Cancer is the leading cause of death across the globe. For years now, researchers have led meticulous studies focused on how to stop this deadly disease in its tracks. How close are we to finding more effective treatments?
The World Health Organization (WHO) note that, worldwide, nearly 1 in 6 deaths are down to cancer. Currently, the most common types of cancer treatment are chemotherapy, radiotherapy, tumour surgery, and — in the case of prostate cancer and breast cancer — hormonal therapy.
However, other types of treatment are beginning to pick up steam: therapies that — on their own or in combination with other treatments — are meant to help defeat cancer more efficiently and, ideally, have fewer side effects.
Innovations in cancer treatment aim to address a set of issues that will typically face healthcare providers and patients, including aggressive treatment accompanied by unwanted side effects, tumour recurrence after treatment, surgery, or both, and aggressive cancers that are resilient to widely utilized treatments.
Below, we review some of the most recent cancer research breakthroughs that give us renewed hope that better therapies and prevention strategies will soon follow suit.
Boosting the immune system's 'arsenal'
One type of therapy that has attracted a lot of attention recently is immunotherapy, which aims to reinforce our own bodies' existing arsenal against foreign bodies and harmful cells: our immune system's response to the spread of cancer tumours.
But many types of cancer cell are so dangerous because they have ways of "duping" the immune system — either into ignoring them altogether or else into giving them a "helping hand." Therefore, some types of aggressive cancer are able to spread more easily and become resistant to chemotherapy or radiotherapy.
However, thanks to in vitro and in vivo experiments, researchers are now learning how they might be able to "deactivate" the cancer cells' protective systems. A study published last year in Nature Immunology found that macrophages, or white blood cells, that are normally tasked with "eating up" cellular debris and other harmful foreign "objects" failed to obliterate the super-aggressive cancer cells.
That was because, in their interaction with the cancer cells, the macrophages read not one but two signals meant to repel their "cleansing" action.
This knowledge, however, also showed the scientists the way forward: by blocking the two relevant signalling pathways, they re-enabled the white blood cells to do their work. Therapeutic viruses and innovative 'vaccines'
A surprising weapon in the fight against cancer could be therapeutic viruses, as revealed by a team from the United Kingdom earlier this year. In their experiments, they managed to use reovirus to attack brain cancer cells while leaving healthy cells alone.
"This is the first time it has been shown that a therapeutic virus is able to pass through the brain-blood barrier," explained the study authors, which "opens up the possibility [that] this type of immunotherapy could be used to treat more people with aggressive brain cancers."
Another area for improvement in immunotherapy is "dendritic vaccines," a strategy wherein dendritic cells (which play a key role in the body's immune response) are collected from a person's body, "armed" with tumour-specific antigens — which will teach them to "hunt" and destroy relevant cancer cells — and injected back into the body to boost the immune system.
In a new study, researchers in Switzerland identified a way to improve the action of these dendritic vaccines by creating artificial receptors able to recognize and "abduct" tiny vesicles that have been linked to cancer tumours' spread in the body.
By attaching these artificial receptors to the dendritic cells in the "vaccines," the therapeutic cells are enabled to recognize harmful cancer cells with more accuracy. Importantly, recent studies have shown that immunotherapy may work best if delivered in tandem with chemotherapy — specifically, if the chemotherapy drugs are delivered first, and they are followed up with immunotherapy.
But this approach does have some pitfalls; it is difficult to control the effects of this combined method, so sometimes, healthy tissue may be attacked alongside cancer tumours. However, scientists from two institutions in North Carolina have developed a substance that, once injected into the body, becomes gel-like: a "bioresponsive scaffold system." The scaffold can hold both chemotherapy and immunotherapy drugs at once, releasing them systematically into primary tumours.
This method allows for better control of both therapies, ensuring that the drugs act on the targeted tumour alone.
The nanoparticle revolution
Speaking of specially developed tools for delivering drugs straight to the tumour and hunting down micro tumours with accuracy and efficiency, the past couple of years have seen a "boom" in nanotechnology and nanoparticle developments for cancer treatments.
nanoparticles
Nanoparticles could be 'a game-changer' in cancer treatment. Nanoparticles are microscopic particles that have garnered so much attention in clinical research, among other fields, because they bring us the chance to develop precise, less invasive methods of tackling the disease. Vitally, they can target cancer cells or cancer tumours without harming healthy cells in the surrounding environment.
Some nanoparticles have now been created to provide very focused hyperthermic treatment, which is a type of therapy that uses hot temperatures to make cancer tumours shrink.
Last year, scientists from China and the U.K. managed to come up with a type of "self-regulating" nanoparticle that was able to expose tumours to heat while avoiding contact with healthy tissue. "This could potentially be a game-changer in the way we treat people who have cancer," said one of the researchers in charge of this project.
These tiny vehicles can also be used to target cancer stem-like cells, which are undifferentiated cells that have been linked to the resilience of certain types of cancer in the face of traditional treatments such as chemotherapy.
Thus, nanoparticles can be "loaded" with drugs and set to "hunt down" cancer stem cells to prevent the growth or recurrence of tumours. Scientists have experimented with drug-filled nanoparticles in the treatment of various types of cancer, including breast cancer and endometrial cancer.
No less importantly, minuscule vehicles called "nanoprobes" can be used to detect the presence of micrometastases, which are secondary tumours so tiny that they cannot be seen using traditional methods.
Source: Medical News Today
Dr Steven K. Libutti, director of the Rutgers Cancer Institute of New Jersey in New Brunswick, calls micrometastases "the Achilles' heel of surgical management for cancer" and argues that nanoprobes go a long way to solving [such] problems."