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Major breakthrough: 100% cure for colorectal cancer in animal experiments!
Major breakthrough: 100% cure for colorectal cancer in animal experiments! When can it be used clinically?
Colorectal cancer is a relatively common cancer. In 2018, there were more than 1.8 million new cases of colorectal cancer worldwide, and 881,000 people died of colorectal cancer. The incidence and mortality of colorectal cancer in some countries are also increasing year by year, and the situation of prevention and treatment is still severe.
At present, the early cure rate of colorectal cancer can reach more than 80%. After timely intervention of colorectal cancer in the middle stage, the cure rate can also reach 60%. Compared with other cancers, the prognosis is relatively good, and most patients can achieve it. “Survival with tumor”.
Recently, a breakthrough cancer treatment research has brought good news again!
“We have achieved a 100% cure for colorectal cancer in animal experiments!”
Recently, a study published by the team of Dr. Zhang Jie, a member of the National Academy of Engineering, has attracted attention. By using the human platelet membrane to wrap the bionic nanoparticle formula PNP-R848 loaded with immunotherapy drugs, the researchers achieved 100% cure for colorectal cancer in mouse animal experiments.
T lymphocytes can kill foreign pathogens or tumors. The formula PNP-R848 can activate T lymphocytes and promote T lymphocytes to play the function of killing tumor cells.
On the 56th day of treatment, the researchers injected three times the amount of cancer cells into the mice. On the 140th day of treatment, the researchers injected five times the amount of cancer cells into the mice at different locations, and then stopped the drug injection.
It was found that although the new tumor continued to grow, it disappeared naturally when it reached 50mm³. Researchers believe that the emergence of this phenomenon indicates that after treatment, the solid tumors in the mice have completely disappeared, and the mice have the ability to self-cancer immunity.
This research is a breakthrough in the treatment of solid tumors. Currently, the research of Dr. Zhang Jie’s team has been supported by the US Food and Drug Administration’s expert panel, and it will soon enter standardization and large-scale production.
Cancer treatment focus-immunotherapy
Regarding the treatment of tumors, the traditional ones include surgery, radiotherapy and chemotherapy. In recent years, with the rapid development of the medical level, immunotherapy has become the focus of treatment in the field of oncology.
Immunotherapy is to use the body’s own immune system to kill tumors. The mechanism of immunotherapy is to target and eliminate tumor cells by activating T cells, NK cells and other killer lymphocytes, and activate the response of the patient’s anti-tumor immune system to achieve the goal of killing tumor cells.
Taking liver cancer as an example, treatment methods for liver cancer include surgery, chemotherapy, targeted therapy, etc., but the treatment effect is not satisfactory, with a 5-year survival rate of only 12.5%. Therefore, immune combination therapy has become a new idea for the treatment of liver cancer.
Clinical trial data show that the objective remission rate of immune combination therapy for advanced liver cancer is 35.6%. In addition, some patients achieved complete remission, that is, the tumor disappeared completely. Moreover, the patients are well tolerated and no new safety issues have arisen.
Taking nasopharyngeal cancer as an example, the data shows that there were 133,000 new cases of nasopharyngeal cancer in the world last year, of which about 50% were new cases in China. Compared with other refractory cancers, the local control rate and 5-year survival rate of nasopharyngeal carcinoma are relatively ideal. However, the chance of recurrence of nasopharyngeal carcinoma is higher after treatment.
Clinical data shows that 20%-30% of patients with nasopharyngeal carcinoma have a local recurrence within 5 years after radiotherapy. With teriplizumab becoming the world’s first anti-PD-1 monoclonal antibody approved for the treatment of nasopharyngeal cancer, it means that the field of nasopharyngeal cancer has achieved a zero breakthrough in immunotherapy. Studies have shown that in patients with relapsed/metastatic nasopharyngeal carcinoma who have received at least second-line system chemotherapy failure, the objective response rate of teriprizumab monotherapy was 23.9%, and the median overall survival time reached 15.1 months.
However, immunotherapy also has shortcomings. Not all cancer patients can produce the same therapeutic effect. Some patients have better results after immunotherapy, and some patients have poor results after immunotherapy. At present, only cancers such as ovarian cancer, lung cancer, colorectal cancer, and melanoma have better immune effects.
Immunotherapy also has limitations
However, we also have to face up to the fact that immunotherapy is not a panacea, and there are limitations. For example, not all types of cancer are suitable for immunotherapy. In addition, the limitations of immunotherapy include:
1. Short drug half-life
Drug half-life refers to the time required for the drug to reach the human body, and then after digestion and absorption into the blood circulation, the concentration of the drug in the human body’s plasma drops by half.
According to data, the approved antibodies targeting the PD-1/PD-L1 pathway have a half-life of about 5-20 days and are easily eliminated by the circulatory system and immune system as foreign bodies. This means that only frequent administration can maintain the efficacy of the drug. Therefore, experts believe that it is very important to choose a suitable drug carrier.
2. Weak monitoring ability
PD-L1 secreted on the surface of tumor cells can bind to PD-1 on the surface of T cells, inhibit the activity of T cells, reduce the monitoring ability of immune cells, and finally escape the surveillance and killing of the immune system.
3. Slow onset
The speed of onset of immunotherapy is very slow. It usually takes 3-4 months to see the effect of the treatment, and sometimes there may even be false progress. For example, the results of imaging examinations showed that after immunotherapy, the tumor not only did not shrink, but increased.
4. There are also side effects
Immune system is a balanced state. While T cells activated by immunotherapy kill tumor cells, they can also damage normal cells and cause a series of side effects, such as nausea, vomiting, respiratory failure, skin rash, hepatitis, nephritis, pneumonia, etc. However, with proper treatment, the side effects can subside in a short period of time.
But in general, immunotherapy has small side effects and long-lasting effects, and can significantly extend survival time. It is currently a tumor treatment method that is generally optimistic by the medical community. For cancer patients, immunotherapy may be effective when there is no way out and other treatments do not work.
(source:internet, reference only)