Some time ago, the good news of oncolytic virus therapy continued, allowing our readers to understand such a "domesticated virus" to fight cancer treatment. Such a therapy is seen as a new solution to "attack poison with poison".
However, the virus is also strong and weak. Viruses that can be used to make oncolytic virus products are all types of viruses that have been genetically edited or screened and have very little damage to the patient's normal cells.
And this time, the other therapy we want to tell you is not "soft", directly using another microorganism that is daunting - malaria parasite.
Of course, this article can only be said to be analyzed and interpreted from the existing theoretical basis, and the actual clinical trial effect is still unknown. Whether there is value, whether to apply for participation, these major decisions must be made after reading all the information, combined with their own rational thinking to make a judgment.
The biggest cancer hot news in the Spring Festival of 2019: Malaria parasite anti-cancer
At the beginning of 2019, the biggest hot news in the field of cancer treatment was the fight against cancer of malaria parasites. At the time, news reports reported that calls to consult clinical trials were all going to explode.
In addition to the attention brought by the mainstream media's "likes", this heat actually multiplied on the "hitchhiking" of PD-1 inhibitors at that time. The popularity of PD-1 inhibitors has given the immune system more attention to the function of treating cancer. Parasite therapy, which is also used to activate the body's immune function, has naturally received more expectations. Many of our patients also began to pay attention to this therapy from this period, or a year or two earlier.
What is the principle of malaria parasite anti-cancer? This starts with the characteristics of malaria.
Malaria parasites are the main culprits of malaria, and patients with malaria are most characteristic of cyclical fever, even high fever.
The relationship between "heat" and "treating cancer" came sooner. In 1866, Bush, a physician from Germany, published the first official article on the use of "heat" to treat cancer. Bush describes the case of a patient with a malignant tumor on the face who miraculously disappeared after contracting erysipelas and developing a high fever! Depending on the patient's condition, Bush speculates that "heat" may help treat cancer.
"Hot dead cancer cells"? What exactly is the relationship between fever and cancer?
I believe that everyone has some understanding of the mechanism of "fever". Fever, also known as fever, refers to the body's excessive heat energy or imbalance in the body's body's body temperature regulation, resulting in the body's temperature exceeding the temperature setpoint, or the temperature setting value itself is too high.
Fever can be caused by a variety of diseases, including various infections, inflammation, and non-infectious vasculitis, blood clots, and cancer. Usually, when the body temperature rises, the function of immune cells will also increase, and the ability to kill bacteria and viruses will increase; the reproductive ability of various bacteria and viruses in the human body will also decrease due to the increase in temperature, but healthy human cells will not be affected.
In fact, it's not just bacteria or viruses that are affected—cancer cells, and lesions where cancer cells congregate, also change as temperatures rise.
Success also bleeds, and defeat also bleeds
We all know that cancer cells have a proliferative capacity that far exceeds that of normal somatic cells. What provides "logistical support" for this powerful proliferative ability is a large number of blood vessels that proliferate due to cancer cells.
Tumor foci that are growing rapidly and expanding all have a very rich blood supply. The blood vessels they rely on are usually not normal blood vessels in the human body, but some additional proliferating blood vessels (which is also one of the theoretical bases for anti-angiogenic drugs, which limit the expansion of tumor lesions by inhibiting the generation of additional blood vessels).
Applying heat to normal somatic cells, somatic cells "take away" this extra heat by dilating capillaries and increasing blood flow, so even if a part of the body is slightly heated, the body temperature will not rise too severely.
However, the blood vessels in the tumor lesion are not perfect, and the capillaries are usually in a dilated state, and the amount of blood flow in the blood vessels cannot be controlled like normal tissues. Therefore, the heat applied to the tumor lesion will accumulate and quickly increase the temperature inside the lesion, usually, the temperature inside the tumor tissue will be 4 to 8 ° C higher than the surrounding normal tissue; and the temperature inside the tumor lesion can be 2 ~ 3 ° C higher than the surrounding temperature. Such an abnormal temperature increase, in theory, can directly cause the death of some cancer cells.
High temperature, the "pusher" of cancer cell death
High temperatures can damage cell membranes and denature proteins. According to the existing research data, when the temperature reaches above 42.5 ° C, the survival rate of cells will drop sharply.
When the temperature rises, the metabolic rate of the cells increases, and the inside of the tumor foci gradually enters a hypoxic state. At this time, the anaerobic fermentation of the cells is enhanced, a large number of acidic metabolites (lactic acid) are produced, and the pH in the lesion is reduced. In such an internal environment, cells are more likely to be killed by high temperatures.
Stimulate natural immunity and let the "professional cells" do the professional thing
The high fever caused by malaria and the stimulation of malaria parasite infections can strongly activate the body's non-specific immune function. Some immune cells, such as NK cells, which play a very important role in the body's anti-cancer process, will significantly increase in activity in this process.
NK cells with stronger activity are more likely to kill some cancer cells "by hand".
The "problem" faced by malaria parasites in the fight against cancer
Even with a lot of theoretical support, clinical trials of malaria parasites for the treatment of cancer are still facing many "problems".
The first one is ethics. The benefits and harms of malaria in already vulnerable cancer patients are like two ends of a scale that are difficult to balance. Researchers are constantly revising the protocol to avoid unnecessary harm to patients, and reviewers are hesitant to let such a scheme appear to patients.
The other is the lack of data support. This is a completely new treatment option that has not been proven, and when research was conducted in the United States in the early years, it did not get any decisive data, and it was even strongly questioned at one point.
These are all obstacles that must be faced in the development of this new therapy. We can't predict whether it will succeed or fail in the future, but we will keep an eye on more trial results.
At the very least, as a means of treating "terminally ill patients without drugs available," this therapy can still bring some new hope to these patients.
Malaria parasite clinical trial recruitment is simple inclusion criteria
1. Age 18 to 80 years old, male or female;
2. Patients with malignant solid tumors, including prostate cancer, ovarian cancer, lung cancer, colorectal cancer, thyroid cancer, sarcoma, etc. failure of previous standard treatments, or absence of standard treatments, or the patient and the treating physician deem standard treatment inappropriate;
3. Some patients with primary central nervous system tumors or solid tumor brain metastases can also be enrolled.
*Gene Drug Collection Reminder: The drugs and protocols involved in this article are still in the clinical research stage, and the data sources are published papers or conference abstracts, which are for professional reference only and cannot be used as a guarantee for the effect of real-world applications. Clinical trials of new drugs should be conducted under the guidance of a doctor or professional, and Gene Drugs does not recommend that patients use any of the drugs mentioned herein on their own.
■ This article is original by Erica, the author of Gene Drug Collection, and please do not reprint it without permission.
*Gene Drug Hui is the public account of medical science popularization and clinical trial recruitment under the Global Oncologist Network, and produces high-quality cancer science articles every day to help patients take less/no detours on the road of anti-cancer, and finally successfully defeat the disease!