Overview

Treatment for cancers has multiplied throughout the decades, and it is daunting to understand the therapies available. One particular therapy, electromagnetic therapy, has been subject to varying opinions and can be difficult to comprehend. As such, the values and limitations of electromagnetic therapy will be discussed more simply below in hopes of answering any burning questions. 

What is Cancer?

Cancer is one of the major diseases in the modern world and is the leading cause of death¹ as new medicine is continually developed to treat other diseases. It is, however, a broad term that encompasses more than 200 different types of diseases in different areas of the body. Collectively, there are multiple hallmarks (i.e. traits) of cancer, and although each hallmark is involved in the complex spread of cancer, the main characteristic of cancer is the abnormal growth of cells, creating tumours.² 

Tumours can present as either benign or malignant.³ The abnormal growth of cells causes both benign and malignant tumours, however, benign tumours stay localised within the area of origin, whereas malignant tumours have the possibility of spreading to other areas of the body. This spread, known as metastasis, is dangerous as it can prevent the normal function of important organs. As such, malignant tumours are the only abnormal growth of cells labelled as ‘cancerous’.

Due to the complex nature of cancer, the process for scientists to discover treatment options has been difficult.⁴ Despite this, new treatment approaches have been created, and significant advances have been made. 

Cancer treatment & a brief history of electromagnetic therapy

There are a multitude of cancer treatment options, and treatment options depend on the cancer type. The conventional forms of cancer treatment include chemotherapy, surgery, and radiotherapy. These treatments can also be used in combination with each other to remove as much of the cancer as possible. Other newer forms of therapies have been used for treating cancer, examples including stem cell therapy and targeted therapy.⁴ 

These therapies are subject to unwanted side effects, and therefore other approaches are still considered. There have been alternative therapies that have been proposed that have been used previously for other types of diseases/pain management. One example is electromagnetic therapy.

From humans’ first discovery of ‘animal electricity,’ in the 18^th Century (i.e., the understanding that current/electricity is used in muscle contractions),⁵ researchers have become interested in how these processes work. Further scientific development found that when electricity moves (i.e. a current), magnetic fields are formed.⁶

It was not until the 1950’s however that these principles were first applied in a clinical setting. To this day, the use of electromagnetic devices has not yet become commonplace in the medical field, but the few that exist have had major impacts on diagnosing illnesses. These include the magnetic resonance imaging (MRI) scan, and X-ray scans.

Although these technologies have made a significant impact on diagnosis, the use of electromagnetic principles in medical treatment needs to be studied further. For example, some Electromagnetic therapies (EMT) have been subject to debate due to the inconclusive results in treating other diseases, cancer, and pain management.^7,8,9

There are studies that show some EMT types may be more effective when applied in conjunction with conventional treatment methods compared to using EMT alone Therefore, it is important to understand the functionality of certain EMT types before they can be trusted in a clinical environment.¹²

Functionality of electromagnetic therapy

Electromagnetic therapy types

There are multiple types of electromagnetic therapies that have existed and/or have been in development since the 1950’s. There are two major EMT types provided below, although other EMT types exist with limited literature:

• Electromagnetic hyperthermia therapy
• Pulsed electromagnetic field therapy (PEMF)

There are values and limitations to each of the therapy types, and they are still subject to research currently, as several of the mechanisms for how these therapies function biologically are unknown. 

How do these therapies work? 

Electromagnetic hyperthermia

Hyperthermia, by definition, means a high temperature. In clinical use against cancer tumours, hyperthermia to temperatures of 40–43^oC can be applied to either:

• Increase the efficacy of chemotherapy and radiotherapy 
• Increase the immune system response rate to cancer over time¹⁰ 

Hyperthermia of the tumour can often be achieved using external techniques, including electromagnetic methods through radiofrequency (RF) and microwaves (MW). RF and MW technologies are the most common methods for hyperthermia-based cancer treatment and they can be used:

• On the tumours locally
• In the spaces between organs
• On the entire body^10,11 

