially created in 1991 as the Office of Alternative Medicine (OAM) ...
. retrieved 3 February 2008. CAM use is common among people with cancer.
Most complementary and alternative medicines for cancer have not been rigorously studied or tested. Some alternative treatments that have been proven ineffective continue to be marketed and promoted.
References
External links
"Questionable Cancer Therapies"
clinicaltrials.gov
{{DEFAULTSORT:Experimental Cancer Treatment
Emerging technologies