There are many ways to treat cancer, and some of them are nearly as frightening as the disease itself. But today, researchers are beginning to unravel some new approaches, including one that comes from seemingly miraculous recoveries in cancer patients who experienced severe fever.
And the interesting part is that gold might be just the ingredient needed to take advantage of a weakness some cancers have to a sudden increase in our body temperature.
That’s important, because cancer isn’t going away.
That’s the equivalent of 5,250 new cases of cancer each day. Cancer is an enormous health concern.
The leading treatment options for cancer aren’t always successful and carry with them a slew of possible side effects such as nausea, vomiting, hair loss, increased risk of infections, and the possibility of secondary tumors.
Hyperthermia, also known as overheating, is a therapy that uses heat to kill cancer cells. It’s best used alongside other therapies such as chemotherapy or radiation therapy.
Cancer Is a Problem
Cancer is a serious health concern worldwide.According to recent data by the American Cancer Society, U.S. females have a 38.5 percent chance of developing invasive cancer over their lifetime, while males have a 40.2 percent chance.
Cancer becomes invasive when it spreads beyond the layer of tissue where it developed and into surrounding healthy tissues and lymph nodes.
Leading Treatment Options for Cancer Aren’t Ideal
Since cancer is so varied, there’s no single, fully comprehensive approach to treatment. Leading treatment options include surgery, radiotherapy, chemotherapy, and immunotherapy.While surgery is generally considered an effective therapy for early-stage cancers, it isn’t ideal for metastatic cancers since the cancer cells have spread to other regions of the body. In some cases, even if surgery is done early on, the cancer can return.
Radiation therapy uses high-energy radiation to damage the DNA of cancer cells. This type of therapy often also damages surrounding healthy tissue. As with surgery, it is difficult to treat metastatic cancer with radiation therapy.
Chemotherapy can treat many different types of cancer, even if the cancer has metastasized. Unfortunately, chemotherapy drugs can be toxic to healthy, non-cancerous tissues of the body.
A significant problem with radiation therapy and chemotherapy is that both can cause cancer, making secondary cancer a serious possible side-effect.
Immunotherapy is a cancer therapy that helps the immune system fight cancer. As a biological therapy, this treatment uses substances produced by other living organisms.
There are several types of immunotherapy treatments including T-cell transfer therapy, monoclonal antibodies, immune system modulators, treatment vaccines, and immune checkpoint inhibitors.
While side effects from immunotherapy typically aren’t as troublesome as the side effects from chemotherapy, they can still occur.
Since the body’s immune system has been amped up to fight against cancer cells, there may be some collateral damage to healthy cells, such as flu-like symptoms, heart palpitations, and organ inflammation.
Hyperthermia as Approach to Cancer Treatment
In the 1800s, doctors began noticing a number of intriguing cases of cancer patients who, after suffering high fevers from contracting erysipelas, found their cancer symptoms decreased. Some patients experienced complete tumor regression.Erysipelas is a skin infection caused by Streptococcus bacteria, typically S. aureus or S. pyogenes. A key feature of the infection is a fever, which may be very high.
The patient’s body temperature rose to 105 degrees. Days after the fever began, his tumor started to shrink. Remarkably, within two weeks, the tumor was gone.
Coley spent years perfecting bacterial injections to treat tumors. These formulations became known as Coley’s toxins.
One pharmaceutical company created preparations of Coley’s toxins from 1899 to 1951, making the treatment available to physicians in the United States and Europe.
Soft-tissue sarcomas are cancers that form in muscles, fat, nerves, the lining of joints, blood vessels, and tendons.
In 1962, the FDA removed Coley’s toxins from the list of approved drugs, so it became illegal to use this toxin to treat cancer. At this time surgery, radiotherapy, and chemotherapy were becoming mainstays of cancer treatment.
Though these other therapies took the spotlight, scientists continued to research how hyperthermia reduces tumors.
What We Know Now About Heat and Cancer
Tumors are generally more acidic than regular tissues and they often have regions of hypoxia (inadequate oxygen supply). A study in the International Journal of Hyperthermia notes these two factors make tumors resistant to chemotherapy and radiation, but more susceptible to heat stress.Hyperthermia can initiate both of these cell death pathways in a single tumor simultaneously. The amount of necrosis versus apoptosis occurring in the tumor depends on several factors, especially the degree of heat applied.
Apoptosis is a much “cleaner” and more organized process than necrosis. Necrosis is destructive to surrounding tissue, so it’s important for doctors to choose the intensity and duration of heat treatment carefully.
The question is, how do we directly target tumor cells with hyperthermia so as not to damage healthy tissue?
Nanoparticles
The trick to truly effective hyperthermia is to get the heat inside the tumor without heating all the tissue around it, and nanoparticles are key to that capability. Using nanoparticles and near-infrared light to generate heat in a tumor is minimally invasive, more uniform, and much more precise in targeting the tumor on a cellular level.Nanoparticles are tiny, though they do vary in size from 1 to 100 nanometers (nm), though some scientists would argue nanoparticles can be up to 1000 nm in size.
If one of your hairs were blown up to be the size of a telephone pole, a nanoparticle would be a little dot with a diameter about as wide as the thickness of a piece of paper.
How Would Nanoparticles Get Into Tumor?
The blood vessels in tumors are different from the blood vessels in a typical organ. The tumor is not healthy, normal tissue, so the blood vessels that feed it aren’t normal or healthy either.Healthy blood vessels that bring oxygenated blood into tissues have small gaps between the endothelial cells which line the blood vessels. Imagine a tiny straw with little slits in it. These endothelial cells are surrounded by smooth muscle cells. Imagine another straw, which is much stronger and slightly larger, with the smaller straw inside.
Your body relies partly on the lymphatic system to clear out the waste of dead cells and other body processes. Imagine a system very much like all your blood vessels but with a different role.
In a tumor, lymphatic vessels are compressed, causing poor lymphatic drainage out of the tumor.
Gold Nanoparticles Ideal for Photothermal Therapy
Gold nanoparticles are an ideal candidate for photothermal therapy, which typically uses infrared light to heat tissues. This form of light can penetrate deep into the body. That’s good, but even better if the heat is more intense in the area of the tumor. In that scenario, you don’t have to risk damaging other tissues as much.That’s where gold becomes essential. Gold is fairly biocompatible as it is an inert metal. Gold nanoparticles can absorb light energy and heat up to above 113 degrees Fahrenheit.
The size of the gold nanoparticles matter. In general, smaller metallic nanoparticles more efficiently convert light energy to heat energy than larger metallic nanoparticles do.
First, the gold nanoparticles can be heated to high temperatures (higher than 113 degrees Fahrenheit) for several minutes. This leads to cell death through thermal ablation. The downside is that this can trigger the blood to stop flowing through the tumor and the tumor may hemorrhage. This would inhibit further treatment with a secondary therapy.
Pair Photothermal Therapy With Another Therapy
Because the blood vessels that feed the tumor aren’t healthy, there may be areas of a tumor that don’t have good blood supply—this is why certain regions of a tumor may be hypoxic.The nanoparticles may not accumulate in these regions since the blood supply is deficient, which means photothermal therapy alone may not destroy all the cancer cells in the tumor.
