Last Updated on 21 June 2024
Despite advances in Science and Medicine, which allowed to stop the progression of several kinds of malignant tumors, metastatic cancer is still considered a life-threatening disease.
However, modern oncology implemented new therapeutic strategies to effectively cure metastasized cancer. One of these is cryoablation.
Through an overview on the cure and a collection of clinical trials to treat some of the most severe metastatic cancers of today, the article investigated if cryoablation is really an effective cancer therapy or not.
What Is Cryoablation?
Cryoablation, also called cryotherapy, is a non-invasive surgical technique that aims to freeze and destroy cancer cells through the utilization of a low temperature gas, such as liquid nitrogen, argon or carbon dioxide. For this feature, cryoablation is even known as cryosurgery.
The treatment is performed with a needle called cryoprobe, which, in turn, is inserted in the skin to directly reach the cancer. For this further characteristic, the procedure is also called percutaneous cryoablation. Then, running through the needle, a gas gets pumped into the tissue to freeze the cancer cells. The temperature to freeze the tumor is around -190, -78.5 degrees. This value depends on the type of gas that gets applied.
Since the process with very low temperature is expensive to perform, many cryosurgeries are executed with carbon dioxide, which requires a more reasonable temperature (so to speak) of – 78 degrees.
Afterwards, the treated tissue is left to thaw for a few minutes.
With this procedure, cancer cells are subjected to cellular damage and a stress response that activate self-destruction processes called necrosis and apoptosis. We have necrosis when a body tissue dies from inflammation and lack of blood.
We have apoptosis when cells literally disintegrate themselves without inflammation. Cell death occurs upon the action of the immune system or thanks to effective medical treatments like this.
Moreover, cryoablation creates ice crystals on the membrane of cancer cells during the phases of freezing and thawing. All this causes a metabolic disturbance in the mitochondrial structure of these same cells. The ice crystals break the tumor and activate its death.
Cryoablation is used to treat both benign and malignant cancers, especially recurrent cancer with metastasis.
The big goal of modern oncology is just the one to cure metastatic cancer with more and more innovative treatments.
Can, hence, cryoablation be an innovation in this field? To answer the question, you need to understand when this treatment can be used.
When Is Cryoablation Used?
Cryoablation is not so recent and innovative, as you might think. It is, in fact, a modern evolution of the cold therapy already used in 3000 B.C.
In the ancient times, cold therapy was used to treat traumas, injuries and inflammation. Cold packs were, in fact, placed on swollen knees to make them heal. The healing process was defined as cauterization and the following therapy was named cryocautery.
Nowadays, cryocautery has turned into cryosurgery because it does not treat only external tissues, but internal diseases, as well. It is also known as cryoablation because it derives from ablation, defined, according to Oxford Dictionary, as the surgical removal of body tissue and the removal of snow and ice from a glacier or iceberg by melting or evaporation.
In medical terms, Cryoablation leverages the same principle: it freezes the carcinogenic tissue to destroy and remove it.
It is used to cure cancer when the traditional surgical intervention is impossible to be performed.
Breast, kidney, eye, prostate and bone cancers are the most treated with cryoablation, for example.
But cryosurgery is also applied to cure liver, lung and cervical cancers.
All these cancers have a five-year high survival rate thanks to this therapy (from 60 to 100%).
Sometimes, cryoablation is used to treat other metastatic tumors such as melanoma, mesothelioma, ovarian, brain, colorectal and pancreatic cancers.
The most aggressive forms of these cancers have a low survival rate, even though, by now, early prevention made these malignant tumors more and more curable.
For this reason, I decided to focus the attention on these extremely malignant cancers, because there is a hope for them, as well.
In the following paragraph, you’ll find a detailed report about cryoablation for metastatic melanoma, mesothelioma, ovarian, brain, colorectal and pancreatic cancers.
Cryoablation for Metastatic Melanoma
As regards metastatic tumors, melanoma is the most critical skin cancer, because the metastases easily disseminate in other organs which are hard to treat.
However, in addition to Immune Checkpoint Inhibitors (ICI), cryoablation is considered a secure and effective therapeutic option for unresectable metastatic melanomas.
Indeed, in this type of cancer, cryoablation is usually combined with immunotherapies, such as ICI, in order to boost the reaction of the immune system against the tumor.
The double therapeutic combination may induce side effects, such as adrenal disorders.
But, according to a clinical trial published in the Journal of Clinical Oncology and performed on 17 patients “Cryoablation in patients with unresectable melanoma following progression on ICI is feasible with an acceptable side effect profile. Efficacy data of this potentially synergistic approach in metastatic melanoma is encouraging.”
Cryoablation for Metastatic Mesothelioma
Mesothelioma is the most aggressive metastatic cancer affecting lungs. It mainly occurs for asbestos exposure.
According to recent studies reported by Mesothelioma.com, cryoablation for malignant mesothelioma showed to be an effective treatment that improved the survival rate of patients. Moreover, this treatment seems to increase the activity of T-cells, killer T cells and the production of interferon. These are the natural weapons that the immune system has to destroy infections and cancer.
Usually, for mesothelioma, cryoablation is used when other treatments don’t work.
Cryoablation for Metastatic Ovarian Cancer
For ovarian cancer, cryoablation is used only as a palliative treatment, when a surgical intervention can’t be executed or when the tumor does not respond to chemo and radiotherapy.
Recent applications of this treatment are extremely encouraging only to cure secondary ovarian metastases stemming from other cancers, but this success may be a clue to effectively treat primary malignant ovarian cancers.
