Author: Igor Belotserkovsky
Scientists from Belarus and the United States have developed a new method for detecting residual cancer cells. This method also contributes to their destruction. This is done with the help of nanobubbles generated in some cancer cells. The method was successfully tested on laboratory mice with implanted head and neck cancer cells. Although scientists are only at the beginning of the road, they call their discovery a small revolution in the fight against cancer.
The results of the research titled “Intraoperative diagnostics and elimination of residual microtumors with plasmonic nanobubbles” was published in the prestigious science journal Nature Nanotechnology on 15 February. To learn more about the successes of oncologists, BelTA talked to Igor Belotserkovsky, PhD in Medical Sciences, one of the authors of the research, the leader of the head and neck tumor research team at the Aleksandrov National Cancer Center.
Mr Belotserkovsky, what is the share of head and neck tumors in the structure of other localizations?
In the total structure of oncological morbidity, the share of head and neck tumors is 3-4% (excluding skin cancer). Larynx and oral cavity cancer are diagnosed most frequently. For example, in 2014 laryngeal cancer was detected in 604 Belarusians, oro-pharyngo-laryngeal cancer in 1,338 people. Men fall ill ten times more often.
Despite the fact that head and neck cancers are categorized as tumors of outside localization, many patients with cancer have their disease diagnosed when it has already reached an advanced stage. This is due to the social aspect. In most cases cancer patients are alcohol and smoking abusers. In 2014, 50% of laryngeal cancer cases were found at an early stage, as was 30% of cases of oral cavity cancer.
Why has it been decided to test the new method specifically on head and neck tumors?
Head and neck account for 9% of the total body surface area. Yet, this is where many important organs are located. If one of these organs is affected by cancer, oncologists have to work in a small body region. When removing a tumor, a surgeon cannot cut out much of the normal tissue surrounding it. He has to remove the parts affected by cancer and ensure no damage is done to vitally important structures.
For this reason, the radicality of head and neck cancer surgeries is strongly debated. Some reputable specialists believe that many head and neck surgeries are conditionally radical. We remove the visible tumor, and some unnoticed microscopic metastatic cancer cells may remain in the body. These cells cause cancer recurrences that are more difficult to treat, because they are more resistant to drugs, chemotherapy, and radiation therapy.
What is special about this new treatment method?
Its breakthrough nature is seen in our ability to spot and eliminate residual cancer cells during the surgery, right after the removal of the visible tumor. Today there is no fast, accurate and safe method for detection of individual cancer cells and microtumors in the tumor removal zone to be used during the surgery.
The method is based on the utilization of gold nanoparticles and laser radiation to generate nanobubbles inside tumor cells. The nanobubbles, in turn, are detected with an acoustic probe. For this purpose, the gold nanoparticles are decorated with special antibodies that identify cancer cells and gather in clusters only around the tumor, thereby ensuring no damage is done to healthy tissue.
The approach has been successfully tested on lab mice. The animals of the research and control groups underwent the same operations to remove implanted head and neck tumors. With additional minimal surgery conducted after detection of residual cancer cells with plasmonic nanobubbles, the survival rate in the research group was 100%. Meanwhile, the control group mice underwent only a standard surgery and died of progressing tumor. By the way, nanobubbles helped eliminate inoperable microtumors.
The idea is to reduce the frequency of tumor recurrence. The procedure is as follows: a patient gets an injection with gold nanoparticles before the surgery. After the tumor is removed, the tumor bed is treated with laser which activates nanobubbles that quickly expand and burst, ripping apart the residual cancer cells.
We expect that the new method will help reduce the number of local recurrences. It will allow a maximum radical removal of tumors. Oncologists will be able to eliminate cancer cells, which may cause recurrences, at the microlevel.
When do you plan clinical tests?
We are ready to conduct the tests, here in Belarus. Our center has a high level of credibility in research. Foreign companies annually run nearly 30-40 clinical tests in the Aleksandrov National Cancer Center.
However, it is still early to talk about the date for clinical testing of the new method. There is a certain algorithm to follow. It can take up 3 to 4 years from research to the final product.
What are the prospects for the plasmonic nanobubbles technology?
Proceeding from the results of the experiment, we can say it is a small victory over cancer. However, I would like to reiterate that in interpreting our successes we do not go beyond the framework of the experiment. In the future this technology can be used to treat other types of cancer.
How long did the research take? Who financed the studies?
This is a Belarusian-U.S. project launched some three years ago. Dmitry Lapotko, head of laser science at medical nanotechnology group Masimo Corporation, is the leading researcher. The project was financed by Gillson Langenbough Foundation, Houston, TX and the National Science Foundation of the United States.
Thank you for the interview. We wish you every success with this important project.