The use of electromagnetic waves, particularly in the form of Tumor Treating Fields (TTFields), as a treatment for cancer has been a topic of research for over a century. TTFields are a type of therapy that uses low-intensity, alternating electric fields to disrupt the division of cancer cells. Novocure's device, Optune, is an FDA-approved TTFields therapy for certain types of cancer, including glioblastoma and mesothelioma. The underlying science and theory behind why TTFields work are based on several key principles:
Mechanism of Action
Disruption of Mitosis:
Cancer cells are known for their rapid and uncontrolled division. During cell division (mitosis), cells undergo a series of steps to replicate their DNA and divide into two new cells.
TTFields target cells during mitosis, specifically during the metaphase and anaphase stages when the chromosomes are being separated.
The alternating electric fields interfere with the proper alignment and separation of the chromosomes, leading to mitotic disruption. This can result in cell cycle arrest, apoptosis (programmed cell death), or the formation of abnormal cells that cannot survive.
Electrophysical Properties of Cells:
Cancer cells have distinct electrophysical properties compared to normal cells. They are more susceptible to the effects of electric fields due to their high mitotic activity and specific electrical characteristics.
TTFields are designed to exploit these differences, selectively targeting cancer cells while sparing most normal cells.
Microtubule Disruption:
Microtubules are essential components of the cell's cytoskeleton and play a critical role in the separation of chromosomes during cell division.
TTFields can interfere with the polymerization and depolymerization of microtubules, further hampering the mitotic process and leading to cell death.
Clinical Evidence
Glioblastoma:
Optune has been shown to improve survival rates and progression-free survival in patients with glioblastoma, an aggressive type of brain cancer.
Clinical trials have demonstrated that when used in combination with standard treatments like chemotherapy, TTFields significantly extend the overall survival of patients.
Mesothelioma:
The FDA also approved Optune for use in patients with malignant pleural mesothelioma, based on clinical evidence showing improved survival rates when used alongside standard treatments.
Safety and Side Effects
TTFields therapy is generally well-tolerated with a favorable safety profile. The most common side effects are skin irritation and mild discomfort at the site where the electrodes are placed on the scalp.
Because TTFields are non-invasive and targeted, they do not carry the systemic side effects typically associated with conventional cancer treatments like chemotherapy and radiation therapy.
Ongoing Research
Research continues to explore the efficacy of TTFields in other types of cancer and to optimize the delivery and effectiveness of the therapy.
Studies are also investigating the combination of TTFields with other emerging cancer treatments, such as immunotherapy and targeted therapies.
In summary, TTFields therapy works by exploiting the unique electrical properties and mitotic behavior of cancer cells to disrupt their division and induce cell death. Novocure's Optune device represents a significant advancement in the non-invasive treatment of certain aggressive cancers, offering patients a new therapeutic option that complements existing treatments.