A case study reported on the National Library of Medicine, for instance, revealed that a 67-year-old woman affected by bowel metastatic cancer and with a mass of 6 cm on the ovary, confirmed as carcinoid tumor metastasis, has been undergone to cryoablation with a 10-minute freeze and 8-minute thaw, followed by 10 minute freeze. After five weeks, the ovarian lesion decreased to 4.9 cm.
Cryoablation for Metastatic Brain Cancer
The brain is a very sensitive and delicate organ which controls nearly every bodily and spiritual function of our life. For this reason, the treatment to cure any metastatic brain cancer must aim to preserve or restore its essential functions.
The effectiveness of cryoablation also depends on the type and number of cancerous lesions. Indeed, the brain is the site of both primary tumors and secondary metastases originating from cancers situated in other parts of the body, such as the colon-rectal carcinoma.
Early treatments with cryoablation were performed in 2010 in a clinical trial that enrolled seven patients affected by cystic metastatic brain tumors.
The procedure was carried out through transcranial cryoablation guided by resonance magnetic imaging (MRI). The pressurized gas injected was argon.
All the patients tolerated the treatment and experienced no neurological disorders. One of them died after 12 days. This sorrowful event usually happens when a patient is severely debilitated by the terminal stage of the disease.
However, the final conclusion of the study was that “MR-guided and monitored metastasis brain tumor cryoablation is technically feasible and may represent an alternative treatment in selected patients.”
Furthermore, a French study published in 2020 by ScienceDirect revealed that cryoablation can be performed to cure cerebral glioblastoma in combination with immunotherapy, vaccines, and tumoricidal viruses which are capable of destroying the malignant cancer cells.
Specifically, according to the study, “One of the consequences of cryosurgery is the necrotic tissue promotes the release of soluble antigens stimulating the production of specific antitumor antibodies and increasing the activation of the immune system.”
The conclusion of this European research was that MR-guided Cryoablation potentially offers anti-tumor immunity for recurrent glioblastoma and represents a therapeutic progress in the treatment of this type of metastatic cancer. Many trials were executed on animals, and, obviously, the results on humans will have to get carefully monitored over time.
Cryoablation for Metastatic Colorectal Cancer
Maybe you don’t know that metastasized colorectal cancer is a true killer. The metastases of this malignant cancer are aggressive and extremely invasive, especially in the colorectal adenocarcinoma. They infiltrate every district of the body, including bones and brain.
It was just for the colorectal metastases in the brain and in the bones that I lost my beloved dad in 2004. But, today, thanks to treatments such as cryoablation, the outcome would be totally different.
Recurrent metastatic colorectal cancer can be treated with cryoablation. In clinical practice, this treatment is applied both as a palliative and a therapeutic cure.
Palliative cryoablation is performed for unresectable colorectal hepatic metastases, and, according to the Annals of Palliative Medicine, it has the potential for long-term survival.
A therapeutic usage of cryoablation is applied for oligometastatic colorectal cancer, while for more limited lesions, the most used treatment is Radiofrequency Ablation, namely the removal of the tumor through fulguration generated by electric current.
Currently, cryosurgery is used as a complementary treatment for low rectal and anal cancers, because, nowadays, metastatic colorectal cancer is mainly cured with monoclonal antibodies.
However, cryoablation is considered a good option for unresectable colorectal metastases which can’t be removed surgically.
Just think that a Chinese hospital has practiced cryosurgery for colorectal cancer since 1976.
Cryoablation for Metastatic Pancreatic Cancer
Pancreatic cancer is still today the deadliest malignant tumor that can affect an internal organ. Belonging to the so-called solid tumors (it means they are made of a solid structure without cysts containing liquid substances), pancreatic cancer is extremely aggressive and invasive and with an easy and quick tendency to metastasize. That happens because this tumor is hard to diagnose at the early stage, and, usually, is detected when it causes symptoms. But the symptomatic stage of a pancreatic cancer is often a signal of possible metastases.
Moreover, metastatic pancreatic cancer is also the most recurrent among all metastatic tumors, despite surgery, chemo and other treatments. For this characteristic, it is also defined as a “tenacious tumor”, because its malignant cells seem to have a strong desire to survive. After a cell killing therapy, indeed, they return over and over again.
This unpleasurable problem occurs with cryoablation, also. The treatment, in fact, kills the metastases, but the new malignant cells reappear quickly.
The same problem has been seen with thermal ablation, a process that tries to kill the cancer cells with heat.
To eliminate this complication, metastasized pancreatic cancers are treated with a combination of hot and cold. The malignant cells are frozen and, then, hotted.
The thermal shock severely damages the mitochondrial structure of the cancer cells, and reduces their recurrence, improving the survival rate of the patients.
Unfortunately, cryoablation does not work with this obstinate type of metastatic cancer. The stand-alone cryosurgery is, in fact, used as palliative therapy, while curative cryotherapy is always combined with other treatments.
Conclusion
As you can see, cryoablation can be applied to cure several types of metastatic cancer. In many cases, it is an effective and successful therapy. In other more aggressive and recurrent cancers, it is used as palliative treatment, to relieve pain, for example.
It is frequent using cryotherapy in combination with another treatment, such as immunotherapy. The synergic approach is surely the one which brings the most effective results.
It is also pivotal to remember that cryoablation is not a procedure that freezes a piece of meat to store in the fridge, it is a method that tries to cure malignant cancers or stop their recurrence and progression.
But we are still in the field of trials, where a new cure sometimes works and sometimes does not.
Cryoablation can replace radiotherapy, as well, especially for metastases which don’t respond to the radiant treatment, such as in the bones. When this option fails, Science and Medicine have further therapeutic strategies to kill cancer and save lives, such as tumoricidal viruses and radiofrequency ablation.
But these are other stories to be investigated in the future…