RF and MW produce energy that is absorbed by the human tissue. All tissue types, characteristically, are poor absorbers of heat and cannot conduct electricity well. Therefore, the electromagnetic energy, unable to be transformed into other energy, is absorbed and becomes heat (known as the law of conservation of energy). The introduction of heat has been shown to increase blood flow, therefore allowing chemotherapy to travel throughout the body quickly and efficiently.^10,12 

The combination of electromagnetic hyperthermia with chemotherapy and/or radiotherapy has been shown to both doubly increase tumour control and the probability of being cured.¹² There are some limitations with electromagnetic hyperthermia, as the electromagnetic waves decrease in power exponentially with tissue depth.¹⁰

This can be improved by placing antennas to amplify the wave (known as constructive wave interference).¹³ This can be uncomfortable for patients, as antennas need to be placed near the tumour site, in other words, may result in placement in body cavities such as the anus and vagina for diseases such as prostate and cervical cancer. Other side effects include:

• Bleeding 
• Blood clots
• Burns
• Blistering¹¹

Nevertheless, the side effects shown by electromagnetic hyperthermia have not shown toxicity towards cells, which is shown in conventional therapies (e.g. chemotherapy).^14,15 

Pulsed electromagnetic field therapy (PEMF)

The biological mechanism for how PEMF works is still debated, but scientists have hypothesised that PEMF involves the use of low-frequency waves that emulate mechanical forces that are relevant to wound healing.^7,16,17 Multiple studies have shown PEMF to have positive effects on bone- and joint-related problems but is still not a common treatment due to clinical trials having different experimental parameters.^18–22 Simply, the type of frequency and type of bone fractures varied heavily between studies, and are difficult to compare.¹⁶ Nevertheless, the majority have shown positive effects.^16-23 

Two studies have completed extensive literature reviews for particular hallmarks of cancer: programmed cell death (apoptosis) and the formation of blood vessels (angiogenesis).^23-25 Cancer has the ability to evade apoptosis and the ability to bring more nutrients to the tumour site through angiogenesis.²⁵ To target these hallmarks, PEMF should aim to increase the rate of apoptosis, and decrease the rate of angiogenesis. 

Although positive effects have been documented, the studies on their own are not enough to make conclusions on the use of PEMF on cancer. The reviewed studies on apoptosis found that cancer cell death occurred and could be potentially used in conjunction with conventional therapies. However, other studies showed no difference between the treated and untreated cells, and some studies even showed negative effects (e.g. reduction of cellular processes).²³ 

Similarly, the review of angiogenesis studies showed inconclusive results, as PEMF could both promote and inhibit blood vessels depending on the frequency of the PEMF. However, since the studies were inconsistent with their experimental parameters, it is difficult to assess how PEMF can be used clinically.

Additionally, it implies that PEMF is complex and does not depend on the frequency or the intensity of the electromagnetic wave and that it may be due to the cells themselves.²⁴ Other limitations included the possibility of cellular stress and hormone disruption.

These studies have looked at using PEMF on isolated cancer cells, and therefore have not been tested in humans.^22-27 Therefore, side effects and efficacy of the treatment may differ in a human model. Conclusively, PEMF has the potential to be used clinically for cancer, but more studies need to be conducted on its risks/safety. 

Summary

EMT is an umbrella term encompassing multiple types of therapies. The amount of EMTs has been increasing and is becoming more understood by scientists. EMTs have been tested on various diseases, but have not been researched extensively for cancer treatment.

Depending on the type of EMT, many studies have shown potential to treat cancer, (electromagnetic hyperthermia), but some are still inconclusive (PEMF). The collaboration between scientists and clinicians can lead to a better understanding of EMTs, and in conjunction with conventional therapies (chemotherapy, radiotherapy, and surgery) can heavily decrease cancer growth.

As cancer is a complex disease by nature, researchers across multiple disciplines (physics, chemistry and biology alike) aim to increase their knowledge of the dynamics of cancer and create breakthrough treatments. As cancer becomes a leading disease worldwide, it is important for patients to understand the possible available therapies.